WorldWideScience

Sample records for dynamic near-infrared optical

  1. Hierarchical Models for Type Ia Supernova Light Curves in the Optical and Near Infrared

    Science.gov (United States)

    Mandel, Kaisey; Narayan, G.; Kirshner, R. P.

    2011-01-01

    I have constructed a comprehensive statistical model for Type Ia supernova optical and near infrared light curves. Since the near infrared light curves are excellent standard candles and are less sensitive to dust extinction and reddening, the combination of near infrared and optical data better constrains the host galaxy extinction and improves the precision of distance predictions to SN Ia. A hierarchical probabilistic model coherently accounts for multiple random and uncertain effects, including photometric error, intrinsic supernova light curve variations and correlations across phase and wavelength, dust extinction and reddening, peculiar velocity dispersion and distances. An improved BayeSN MCMC code is implemented for computing probabilistic inferences for individual supernovae and the SN Ia and host galaxy dust populations. I use this hierarchical model to analyze nearby Type Ia supernovae with optical and near infared data from the PAIRITEL, CfA3, and CSP samples and the literature. Using cross-validation to test the robustness of the model predictions, I find that the rms Hubble diagram scatter of predicted distance moduli is 0.11 mag for SN with optical and near infrared data versus 0.15 mag for SN with only optical data. Accounting for the dispersion expected from random peculiar velocities, the rms intrinsic prediction error is 0.08-0.10 mag for SN with both optical and near infrared light curves. I discuss results for the inferred intrinsic correlation structures of the optical-NIR SN Ia light curves and the host galaxy dust distribution captured by the hierarchical model. The continued observation and analysis of Type Ia SN in the optical and near infrared is important for improving their utility as precise and accurate cosmological distance indicators.

  2. Near-infrared selective dynamic windows controlled by charge transfer impedance at the counter electrode.

    Science.gov (United States)

    Pattathil, Praveen; Scarfiello, Riccardo; Giannuzzi, Roberto; Veramonti, Giulia; Sibillano, Teresa; Qualtieri, Antonio; Giannini, Cinzia; Cozzoli, P Davide; Manca, Michele

    2016-12-08

    Recent developments in the exploitation of transparent conductive oxide nanocrystals paved the way to the realization of a new class of electrochemical systems capable of selectively shielding the infrared heat loads carried by sunlight and prospected the blooming of a key enabling technology to be implemented in the next generation of "zero-energy" building envelopes. Here we report the fabrication of a set of electrochromic devices embodying an engineered nanostructured electrode made by high aspect-ratio tungsten oxide nanorods, which allow for selectively and dynamically controlling sunlight transmission over the near-infrared to visible range. Varying the intensity of applied voltage makes the spectral response of the device change across three different optical regimes, namely fully transparent, near-infrared only blocking and both visible and near-infrared blocking. It is demonstrated that the degree of reversible modulation of the thermal radiation entering the glazing element can approach a remarkable 85%, accompanied by only a modest reduction in the luminous transmittance.

  3. Single-walled carbon nanotubes as near-infrared optical biosensors for life sciences and biomedicine.

    Science.gov (United States)

    Jain, Astha; Homayoun, Aida; Bannister, Christopher W; Yum, Kyungsuk

    2015-03-01

    Single-walled carbon nanotubes that emit photostable near-infrared fluorescence have emerged as near-infrared optical biosensors for life sciences and biomedicine. Since the discovery of their near-infrared fluorescence, researchers have engineered single-walled carbon nanotubes to function as an optical biosensor that selectively modulates its fluorescence upon binding of target molecules. Here we review the recent advances in the single-walled carbon nanotube-based optical sensing technology for life sciences and biomedicine. We discuss the structure and optical properties of single-walled carbon nanotubes, the mechanisms for molecular recognition and signal transduction in single-walled carbon nanotube complexes, and the recent development of various single-walled carbon nanotube-based optical biosensors. We also discuss the opportunities and challenges to translate this emerging technology into biomedical research and clinical use, including the biological safety of single-walled carbon nanotubes. The advances in single-walled carbon nanotube-based near-infrared optical sensing technology open up a new avenue for in vitro and in vivo biosensing with high sensitivity and high spatial resolution, beneficial for many areas of life sciences and biomedicine. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Ultrafast stimulated Raman spectroscopy in the near-infrared region

    International Nuclear Information System (INIS)

    Takaya, Tomohisa

    2016-01-01

    A number of electronic transitions in the near-infrared wavelength region are associated with migration or delocalization of electrons in large molecules or molecular systems. Time-resolved near-infrared Raman spectroscopy will be a powerful tool for investigating the structural dynamic of samples with delocalized electrons. However, the sensitivity of near-infrared spontaneous Raman spectrometers is significantly low due to an extremely small probability of Raman scattering and a low sensitivity of near-infrared detectors. Nonlinear Raman spectroscopy is one of the techniques that can overcome the sensitivity problems and enable us to obtain time-resolved Raman spectra in resonance with near-IR transitions. In this article, the author introduces recent progress of ultrafast time-resolved near-infrared stimulated Raman spectroscopy. Optical setup, spectral and temporal resolution, and applications of the spectrometer are described. (author)

  5. Advances in near-infrared measurements

    CERN Document Server

    Patonay, Gabor

    1991-01-01

    Advances in Near-Infrared Measurements, Volume 1 provides an overview of near-infrared spectroscopy. The book is comprised of six chapters that tackle various areas of near-infrared measurement. Chapter 1 discusses remote monitoring techniques in near-infrared spectroscopy with an emphasis on fiber optics. Chapter 2 covers the applications of fibers using Raman techniques, and Chapter 3 tackles the difficulties associated with near-infrared data analysis. The subsequent chapters present examples of the capabilities of near-infrared spectroscopy from various research groups. The text wi

  6. THELI: CONVENIENT REDUCTION OF OPTICAL, NEAR-INFRARED, AND MID-INFRARED IMAGING DATA

    International Nuclear Information System (INIS)

    Schirmer, M.

    2013-01-01

    The last 15 years have seen a surge of new multi-chip optical and near-IR imagers. While some of them are accompanied by specific reduction pipelines, user-friendly and generic reduction tools are uncommon. In this paper I introduce THELI, an easy-to-use graphical interface driving an end-to-end pipeline for the reduction of any optical, near-IR, and mid-IR imaging data. The advantages of THELI when compared to other approaches are highlighted. Combining a multitude of processing algorithms and third party software, THELI provides researchers with a single, homogeneous tool. A short learning curve ensures quick success for new and more experienced observers alike. All tasks are largely automated, while at the same time a high level of flexibility and alternative reduction schemes ensure that widely different scientific requirements can be met. Over 90 optical and infrared instruments at observatories world-wide are pre-configured, while more can be added by the user. The Appendices contain three walk-through examples using public data (optical, near-IR, and mid-IR). Additional extensive documentation for training and troubleshooting is available online

  7. Near-Infrared Diffuse Optical Tomography

    Directory of Open Access Journals (Sweden)

    A. H. Hielscher

    2002-01-01

    Full Text Available Diffuse optical tomography (DOT is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI or X-ray computerized tomography (CT, DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals.

  8. Optical and near-infrared imaging of faint Gigahertz Peaked Spectrum sources

    NARCIS (Netherlands)

    Snellen, IAG; Schilizzi, RT; de Bruyn, AG; Miley, GK; Rottgering, HJA; McMahon, RG; Fournon, IP

    1998-01-01

    A sample of 47 faint Gigahertz Peaked Spectrum (GPS) radio sources selected from the Westerbork Northern Sky Survey (WENSS) has been imaged in the optical and near-infrared, resulting in an identification fraction of 87 per cent. The R - I and R - K colours of the faint optical counterparts are as

  9. Optical nonlinearities and ultrafast all-optical switching of m-plane GaN in the near-infrared

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yu; Zhou, Feng; Yang, Junyi; Yang, Yong [College of Physics, Optoelectronics and Energy, Soochow University, 215006 Suzhou (China); Xiao, Zhengguo; Wu, Xingzhi [Department of Physics, Harbin Institute of Technology, 150001 Harbin (China); Song, Yinglin, E-mail: ylsong@hit.edu.cn [College of Physics, Optoelectronics and Energy, Soochow University, 215006 Suzhou (China); Department of Physics, Harbin Institute of Technology, 150001 Harbin (China)

    2015-06-22

    We reported a systematic investigation on the three-photon absorption (3PA) spectra and wavelength dispersion of Kerr refraction of bulk m-plane GaN crystal with both polarization E⊥c and E//c by femtosecond Z-scan technique in the near-infrared region from 760 to 1030 nm. Both 3PA spectra and Kerr refraction dispersion were in good agreement with two-band models. The calculated nonlinear figure of merit and measured ultrafast nonlinear refraction dynamics via femtosecond pump-probe with phase object method revealed that m-plane GaN would be a promising candidate for ultrafast all-optical switching and autocorrelation applications at telecommunication wavelengths.

  10. Near-Infrared Optical Imaging of Integrin αvβ3 in Human Tumor Xenografts

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2004-10-01

    Full Text Available In vivo optical imaging is potentially useful for evaluating the presence of tumor markers that are targets of molecular medicine. Here we report the synthesis and characterization of integrin αvβ3-targeted peptide cyclo(Lys–Arg–Gly–Asp–Phe [c(KRGDf] labeled with fluorescence dyes with wavelength spanning from the visible/near infrared (Cy5.5 to the true near infrared (IRDye800 for optical imaging. In vitro, the peptide–dye conjugates bound specifically to tumor cells expressing αvβ3. When administered intravenously into mice at a dose of 6 nmol/mouse, the conjugates accumulated in tumors expressing αvβ3. The tumor-to-background ratios for human KS1767 Kaposi's sarcoma in mice injected with Cy5.5–c(KRGDf and Cy5.5 were 5.5 and 1.5, respectively. Preinjection of c(KRGDf blocked the uptake of Cy5.5–c(KRGDf in tumors by 89%. In αvβ3-positive M21 and αvβ3-negative M21-L human melanoma, fluorescence intensity in the tumor of mice injected with IRDye800–c(KRGDf was 2.3 and 1.3 times that in normal tissue, respectively. Dynamic imaging revealed that Cy5.5–c(KRGDf was rapidly taken up by KS1767 tumor immediately after bolus injection. The rate of its uptake in the tumor was reduced by preinjection of c(KRGDf in an interval time-dependent manner. Our data suggest that near-infrared fluorescence imaging may be applied to the detection of tumors expressing integrin αvβ3 and to the assessment of the optimal biological dose and schedule of targeted therapies.

  11. Optical and near-infrared study of the AM Herculis-type binary CW 1103 + 254

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, J [Anglo-Australian Observatory, Epping (Australia); Watts, D J [Tasmania Univ., Sandy Bay (Australia). Dept. of Physics; Sherrington, M R [Leicester Univ. (UK). Dept. of Astronomy

    1985-07-15

    The AM Herculis-type binary CW 1103+254 has been observed using optical and near-infrared photometry and polarimetry, and optical spectroscopy and spectropolarimetry. It is found that from such a set of observations it is relatively easy to distinguish all the main components of the system.

  12. Near-infrared light-responsive dynamic wrinkle patterns.

    Science.gov (United States)

    Li, Fudong; Hou, Honghao; Yin, Jie; Jiang, Xuesong

    2018-04-01

    Dynamic micro/nanopatterns provide an effective approach for on-demand tuning of surface properties to realize a smart surface. We report a simple yet versatile strategy for the fabrication of near-infrared (NIR) light-responsive dynamic wrinkles by using a carbon nanotube (CNT)-containing poly(dimethylsiloxane) (PDMS) elastomer as the substrate for the bilayer systems, with various functional polymers serving as the top stiff layers. The high photon-to-thermal energy conversion of CNT leads to the NIR-controlled thermal expansion of the elastic CNT-PDMS substrate, resulting in dynamic regulation of the applied strain (ε) of the bilayer system by the NIR on/off cycle to obtain a reversible wrinkle pattern. The switchable surface topological structures can transfer between the wrinkled state and the wrinkle-free state within tens of seconds via NIR irradiation. As a proof-of-concept application, this type of NIR-driven dynamic wrinkle pattern was used in smart displays, dynamic gratings, and light control electronics.

  13. ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Kouzuma, S.; Yamaoka, H.

    2012-01-01

    We present the properties of the ensemble variability V for nearly 5000 near-infrared active galactic nuclei (AGNs) selected from the catalog of Quasars and Active Galactic Nuclei (13th Edition) and the SDSS-DR7 quasar catalog. From three near-infrared point source catalogs, namely, Two Micron All Sky Survey (2MASS), Deep Near Infrared Survey (DENIS), and UKIDSS/LAS catalogs, we extract 2MASS-DENIS and 2MASS-UKIDSS counterparts for cataloged AGNs by cross-identification between catalogs. We further select variable AGNs based on an optimal criterion for selecting the variable sources. The sample objects are divided into subsets according to whether near-infrared light originates by optical emission or by near-infrared emission in the rest frame; and we examine the correlations of the ensemble variability with the rest-frame wavelength, redshift, luminosity, and rest-frame time lag. In addition, we also examine the correlations of variability amplitude with optical variability, radio intensity, and radio-to-optical flux ratio. The rest-frame optical variability of our samples shows negative correlations with luminosity and positive correlations with rest-frame time lag (i.e., the structure function, SF), and this result is consistent with previous analyses. However, no well-known negative correlation exists between the rest-frame wavelength and optical variability. This inconsistency might be due to a biased sampling of high-redshift AGNs. Near-infrared variability in the rest frame is anticorrelated with the rest-frame wavelength, which is consistent with previous suggestions. However, correlations of near-infrared variability with luminosity and rest-frame time lag are the opposite of these correlations of the optical variability; that is, the near-infrared variability is positively correlated with luminosity but negatively correlated with the rest-frame time lag. Because these trends are qualitatively consistent with the properties of radio-loud quasars reported

  14. Near-Infrared Wireless Optical Communication with Particulates In-Suspension over the Underwater Channel

    KAUST Repository

    Lee, It Ee; Guo, Yong; Ng, Tien Khee; Park, Kihong; Alouini, Mohamed-Slim; Ooi, Boon S.

    2017-01-01

    We demonstrate a gigabit near-infrared-based underwater wireless optical communication link using an 808-nm laser diode to mitigate the particle scattering effect in turbid medium. An improvement in the error performance is observed with increasing

  15. Near-Infrared Wireless Optical Communication with Particulates In-Suspension over the Underwater Channel

    KAUST Repository

    Lee, It Ee

    2017-05-08

    We demonstrate a gigabit near-infrared-based underwater wireless optical communication link using an 808-nm laser diode to mitigate the particle scattering effect in turbid medium. An improvement in the error performance is observed with increasing concentrations.

  16. OPTICAL AND NEAR-INFRARED SHOCKS IN THE L988 CLOUD COMPLEX

    International Nuclear Information System (INIS)

    Walawender, J.; Reipurth, B.; Bally, J.

    2013-01-01

    We have searched the Lynds 988 dark cloud complex for optical (Hα and [S II]) and near-IR (H 2 2.12 μm) shocks from protostellar outflows. We find 20 new Herbig-Haro objects and 6 new H 2 shocks (MHO objects), 3 of which are cross detections. Using the morphology in the optical and near-IR, we connect several of these shocks into at least five distinct outflow systems and identify their source protostars from catalogs of infrared sources. Two outflows in the cloud, from IRAS 21014+5001 and IRAS 21007+4951, are in excess of 1 pc in length. The IRAS 21007+4951 outflow has carved a large cavity in the cloud through which background stars can be seen. Also, we have found an optical shock which is the counterflow to the previously discovered ''northwest outflow'' from LkHα 324SE

  17. MOONS: a multi-object optical and near-infrared spectrograph for the VLT

    NARCIS (Netherlands)

    Cirasuolo, M.; Afonso, J.; Bender, R.; Bonifacio, P.; Evans, C.; Kaper, L.; Oliva, Ernesto; Vanzi, Leonardo; Abreu, Manuel; Atad-Ettedgui, Eli; Babusiaux, Carine; Bauer, Franz E.; Best, Philip; Bezawada, Naidu; Bryson, Ian R.; Cabral, Alexandre; Caputi, Karina; Centrone, Mauro; Chemla, Fanny; Cimatti, Andrea; Cioni, Maria-Rosa; Clementini, Gisella; Coelho, João.; Daddi, Emanuele; Dunlop, James S.; Feltzing, Sofia; Ferguson, Annette; Flores, Hector; Fontana, Adriano; Fynbo, Johan; Garilli, Bianca; Glauser, Adrian M.; Guinouard, Isabelle; Hammer, Jean-François; Hastings, Peter R.; Hess, Hans-Joachim; Ivison, Rob J.; Jagourel, Pascal; Jarvis, Matt; Kauffman, G.; Lawrence, A.; Lee, D.; Li Causi, G.; Lilly, S.; Lorenzetti, D.; Maiolino, R.; Mannucci, F.; McLure, R.; Minniti, D.; Montgomery, D.; Muschielok, B.; Nandra, K.; Navarro, R.; Norberg, P.; Origlia, L.; Padilla, N.; Peacock, J.; Pedicini, F.; Pentericci, L.; Pragt, J.; Puech, M.; Randich, S.; Renzini, A.; Ryde, N.; Rodrigues, M.; Royer, F.; Saglia, R.; Sánchez, A.; Schnetler, H.; Sobral, D.; Speziali, R.; Todd, S.; Tolstoy, E.; Torres, M.; Venema, L.; Vitali, F.; Wegner, M.; Wells, M.; Wild, V.; Wright, G.

    MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A study. The baseline design consists of ~1000 fibers deployable over a field of view of ~500 square arcmin, the largest patrol field offered by

  18. Ages of galaxy bulges and disks from optical and near-infrared colors

    NARCIS (Netherlands)

    Peletier, RF; Balcells, M

    We compare optical and near-infrared colors of disks and bulges in a diameter-limited sample of inclined, bright, nearby, early-type spirals. Color profiles along wedge apertures at 15 degrees from the major axis and on the minor axis on the side of the galaxy opposite to the dust lane are used to

  19. OPTICAL AND NEAR-INFRARED SHOCKS IN THE L988 CLOUD COMPLEX

    Energy Technology Data Exchange (ETDEWEB)

    Walawender, J. [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Reipurth, B. [Institute for Astronomy, University of Hawaii at Manoa, Hilo, HI 96720 (United States); Bally, J., E-mail: joshw@naoj.org [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States)

    2013-09-15

    We have searched the Lynds 988 dark cloud complex for optical (H{alpha} and [S II]) and near-IR (H{sub 2} 2.12 {mu}m) shocks from protostellar outflows. We find 20 new Herbig-Haro objects and 6 new H{sub 2} shocks (MHO objects), 3 of which are cross detections. Using the morphology in the optical and near-IR, we connect several of these shocks into at least five distinct outflow systems and identify their source protostars from catalogs of infrared sources. Two outflows in the cloud, from IRAS 21014+5001 and IRAS 21007+4951, are in excess of 1 pc in length. The IRAS 21007+4951 outflow has carved a large cavity in the cloud through which background stars can be seen. Also, we have found an optical shock which is the counterflow to the previously discovered ''northwest outflow'' from LkH{alpha} 324SE.

  20. The second Herschel-ATLAS Data Release - III. Optical and near-infrared counterparts in the North Galactic Plane field

    Science.gov (United States)

    Furlanetto, C.; Dye, S.; Bourne, N.; Maddox, S.; Dunne, L.; Eales, S.; Valiante, E.; Smith, M. W.; Smith, D. J. B.; Ivison, R. J.; Ibar, E.

    2018-05-01

    This paper forms part of the second major public data release of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). In this work, we describe the identification of optical and near-infrared counterparts to the submillimetre detected sources in the 177 deg2 North Galactic Plane (NGP) field. We used the likelihood ratio method to identify counterparts in the Sloan Digital Sky Survey and in the United Kingdom InfraRed Telescope Imaging Deep Sky Survey within a search radius of 10 arcsec of the H-ATLAS sources with a 4σ detection at 250 μm. We obtained reliable (R ≥ 0.8) optical counterparts with r performance of the likelihood ratio method to identify optical and near-infrared counterparts taking into account the depth and area of both input catalogues. Using catalogues with the same surface density of objects in the overlapping ˜25 deg2 area, we obtained that the reliable fraction in the near-infrared (54.8 per cent) is significantly higher than in the optical (36.4 per cent). Finally, using deep radio data which covers a small region of the NGP field, we found that 80-90 per cent of our reliable identifications are correct.

  1. Near-infrared hyperspectral imaging of water evaporation dynamics for early detection of incipient caries.

    Science.gov (United States)

    Usenik, Peter; Bürmen, Miran; Fidler, Aleš; Pernuš, Franjo; Likar, Boštjan

    2014-10-01

    Incipient caries is characterized as demineralization of the tooth enamel reflecting in increased porosity of enamel structure. As a result, the demineralized enamel may contain increased amount of water, and exhibit different water evaporation dynamics than the sound enamel. The objective of this paper is to assess the applicability of water evaporation dynamics of sound and demineralized enamel for detection and quantification of incipient caries using near-infrared hyperspectral imaging. The time lapse of water evaporation from enamel samples with artificial and natural caries lesions of different stages was imaged by a near-infrared hyperspectral imaging system. Partial least squares regression was used to predict the water content from the acquired spectra. The water evaporation dynamics was characterized by a first order logarithmic drying model. The calculated time constants of the logarithmic drying model were used as the discriminative feature. The conducted measurements showed that demineralized enamel contains more water and exhibits significantly faster water evaporation than the sound enamel. By appropriate modelling of the water evaporation process from the enamel surface, the contrast between the sound and demineralized enamel observed in the individual near infrared spectral images can be substantially enhanced. The presented results indicate that near-infrared based prediction of water content combined with an appropriate drying model presents a strong foundation for development of novel diagnostic tools for incipient caries detection. The results of the study enhance the understanding of the water evaporation process from the sound and demineralized enamel and have significant implications for the detection of incipient caries by near-infrared hyperspectral imaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Type Ia Supernova Light Curve Inference: Hierarchical Models for Nearby SN Ia in the Optical and Near Infrared

    Science.gov (United States)

    Mandel, Kaisey; Kirshner, R. P.; Narayan, G.; Wood-Vasey, W. M.; Friedman, A. S.; Hicken, M.

    2010-01-01

    I have constructed a comprehensive statistical model for Type Ia supernova light curves spanning optical through near infrared data simultaneously. The near infrared light curves are found to be excellent standard candles (sigma(MH) = 0.11 +/- 0.03 mag) that are less vulnerable to systematic error from dust extinction, a major confounding factor for cosmological studies. A hierarchical statistical framework incorporates coherently multiple sources of randomness and uncertainty, including photometric error, intrinsic supernova light curve variations and correlations, dust extinction and reddening, peculiar velocity dispersion and distances, for probabilistic inference with Type Ia SN light curves. Inferences are drawn from the full probability density over individual supernovae and the SN Ia and dust populations, conditioned on a dataset of SN Ia light curves and redshifts. To compute probabilistic inferences with hierarchical models, I have developed BayeSN, a Markov Chain Monte Carlo algorithm based on Gibbs sampling. This code explores and samples the global probability density of parameters describing individual supernovae and the population. I have applied this hierarchical model to optical and near infrared data of over 100 nearby Type Ia SN from PAIRITEL, the CfA3 sample, and the literature. Using this statistical model, I find that SN with optical and NIR data have a smaller residual scatter in the Hubble diagram than SN with only optical data. The continued study of Type Ia SN in the near infrared will be important for improving their utility as precise and accurate cosmological distance indicators.

  3. Wide-area remote-sensing system of pollution and gas dispersal by near-infrared absorption based on low-loss optical fiber network

    Science.gov (United States)

    Inaba, H.

    1986-01-01

    An all optical remote sensing system utilizing long distance, ultralow loss optical fiber networks is studied and discussed for near infrared absorption measurements of combustible and/or explosive gases such as CH4 and C3H8 in our environment, including experimental results achieved in a diameter more than 20 km. The use of a near infrared wavelength range is emphasized.

  4. Exploring process dynamics by near infrared spectroscopy in lactic fermentations

    DEFF Research Database (Denmark)

    Svendsen, Carina; Cieplak, Tomasz; van der Berg, Franciscus Winfried J

    2016-01-01

    In the industrial production of yoghurt, measurement of pH is normally the only in-line technique applied as a real-time monitoring signalfor following the dynamics during the fermentation process. However, every dairy company would benefit from an in-line technique giving information about...... the chemical composition, physical/textural properties and/or microbial contamination. In this study lactic fermentation batches with the starter bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are explored by in-line near infrared (NIR) spectroscopy. The dynamics obtained...

  5. Determination of ultraviolet extinction from the optical and near-infrared

    International Nuclear Information System (INIS)

    Cardelli, J.A.; Clayton, G.C.; Mathis, J.S.

    1988-01-01

    The correlation of optical-near-infrared photometry for a sample of stars with well-determined ultraviolet extinction is examined. A good correlation is found; in particular, it is found that the value of total-to-selective extinction correlates well with the level of linear UV background extinction found from the UV curve parameterization of Fitzpatrick and Massa. An analytic expression is given for an improved estimate for the UV extinction law that can be obtained from optically determined values of R. For R values outside the range R = 3.1 -3.5, use of the analytic expressions given here will result in a more accurate representation of the applicable UV extinction than using the standard techniques of assuming the average curve or ironing out the bump. 19 references

  6. Organic-inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency

    Science.gov (United States)

    Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

    2018-03-01

    Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

  7. Near-simultaneous optical and infrared spectrophotometry of active galaxies

    International Nuclear Information System (INIS)

    Yates, M.G.; Garden, R.P.

    1989-01-01

    We present optical and infrared spectrophotometry for a sample of eight optically bright quasars, and the broad-line radio galaxy (BLRG) 3C 120. The optical and infrared spectrophotometry is separated by only five weeks, thus we have been able to minimize uncertainties due to variations in the objects. We compare our observed Paα/Hα and Hα/Hβ ratios with a large number of current photoionization models. We find that none of these models are able to reproduce our observed values of Paα/Hα in any of the active galaxies except the quasars 3C 273 and 0736+017. (author)

  8. Quantitative real-time monitoring of dryer effluent using fiber optic near-infrared spectroscopy.

    Science.gov (United States)

    Harris, S C; Walker, D S

    2000-09-01

    This paper describes a method for real-time quantitation of the solvents evaporating from a dryer. The vapor stream in the vacuum line of a dryer was monitored in real time using a fiber optic-coupled acousto-optic tunable filter near-infrared (AOTF-NIR) spectrometer. A balance was placed in the dryer, and mass readings were recorded for every scan of the AOTF-NIR. A partial least-squares (PLS) calibration was subsequently built based on change in mass over change in time for solvents typically used in a chemical manufacturing plant. Controlling software for the AOTF-NIR was developed. The software collects spectra, builds the PLS calibration model, and continuously fits subsequently collected spectra to the calibration, allowing the operator to follow the mass loss of solvent from the dryer. The results indicate that solvent loss can be monitored and quantitated in real time using NIR for the optimization of drying times. These time-based mass loss values have also been used to calculate "dynamic" vapor density values for the solvents. The values calculated are in agreement with values determined from the ideal gas law and could prove valuable as tools to measure temperature or pressure indirectly.

  9. Smart optical probes for near-infrared fluorescence imaging of Alzheimer's disease pathology

    International Nuclear Information System (INIS)

    Raymond, Scott B.; Bacskai, Brian J.; Skoch, Jesse; Hills, Ivory D.; Swager, Timothy M.; Nesterov, Evgueni E.

    2008-01-01

    Near-infrared fluorescent probes for amyloid-beta (Aβ) are an exciting option for molecular imaging in Alzheimer's disease research and may translate to clinical diagnostics. However, Aβ-targeted optical probes often suffer from poor specificity and slow clearance from the brain. We are designing smart optical probes that emit characteristic fluorescence signal only when bound to Aβ. We synthesized a family of dyes and tested Aβ-binding sensitivity with fluorescence spectroscopy and tissue-staining. Select compounds exhibited Aβ-dependent changes in fluorescence quantum yield, lifetime, and emission spectra that may be imaged microscopically or in vivo using new lifetime and spectral fluorescence imaging techniques. Smart optical probes that turn on when bound to Aβ will improve amyloid detection and may enable quantitative molecular imaging in vivo. (orig.)

  10. Optical - Near Infrared Photometric Calibration of M-dwarf Metallicity and Its Application

    OpenAIRE

    Hejazi, Neda; De Robertis, Michael M.; Dawson, Peter C.

    2015-01-01

    Based on a carefully constructed sample of dwarf stars, a new optical-near infrared photometric calibration to estimate the metallicity of late-type K and early-to-mid-type M dwarfs is presented. The calibration sample has two parts; the first part includes 18 M dwarfs with metallicities determined by high-resolution spectroscopy and the second part contains 49 dwarfs with metallicities obtained through moderate-resolution spectra. By applying this calibration to a large sample of around 1.3 ...

  11. On the age and metallicity estimation of spiral galaxies using optical and near-infrared photometry

    NARCIS (Netherlands)

    Lee, Hyun-Chul; Worthey, Guy; Trager, Scott C.; Faber, S. M.

    2007-01-01

    In integrated light, some color-color diagrams that use optical and near-infrared photometry show surprisingly orthogonal grids as age and metallicity are varied, and they are coming into common usage for estimating the average age and metallicity of spiral galaxies. In this paper we reconstruct

  12. Optical and Near-infrared Study of Nova V2676 Oph 2012

    Energy Technology Data Exchange (ETDEWEB)

    Raj, A. [Korea Astronomy and Space Science Institute, Daejeon, 34055 (Korea, Republic of); Das, R. K. [Department of Astrophysics and Cosmology, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700106 (India); Walter, F. M., E-mail: ashish.raj@iiap.res.in [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

    2017-02-01

    We present optical spectrophotometric and near-infrared (NIR) photometric observations of the nova V2676 Oph covering the period from 2012 March 29 through 2015 May 8. The optical spectra and photometry of the nova have been taken from SMARTS and Asiago; the NIR photometry was obtained from SMARTS and Mt. Abu. The spectra were dominated by strong H i lines from the Balmer series, Fe ii, N i, and [O i] lines in the initial days, typical of an Fe ii type nova. The measured FWHM for the H β and H α lines was 800–1200 km s{sup −1}. There was pronounced dust formation starting 90 days after the outburst. The J − K color was the largest among recent dust-forming novae.

  13. Optical design and fabrication of palm/fingerprint uniform illumination system with a high-power near-infrared light-emitting diode.

    Science.gov (United States)

    Jing, Lei; Wang, Yao; Zhao, Huifu; Ke, Hongliang; Wang, Xiaoxun; Gao, Qun

    2017-06-10

    In order to meet the requirements of uniform illumination for optical palm/fingerprint instruments and overcome the shortcomings of the poor uniform illumination on the working plane of the optical palm/fingerprint prism, a novel secondary optical lens with a free-form surface, compact structure, and high uniformity is presented in this paper. The design of the secondary optical lens is based on emission properties of the near-infrared light-emitting diode (LED) and basic principles of non-imaging optics, especially considering the impact of the thickness of the prism in the design. Through the numerical solution of Snell's law in geometric optics, we obtain the profile of the free-form surface of the lens. Using the optical software TracePro, we trace and simulate the illumination system. The results show that the uniformity is 89.8% on the working plane of the prism, and the test results show that the actual uniformity reaches 85.7% in the experiment, which provides an effective way for realizing a highly uniform illumination system with high-power near-infrared LED.

  14. The near infrared polarization of NGC 7023

    International Nuclear Information System (INIS)

    Sellgren, K.

    1984-01-01

    NGC 7023 is a visual reflection nebula whose low optical depth at near infrared wavelengths suggests it may be well-suited to analysis of the near infrared scattering properties of dust. While processes other than scattered light dominate the near infrared emission of NGC 7023, a detectable scattered light component remains, as can be demonstrated by polarization measurements. Polarization at 2.2 μm has been detected at two positions in NGC 7023. The polarization angles at these two positions are perpendicular to the line between each nebular position and the star which illuminates the visual reflection nebulosity, indicating that the polarization mechanism is most likely the scattering of starlight from this star. (author)

  15. Far-infrared properties of optically selected quasars

    International Nuclear Information System (INIS)

    Edelson, R.A.

    1986-01-01

    The far-infrared properties of 10, optically selected quasars were studied on the basis of pointed IRAS observations and ground-based near-infrared and radio measurements. Nine of these quasars were detected in at least three IRAS bands. The flat spectral energy distributions characterizing these optically selected quasars together with large 60-100-micron luminosities suggest that the infrared emission is dominated by nonthermal radiation. Seven of the nine quasars with far-infrared detections were found to have low-frequency turnovers. 12 references

  16. Novel concepts in near-field optics: from magnetic near-field to optical forces

    Science.gov (United States)

    Yang, Honghua

    Driven by the progress in nanotechnology, imaging and spectroscopy tools with nanometer spatial resolution are needed for in situ material characterizations. Near-field optics provides a unique way to selectively excite and detect elementary electronic and vibrational interactions at the nanometer scale, through interactions of light with matter in the near-field region. This dissertation discusses the development and applications of near-field optical imaging techniques, including plasmonic material characterization, optical spectral nano-imaging and magnetic field detection using scattering-type scanning near-field optical microscopy (s-SNOM), and exploring new modalities of optical spectroscopy based on optical gradient force detection. Firstly, the optical dielectric functions of one of the most common plasmonic materials---silver is measured with ellipsometry, and analyzed with the Drude model over a broad spectral range from visible to mid-infrared. This work was motivated by the conflicting results of previous measurements, and the need for accurate values for a wide range of applications of silver in plasmonics, optical antennas, and metamaterials. This measurement provides a reference for dielectric functions of silver used in metamaterials, plasmonics, and nanophotonics. Secondly, I implemented an infrared s-SNOM instrument for spectroscopic nano-imaging at both room temperature and low temperature. As one of the first cryogenic s-SNOM instruments, the novel design concept and key specifications are discussed. Initial low-temperature and high-temperature performances of the instrument are examined by imaging of optical conductivity of vanadium oxides (VO2 and V2O 3) across their phase transitions. The spectroscopic imaging capability is demonstrated on chemical vibrational resonances of Poly(methyl methacrylate) (PMMA) and other samples. The third part of this dissertation explores imaging of optical magnetic fields. As a proof-of-principle, the magnetic

  17. DISCOVERING THE MISSING 2.2 < z < 3 QUASARS BY COMBINING OPTICAL VARIABILITY AND OPTICAL/NEAR-INFRARED COLORS

    International Nuclear Information System (INIS)

    Wu Xuebing; Wang Ran; Bian Fuyan; Jiang Linhua; Fan Xiaohui; Schmidt, Kasper B.

    2011-01-01

    The identification of quasars in the redshift range 2.2 < z < 3 is known to be very inefficient because the optical colors of such quasars are indistinguishable from those of stars. Recent studies have proposed using optical variability or near-infrared (near-IR) colors to improve the identification of the missing quasars in this redshift range. Here we present a case study combining both methods. We select a sample of 70 quasar candidates from variables in Sloan Digital Sky Survey (SDSS) Stripe 82, which are non-ultraviolet excess sources and have UKIDSS near-IR public data. They are clearly separated into two parts on the Y - K/g - z color-color diagram, and 59 of them meet or lie close to a newly proposed Y - K/g - z selection criterion for z < 4 quasars. Of these 59 sources, 44 were previously identified as quasars in SDSS DR7, and 35 of them are quasars at 2.2 < z < 3. We present spectroscopic observations of 14 of 15 remaining quasar candidates using the Bok 2.3 m telescope and the MMT 6.5 m telescope, and successfully identify all of them as new quasars at z = 2.36-2.88. We also apply this method to a sample of 643 variable quasar candidates with SDSS-UKIDSS nine-band photometric data selected from 1875 new quasar candidates in SDSS Stripe 82 given by Butler and Bloom based on the time-series selections, and find that 188 of them are probably new quasars with photometric redshifts at 2.2 < z < 3. Our results indicate that the combination of optical variability and optical/near-IR colors is probably the most efficient way to find 2.2 < z < 3 quasars and is very helpful for constructing a complete quasar sample. We discuss its implications for ongoing and upcoming large optical and near-IR sky surveys.

  18. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

    OpenAIRE

    Zhu, Lei; Guo, Ning; Li, Quanzheng; Ma, Ying; Jacboson, Orit; Lee, Seulki; Choi, Hak Soo; Mansfield, James R.; Niu, Gang; Chen, Xiaoyuan

    2012-01-01

    Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide. Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)...

  19. THE HIGH A{sub V} Quasar Survey: Reddened Quasi-Stellar Objects selected from optical/near-infrared photometry. II

    Energy Technology Data Exchange (ETDEWEB)

    Krogager, J.-K.; Fynbo, J. P. U.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Geier, S. [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Venemans, B. P. [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Ledoux, C. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Møller, P. [European Southern Observatory, Karl-Schwarzschildstrasse 2, D-85748 Garching bei München (Germany); Noterdaeme, P. [Institut d’Astrophysique de Paris, CNRS-UPMC, UMR7095, 98bis bd Arago, F-75014 Paris (France); Kangas, T.; Pursimo, T.; Smirnova, O. [Nordic Optical Telescope, Apartado 474, E-38700 Santa Cruz de La Palma (Spain); Saturni, F. G. [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500 Piikkiö (Finland)

    2015-03-15

    Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the ones used by the Sloan Digital Sky Survey (SDSS). To overcome this bias against red QSOs, we employ a combined optical and near-infrared (near-IR) color selection. In this paper, we present a spectroscopic follow-up campaign of a sample of red candidate QSOs which were selected from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS photometry are supplemented by mid-infrared photometry from the Wide-field Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are confirmed to be QSOs. We use a statistical algorithm to identify sightlines with plausible intervening absorption systems and identify nine such cases assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We find absorption systems toward 30 QSOs, 2 of which are consistent with the best-fit absorber redshift from the statistical modeling. Furthermore, we observe a broad range in SED properties of the QSOs as probed by the rest-frame 2 μm flux. We find QSOs with a strong excess as well as QSOs with a large deficit at rest-frame 2 μm relative to a QSO template. Potential solutions to these discrepancies are discussed. Overall, our study demonstrates the high efficiency of the optical/near-IR selection of red QSOs.

  20. PENETRATING THE HOMUNCULUS-NEAR-INFRARED ADAPTIVE OPTICS IMAGES OF ETA CARINAE

    International Nuclear Information System (INIS)

    Artigau, Etienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-01-01

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the 'butterfly nebula', outlined by bright Brγ and H 2 emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in η Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10 0 -20 0 above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star.

  1. Near infrared optical biosensor based on peptide functionalized single-walled carbon nanotubes hybrids for 2,4,6-trinitrotoluene (TNT) explosive detection.

    Science.gov (United States)

    Wang, Jin

    2018-06-01

    A near infrared (NIR) optical biosensor based on peptide functionalized single-walled carbon nanotubes (SWCNTs) hybrids for 2,4,6-trinitrotoluene (TNT) explosive detection was developed. The TNT binding peptide was directly anchored on the sidewall of the SWCNTs using the π-π interaction between the aromatic amino acids and SWCNTs, forming the peptide-SWCNTs hybrids for near infrared absorption spectra measurement. The evidence of the morphology of peptide-SWCNTs hybrids was obtained using atomic force microscopy (AFM). The results demonstrated that peptide-SWCNTs hybrids based NIR optical biosensor exhibited sensitive and highly selective for TNT explosive determination, addressing a promising optical biosensor for security application. Copyright © 2018. Published by Elsevier Inc.

  2. Sensores ópticos com detecção no infravermelho próximo e médio Near and mid infrared optical sensors

    Directory of Open Access Journals (Sweden)

    Kássio M. G. Lima

    2009-01-01

    Full Text Available Optical chemical sensors with detection in the near and mid infrared region are reviewed. Fundamental concepts of infrared spectroscopy and optical chemical sensors are briefly described, before presenting some aspects on optical chemical sensors, such as synthesis of NIR and IR reagents, preparation of new materials as well as application in determinations of species of biological, industrial and environmental importance.

  3. Near-Infrared and Optical Beam Steering and Frequency Splitting in Air-Holes-in-Silicon Inverse Photonic Crystals

    Science.gov (United States)

    2017-01-01

    We present the design of a dielectric inverse photonic crystal structure that couples line-defect waveguide propagating modes into highly directional beams of controllable directionality. The structure utilizes a triangular lattice made of air holes drilled in an infinitely thick Si slab, and it is designed for operation in the near-infrared and optical regime. The structure operation is based on the excitation and manipulation of dark dielectric surface states, in particular on the tailoring of the dark states’ coupling to outgoing radiation. This coupling is achieved with the use of properly designed external corrugations. The structure adapts and matches modes that travel through the photonic crystal and the free space. Moreover it facilitates the steering of the outgoing waves, is found to generate well-defined, spatially and spectrally isolated beams, and may serve as a frequency splitting component designed for operation in the near-infrared regime and in particular the telecom optical wavelength band. The design complies with the state-of-the-art Si nanofabrication technology and can be directly scaled for operation in the optical regime. PMID:29541653

  4. NONINVASIVE OPTICAL IMAGING OF STAPHYLOCOCCUS AUREUS INFECTION IN VIVO USING AN ANTIMICROBIAL PEPTIDE FRAGMENT BASED NEAR-INFRARED FLUORESCENT PROBES

    Directory of Open Access Journals (Sweden)

    CUICUI LIU

    2013-07-01

    Full Text Available The diagnosis of bacterial infections remains a major challenge in medicine. Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as light-emitting enzymes or fluorescent proteins. However, there are many circumstances where genetic reporters are not applicable, and there is an urgent need for exogenous synthetic probes that can selectively target bacteria. Optical imaging of bacteria in vivo is much less developed than methods such as radioimaging and MRI. Furthermore near-infrared (NIR dyes with emission wavelengths in the region of 650–900 nm can propagate through two or more centimeters of tissue and may enable deeper tissue imaging if sensitive detection techniques are employed. Here we constructed an antimicrobial peptide fragment UBI29-41-based near-infrared fluorescent imaging probe. The probe is composed of UBI29-41 conjugated to a near infrared dye ICG-Der-02. UBI29-41 is a cationic antimicrobial peptide that targets the anionic surfaces of bacterial cells. The probe allows detection of Staphylococcus aureus infection (5 × 107 cells in a mouse local infection model using whole animal near-infrared fluorescence imaging. Furthermore, we demonstrate that the UBI29-41-based imaging probe can selectively accumulate within bacteria. The significantly higher accumulation in bacterial infection suggests that UBI29-41-based imaging probe may be a promising imaging agent to detect bacterial infections.

  5. Optical and near-infrared IFU spectroscopy of the nuclear region of the AGN-starburst galaxy NGC 7582

    Science.gov (United States)

    Ricci, T. V.; Steiner, J. E.; May, D.; Garcia-Rissmann, A.; Menezes, R. B.

    2018-02-01

    NGC 7582 is an SB(s)ab galaxy which displays evidences of simultaneous nuclear activity and star formation in its centre. Previous optical observations revealed, besides the H II regions, an ionization cone and a gas disc in its central part. Hubble Space Telescope (HST) images in both optical and infrared bands show the active galactic nuclei (AGNs) and a few compact structures that are possibly associated with young stellar clusters. In order to study in detail both the AGN and evidence for star formation, we analyse optical (Gemini Multi-Object Spectrograph) and near-infrared (Spectrograph for Integral Field Observations in the Near Infrared) archival data cubes. We detected five nebulae with strong He II λ4686 emission in the same region where an outflow is detected in the [O III] λ5007 kinematic map. We interpreted this result as clouds that are exposed to high-energy photons emerging from the AGN throughout the ionization cone. We also detected Wolf-Rayet features which are related to emission of one of the compact clusters seen in the HST image. Broad Hα and Br γ components are detected at the position of the nucleus. [Fe II] λ1.644 μm, H2λ2.122 μm and Br γ flux maps show two blobs, one north and the other south from the nucleus, that seem to be associated with five previously detected mid-infrared sources. Two of the five He II nebulae are partially ionized by photons from starbursts. However, we conclude that the main source of excitation of these blobs is the AGN jet/disc. The jet orientation indicates that the accretion disc is nearly orthogonal to the dusty torus.

  6. [Rapid discriminating hogwash oil and edible vegetable oil using near infrared optical fiber spectrometer technique].

    Science.gov (United States)

    Zhang, Bing-Fang; Yuan, Li-Bo; Kong, Qing-Ming; Shen, Wei-Zheng; Zhang, Bing-Xiu; Liu, Cheng-Hai

    2014-10-01

    In the present study, a new method using near infrared spectroscopy combined with optical fiber sensing technology was applied to the analysis of hogwash oil in blended oil. The 50 samples were a blend of frying oil and "nine three" soybean oil according to a certain volume ratio. The near infrared transmission spectroscopies were collected and the quantitative analysis model of frying oil was established by partial least squares (PLS) and BP artificial neural network The coefficients of determina- tion of calibration sets were 0.908 and 0.934 respectively. The coefficients of determination of validation sets were 0.961 and 0.952, the root mean square error of calibrations (RMSEC) was 0.184 and 0.136, and the root mean square error of predictions (RMSEP) was all 0.111 6. They conform to the model application requirement. At the same time, frying oil and qualified edible oil were identified with the principal component analysis (PCA), and the accurate rate was 100%. The experiment proved that near infrared spectral technology not only can quickly and accurately identify hogwash oil, but also can quantitatively detect hog- wash oil. This method has a wide application prospect in the detection of oil.

  7. Optical and near-infrared photometric study of NGC 6724

    Science.gov (United States)

    Bendary, Reda; Tadross, Ashraf; Hasan, Priya; Osman, Anas; Essam, Ahmed

    2018-02-01

    BVRI CCD photometry of the poorly studied open cluster NGC 6724 has been carried out down to a limiting magnitude of V∼20 mag. The stars of the cluster have been observed using the Newtonian focus (f/4.84) of the 74-inch telescope at Kottamia Astronomical Observatory in Egypt. Also, the 2MASS - JHK system is used to confirm the results we obtained. The main photometric parameters have been estimated for the present object; the diameter is found to be 6 arcmin, the distance is 1530±60 pc from the Sun and the age is 900±50 Myr. The optical reddening E(B-V)=0.65 {mag}, while the infrared reddening is E(J-H)=0.20 {mag}. The slope of the mass function distribution and the relaxation time estimations indicate that cluster NGC 6724 is dynamically relaxed.

  8. Time-series surveys and pulsating stars: The near-infrared perspective

    Directory of Open Access Journals (Sweden)

    Matsunaga Noriyuki

    2017-01-01

    Full Text Available The purpose of this review is to discuss the advantages and problems of nearinfrared surveys in observing pulsating stars in the Milky Way. One of the advantages of near-infrared surveys, when compared to optical counterparts, is that the interstellar extinction is significantly smaller. As we see in this review, a significant volume of the Galactic disk can be reached by infrared surveys but not by optical ones. Towards highly obscured regions in the Galactic mid-plane, however, the interstellar extinction causes serious problems even with near-infrared data in understanding the observational results. After a review on previous and current near-infrared surveys, we discuss the effects of the interstellar extinction in optical (including Gaia to near-infrared broad bands based on a simple calculation using synthetic spectral energy distribution. We then review the recent results on classical Cepheids towards the Galactic center and the bulge, as a case study, to see the impact of the uncertainty in the extinction law. The extinction law, i.e. the wavelength dependency of the extinction, is not fully characterized, and its uncertainty makes it hard to make the correction. Its characterization is an urgent task in order to exploit the outcomes of ongoing large-scale surveys of pulsating stars, e.g. for drawing a map of pulsating stars across the Galactic disk.

  9. The Andromeda Optical and Infrared Disk Survey

    Science.gov (United States)

    Sick, J.; Courteau, S.; Cuillandre, J.-C.

    2014-03-01

    The Andromeda Optical and Infrared Disk Survey has mapped M31 in u* g' r' i' JKs wavelengths out to R = 40 kpc using the MegaCam and WIRCam wide-field cameras on the Canada-France-Hawaii Telescope. Our survey is uniquely designed to simultaneously resolve stars while also carefully reproducing the surface brightness of M31, allowing us to study M31's global structure in the context of both resolved stellar populations and spectral energy distributions. We use the Elixir-LSB method to calibrate the optical u* g' r' i' images by building real-time maps of the sky background with sky-target nodding. These maps are stable to μg ≲ 28.5 mag arcsec-2 and reveal warps in the outer M31 disk in surface brightness. The equivalent WIRCam mapping in the near-infrared uses a combination of sky-target nodding and image-to-image sky offset optimization to produce stable surface brightnesses. This study enables a detailed analysis of the systematics of spectral energy distribution fitting with near-infrared bands where asymptotic giant branch stars impose a significant, but ill-constrained, contribution to the near-infrared light of a galaxy. Here we present panchromatic surface brightness maps and initial results from our near-infrared resolved stellar catalog.

  10. Near-infrared neuroimaging with NinPy

    Directory of Open Access Journals (Sweden)

    Gary E Strangman

    2009-05-01

    Full Text Available There has been substantial recent growth in the use of non-invasive optical brain imaging in studies of human brain function in health and disease. Near-infrared neuroimaging (NIN is one of the most promising of these techniques and, although NIN hardware continues to evolve at a rapid pace, software tools supporting optical data acquisition, image processing, statistical modeling and visualization remain less refined. Python, a modular and computationally efficient development language, can support functional neuroimaging studies of diverse design and implementation. In particular, Python's easily readable syntax and modular architecture allow swift prototyping followed by efficient transition to stable production systems. As an introduction to our ongoing efforts to develop Python software tools for structural and functional neuroimaging, we discuss: (i the role of noninvasive diffuse optical imaging in measuring brain function, (ii the key computational requirements to support NIN experiments, (iii our collection of software tools to support near-infrared neuroimaging, called NinPy, and (iv future extensions of these tools that will allow integration of optical with other structural and functional neuroimaging data sources. Source code for the software discussed here will be made available at www.nmr.mgh.harvard.edu/Neural_SystemsGroup/software.html.

  11. Analysis of near-field components of a plasmonic optical antenna and their contribution to quantum dot infrared photodetector enhancement.

    Science.gov (United States)

    Gu, Guiru; Vaillancourt, Jarrod; Lu, Xuejun

    2014-10-20

    In this paper, we analyze near-field vector components of a metallic circular disk array (MCDA) plasmonic optical antenna and their contribution to quantum dot infrared photodetector (QDIP) enhancement. The near-field vector components of the MCDA optical antenna and their distribution in the QD active region are simulated. The near-field overlap integral with the QD active region is calculated at different wavelengths and compared with the QDIP enhancement spectrum. The x-component (E(x)) of the near-field vector shows a larger intensity overlap integral and stronger correlation with the QDIP enhancement than E(z) and thus is determined to be the major near-field component to the QDIP enhancement.

  12. Effect of mechanical optical clearing on near-infrared spectroscopy.

    Science.gov (United States)

    Idelson, Christopher R; Vogt, William C; King-Casas, Brooks; LaConte, Stephen M; Rylander, Christopher G

    2015-08-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations. © 2015 Wiley Periodicals, Inc.

  13. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

    Directory of Open Access Journals (Sweden)

    Lei Zhu, Ning Guo, Quanzheng Li, Ying Ma, Orit Jacboson, Seulki Lee, Hak Soo Choi, James R. Mansfield, Gang Niu, Xiaoyuan Chen

    2012-01-01

    Full Text Available Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide.Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data.Results: The dual-labeled probe 64Cu-RGD-C(DOTA-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp derived from dynamic optical imaging (1.762 ± 0.020 is comparable to that from dynamic PET (1.752 ± 0.026.Conclusion: The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  14. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe.

    Science.gov (United States)

    Zhu, Lei; Guo, Ning; Li, Quanzheng; Ma, Ying; Jacboson, Orit; Lee, Seulki; Choi, Hak Soo; Mansfield, James R; Niu, Gang; Chen, Xiaoyuan

    2012-01-01

    The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/(64)Cu dual-labeled cyclic RGD peptide. The integrin α(v)β(3) binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD) method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data. The dual-labeled probe (64)Cu-RGD-C(DOTA)-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp) derived from dynamic optical imaging (1.762 ± 0.020) is comparable to that from dynamic PET (1.752 ± 0.026). The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  15. Near-infrared optical imaging of nucleic acid nanocarriers in vivo.

    Science.gov (United States)

    Rome, Claire; Gravier, Julien; Morille, Marie; Divita, Gilles; Bolcato-Bellemin, Anne-Laure; Josserand, Véronique; Coll, Jean-Luc

    2013-01-01

    Noninvasive, real-time optical imaging methods are well suited to follow the in vivo distribution of nucleic acid nanocarriers, their dissociation, and the resulting gene expression or inhibition. Indeed, most small animal imaging devices perform bioluminescence and fluorescence measurements without moving the animal, allowing a simple, rapid, and cost-effective method of investigation of several parameters at a time, in longitudinal experiments that can last for days or weeks.Here we help the reader in choosing adapted near-infrared (NIR) fluorophores or pairs of fluorophores for Förster resonance energy transfer assays, imaging of reporter genes, as well as nanocarriers for in vivo gene and siRNA delivery. In addition, we present the labeling methods of these macromolecules and of their payload and the protocols to detect them using bioluminescence and NIR fluorescence imaging in mice.

  16. Near-infrared fluorescent aza-BODIPY dye-loaded biodegradable polymeric nanoparticles for optical cancer imaging

    International Nuclear Information System (INIS)

    Hamon, Casey L.; Dorsey, Christopher L.; Özel, Tuğba; Barnes, Eugenia M.; Hudnall, Todd W.; Betancourt, Tania

    2016-01-01

    Nanoparticles are being readily investigated as carriers for the delivery of imaging and therapeutic agents for the detection, monitoring, and treatment of cancer and other diseases. In the present work, the preparation of biodegradable polymeric nanoparticles loaded with a near-infrared fluorescent aza-boron dipyrromethene (NIR-BODIPY) derivative, and their use as contrast agents for optical imaging in cancer are described. Nanoparticles were prepared by nanoprecipitation of amphiphilic block copolymers of poly(lactic acid) and poly(ethylene glycol). The size, morphology, dye loading, spectral properties, quantum yield, cytocompatibility, and in vitro NIR imaging potential of the nanoparticles in breast and ovarian cancer cells were evaluated. Spherical nanoparticles of 30–70 nm in diameter were loaded with 0.73 w/w% BODIPY derivative. At this loading, the dye presented a fluorescence quantum yield in the same order of magnitude as in solution. Nanoparticle suspensions at concentrations up to 580 μg/mL were cytocompatible to breast (MDA-MB-231) and ovarian (SKOV-3 and Caov-3) cancer cells after a four-hour incubation period. Fluorescence microscopy images demonstrated the ability of the nanoparticles to act as imaging agents in all three cell lines in as little as 1 hour. The results shown indicate the potential of these NIR-BODIPY-loaded nanoparticles as contrast agents for near-infrared optical imaging in cancer.Graphical abstract

  17. Near-infrared fluorescent aza-BODIPY dye-loaded biodegradable polymeric nanoparticles for optical cancer imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hamon, Casey L.; Dorsey, Christopher L. [Texas State University, Department of Chemistry and Biochemistry (United States); Özel, Tuğba [Texas State University, Materials Science, Engineering, and Commercialization Program (United States); Barnes, Eugenia M.; Hudnall, Todd W.; Betancourt, Tania, E-mail: tb26@txstate.edu [Texas State University, Department of Chemistry and Biochemistry (United States)

    2016-07-15

    Nanoparticles are being readily investigated as carriers for the delivery of imaging and therapeutic agents for the detection, monitoring, and treatment of cancer and other diseases. In the present work, the preparation of biodegradable polymeric nanoparticles loaded with a near-infrared fluorescent aza-boron dipyrromethene (NIR-BODIPY) derivative, and their use as contrast agents for optical imaging in cancer are described. Nanoparticles were prepared by nanoprecipitation of amphiphilic block copolymers of poly(lactic acid) and poly(ethylene glycol). The size, morphology, dye loading, spectral properties, quantum yield, cytocompatibility, and in vitro NIR imaging potential of the nanoparticles in breast and ovarian cancer cells were evaluated. Spherical nanoparticles of 30–70 nm in diameter were loaded with 0.73 w/w% BODIPY derivative. At this loading, the dye presented a fluorescence quantum yield in the same order of magnitude as in solution. Nanoparticle suspensions at concentrations up to 580 μg/mL were cytocompatible to breast (MDA-MB-231) and ovarian (SKOV-3 and Caov-3) cancer cells after a four-hour incubation period. Fluorescence microscopy images demonstrated the ability of the nanoparticles to act as imaging agents in all three cell lines in as little as 1 hour. The results shown indicate the potential of these NIR-BODIPY-loaded nanoparticles as contrast agents for near-infrared optical imaging in cancer.Graphical abstract.

  18. Optical and Near-infrared Spectra of σ Orionis Isolated Planetary-mass Objects

    Energy Technology Data Exchange (ETDEWEB)

    Zapatero Osorio, M. R. [Centro de Astrobiología (CSIC-INTA), Crta. Ajalvir km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Béjar, V. J. S. [Instituto de Astrofísica de Canarias, C/. Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Ramírez, K. Peña, E-mail: mosorio@cab.inta-csic.es, E-mail: vbejar@iac.es, E-mail: karla.pena@uantof.cl [Unidad de Astronomía de la Universidad de Antofagasta, Av. U. de Antofagasta. 02800 Antofagasta (Chile)

    2017-06-10

    We have obtained low-resolution optical (0.7–0.98 μ m) and near-infrared (1.11–1.34 μ m and 0.8–2.5 μ m) spectra of 12 isolated planetary-mass candidates ( J = 18.2–19.9 mag) of the 3 Myr σ Orionis star cluster with the aim of determining the spectroscopic properties of very young, substellar dwarfs and assembling a complete cluster mass function. We have classified our targets by visual comparison with high- and low-gravity standards and by measuring newly defined spectroscopic indices. We derived L0–L4.5 and M9–L2.5 using high- and low-gravity standards, respectively. Our targets reveal clear signposts of youth, thus corroborating their cluster membership and planetary masses (6–13 M {sub Jup}). These observations complete the σ Orionis mass function by spectroscopically confirming the planetary-mass domain to a confidence level of ∼75%. The comparison of our spectra with BT-Settl solar metallicity model atmospheres yields a temperature scale of 2350–1800 K and a low surface gravity of log g ≈ 4.0 [cm s{sup −2}], as would be expected for young planetary-mass objects. We discuss the properties of the cluster’s least-massive population as a function of spectral type. We have also obtained the first optical spectrum of S Ori 70, a T dwarf in the direction of σ Orionis. Our data provide reference optical and near-infrared spectra of very young L dwarfs and a mass function that may be used as templates for future studies of low-mass substellar objects and exoplanets. The extrapolation of the σ Orionis mass function to the solar neighborhood may indicate that isolated planetary-mass objects with temperatures of ∼200–300 K and masses in the interval 6–13 M {sub Jup} may be as numerous as very low-mass stars.

  19. NEAR-INFRARED ADAPTIVE OPTICS IMAGING OF INFRARED LUMINOUS GALAXIES: THE BRIGHTEST CLUSTER MAGNITUDE-STAR FORMATION RATE RELATION

    International Nuclear Information System (INIS)

    Randriamanakoto, Z.; Väisänen, P.; Escala, A.; Kankare, E.; Kotilainen, J.; Mattila, S.; Ryder, S.

    2013-01-01

    We have established a relation between the brightest super star cluster (SSC) magnitude in a galaxy and the host star formation rate (SFR) for the first time in the near-infrared (NIR). The data come from a statistical sample of ∼40 luminous IR galaxies (LIRGs) and starbursts utilizing K-band adaptive optics imaging. While expanding the observed relation to longer wavelengths, less affected by extinction effects, it also pushes to higher SFRs. The relation we find, M K ∼ –2.6log SFR, is similar to that derived previously in the optical and at lower SFRs. It does not, however, fit the optical relation with a single optical to NIR color conversion, suggesting systematic extinction and/or age effects. While the relation is broadly consistent with a size-of-sample explanation, we argue physical reasons for the relation are likely as well. In particular, the scatter in the relation is smaller than expected from pure random sampling strongly suggesting physical constraints. We also derive a quantifiable relation tying together cluster-internal effects and host SFR properties to possibly explain the observed brightest SSC magnitude versus SFR dependency

  20. Breast phantom for mammary tissue characterization by near infrared spectroscopy

    International Nuclear Information System (INIS)

    Miranda, D A; Cristiano, K L; Gutiérrez, J C

    2013-01-01

    Breast cancer is a disease associated to a high morbidity and mortality in the entire world. In the study of early detection of breast cancer the development of phantom is so important. In this research we fabricate a breast phantom using a ballistic gel with special modifications to simulate a normal and abnormal human breast. Optical properties of woman breast in the near infrared region were modelled with the phantom we developed. The developed phantom was evaluated with near infrared spectroscopy in order to study its relation with breast tissue. A good optical behaviour was achieved with the model fabricated

  1. Comparison of stellar population model predictions using optical and infrared spectroscopy

    Science.gov (United States)

    Baldwin, C.; McDermid, R. M.; Kuntschner, H.; Maraston, C.; Conroy, C.

    2018-02-01

    We present Gemini/GNIRS cross-dispersed near-infrared spectra of 12 nearby early-type galaxies, with the aim of testing commonly used stellar population synthesis models. We select a subset of galaxies from the ATLAS3D sample which span a wide range of ages (single stellar population equivalent ages of 1-15 Gyr) at approximately solar metallicity. We derive star formation histories using four different stellar population synthesis models, namely those of Bruzual & Charlot, Conroy, Gunn & White, Maraston & Strömbäck and Vazdekis et al. We compare star formation histories derived from near-infrared spectra with those derived from optical spectra using the same models. We find that while all models agree in the optical, the derived star formation histories vary dramatically from model to model in the near-infrared. We find that this variation is largely driven by the choice of stellar spectral library, such that models including high-quality spectral libraries provide the best fits to the data, and are the most self-consistent when comparing optically derived properties with near-infrared ones. We also find the impact of age variation in the near-infrared to be subtle, and largely encoded in the shape of the continuum, meaning that the common approach of removing continuum information with a high-order polynomial greatly reduces our ability to constrain ages in the near-infrared.

  2. Towards phonon photonics: scattering-type near-field optical microscopy reveals phonon-enhanced near-field interaction

    International Nuclear Information System (INIS)

    Hillenbrand, Rainer

    2004-01-01

    Diffraction limits the spatial resolution in classical microscopy or the dimensions of optical circuits to about half the illumination wavelength. Scanning near-field microscopy can overcome this limitation by exploiting the evanescent near fields existing close to any illuminated object. We use a scattering-type near-field optical microscope (s-SNOM) that uses the illuminated metal tip of an atomic force microscope (AFM) to act as scattering near-field probe. The presented images are direct evidence that the s-SNOM enables optical imaging at a spatial resolution on a 10 nm scale, independent of the wavelength used (λ=633 nm and 10 μm). Operating the microscope at specific mid-infrared frequencies we found a tip-induced phonon-polariton resonance on flat polar crystals such as SiC and Si 3 N 4 . Being a spectral fingerprint of any polar material such phonon-enhanced near-field interaction has enormous applicability in nondestructive, material-specific infrared microscopy at nanoscale resolution. The potential of s-SNOM to study eigenfields of surface polaritons in nanostructures opens the door to the development of phonon photonics--a proposed infrared nanotechnology that uses localized or propagating surface phonon polaritons for probing, manipulating and guiding infrared light in nanoscale devices, analogous to plasmon photonics

  3. ARNICA, the Arcetri near-infrared camera: Astronomical performance assessment.

    Science.gov (United States)

    Hunt, L. K.; Lisi, F.; Testi, L.; Baffa, C.; Borelli, S.; Maiolino, R.; Moriondo, G.; Stanga, R. M.

    1996-01-01

    The Arcetri near-infrared camera ARNICA was built as a users' instrument for the Infrared Telescope at Gornergrat (TIRGO), and is based on a 256x256 NICMOS 3 detector. In this paper, we discuss ARNICA's optical and astronomical performance at the TIRGO and at the William Herschel Telescope on La Palma. Optical performance is evaluated in terms of plate scale, distortion, point spread function, and ghosting. Astronomical performance is characterized by camera efficiency, sensitivity, and spatial uniformity of the photometry.

  4. Meeting the Cool Neighbors. XII. An Optically Anchored Analysis of the Near-infrared Spectra of L Dwarfs

    Science.gov (United States)

    Cruz, Kelle L.; Núñez, Alejandro; Burgasser, Adam J.; Abrahams, Ellianna; Rice, Emily L.; Reid, I. Neill; Looper, Dagny

    2018-01-01

    Discrepancies between competing optical and near-infrared (NIR) spectral typing systems for L dwarfs have motivated us to search for a classification scheme that ties the optical and NIR schemes together, and addresses complexities in the spectral morphology. We use new and extant optical and NIR spectra to compile a sample of 171 L dwarfs, including 27 low-gravity β and γ objects, with spectral coverage from 0.6–2.4 μm. We present 155 new low-resolution NIR spectra and 19 new optical spectra. We utilize a method for analyzing NIR spectra that partially removes the broad-band spectral slope and reveals similarities in the absorption features between objects of the same optical spectral type. Using the optical spectra as an anchor, we generate near-infrared spectral average templates for L0–L8, L0–L4γ, and L0–L1β type dwarfs. These templates reveal that NIR spectral morphologies are correlated with the optical types. They also show the range of spectral morphologies spanned by each spectral type. We compare low-gravity and field-gravity templates to provide recommendations on the minimum required observations for credibly classifying low-gravity spectra using low-resolution NIR data. We use the templates to evaluate the existing NIR spectral standards and propose new ones where appropriate. Finally, we build on the work of Kirkpatrick et al. to provide a spectral typing method that is tied to the optical and can be used when only H or K band data are available. The methods we present here provide resolutions to several long-standing issues with classifying L dwarf spectra and could also be the foundation for a spectral classification scheme for cloudy exoplanets.

  5. Optical properties of Nd3+ doped barium lithium fluoroborate glasses for near-infrared (NIR) emission

    Science.gov (United States)

    Mariselvam, K.; Arun Kumar, R.; Suresh, K.

    2018-04-01

    The neodymium doped barium lithium fluoroborate (Nd3+: BLFB) glasses with the chemical composition (70-x) H3BO3 - 10 Li2CO3 - 10 BaCO3- 5 CaF2-5 ZnO - x Nd2O3 (where x = 0.05, 0.1, 0.25, 0.5, 1, 2 in wt %) have been prepared by the conventional melt quenching technique and characterised through optical absorption, near infrared emission and decay-time measurements. The x-ray diffraction studies confirm the amorphous nature of the prepared glasses. The optical absorption spectra and emission spectra were recorded in the wavelength ranges of 190-1100 nm. The optical band gap (Eg) and Urbach energy (ΔE) values were calculated from the absorption spectra. The Judd-Ofelt intensity parameters were determined from the systematic analysis of the absorption spectrum of neodymium ions in the prepared glasses. The emission spectra exhibited three prominent peaks at 874, 1057, 1331 nm corresponding to the 4F3/2 → 4I9/2, 11/2, 13/2 transitions levels respectively in the near infrared region. The emission intensity of the 4F3/2 → 4I11/2 transition increases with the increase in neodymium concentration up to 0.5 wt% and the concentration quenching mechanism was observed for 1 wt% and 2 wt% concentrations. The lifetime of the 4F3/2 level was found to decrease with increasing Nd3+ ion concentration. The nature of energy transfer process was a single exponential curve which was studied for all the glasses and analysed.

  6. Generation of broadly tunable picosecond mid-infrared laser and sensitive detection of a mid-infrared signal by parametric frequency up-conversion in MgO:LiNbO3 optical parametric amplifiers

    International Nuclear Information System (INIS)

    Zhang Qiu-Lin; Zhang Jing; Qiu Kang-Sheng; Zhang Dong-Xiang; Feng Bao-Hua; Zhang Jing-Yuan

    2012-01-01

    Picosecond optical parametric generation and amplification in the near-infrared region within 1.361–1.656 μm and the mid-infrared region within 2.976–4.875 μm is constructed on the basis of bulk MgO:LiNbO 3 crystals pumped at 1.064 μm. The maximum pulse energy reaches 1.3 mJ at 1.464 μm and 0.47 mJ at 3.894 μm, corresponding to a pump-to-idler photon conversion efficiency of 25%. By seeding the hard-to-measure mid-infrared radiation as the idler in the optical parametric amplification and measuring the amplified and frequency up-converted signal in the near-infrared or even visible region, one can measure very week mid-infrared radiation with ordinary detectors, which are insensitive to mid-infrared radiation, with a very high gain. A maximum gain factor of about 7 × 10 7 is achieved at the mid-infrared wavelength of 3.374 μm and the corresponding energy detection limit is as low as about 390 aJ per pulse. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  7. Near Infrared Characterization of Hetero-Core Optical Fiber SPR Sensors Coated with Ta2O5 Film and Their Applications

    Directory of Open Access Journals (Sweden)

    Kazuhiro Watanabe

    2012-02-01

    Full Text Available This paper describes the characteristics of optical fiber sensors with surface plasmon resonance (SPR at 1,310 nm in which the scattering loss of silica optical fiber is low. SPR operation in the infrared wavelength range is achieved by coating a thin tantalum pentaoxide (Ta2O5 film. The novelty of this paper lies in the verification of how the hetero-core scheme could be operated as a commercial base candidate in the sense of easy fabrication, sufficient mechanical strength, and significant sensitivity as a liquid detector under the basis of a low loss transmission network in the near infrared wavelength region. The effect of Ta2O5 layer thickness has been experimentally revealed in the wavelength region extending to 1,800 nm by using the hetero-core structured optical fiber. SPR characterizations have been made in the wavelength region 1,000–1,300 nm, showing the feasible operation at the near infrared wavelength and the possible practical applications. In addition, the technique developed in this work has been interestingly applied to a multi-point water-detection and a water-level gauge in which tandem-connected SPR sensors system using hetero-core structured fibers were incorporated. The detailed performance characteristics are also shown on these applications.

  8. OPTICAL-NEAR-INFRARED COLOR GRADIENTS AND MERGING HISTORY OF ELLIPTICAL GALAXIES

    International Nuclear Information System (INIS)

    Kim, Duho; Im, Myungshin

    2013-01-01

    It has been suggested that merging plays an important role in the formation and the evolution of elliptical galaxies. While gas dissipation by star formation is believed to steepen metallicity and color gradients of the merger products, mixing of stars through dissipation-less merging (dry merging) is believed to flatten them. In order to understand the past merging history of elliptical galaxies, we studied the optical-near-infrared (NIR) color gradients of 204 elliptical galaxies. These galaxies are selected from the overlap region of the Sloan Digital Sky Survey (SDSS) Stripe 82 and the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). The use of optical and NIR data (g, r, and K) provides large wavelength baselines, and breaks the age-metallicity degeneracy, allowing us to derive age and metallicity gradients. The use of the deep SDSS Stripe 82 images makes it possible for us to examine how the color/age/metallicity gradients are related to merging features. We find that the optical-NIR color and the age/metallicity gradients of elliptical galaxies with tidal features are consistent with those of relaxed ellipticals, suggesting that the two populations underwent a similar merging history on average and that mixing of stars was more or less completed before the tidal features disappeared. Elliptical galaxies with dust features have steeper color gradients than the other two types, even after masking out dust features during the analysis, which can be due to a process involving wet merging. More importantly, we find that the scatter in the color/age/metallicity gradients of the relaxed and merging feature types decreases as their luminosities (or masses) increase at M > 10 11.4 M ☉ but stays large at lower luminosities. Mean metallicity gradients appear nearly constant over the explored mass range, but a possible flattening is observed at the massive end. According to our toy model that predicts how the distribution of metallicity gradients

  9. The Optical/Near-infrared Extinction Law in Highly Reddened Regions

    Science.gov (United States)

    Hosek, Matthew W., Jr.; Lu, Jessica R.; Anderson, Jay; Do, Tuan; Schlafly, Edward F.; Ghez, Andrea M.; Clarkson, William I.; Morris, Mark R.; Albers, Saundra M.

    2018-03-01

    A precise extinction law is a critical input when interpreting observations of highly reddened sources such as young star clusters and the Galactic Center (GC). We use Hubble Space Telescope observations of a region of moderate extinction and a region of high extinction to measure the optical and near-infrared extinction law (0.8–2.2 μm). The moderate-extinction region is the young massive cluster Westerlund 1 (Wd1; A Ks ∼ 0.6 mag), where 453 proper-motion selected main-sequence stars are used to measure the shape of the extinction law. To quantify the shape, we define the parameter {{ \\mathcal S }}1/λ , which behaves similarly to a color-excess ratio, but is continuous as a function of wavelength. The high-extinction region is the GC (A Ks ∼ 2.5 mag), where 819 red clump stars are used to determine the normalization of the law. The best-fit extinction law is able to reproduce the Wd1 main-sequence colors, which previous laws misestimate by 10%–30%. The law is inconsistent with a single power law, even when only the near-infrared filters are considered, and has A F125W/A Ks and A F814W/A Ks values that are 18% and 24% higher than the commonly used Nishiyama et al. law, respectively. Using this law, we recalculate the Wd1 distance to be 3905 ± 422 pc from published observations of the eclipsing binary W13. This new extinction law should be used for highly reddened populations in the Milky Way, such as the Quintuplet cluster and Young Nuclear Cluster. A python code is provided to generate the law for future use.

  10. Low-temperature optical characterization of a near-infrared single-photon emitter in nanodiamonds

    Energy Technology Data Exchange (ETDEWEB)

    Siyushev, P; Jacques, V; Kaiser, F; Jelezko, F; Wrachtrup, J [3.Physikalisches Institut, Universitaet Stuttgart, D-70550 Stuttgart (Germany); Aharonovich, I; Castelletto, S; Prawer, S [School of Physics, University of Melbourne, VA 3010 (Australia); Mueller, T; Lombez, L; Atatuere, M [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom)], E-mail: v.jacques@physik.uni-stuttgart.de

    2009-11-15

    In this paper, we study the optical properties of single defects emitting in the near infrared (NIR) in nanodiamonds at liquid helium temperature. The nanodiamonds are synthesized using a microwave chemical vapor deposition method followed by nickel implantation and annealing. We show that single defects exhibit several striking features at cryogenic temperature: the photoluminescence is strongly concentrated into a sharp zero-phonon line (ZPL) in the NIR, the radiative lifetime is in the nanosecond range and the emission is linearly polarized. The spectral stability of the defects is then investigated. An optical resonance linewidth of 4 GHz is measured using resonant excitation on the ZPL. Although Fourier-transform-limited emission is not achieved, our results show that it might be possible to use consecutive photons emitted in the NIR by single defects in diamond nanocrystals to perform two photon interference experiments, which are at the heart of linear quantum computing protocols.

  11. Dynamic analysis of temporal moisture profiles in heatset printing studied with near-infrared spectroscopy

    International Nuclear Information System (INIS)

    Tåg, C-M; Toiviainen, M; Juuti, M; Gane, P A C

    2010-01-01

    Dynamic analysis of the water transfer onto coated paper, and its permeation and absorption into the porous structure were studied online in a full-scale heatset web offset printing environment. The moisture content of the paper was investigated at five different positions during the printing process. Changes in the moisture content of the paper were studied as a function of the web temperature, printing speed and silicone application in the folding unit positioned after the hot air drying oven. Additionally, the influence of fountain solution composition on the pick-up by the paper was investigated. The water content of the fountain solution transferred to the paper from the printing units was observed as changes in near-infrared absorbance. A calibration data set enabled the subsequent quantification of the dynamic moisture content of the paper at the studied locations. An increase in the printing speed reduced the water transfer to the paper and an increase in web temperature resulted in a reduction in the moisture content. An increase in the dosage level of the water–silicone mixture was observed as a re-moistening effect of the paper. Differences in the drying strategy resulted in different moisture profiles depending on the type of fountain solution used. As a conclusion, the near-infrared signal provides an effective way to characterize the moisture dynamics online at different press units

  12. Image-guided cancer surgery using near-infrared fluorescence

    Science.gov (United States)

    Vahrmeijer, Alexander L.; Hutteman, Merlijn; van der Vorst, Joost R.; van de Velde, C.J.H.; Frangioni, John V.

    2013-01-01

    Paradigm shifts in surgery arise when surgeons are empowered to perform surgery faster, better, and/or less expensively. Optical imaging that exploits invisible near-infrared fluorescent light has the potential to improve cancer surgery outcomes while minimizing anesthesia time and lowering healthcare costs. Because of this, the last few years have witnessed an explosion of proof-of-concept clinical trials in the field. In this review, we introduce the concept of near-infrared fluorescence imaging for cancer surgery, review the clinical trial literature to date, outline the key issues pertaining to imaging system and contrast agent optimization, discuss limitations and leverage, and provide a framework for making the technology available for the routine care of cancer patients in the near future. PMID:23881033

  13. low-Cost, High-Performance Alternatives for Target Temperature Monitoring Using the Near-Infrared Spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Virgo, Mathew [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin J. [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-02-01

    A process is being developed for commercial production of the medical isotope Mo-99 through a photo-nuclear reaction on a Mo-100 target using a highpower electron accelerator. This process requires temperature monitoring of the window through which a high-current electron beam is transmitted to the target. For this purpose, we evaluated two near infrared technologies: the OMEGA Engineering iR2 pyrometer and the Ocean Optics Maya2000 spectrometer with infrared-enhanced charge-coupled device (CCD) sensor. Measuring in the near infrared spectrum, in contrast to the long-wavelength infrared spectrum, offers a few immediate advantages: (1) ordinary glass or quartz optical elements can be used; (2) alignment can be performed without heating the target; and (3) emissivity corrections to temperature are typically less than 10%. If spatial resolution is not required, the infrared pyrometer is attractive because of its accuracy, low cost, and simplicity. If spatial resolution is required, we make recommendations for near-infrared imaging based on our data augmented by calculations

  14. Pulsed near-infrared photoacoustic spectroscopy of blood

    Science.gov (United States)

    Laufer, Jan G.; Elwell, Clare E.; Delpy, Dave T.; Beard, Paul C.

    2004-07-01

    The aim of this study was to use pulsed near infrared photoacoustic spectroscopy to determine the oxygen saturation (SO2) of a saline suspension of red blood cells in vitro. The photoacoustic measurements were made in a cuvette which formed part of a larger circuit through which the red blood cell suspension was circulated. Oxygen saturation of the red blood cell suspension was altered between 2-3% to 100% in step increments using a membrane oxygenator and at each increment an independent measurement of oxygen saturation was made using a co-oximeter. An optical parametric oscillator laser system provided nanosecond excitation pulses at a number of wavelengths in the near-infrared spectrum (740-1040nm) which were incident on the cuvette. The resulting acoustic signals were detected using a broadband (15MHz) Fabry-Perot polymer film transducer. The optical transport coefficient and amplitude were determined from the acoustic signals as a function of wavelength. These data were then used to calculate the relative concentrations of oxy- and deoxyhaemoglobin, using their known specific absorption coefficients and an empirically determined wavelength dependence of optical scattering over the wavelength range investigated. From this, the oxygen saturation of the suspension was derived with an accuracy of +/-5% compared to the co-oximeter SO2 measurements.

  15. pH-stimuli-responsive near-infrared optical imaging nanoprobe based on poly(γ-glutamic acid)/poly(β-amino ester) nanoparticles

    International Nuclear Information System (INIS)

    Park, Hye Sun; Lee, Jung Eun; Cho, Mi Young; Noh, Young-Woock; Lim, Yong Taik; Sung, Moon Hee; Poo, Haryoung; Hong, Kwan Soo

    2011-01-01

    pH-stimuli-responsive near-infrared optical imaging nanoprobes are designed and synthesized in this study in a facile one-step synthesis process based on the use of the biocompatible and biodegradable polymer poly(γ-glutamic acid) (γ-PGA)/poly(β-amino ester) (PBAE). PBAE has good transfection efficiency and promotes degradation properties under acidic conditions. This pH-responsive degradability can be used for the effective release of encapsulating materials after cellular uptake. As an optical imaging probe, indocyanine green (ICG) is an FDA-approved near-infrared fluorescent dye with a quenching property at a high concentration. In this regard, we focus here on the rapid degradation of PBAE in an acidic environment, in which the nanoparticles are disassembled. This allows the ICG dyes to show enhanced fluorescence signals after being releasing from the particles. We demonstrated this principle in cellular uptake experiments. We expect that the developed pH-stimuli-responsive smart nanoprobes can be applied in intracellular delivery signaling applications.

  16. Impedance measurements on a fast transition-edge sensor for optical and near-infrared range

    International Nuclear Information System (INIS)

    Taralli, E; Portesi, C; Lolli, L; Monticone, E; Rajteri, M; Novikov, I; Beyer, J

    2010-01-01

    Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 μm x 20 μm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C, thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.

  17. Simultaneous optical and infrared polarization measurements of blazars

    International Nuclear Information System (INIS)

    Brindle, C.; Hough, J.H.; Bailey, J.A.; Axon, D.J.; Hyland, A.R.

    1986-01-01

    Measurements are presented of the polarization and flux of a sample of 28 blazars (21 BL Lacs and 7 OVV quasars) at optical and near-infrared wavelengths, with repeated observations for some objects. For 20 objects, these are the first reported polarization measurements in either the optical or infrared, and for most of them the first simultaneous measurements at these wavelengths. Out of a total of 42 observations a spectral dependence of polarization level and position angle is found, although not necessarily occurring together, on 15 occasions. (author)

  18. Optics Alignment of a Balloon-Borne Far-Infrared Interferometer BETTII

    Science.gov (United States)

    Dhabal, Arnab; Rinehart, Stephen A.; Rizzo, Maxime J.; Mundy, Lee; Sampler, Henry; Juanola Parramon, Roser; Veach, Todd; Fixsen, Dale; Vila Hernandez De Lorenzo, Jor; Silverberg, Robert F.

    2017-01-01

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-m baseline far-infrared (FIR: 30 90 micrometer) interferometer providing spatially resolved spectroscopy. The initial scientific focus of BETTII is on clustered star formation, but this capability likely has a much broader scientific application.One critical step in developing an interferometer, such as BETTII, is the optical alignment of the system. We discuss how we determine alignment sensitivities of different optical elements on the interferogram outputs. Accordingly, an alignment plan is executed that makes use of a laser tracker and theodolites for precise optical metrology of both the large external optics and the small optics inside the cryostat. We test our alignment on the ground by pointing BETTII to bright near-infrared sources and obtaining their images in the tracking detectors.

  19. THE SPITZER MID-INFRARED ACTIVE GALACTIC NUCLEUS SURVEY. I. OPTICAL AND NEAR-INFRARED SPECTROSCOPY OF OBSCURED CANDIDATES AND NORMAL ACTIVE GALACTIC NUCLEI SELECTED IN THE MID-INFRARED

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Ridgway, S. E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Gates, E. L. [UCO/Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Nielsen, D. M. [Department of Astronomy, University of Wisconsin, 475 N. Charter Street, Madison, WI 53706 (United States); Petric, A. O. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Sajina, A. [Department of Physics and Astronomy, Tuffs University, 212 College Avenue, Medford, MA 02155 (United States); Urrutia, T. [Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Cox Drews, S. [946 Mangrove Avenue 102, Sunnyvale, CA 94086 (United States); Harrison, C. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Seymour, N. [CSIRO, P.O. Box 76, Epping, NSW 1710 (Australia); Storrie-Lombardi, L. J. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2013-10-01

    We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate active galactic nuclei (AGNs) selected in the mid-infrared. This survey selects both normal and obscured AGNs closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L {sub bol} ∼ 10{sup 10} L {sub ☉} to highly luminous quasars (L {sub bol} ∼ 10{sup 14} L {sub ☉}), all with redshifts ranging from 0 to 4.3. Samples of candidate AGNs were selected with mid-infrared color cuts at several different 24 μm flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGNs and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type 1 AGNs with blue continua, 294 (44%) are type 2 objects with extinctions A{sub V} ∼> 5 toward their AGNs, 96 (14%) are AGNs with lower extinctions (A{sub V} ∼ 1), and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. Of the survey objects 50% have L {sub bol} > 10{sup 12} L {sub ☉}, in the quasar regime. We present composite spectra for type 2 quasars and objects with no signs of AGN activity in their spectra. We also discuss the mid-infrared—emission-line luminosity correlation and present the results of cross correlations with serendipitous X-ray and radio sources. The results show that: (1) obscured objects dominate the overall AGN population, (2) mid-infrared selected AGN candidates exist which lack AGN signatures in their optical spectra but have AGN-like X-ray or radio counterparts, and (3) X-ray and optical classifications of obscured and unobscured AGNs often differ.

  20. [Design of flat field holographic concave grating for near-infrared spectrophotometer].

    Science.gov (United States)

    Xiang, Xian-Yi; Wen, Zhi-Yu

    2008-07-01

    Near-infrared spectrum analysis can be used to determine the nature or test quantitatively some chemical compositions by detecting molecular double frequency and multiple frequency absorption. It has been used in agriculture, biology, petrifaction, foodstuff, medicament, spinning and other fields. Near-infrared spectrophotometer is the main apparatus for near-infrared spectrum analysis, and the grating is the most important part of the apparatus. Based on holographic concave grating theory and optic design software CODE V, a flat field holographic concave grating for near-infrared spectrophotometer was designed from primary structure, which relied on global optimization of the software. The contradiction between wide spectrum bound and limited spectrum extension was resolved, aberrations were reduced successfully, spectrum information was utilized fully, and the optic structure of spectrometer was highly efficient. Using CODE V software, complex high-order aberration equations need not be solved, the result can be evaluated quickly, flat field and resolving power can be kept in balance, and the work efficiency is also enhanced. A paradigm of flat field holographic concave grating is given, it works between 900 nm to 1 700 nm, the diameter of the concave grating is 25 mm, and F/ # is 1. 5. The design result was analyzed and evaluated. It was showed that if the slit source, whose width is 50 microm, is used to reconstruction, the theoretic resolution capacity is better than 6.3 nm.

  1. Quantitative wound healing studies using a portable, low cost, handheld near-infrared optical scanner: preliminary sensitivity and specificity analysis

    Science.gov (United States)

    Lei, Jiali; Rodriguez, Suset; Jayachandran, Maanasa; Solis, Elizabeth; Gonzalez, Stephanie; Perez-Clavijo, Francesco; Wigley, Stephen; Godavarty, Anuradha

    2016-03-01

    Lower extremity ulcers are devastating complications that are still un-recognized. To date, clinicians employ visual inspection of the wound site during its standard 4-week of healing process via monitoring of surface granulation. A novel ultra-portable near-infrared optical scanner (NIROS) has been developed at the Optical Imaging Laboratory that can perform non-contact 2D area imaging of the wound site. From preliminary studies it was observed that the nonhealing wounds had a greater absorption contrast with respect to the normal site, unlike in the healing wounds. Currently, non-contact near-infrared (NIR) imaging studies were carried out on 22 lower extremity wounds at two podiatric clinics, and the sensitivity and specificity of the scanner evaluated. A quantitative optical biometric was developed that differentiates healing from non-healing wounds, based on the threshold values obtained during ROC analysis. In addition, optical images of the wound obtained from weekly imaging studies are also assessed to determine the ability of the device to predict wound healing consistently on a periodic basis. This can potentially impact early intervention in the treatment of lower extremity ulcers when an objective and quantitative wound healing approach is developed. Lastly, the incorporation of MATLAB graphical user interface (GUI) to automate the process of image acquisition, image processing and image analysis realizes the potential of NIROS to perform non-contact and real-time imaging on lower extremity wounds.

  2. Near-infrared line identification in type Ia supernovae during the transitional phase

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R. [Homer L. Dodge Department of Physics and Astronomy, 440 West Brooks Street, Room 100, Norman, OK 73019 (United States); Parrent, Jerod T. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Thomas, R. C. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94720 (United States); Marion, G. H. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States)

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  3. An optical and near-infrared polarization survey of Seyfert and broad-line radio galaxies. Pt. 1

    International Nuclear Information System (INIS)

    Brindle, C.; Hough, J.H.; Bailey, J.A.; Axon, D.J.; Ward, M.J.; McLean, I.S.

    1990-01-01

    We present new broad-band optical and near-infrared (0.44-2.2 μm) flux density and polarization measurements of a sample of 71 Seyfert galaxies and three broad-line radio galaxies. We confirm the results of earlier studies which show that the polarization of Seyferts is generally low in the V-band and at longer wavelengths, but in the B-band somewhat higher polarizations are commonly found. After correction has been made for the effects of stellar dilution, we find that Seyfert 2 nuclei are probably more highly polarized than Seyfert 1's. The small sample of Seyfert 2's selected using the 'warm' IRAS colour criterion tend to be more highly polarised than those selected by optical techniques. (author)

  4. DISCOVERY OF THE VERY RED NEAR-INFRARED AND OPTICAL AFTERGLOW OF THE SHORT-DURATION GRB 070724A

    International Nuclear Information System (INIS)

    Berger, E.; Cenko, S. B.; Fox, D. B.; Cucchiara, A.

    2009-01-01

    We report the discovery of the near-infrared and optical afterglow of the short-duration gamma-ray burst GRB 070724A. The afterglow is detected in iJHK s observations starting 2.3 hr after the burst with K s = 19.59 ± 0.16 mag and i = 23.79 ± 0.07 mag, but is absent in images obtained 1.3 yr later. Fading is also detected in the K s band between 2.8 and 3.7 hr at a 4σ significance level. The optical/near-IR spectral index, β O,NIR ∼ -2, is much redder than expected in the standard afterglow model, pointing to either significant dust extinction, A host V ∼ 2 mag, or a non-afterglow origin for the near-IR emission. The case for extinction is supported by a shallow optical to X-ray spectral index, consistent with the definition for 'dark bursts', and a normal near-IR to X-ray spectral index. Moreover, a comparison to the optical discovery magnitudes of all short GRBs with optical afterglows indicates that the near-IR counterpart of GRB 070724A is one of the brightest to date, while its observed optical emission is one of the faintest. In the context of a non-afterglow origin, the near-IR emission may be dominated by a mini-supernova (mini-SN), leading to an estimated ejected mass of M ∼ 10 -4 M sun and a radioactive energy release efficiency of f ∼ 5 x 10 -3 (for v ∼ 0.3c). However, the mini-SN model predicts a spectral peak in the UV rather than near-IR, suggesting that this is either not the correct interpretation or that the mini-SN models need to be revised. Finally, the afterglow coincides with a star-forming galaxy at z = 0.457, previously identified as the host based on its coincidence with the X-ray afterglow position (∼2'' radius). Our discovery of the optical/near-IR afterglow makes this association secure, and furthermore localizes the burst to the outskirts of the galaxy, with an offset of 4.8 ± 0.1 kpc relative to the host center. At such a large offset, the possible large extinction points to a dusty environment local to the burst and

  5. The near-infrared continua of BL Lacertae objects

    International Nuclear Information System (INIS)

    Allen, D.A.; Ward, M.J.; Hyland, A.R.

    1982-01-01

    Accurate photometry at J, H and K (1.2 to 2.2 μm) has been secured of 53 BL Lac objects. A power-law continuum is an exceptionally good fit to the data, and the colours are distinct from those of quasars. There is no indication of the additional infrared continuum seen in quasars and which is believed to arise in circumnuclear dust. We argue that dust is very scarce in the nuclei of BL Lac objects, and thus we expect gas to be equally scarce. Hence we attribute the lack of optical emission lines to an absence of ionized nuclear gas. We further argue that BL Lac objects could underlie quasars, the latter exhibiting line and thermal continuum emission at ultraviolet, optical and near-infrared wavelengths due to the presence of circumnuclear gas and dust. The strong-lined optically violent variable quasars have colours typical of BL Lac objects rather than quasars, and may represent intermediate cases. The JHK colours of the BL Lac objects overlap with those of the empty-radio-field infrared sources. Such objects probably represent the redder extreme of a range of spectral indices in BL Lac objects. (author)

  6. Design of a Solar Greenhouse with Energy Delivery by the Conversion of Near Infrared Radiation - Part 1 Optics and PV-cells

    NARCIS (Netherlands)

    Gert-Jan Swinkels; Piet Sonneveld; G.P.A. Bot

    2009-01-01

    In this paper the design and development of a new type of greenhouse with an integrated filter for reflecting near infrared radiation (NIR) and a solar energy delivery system is described. Especially the optical parts as the spectral selective film, the properties of the circular reflector and the

  7. Design of a Solar Greenhouse with energy Delivery by the Conversion of Near Infrared Radiation. Part 1. Optics and PV-Cells

    NARCIS (Netherlands)

    Sonneveld, P.J.; Swinkels, G.L.A.M.; Bot, G.P.A.

    2009-01-01

    In this paper the design and development of a new type of greenhouse with an integrated filter for reflecting near infrared radiation (NIR) and a solar energy delivery system is described. Especially the optical parts as the spectral selective film, the properties of the circular reflector and the

  8. Brain plasticity and rehabilitation by using Near-Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Balconi Michela

    2016-04-01

    Full Text Available The present review elucidated the use of optical imaging technique (Near-Infrared Spectroscopy, NIRS to better explain the brain plasticity for learning mechanisms, rehabilitation and post-traumatic brain recovery. Some recent applications were discussed, with specific focus on the usability of integrated measures (such as electroencephalography, EEG-NIRS; Transcranial Magnet Stimulation, TMS-NIRS to study plasticity and its dynamic effects. NIRS-Neurofeedback and NIRS-BCI (Brain Computer Interface were also explored as possible tools to produce a specific long-lasting learning in relationship with a specific cognitive domain. Finally a proficient domain where NIRS was found to be useful to test neuroplasticity is the interpersonal brain-to-brain coupling, termed “hyperscanning”, a new emerging paradigm in neuroscience which measures brain activity from two or more people simultaneously.

  9. Design of a multiband near-infrared sky brightness monitor using an InSb detector.

    Science.gov (United States)

    Dong, Shu-Cheng; Wang, Jian; Tang, Qi-Jie; Jiang, Feng-Xin; Chen, Jin-Ting; Zhang, Yi-Hao; Wang, Zhi-Yue; Chen, Jie; Zhang, Hong-Fei; Jiang, Hai-Jiao; Zhu, Qing-Feng; Jiang, Peng; Ji, Tuo

    2018-02-01

    Infrared sky background level is an important parameter of infrared astronomy observations from the ground, particularly for a candidate site of an infrared capable observatory since low background level is required for such a site. The Chinese astronomical community is looking for a suitable site for a future 12 m telescope, which is designed for working in both optical and infrared wavelengths. However, none of the proposed sites has been tested for infrared observations. Nevertheless, infrared sky background measurements are also important during the design of infrared observing instruments. Based on the requirement, in order to supplement the current site survey data and guide the design of future infrared instruments, a multiband near-infrared sky brightness monitor (MNISBM) based on an InSb sensor is designed in this paper. The MNISBM consists of an optical system, mechanical structure and control system, detector and cooler, high gain readout electronics, and operational software. It is completed and tested in the laboratory. The results show that the sensitivity of the MNISBM meets the requirements of the measurement of near-infrared sky background level of several well-known astronomical infrared observing sites.

  10. Design of a multiband near-infrared sky brightness monitor using an InSb detector

    Science.gov (United States)

    Dong, Shu-cheng; Wang, Jian; Tang, Qi-jie; Jiang, Feng-xin; Chen, Jin-ting; Zhang, Yi-hao; Wang, Zhi-yue; Chen, Jie; Zhang, Hong-fei; Jiang, Hai-jiao; Zhu, Qing-feng; Jiang, Peng; Ji, Tuo

    2018-02-01

    Infrared sky background level is an important parameter of infrared astronomy observations from the ground, particularly for a candidate site of an infrared capable observatory since low background level is required for such a site. The Chinese astronomical community is looking for a suitable site for a future 12 m telescope, which is designed for working in both optical and infrared wavelengths. However, none of the proposed sites has been tested for infrared observations. Nevertheless, infrared sky background measurements are also important during the design of infrared observing instruments. Based on the requirement, in order to supplement the current site survey data and guide the design of future infrared instruments, a multiband near-infrared sky brightness monitor (MNISBM) based on an InSb sensor is designed in this paper. The MNISBM consists of an optical system, mechanical structure and control system, detector and cooler, high gain readout electronics, and operational software. It is completed and tested in the laboratory. The results show that the sensitivity of the MNISBM meets the requirements of the measurement of near-infrared sky background level of several well-known astronomical infrared observing sites.

  11. Structural and Visible-Near Infrared Optical Properties of Cr-Doped TiO2 for Colored Cool Pigments

    Science.gov (United States)

    Yuan, Le; Weng, Xiaolong; Zhou, Ming; Zhang, Qingyong; Deng, Longjiang

    2017-11-01

    Chromium-doped TiO2 pigments were synthesized via a solid-state reaction method and studied with X-ray diffraction, SEM, XPS, and UV-VIS-NIR reflectance spectroscopy. The incorporation of Cr3+ accelerates the transition from the anatase phase to the rutile phase and compresses the crystal lattice. Moreover, the particle morphology, energy gap, and reflectance spectrum of Cr-doped TiO2 pigments is affected by the crystal structure and doping concentration. For the rutile samples, some of the Cr3+ ions are oxidized to Cr4+ after sintering at a high temperature, which leads to a strong near-infrared absorption band due to the 3A2 → 3 T1 electric dipole-allowed transitions of Cr4+. And the decrease of the band gap causes an obvious redshift of the optical absorption edges as the doping concentration increases. Thus, the VIS and near-infrared average reflectance of the rutile Ti1 - x Cr x O2 sample decrease by 60.2 and 58%, respectively, when the Cr content increases to x = 0.0375. Meanwhile, the color changes to black brown. However, for the anatase Ti1 - x Cr x O2 pigments, only the VIS reflection spectrum is inhibited by forming some characteristic visible light absorption peaks of Cr3+. The morphology, band gap, and NIR reflectance are not significantly affected. Finally, a Cr-doped anatase TiO2 pigment with a brownish-yellow color and 90% near-infrared reflectance can be obtained.

  12. The black hole mass of NGC 4151. II. Stellar dynamical measurement from near-infrared integral field spectroscopy

    International Nuclear Information System (INIS)

    Onken, Christopher A.; Ferrarese, Laura; Valluri, Monica; Brown, Jonathan S.; McGregor, Peter J.; Peterson, Bradley M.; Pogge, Richard W.; Bentz, Misty C.; Vestergaard, Marianne; Storchi-Bergmann, Thaisa; Riffel, Rogemar A.

    2014-01-01

    We present a revised measurement of the mass of the central black hole (M BH ) in the Seyfert 1 galaxy NGC 4151. The new stellar dynamical mass measurement is derived by applying an axisymmetric orbit-superposition code to near-infrared integral field data obtained using adaptive optics with the Gemini Near-infrared Integral Field Spectrograph (NIFS). When our models attempt to fit both the NIFS kinematics and additional low spatial resolution kinematics, our results depend sensitively on how χ 2 is computed—probably a consequence of complex bar kinematics that manifest immediately outside the nuclear region. The most robust results are obtained when only the high spatial resolution kinematic constraints in the nuclear region are included in the fit. Our best estimates for the black hole mass and H-band mass-to-light ratio are M BH ∼ 3.76 ± 1.15 × 10 7 M ☉ (1σ error) and Y H ∼ 0.34 ± 0.03 M ☉ /L ☉ (3σ error), respectively (the quoted errors reflect the model uncertainties). Our black hole mass measurement is consistent with estimates from both reverberation mapping (3.57 −0.37 +0.45 ×10 7 M ⊙ ) and gas kinematics (3.0 −2.2 +0.75 ×10 7 M ⊙ ; 1σ errors), and our best-fit mass-to-light ratio is consistent with the photometric estimate of Y H = 0.4 ± 0.2 M ☉ /L ☉ . The NIFS kinematics give a central bulge velocity dispersion σ c = 116 ± 3 km s –1 , bringing this object slightly closer to the M BH -σ relation for quiescent galaxies. Although NGC 4151 is one of only a few Seyfert 1 galaxies in which it is possible to obtain a direct dynamical black hole mass measurement—and thus, an independent calibration of the reverberation mapping mass scale—the complex bar kinematics makes it less than ideally suited for this purpose.

  13. Wideband giant optical activity and negligible circular dichroism of near-infrared chiral metamaterial based on a complementary twisted configuration

    International Nuclear Information System (INIS)

    Zhu, Weiren; Rukhlenko, Ivan D; Premaratne, Malin; Huang, Yongjun; Wen, Guangjun

    2013-01-01

    We theoretically analyze the near-infrared properties of a chiral metamaterial constituting an array of twisted crosses and complementary crosses made of silver. Through rigorous full-wave numerical simulations, we demonstrate that this type of metamaterial exhibits wideband giant optical activity, with a polarization azimuth rotation angle reaching values as large as 1900 ∘ per wavelength. Owing to the negligible loss at optical frequencies in the dielectric (magnesium fluoride) making up the metamaterial, we observe negligible circular dichroism and low dispersion of the polarization azimuth rotation angle over a wide frequency band. We envision that this type of chiral metamaterial will find extensive applications in optical communication systems and biological sensing. (paper)

  14. Optical reprogramming of human somatic cells using ultrashort Bessel-shaped near-infrared femtosecond laser pulses

    Science.gov (United States)

    Uchugonova, Aisada; Breunig, Hans Georg; Batista, Ana; König, Karsten

    2015-11-01

    We report a virus-free optical approach to human cell reprogramming into induced pluripotent stem cells with low-power nanoporation using ultrashort Bessel-shaped laser pulses. Picojoule near-infrared sub-20 fs laser pulses at a high 85 MHz repetition frequency are employed to generate transient nanopores in the membrane of dermal fibroblasts for the introduction of four transcription factors to induce the reprogramming process. In contrast to conventional approaches which utilize retro- or lentiviruses to deliver genes or transcription factors into the host genome, the laser method is virus-free; hence, the risk of virus-induced cancer generation limiting clinical application is avoided.

  15. Bandwidth enhancement of wireless optical communication link using a near-infrared laser over turbid underwater channel

    KAUST Repository

    Lee, It Ee

    2017-11-30

    Underwater wireless optical communication (UWOC) has been widely studied as a promising alternative to establish reliable short-range marine communication links. Microscopic particulates suspended in various ocean, harbor and natural waters will alter the propagation characteristics of the optical signals underwater. In this paper, we demonstrate a gigabit near-infrared (NIR)-based UWOC link using an 808-nm laser diode, to examine the feasibility of the proposed system in mitigating the particle scattering effect over turbid waters. We show that the NIR wavelengths presents greater resilience to the aqueous suspension of these micro-sized particles with a smaller scattering effect due to its longer wavelength, as evident by the smaller variations in the optical beam transmittance. It is also observed that the error performance is improved at higher concentrations albeit the significant reduction in received signal power. We further demonstrate that the overall frequency response of the system exhibits a bandwidth enhancement up to a few tens of MHz with increasing concentrations.

  16. Effects of post heat treatment on near infrared photoluminescence of YAG:Yb{sup 3+} nanoparticles synthesized by glycothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Asakura, Ryo; Isobe, Tetsuhiko, E-mail: isobe@applc.keio.ac.jp

    2014-02-15

    Influence of post heat treatment on particulate, structural, surface, and optical properties of YAG:Yb{sup 3+} nanoparticles prepared by glycothermal method is studied to understand factors for determining photoluminescence intensity. Characterization is performed on electron microscopy, X-ray diffractometry, infrared absorption spectroscopy, and optical measurements. Near infrared emission under 940 nm near infrared excitation is observed at 1029 nm corresponding to {sup 2}F{sub 5/2}→{sup 2}F{sub 7/2} transition of Yb{sup 3+}. Subsequent heat treatment causes crystallite growth and elimination of hydroxyl groups, resulting in an enhancement of the near infrared emission. -- Highlights: • YAG:Yb{sup 3+} nanoparticles of ca. 10 nm are prepared by glycothermal method at 300 °C. • 1029 nm near infrared emission takes place under 940 nm near infrared excitation. • Emission and excitation correspond to {sup 2}F{sub 5/2}→{sup 2}F{sub 7/2} transition of Yb{sup 3+}. • Subsequent heat treatment causes crystallite growth and elimination of hydroxyl groups, resulting in enhancement of near infrared emission.

  17. TIFR Near Infrared Imaging Camera-II on the 3.6 m Devasthal Optical Telescope

    Science.gov (United States)

    Baug, T.; Ojha, D. K.; Ghosh, S. K.; Sharma, S.; Pandey, A. K.; Kumar, Brijesh; Ghosh, Arpan; Ninan, J. P.; Naik, M. B.; D’Costa, S. L. A.; Poojary, S. S.; Sandimani, P. R.; Shah, H.; Krishna Reddy, B.; Pandey, S. B.; Chand, H.

    Tata Institute of Fundamental Research (TIFR) Near Infrared Imaging Camera-II (TIRCAM2) is a closed-cycle Helium cryo-cooled imaging camera equipped with a Raytheon 512×512 pixels InSb Aladdin III Quadrant focal plane array (FPA) having sensitivity to photons in the 1-5μm wavelength band. In this paper, we present the performance of the camera on the newly installed 3.6m Devasthal Optical Telescope (DOT) based on the calibration observations carried out during 2017 May 11-14 and 2017 October 7-31. After the preliminary characterization, the camera has been released to the Indian and Belgian astronomical community for science observations since 2017 May. The camera offers a field-of-view (FoV) of ˜86.5‧‧×86.5‧‧ on the DOT with a pixel scale of 0.169‧‧. The seeing at the telescope site in the near-infrared (NIR) bands is typically sub-arcsecond with the best seeing of ˜0.45‧‧ realized in the NIR K-band on 2017 October 16. The camera is found to be capable of deep observations in the J, H and K bands comparable to other 4m class telescopes available world-wide. Another highlight of this camera is the observational capability for sources up to Wide-field Infrared Survey Explorer (WISE) W1-band (3.4μm) magnitudes of 9.2 in the narrow L-band (nbL; λcen˜ 3.59μm). Hence, the camera could be a good complementary instrument to observe the bright nbL-band sources that are saturated in the Spitzer-Infrared Array Camera (IRAC) ([3.6] ≲ 7.92 mag) and the WISE W1-band ([3.4] ≲ 8.1 mag). Sources with strong polycyclic aromatic hydrocarbon (PAH) emission at 3.3μm are also detected. Details of the observations and estimated parameters are presented in this paper.

  18. Near-infrared photometric study of open star cluster IC 1805

    International Nuclear Information System (INIS)

    Sagar, R.; Yu, Q.Z.

    1990-01-01

    The JHK magnitudes of 29 stars in the region of open star cluster IC 1805 were measured. These, and the existing infrared and optical observations, indicate a normal interstellar extinction law in the direction of the cluster. Further, most of the early-type stars have near-infrared fluxes as expected from their spectral types. Patchy distribution of ionized gas and dust appears to be the cause of nonuniform extinction across the cluster face. 36 refs

  19. Low-cost near-infrared imaging device for inspection of historical manuscripts

    International Nuclear Information System (INIS)

    Mohd Ashhar Khalid

    2004-01-01

    Near-infrared (NIR) or sometimes called black light is a waveform beyond visible light and it is not detectable by human eyes. However electronic sensors such as the type used in digital cameras are able to detect signals in the infrared band. To avoid distortion in the pictures obtained near-infrared is blocked by optical filters inserted in digital cameras. By carrying out minor modification allowing near-infrared signal to be imaged while blocking the visible signal, the camera is turned into a low-cost NIR imaging instrument. NIR imaging can be a useful tool in historical manuscript study or restoration. A few applications have been successfully demonstrated in laboratory experiment using the instrument available in MINT. However, due to unavailability of historical items, easily available texts and paintings are used in the demonstrations. This paper reports achievements of early work on the application of digital camera in the detection of damaged prints or writings. (Author)

  20. Dilute bismides for near and mid-infrared applications

    DEFF Research Database (Denmark)

    Song, Yuxin; Gu, Yi; Ye, Hong

    2013-01-01

    Dilute bismides are a group of emerging materials with unique properties. Incorporation of a small amount of Bi in common III–V host materials results in large band-gap reduction and strong spin-orbit splitting, leading to potential applications in near-infrared (NIR) and mid-infrared (MIR......) optoelectronics. Recent progresses on molecular beam epitaxy (MBE) of novel III-Sb-Bi, i.e. GaSbBi and InSbBi thin films from our group are summarised in this paper. Quantum well structures based on GaSbBi and InGaAsBi aiming for the optical communication window were grown and characterized....

  1. THE VARIABLE NEAR-INFRARED COUNTERPART OF THE MICROQUASAR GRS 1758–258

    International Nuclear Information System (INIS)

    Luque-Escamilla, Pedro L.; Martí, Josep; Muñoz-Arjonilla, Álvaro J.

    2014-01-01

    We present a new study of the microquasar system GRS 1758–258 in the near-infrared domain based on archival observations with the Hubble Space Telescope and the NICMOS camera. In addition to confirming the near-infrared counterpart pointed out by Muñoz-Arjonilla et al., we show that this object displays significant photometric variability. From its average magnitudes, we also find that GRS 1758–258 fits well within the correlation between the optical/near-infrared and X-ray luminosity known to exist for low-mass, black-hole candidate X-ray binaries in a hard state. Moreover, the spectral energy distribution built using all radio, near-infrared, and X-ray data available closest in time to the NICMOS observations can be reasonably interpreted in terms of a self-absorbed radio jet and an irradiated accretion disk model around a stellar-mass black hole. All these facts match the expected behavior of a compact binary system and strengthen our confidence in the counterpart identification

  2. Andromeda (M31) optical and infrared disk survey. I. Insights in wide-field near-IR surface photometry

    International Nuclear Information System (INIS)

    Sick, Jonathan; Courteau, Stéphane; Cuillandre, Jean-Charles; McDonald, Michael; De Jong, Roelof; Tully, R. Brent

    2014-01-01

    We present wide-field near-infrared J and K s images of the Andromeda Galaxy (M31) taken with WIRCam at the Canada-France-Hawaii Telescope as part of the Andromeda Optical and Infrared Disk Survey. This data set allows simultaneous observations of resolved stars and near-infrared (NIR) surface brightness across M31's entire bulge and disk (within R = 22 kpc), permitting a direct test of the stellar composition of near-infrared light in a nearby galaxy. Here we develop NIR observation and reduction methods to recover a uniform surface brightness map across the 3° × 1° disk of M31 with 27 WIRCam fields. Two sky-target nodding strategies are tested, and we find that strictly minimizing sky sampling latency cannot improve background subtraction accuracy to better than 2% of the background level due to spatio-temporal variations in the NIR skyglow. We fully describe our WIRCam reduction pipeline and advocate using flats built from night-sky images over a single night, rather than dome flats that do not capture the WIRCam illumination field. Contamination from scattered light and thermal background in sky flats has a negligible effect on the surface brightness shape compared to the stochastic differences in background shape between sky and galaxy disk fields, which are ∼0.3% of the background level. The most dramatic calibration step is the introduction of scalar sky offsets to each image that optimizes surface brightness continuity. Sky offsets reduce the mean surface brightness difference between observation blocks from 1% to <0.1% of the background level, though the absolute background level remains statistically uncertain to 0.15% of the background level. We present our WIRCam reduction pipeline and performance analysis to give specific recommendations for the improvement of NIR wide-field imaging methods.

  3. Analysis of the selected optical parameters of filters protecting against hazardous infrared radiation

    OpenAIRE

    Gralewicz, Grzegorz; Owczarek, Grzegorz

    2016-01-01

    The paper analyses the selected optical parameters of protective optic filters used for protection of the eyes against hazardous radiation within the visible (VIS) and near infrared (NIR) spectrum range. The indexes characterizing transmission and reflection of optic radiation incident on the filter are compared. As it follows from the completed analysis, the newly developed interference filters provide more effective blocking of infrared radiation in comparison with the currently used protec...

  4. TYPE Ia SUPERNOVA LIGHT CURVE INFERENCE: HIERARCHICAL MODELS IN THE OPTICAL AND NEAR-INFRARED

    International Nuclear Information System (INIS)

    Mandel, Kaisey S.; Narayan, Gautham; Kirshner, Robert P.

    2011-01-01

    We have constructed a comprehensive statistical model for Type Ia supernova (SN Ia) light curves spanning optical through near-infrared (NIR) data. A hierarchical framework coherently models multiple random and uncertain effects, including intrinsic supernova (SN) light curve covariances, dust extinction and reddening, and distances. An improved BAYESN Markov Chain Monte Carlo code computes probabilistic inferences for the hierarchical model by sampling the global probability density of parameters describing individual SNe and the population. We have applied this hierarchical model to optical and NIR data of 127 SNe Ia from PAIRITEL, CfA3, Carnegie Supernova Project, and the literature. We find an apparent population correlation between the host galaxy extinction A V and the ratio of total-to-selective dust absorption R V . For SNe with low dust extinction, A V ∼ V ∼ 2.5-2.9, while at high extinctions, A V ∼> 1, low values of R V < 2 are favored. The NIR luminosities are excellent standard candles and are less sensitive to dust extinction. They exhibit low correlation with optical peak luminosities, and thus provide independent information on distances. The combination of NIR and optical data constrains the dust extinction and improves the predictive precision of individual SN Ia distances by about 60%. Using cross-validation, we estimate an rms distance modulus prediction error of 0.11 mag for SNe with optical and NIR data versus 0.15 mag for SNe with optical data alone. Continued study of SNe Ia in the NIR is important for improving their utility as precise and accurate cosmological distance indicators.

  5. A near-infrared relationship for estimating black hole masses in active galactic nuclei

    Science.gov (United States)

    Landt, Hermine; Ward, Martin J.; Peterson, Bradley M.; Bentz, Misty C.; Elvis, Martin; Korista, Kirk T.; Karovska, Margarita

    2013-06-01

    Black hole masses for samples of active galactic nuclei (AGN) are currently estimated from single-epoch optical spectra using scaling relations anchored in reverberation mapping results. In particular, the two quantities needed for calculating black hole masses, namely the velocity and the radial distance of the orbiting gas are derived from the widths of the Balmer hydrogen broad emission lines and the optical continuum luminosity, respectively. We have recently presented a near-infrared (near-IR) relationship for estimating AGN black hole masses based on the widths of the Paschen hydrogen broad emission lines and the total 1 μm continuum luminosity. The near-IR offers several advantages over the optical: it suffers less from dust extinction, the AGN continuum is observed only weakly contaminated by the host galaxy and the strongest Paschen broad emission lines Paα and Paβ are unblended. Here, we improve the calibration of the near-IR black hole mass relationship by increasing the sample from 14 to 23 reverberation-mapped AGN using additional spectroscopy obtained with the Gemini Near-Infrared Spectrograph. The additional sample improves the number statistics in particular at the high-luminosity end.

  6. Optical Activation of Germanium Plasmonic Antennas in the Mid-Infrared

    Science.gov (United States)

    Fischer, Marco P.; Schmidt, Christian; Sakat, Emilie; Stock, Johannes; Samarelli, Antonio; Frigerio, Jacopo; Ortolani, Michele; Paul, Douglas J.; Isella, Giovanni; Leitenstorfer, Alfred; Biagioni, Paolo; Brida, Daniele

    2016-07-01

    Impulsive interband excitation with femtosecond near-infrared pulses establishes a plasma response in intrinsic germanium structures fabricated on a silicon substrate. This direct approach activates the plasmonic resonance of the Ge structures and enables their use as optical antennas up to the mid-infrared spectral range. The optical switching lasts for hundreds of picoseconds until charge recombination redshifts the plasma frequency. The full behavior of the structures is modeled by the electrodynamic response established by an electron-hole plasma in a regular array of antennas.

  7. Near-infrared optical properties of Yb3+-doped silicate glass waveguides prepared by double-energy proton implantation

    Science.gov (United States)

    Shen, Xiao-Liang; Zhu, Qi-Feng; Zheng, Rui-Lin; Lv, Peng; Guo, Hai-Tao; Liu, Chun-Xiao

    2018-03-01

    We report on the preparation and properties of an optical planar waveguide structure operating at 1539 nm in the Yb3+-doped silicate glass. The waveguide was formed by using (470 + 500) keV proton implantation at fluences of (1.0 + 2.0) × 1016 ions/cm2. The waveguiding characteristics including the guided-mode spectrum and the near-field image were investigated by the m-line technique and the finite-difference beam propagation method. The energy distribution for implanted protons and the refractive index profile for the proton-implanted waveguide were simulated by the stopping and range of ions in matter and the reflectivity calculation method. The proton-implanted Yb3+-doped silicate glass waveguide is a candidate for optoelectronic elements in the near-infrared region.

  8. The near-infrared radius-luminosity relationship for active galactic nuclei

    Science.gov (United States)

    Landt, Hermine; Bentz, Misty C.; Peterson, Bradley M.; Elvis, Martin; Ward, Martin J.; Korista, Kirk T.; Karovska, Margarita

    2011-05-01

    Black hole masses for samples of active galactic nuclei (AGNs) are currently estimated from single-epoch optical spectra. In particular, the size of the broad-line emitting region needed to compute the black hole mass is derived from the optical or ultraviolet continuum luminosity. Here we consider the relationship between the broad-line region size, R, and the near-infrared (near-IR) AGN continuum luminosity, L, as the near-IR continuum suffers less dust extinction than at shorter wavelengths and the prospects for separating the AGN continuum from host-galaxy starlight are better in the near-IR than in the optical. For a relationship of the form R∝Lα, we obtain for a sample of 14 reverberation-mapped AGN a best-fitting slope of α= 0.5 ± 0.1, which is consistent with the slope of the relationship in the optical band and with the value of 0.5 naïvely expected from photoionization theory. Black hole masses can then be estimated from the near-IR virial product, which is calculated using the strong and unblended Paschen broad emission lines (Paα or Paβ).

  9. Brown carbon absorption in the red and near-infrared spectral region

    Science.gov (United States)

    Hoffer, András; Tóth, Ádám; Pósfai, Mihály; Eddy Chung, Chul; Gelencsér, András

    2017-06-01

    Black carbon (BC) aerosols have often been assumed to be the only light-absorbing carbonaceous particles in the red and near-infrared spectral regions of solar radiation in the atmosphere. Here we report that tar balls (a specific type of organic aerosol particles from biomass burning) do absorb red and near-infrared radiation significantly. Tar balls were produced in a laboratory experiment, and their chemical and optical properties were measured. The absorption of these particles in the range between 470 and 950 nm was measured with an aethalometer, which is widely used to measure atmospheric aerosol absorption. We find that the absorption coefficient of tar balls at 880 nm is more than 10 % of that at 470 nm. The considerable absorption of red and infrared light by tar balls also follows from their relatively low absorption Ångström coefficient (and significant mass absorption coefficient) in the spectral range between 470 and 950 nm. Our results support the previous finding that tar balls may play an important role in global warming. Due to the non-negligible absorption of tar balls in the near-infrared region, the absorption measured in the field at near-infrared wavelengths cannot solely be due to soot particles.

  10. Silicon based near infrared photodetector using self-assembled organic crystalline nano-pillars

    Energy Technology Data Exchange (ETDEWEB)

    Ajiki, Yoshiharu, E-mail: yoshiharu-ajiki@ot.olympus.co.jp, E-mail: isao@i.u-tokyo.ac.jp [Micromachine Center, 67 Kanda Sakumagashi, Chiyoda-ku, Tokyo 100-0026 (Japan); Kan, Tetsuo [Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Yahiro, Masayuki; Hamada, Akiko; Adachi, Chihaya [Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Adachi, Junji [Office for Strategic Research Planning, Kyushu University, 6-10-1 Hakozaki, Higashi, Fukuoka 812-8581 (Japan); Matsumoto, Kiyoshi [IRT Research Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Shimoyama, Isao, E-mail: yoshiharu-ajiki@ot.olympus.co.jp, E-mail: isao@i.u-tokyo.ac.jp [Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); IRT Research Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

    2016-04-11

    We propose a silicon (Si) based near-infrared photodetector using self-assembled organic crystalline nano-pillars, which were formed on an n-type Si substrate and were covered with an Au thin-film. These structures act as antennas for near-infrared light, resulting in an enhancement of the light absorption on the Au film. Because the Schottky junction is formed between the Au/n-type Si, the electron excited by the absorbed light can be detected as photocurrent. The optical measurement revealed that the nano-pillar structures enhanced the responsivity for the near-infrared light by 89 (14.5 mA/W) and 16 (0.433 mA/W) times compared with those of the photodetector without nano-pillars at the wavelengths of 1.2 and 1.3 μm, respectively. Moreover, no polarization dependency of the responsivity was observed, and the acceptable incident angle ranged from 0° to 30°. These broad responses were likely to be due to the organic nano-pillar structures' having variation in their orientation, which is advantageous for near-infrared detector uses.

  11. TESTING THE HYPOTHESIS THAT METHANOL MASER RINGS TRACE CIRCUMSTELLAR DISKS: HIGH-RESOLUTION NEAR-INFRARED AND MID-INFRARED IMAGING

    International Nuclear Information System (INIS)

    De Buizer, James M.; Bartkiewicz, Anna; Szymczak, Marian

    2012-01-01

    Milliarcsecond very long baseline interferometry maps of regions containing 6.7 GHz methanol maser emission have lead to the recent discovery of ring-like distributions of maser spots and the plausible hypothesis that they may be tracing circumstellar disks around forming high-mass stars. We aimed to test this hypothesis by imaging these regions in the near- and mid-infrared at high spatial resolution and compare the observed emission to the expected infrared morphologies as inferred from the geometries of the maser rings. In the near-infrared we used the Gemini North adaptive optics system of ALTAIR/NIRI, while in the mid-infrared we used the combination of the Gemini South instrument T-ReCS and super-resolution techniques. Resultant images had a resolution of ∼150 mas in both the near-infrared and mid-infrared. We discuss the expected distribution of circumstellar material around young and massive accreting (proto)stars and what infrared emission geometries would be expected for the different maser ring orientations under the assumption that the masers are coming from within circumstellar disks. Based upon the observed infrared emission geometries for the four targets in our sample and the results of spectral energy distribution modeling of the massive young stellar objects associated with the maser rings, we do not find compelling evidence in support of the hypothesis that methanol masers rings reside in circumstellar disks.

  12. A near-infrared, optical, and ultraviolet polarimetric and timing investigation of complex equatorial dusty structures

    Science.gov (United States)

    Marin, F.; Rojas Lobos, P. A.; Hameury, J. M.; Goosmann, R. W.

    2018-05-01

    Context. From stars to active galactic nuclei, many astrophysical systems are surrounded by an equatorial distribution of dusty material that is, in a number of cases, spatially unresolved even with cutting edge facilities. Aims: In this paper, we investigate if and how one can determine the unresolved and heterogeneous morphology of dust distribution around a central bright source using time-resolved polarimetric observations. Methods: We used polarized radiative transfer simulations to study a sample of circumnuclear dusty morphologies. We explored a grid of geometrically variable models that are uniform, fragmented, and density stratified in the near-infrared, optical, and ultraviolet bands, and we present their distinctive time-dependent polarimetric signatures. Results: As expected, varying the structure of the obscuring equatorial disk has a deep impact on the inclination-dependent flux, polarization degree and angle, and time lags we observe. We find that stratified media are distinguishable by time-resolved polarimetric observations, and that the expected polarization is much higher in the infrared band than in the ultraviolet. However, because of the physical scales imposed by dust sublimation, the average time lags of months to years between the total and polarized fluxes are important; these time lags lengthens the observational campaigns necessary to break more sophisticated, and therefore also more degenerated, models. In the ultraviolet band, time lags are slightly shorter than in the infrared or optical bands, and, coupled to lower diluting starlight fluxes, time-resolved polarimetry in the UV appears more promising for future campaigns. Conclusions: Equatorial dusty disks differ in terms of inclination-dependent photometric, polarimetric, and timing observables, but only the coupling of these different markers can lead to inclination-independent constraints on the unresolved structures. Even though it is complex and time consuming, polarized

  13. MIRIS observation of near-infrared diffuse Galactic light

    Science.gov (United States)

    Onishi, Yosuke; Sano, Kei; Matsuura, Shuji; Jeong, Woong-Seob; Pyo, Jeonghyun; Kim, Il-Jong; Seo, Hyun Jong; Han, Wonyong; Lee, DaeHee; Moon, Bongkon; Park, Wonkee; Park, Younsik; Kim, MinGyu; Matsumoto, Toshio; Matsuhara, Hideo; Nakagawa, Takao; Tsumura, Kohji; Shirahata, Mai; Arai, Toshiaki; Ienaka, Nobuyuki

    2018-06-01

    We report near-infrared (IR) observations of high Galactic latitude clouds to investigate diffuse Galactic light (DGL), which is starlight scattered by interstellar dust grains. The observations were performed at 1.1 and 1.6 μm with a wide-field camera instrument, the Multi-purpose Infra-Red Imaging System (MIRIS) onboard the Korean satellite STSAT-3. The DGL brightness is measured by correlating the near-IR images with a far-IR 100 μm map of interstellar dust thermal emission. The wide-field observation of DGL provides the most accurate DGL measurement achieved to-date. We also find a linear correlation between optical and near-IR DGL in the MBM32 field. To study interstellar dust properties in MBM32, we adopt recent dust models with and without μm-sized very large grains and predict the DGL spectra, taking into account the reddening effect of the interstellar radiation field. The result shows that the observed color of the near-IR DGL is closer to the model spectra without very large grains. This may imply that dust growth in the observed MBM32 field is not active owing to the low density of its interstellar medium.

  14. Silicon Nitride Photonic Integration Platforms for Visible, Near-Infrared and Mid-Infrared Applications

    Science.gov (United States)

    Micó, Gloria; Pastor, Daniel; Pérez, Daniel; Doménech, José David; Fernández, Juan; Baños, Rocío; Alemany, Rubén; Sánchez, Ana M.; Cirera, Josep M.; Mas, Roser

    2017-01-01

    Silicon nitride photonics is on the rise owing to the broadband nature of the material, allowing applications of biophotonics, tele/datacom, optical signal processing and sensing, from visible, through near to mid-infrared wavelengths. In this paper, a review of the state of the art of silicon nitride strip waveguide platforms is provided, alongside the experimental results on the development of a versatile 300 nm guiding film height silicon nitride platform. PMID:28895906

  15. MULTI-COLOR OPTICAL AND NEAR-INFRARED LIGHT CURVES OF 64 STRIPPED-ENVELOPE CORE-COLLAPSE SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Bianco, F. B.; Modjaz, M. [Center for Cosmology and Particle Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Hicken, M.; Friedman, A.; Kirshner, R. P.; Challis, P.; Marion, G. H. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bloom, J. S. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Wood-Vasey, W. M. [PITT PACC, Department of Physics and Astronomy, 3941 O' Hara Street, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Rest, A., E-mail: fb55@nyu.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-08-01

    We present a densely sampled, homogeneous set of light curves of 64 low-redshift (z ≲ 0.05) stripped-envelope supernovae (SNe of Type IIb, Ib, Ic, and Ic-BL). These data were obtained between 2001 and 2009 at the Fred L. Whipple Observatory (FLWO) on Mount Hopkins in Arizona, with the optical FLWO 1.2 m and the near-infrared (NIR) Peters Automated Infrared 1.3 m telescopes. Our data set consists of 4543 optical photometric measurements on 61 SNe, including a combination of U BV RI, U BV r{sup ′}i{sup ′}, and u{sup ′} BV r{sup ′}i{sup ′}, and 1919 JHK{sub s} NIR measurements on 25 SNe. This sample constitutes the most extensive multi-color data set of stripped-envelope SNe to date. Our photometry is based on template-subtracted images to eliminate any potential host-galaxy light contamination. This work presents these photometric data, compares them with data in the literature, and estimates basic statistical quantities: date of maximum, color, and photometric properties. We identify promising color trends that may permit the identification of stripped-envelope SN subtypes from their photometry alone. Many of these SNe were observed spectroscopically by the Harvard-Smithsonian Center for Astrophysics (CfA) SN group, and the spectra are presented in a companion paper. A thorough exploration that combines the CfA photometry and spectroscopy of stripped-envelope core-collapse SNe will be presented in a follow-up paper.

  16. Near-infrared observations of IRAS minisurvey galaxies

    International Nuclear Information System (INIS)

    Carico, D.P.; Soifer, B.T.; Elias, J.H.; Matthews, K.; Neugebauer, G.; Beichman, C.; Persson, C.J.; Persson, S.E.

    1987-01-01

    Near infrared photometry at J, H, and K was obtained for 82 galaxies from the IRAS minisurvey. The near infrared colors of these galaxies cover a larger range in J-H and H-K than do normal field spiral galaxies, and evidence is presented of a tighter correlation between the near and far infrared emission in far infrared bright galaxies than exists between the far infrared and the visible emission. These results suggest the presence of dust in the far infrared bright galaxies, with hot dust emission contributing to the 2.2 micron emission, and extinction by dust affecting both the near infrared colors and the visible luminosities. In addition, there is some indication that the infrared emission in many of the minisurvey galaxies is coming from a strong nuclear component

  17. Near-infrared-responsive, superparamagnetic Au@Co nanochains

    Directory of Open Access Journals (Sweden)

    Varadee Vittur

    2017-08-01

    Full Text Available This manuscript describes a new type of nanomaterial, namely superparamagnetic Au@Co nanochains with optical extinctions in the near infrared (NIR. The Au@Co nanochains were synthesized via a one-pot galvanic replacement route involving a redox-transmetalation process in aqueous medium, where Au salt was reduced to form Au shells on Co seed templates, affording hollow Au@Co nanochains. The Au shells serve not only as a protective coating for the Co nanochain cores, but also to give rise to the optical properties of these unique nanostructures. Importantly, these bifunctional, magneto-optical Au@Co nanochains combine the advantages of nanophotonics (extinction at ca. 900 nm and nanomagnetism (superparamagnetism and provide a potentially useful new nanoarchitecture for biomedical or catalytic applications that can benefit from both activation by light and manipulation using an external magnetic field.

  18. Liposomal encapsulation of a near-infrared fluorophore enhances fluorescence quenching and reliable whole body optical imaging upon activation in vivo.

    Science.gov (United States)

    Tansi, Felista L; Rüger, Ronny; Rabenhold, Markus; Steiniger, Frank; Fahr, Alfred; Kaiser, Werner A; Hilger, Ingrid

    2013-11-11

    In the past decade, there has been significant progress in the development of water soluble near-infrared fluorochromes for use in a wide range of imaging applications. Fluorochromes with high photo and thermal stability, sensitivity, adequate pharmacological properties and absorption/emission maxima within the near infrared window (650-900 nm) are highly desired for in vivo imaging, since biological tissues show very low absorption and auto-fluorescence at this spectrum window. Taking these properties into consideration, a myriad of promising near infrared fluorescent probes has been developed recently. However, a hallmark of most of these probes is a rapid clearance in vivo, which hampers their application. It is hypothesized that encapsulation of the near infrared fluorescent dye DY-676-COOH, which undergoes fluorescence quenching at high concentrations, in the aqueous interior of liposomes will result in protection and fluorescence quenching, which upon degradation by phagocytes in vivo will lead to fluorescence activation and enable imaging of inflammation. Liposomes prepared with high concentrations of DY-676-COOH reveal strong fluorescence quenching. It is demonstrated that the non-targeted PEGylated fluorescence-activatable liposomes are taken up predominantly by phagocytosis and degraded in lysosomes. Furthermore, in zymosan-induced edema models in mice, the liposomes are taken up by monocytes and macrophages which migrate to the sites of inflammation. Opposed to free DY-676-COOH, prolonged stability and retention of liposomal-DY-676-COOH is reflected in a significant increase in fluorescence intensity of edema. Thus, protected delivery and fluorescence quenching make the DY-676-COOH-loaded liposomes a highly promising contrast agent for in vivo optical imaging of inflammatory diseases. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Near infrared spatial frequency domain fluorescence imaging of tumor phantoms containing erythrocyte-derived optical nanoplatforms

    Science.gov (United States)

    Burns, Joshua M.; Schaefer, Elise; Anvari, Bahman

    2018-02-01

    Light-activated theranostic constructs provide a multi-functional platform for optical imaging and phototherapeutic applications. Our group has engineered nano-sized vesicles derived from erythrocytes that encapsulate the FDAapproved near infrared (NIR) absorber indocyanine green (ICG). We refer to these constructs as NIR erythrocytemimicking transducers (NETs). Once photo-excited by NIR light these constructs can transduce the photons energy to emit fluorescence, generate heat, or induce chemical reactions. In this study, we investigated fluorescence imaging of NETs embedded within tumor phantoms using spatial frequency domain imaging (SFDI). Using SFDI, we were able to fluorescently image simulated tumors doped with different concentration of NETs. These preliminary results suggest that NETs can be used in conjunction with SFDI for potential tumor imaging applications.

  20. The black hole mass of NGC 4151. II. Stellar dynamical measurement from near-infrared integral field spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Onken, Christopher A.; Ferrarese, Laura [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Valluri, Monica; Brown, Jonathan S. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); McGregor, Peter J. [Research School of Astronomy and Astrophysics, The Australian National University, Canberra, ACT 2611 (Australia); Peterson, Bradley M.; Pogge, Richard W. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Bentz, Misty C. [Department of Physics and Astronomy, Georgia State University, 25 Park Place, Office 610, Atlanta, GA 30303 (United States); Vestergaard, Marianne [Dark Cosmology Centre, The Niels Bohr Institute, Copenhagen University, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Storchi-Bergmann, Thaisa [Universidade Federal do Rio Grande do Sul, Instituto de Física, CP 15051, Porto Alegre 91501-970, RS (Brazil); Riffel, Rogemar A., E-mail: christopher.onken@anu.edu.au, E-mail: mvalluri@umich.edu [Departamento de Física, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil)

    2014-08-10

    We present a revised measurement of the mass of the central black hole (M{sub BH} ) in the Seyfert 1 galaxy NGC 4151. The new stellar dynamical mass measurement is derived by applying an axisymmetric orbit-superposition code to near-infrared integral field data obtained using adaptive optics with the Gemini Near-infrared Integral Field Spectrograph (NIFS). When our models attempt to fit both the NIFS kinematics and additional low spatial resolution kinematics, our results depend sensitively on how χ{sup 2} is computed—probably a consequence of complex bar kinematics that manifest immediately outside the nuclear region. The most robust results are obtained when only the high spatial resolution kinematic constraints in the nuclear region are included in the fit. Our best estimates for the black hole mass and H-band mass-to-light ratio are M{sub BH} ∼ 3.76 ± 1.15 × 10{sup 7} M{sub ☉} (1σ error) and Y{sub H} ∼ 0.34 ± 0.03 M{sub ☉}/L{sub ☉} (3σ error), respectively (the quoted errors reflect the model uncertainties). Our black hole mass measurement is consistent with estimates from both reverberation mapping (3.57{sub −0.37}{sup +0.45}×10{sup 7} M{sub ⊙}) and gas kinematics (3.0{sub −2.2}{sup +0.75}×10{sup 7} M{sub ⊙}; 1σ errors), and our best-fit mass-to-light ratio is consistent with the photometric estimate of Y{sub H} = 0.4 ± 0.2 M{sub ☉}/L{sub ☉}. The NIFS kinematics give a central bulge velocity dispersion σ{sub c} = 116 ± 3 km s{sup –1}, bringing this object slightly closer to the M{sub BH}-σ relation for quiescent galaxies. Although NGC 4151 is one of only a few Seyfert 1 galaxies in which it is possible to obtain a direct dynamical black hole mass measurement—and thus, an independent calibration of the reverberation mapping mass scale—the complex bar kinematics makes it less than ideally suited for this purpose.

  1. Thermal emission from interstellar dust in and near the Pleiades

    International Nuclear Information System (INIS)

    White, R.E.

    1989-01-01

    IRAS survey coadds for a 8.7 deg x 4.3 deg field near the Pleiades provide evidence for dynamical interaction between the cluster and the surrounding interstellar medium. The far-infrared images show large region of faint emission with bright rims east of the cluster, suggestive of a wake. Images of the far-infrared color temperature and 100 micron optical depth reveal temperature maxima and optical depth minima near the bright cluster stars, as well as a strong optical depth peak at the core of the adjacent CO cloud. Models for thermal dust emission near the stars indicate that most of the apparent optical depth minima near stars are illusory, but also provide indirect evidence for small interaction between the stars and the encroaching dust cloud

  2. Thermal emission from interstellar dust in and near the Pleiades

    Science.gov (United States)

    White, Richard E.

    1989-01-01

    IRAS survey coadds for a 8.7 deg x 4.3 deg field near the Pleiades provide evidence for dynamical interaction between the cluster and the surrounding interstellar medium. The far-infrared images show large region of faint emission with bright rims east of the cluster, suggestive of a wake. Images of the far-infrared color temperature and 100 micron optical depth reveal temperature maxima and optical depth minima near the bright cluster stars, as well as a strong optical depth peak at the core of the adjacent CO cloud. Models for thermal dust emission near the stars indicate that most of the apparent optical depth minima near stars are illusory, but also provide indirect evidence for small interaction between the stars and the encroaching dust cloud.

  3. Photographic infrared spectroscopy and near infrared photometry of Be stars

    International Nuclear Information System (INIS)

    Swings, J.P.

    1976-01-01

    Two topics are tackled in this presentation: spectroscopy and photometry. The following definitions are chosen: photographic infrared spectroscopy (wavelengths Hα<=lambda<1.2 μ); near infrared photometry (wavebands: 1.6 μ<=lambda<=20 μ). Near infrared spectroscopy and photometry of classical and peculiar Be stars are discussed and some future developments in the field are outlined. (Auth.)

  4. Assessment of the dynamics of human glymphatic system by near-infrared spectroscopy.

    Science.gov (United States)

    Myllylä, Teemu; Harju, Markus; Korhonen, Vesa; Bykov, Alexander; Kiviniemi, Vesa; Meglinski, Igor

    2017-08-12

    Fluctuations in brain water content has attracted increasing interest, particularly as regards studies of the glymphatic system, which is connected with the complex organization of dural lymphatic vessels, responsible for cleaning tissue. Disturbances of glymphatic circulation are associated with several brain disorders, including dementia. This article introduces an approach to noninvasive measurement of water dynamics in the human brain utilizing near-infrared spectroscopy (NIRS). We demonstrate the possibility to sense dynamic variations of water content between the skull and grey matter, for instance, in the subarachnoid space. Measured fluctuations in water content, especially in the cerebrospinal fluid (CSF), are assumed to be correlated with the dynamics of glymphatic circulation. The sampling volume for the NIRS optode was estimated by Monte Carlo modelling for the wavelengths of 660, 740, 830 and 980 nm. In addition, using combinations of these wavelengths, this article presents the calculation models for quantifying water and haemodynamics. The presented NIRS technique allows long-term functional brain monitoring, including sleeping time. Furthermore, it is used in combination with different magnetic neuroimaging techniques, particularly magnetic resonance encephalography. Using the combined setup, we report the preliminary results on the interaction between CSF and blood oxygen level-dependent fluctuations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The wavelength dependence of gold nanorod-mediated optical breakdown during infrared ultrashort pulses

    Energy Technology Data Exchange (ETDEWEB)

    Davletshin, Yevgeniy R.; Kumaradas, J. Carl [Department of Physics, Ryerson University, Toronto, ON (Canada)

    2017-04-15

    This paper investigates the wavelength dependence of the threshold of gold nanorod-mediated optical breakdown during picosecond and femtosecond near infrared optical pulses. It was found that the wavelength dependence in the picosecond regime is governed solely by the changes of a nanorod's optical properties. On the other hand, the optical breakdown threshold during femtosecond pulse exposure falls within one of two regimes. When the ratio of the maximum electric field from the outside to the inside of the nanorod is less then 7 (the absorption regime) the seed electrons are initiated by photo-thermal emission, and the wavelength dependence in the threshold of optical breakdown is the result of optical properties of the nanoparticle. When the ratio is greater than 7 (the near-field regime) more seed electrons are initiated by multiphoton ionization, and the wavelength dependence of the threshold of optical breakdown results from a combination of nanorod's optical properties and transitions in the order of multiphoton ionization. The findings of this study can guide the design of nanoparticle based optical breakdown applications. This analysis also deepens the understanding of nanoparticle-mediated laser induced breakdown for picosecond and femtosecond pulses at near infrared wavelengths. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Near-infrared light-controlled tunable grating based on graphene/elastomer composites

    Science.gov (United States)

    Wang, Fei; Jia, Shuhai; Wang, Yonglin; Tang, Zhenhua

    2018-02-01

    A near-infrared (nIR) light actuated tunable transmission optical grating based on graphene nanoplatelet (GNP)/polydimethylsiloxane (PDMS) and PDMS is proposed. A simple fabrication protocol is studied that allows integration of the grating with the actuation mechanism; both components are made from soft elastomers, and this ensure the tunability and the light-driven operation of the grating. The resulting grating structure demonstrates continuous period tunability of 2.7% under an actuation power density of 220 mW cm-2 within a period of 3 s and also demonstrates a time-independent characteristic. The proposed infrared activated grating can be developed for wireless remote light splitting in bio/chemical sensing and optical telecommunications applications.

  7. Viscoelastic optical nonlocality of doped cadmium oxide epsilon-near-zero thin films

    Energy Technology Data Exchange (ETDEWEB)

    Luk, Ting S.; De Ceglia, Domenico; Scalora, Michael; Vincenti, Maria A.; Campione, Salvatore; Kelley, Kyle; Maria, Jon-Paul; Keeler, Gordon A.

    2017-08-01

    Optical nonlocalities are elusive and hardly observable in traditional plasmonic materials like noble and alkali metals. Here we experimentally observe and theoretically model viscoelastic nonlocalities in the infrared optical response of a doped, cadmium oxide epsilon-near-zero thin film. The nonlocality is clearly detectable thanks to the low damping rate of conduction electrons and the virtual absence of interband transitions at infrared wavelengths. We describe the motion of conduction electrons using a hydrodynamic model for a viscoelastic fluid, and find excellent agreement with experimental results. The electrons’ elasticity blue-shifts the infrared plasmonic resonance associated with the main epsilon-near-zero mode, and triggers the onset of higher-order resonances due to the excitation of electron-pressure modes above the bulk plasma frequency. We also provide evidence of the existence of nonlocal damping, i.e., viscosity, in the motion of optically-excited conduction electrons using a combination of spectroscopic ellipsometry data and predictions based on the viscoelastic hydrodynamic model.

  8. Apertureless near-field scanning optical microscope working with or without laser source.

    Science.gov (United States)

    Formanek, F; De Wilde, Y; Aigouy, L; Chen, Y

    2004-01-01

    An apertureless near-field scanning optical microscope (ANSOM), used indifferent configurations, is presented. Our versatile home-made setup, based on a sharp tungsten tip glued onto a quartz tuning fork and working in tapping mode, allows to perform imaging over a broad spectral range. We have recorded optical images in the visible (wavelength, lambda = 655 nm) and in the infrared (lambda = 10.6 microm), proving that the setup routinely achieves an optical resolution of images recorded in the visible (lambda = 655 nm) in an inverted configuration where the tip does not perturb the focused spot of the illumination laser. Approach curves as well as image profiles have revealed that on demodulating the optical signal at higher harmonics, we can obtain an effective probe sharpening which results in an improvement of the resolution. Finally, we have presented optical images recorded in the infrared without any illumination, that is, the usual laser source is replaced by a simple heating of the sample. This has shown that the ANSOM can be used as a near-field thermal optical microscope (NTOM) to probe the near field generated by the thermal emission of the sample.

  9. Tunable optical switching in the near-infrared spectral regime by employing plasmonic nanoantennas containing phase change materials.

    Science.gov (United States)

    Savaliya, Priten B; Thomas, Arun; Dua, Rishi; Dhawan, Anuj

    2017-10-02

    We propose the design of switchable plasmonic nanoantennas (SPNs) that can be employed for optical switching in the near-infrared regime. The proposed SPNs consist of nanoantenna structures made up of a plasmonic metal (gold) such that these nanoantennas are filled with a switchable material (vanadium dioxide). We compare the results of these SPNs with inverted SPN structures that consist of gold nanoantenna structures surrounded by a layer of vanadium dioxide (VO 2 ) on their outer surface. These nanoantennas demonstrate switching of electric-field intensity enhancement (EFIE) between two states (On and Off states), which can be induced thermally, optically or electrically. The On and Off states of the nanoantennas correspond to the metallic and semiconductor states, respectively of the VO 2 film inside or around the nanoantennas, as the VO 2 film exhibits phase transition from its semiconductor state to the metallic state upon application of thermal, optical, or electrical energy. We employ finite-difference time-domain (FDTD) simulations to demonstrate switching in the EFIE for four different SPN geometries - nanorod-dipole, bowtie, planar trapezoidal toothed log-periodic, and rod-disk - and compare their near-field distributions for the On and Off states of the SPNs. We also demonstrate that the resonance wavelength of the EFIE spectra gets substantially modified when these SPNs switch between the two states.

  10. Development of Infrared Phase Closure Capability in the Infrared-Optical Telescope Array (IOTA)

    Science.gov (United States)

    Traub, Wesley A.

    2002-01-01

    We completed all major fabrication and testing for the third telescope and phase-closure operation at the Infrared-Optical Telescope Array (IOTA) during this period. In particular we successfully tested the phase-closure operation, using a laboratory light source illuminating the full delay-line optical paths, and using an integrated-optic beam combiner coupled to our Picnic-detector camera. This demonstration is an important and near-final milestone achievement. As of this writing, however, several tasks yet remain, owing to development snags and weather, so the final proof of success, phase-closure observation of a star, is now expected to occur in early 2002, soon after this report has been submitted.

  11. Mapping of calf muscle oxygenation and haemoglobin content during dynamic plantar flexion exercise by multi-channel time-resolved near-infrared spectroscopy

    International Nuclear Information System (INIS)

    Torricelli, Alessandro; Quaresima, Valentina; Pifferi, Antonio; Biscotti, Giovanni; Spinelli, Lorenzo; Taroni, Paola; Ferrari, Marco; Cubeddu, Rinaldo

    2004-01-01

    A compact and fast multi-channel time-resolved near-infrared spectroscopy system for tissue oximetry was developed. It employs semiconductor laser and fibre optics for delivery of optical signals. Photons are collected by eight 1 mm fibres and detected by a multianode photomultiplier. A time-correlated single photon counting board is used for the parallel acquisition of time-resolved reflectance curves. Estimate of the reduced scattering coefficient is achieved by fitting with a standard model of diffusion theory, while the modified Lambert-Beer law is used to assess the absorption coefficient. In vivo measurements were performed on five healthy volunteers to monitor spatial changes in calf muscle (medial and lateral gastrocnemius; MG, LG) oxygen saturation (SmO 2 ) and total haemoglobin concentration (tHb) during dynamic plantar flexion exercise performed at 50% of the maximal voluntary contraction. At rest SmO 2 was 73.0 ± 0.9 and 70.5 ± 1.7% in MG and LG, respectively (P = 0.045). At the end of the exercise, SmO 2 decreased (69.1 ± 1.8 and 63.8 ± 2.1% in MG and LG, respectively; P 2 and tHb

  12. Near-infrared spectroscopy. Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-07-01

    A near-infrared (NIR) spectroscopy system with a remote fiber-optic probe was developed and demonstrated to measure the water content of high-level radioactive wastes from the underground storage tanks at the Hanford Site in richland Washington. The technology was developed as a cost-effective and safer alternative to the thermogravimetric analysis (TGA) technique in use as the baseline. This work was supported by the Tanks Focus Area (TFA) within the Department of Energy's (DOE) Office of Science and Technology (OST) in cooperation with the Hanford Tank Waste Remediation System (TWRS) Program

  13. THE 1.6 μm NEAR-INFRARED NUCLEI OF 3C RADIO GALAXIES: JETS, THERMAL EMISSION, OR SCATTERED LIGHT?

    International Nuclear Information System (INIS)

    Baldi, Ranieri D.; Chiaberge, Marco; Sparks, William; Macchetto, F. Duccio; Capetti, Alessandro; O'Dea, Christopher P.; Axon, David J.; Baum, Stefi A.; Quillen, Alice C.

    2010-01-01

    Using HST NICMOS 2 observations we have measured 1.6 μm near-infrared nuclear luminosities of 100 3CR radio galaxies with z < 0.3, by modeling and subtracting the extended emission from the host galaxy. We performed a multiwavelength statistical analysis (including optical and radio data) of the properties of the nuclei following classification of the objects into FR I and FR II, and low-ionization galaxies (LIGs), high-ionization galaxies (HIGs), and broad-line objects (BLOs) using the radio morphology and optical spectra, respectively. The correlations among near-infrared, optical, and radio nuclear luminosity support the idea that the near-infrared nuclear emission of FR Is has a non-thermal origin. Despite the difference in radio morphology, the multiwavelength properties of FR II LIG nuclei are statistically indistinguishable from those of FR Is, an indication of a common structure of the central engine. All BLOs show an unresolved near-infrared nucleus and a large near-infrared excess with respect to FR II LIGs and FR Is of equal radio core luminosity. This requires the presence of an additional (and dominant) component other than the non-thermal light. Considering the shape of their spectral energy distribution, we ascribe the origin of their near-infrared light to hot circumnuclear dust. A near-infrared excess is also found in HIGs, but their nuclei are substantially fainter than those of BLO. This result indicates that substantial obscuration along the line of sight to the nuclei is still present at 1.6 μm. Nonetheless, HIG nuclei cannot simply be explained in terms of dust obscuration: a significant contribution from light reflected in a circumnuclear scattering region is needed to account for their multiwavelength properties.

  14. Enhanced optical confinement of dye-doped dielectric nanoparticles using a picosecond-pulsed near-infrared laser

    International Nuclear Information System (INIS)

    Kittiravechote, A; Chiang, W-Y; Usman, A; Liau, I; Masuhara, H

    2014-01-01

    We demonstrate a novel strategy to increase the capability of confining numerous dye-doped polymeric nanobeads (diameter 100 nm) with laser trapping. Unlike most classical works of optical trapping that address mainly the stiffness of the optical trap, our work concerns an increase in the number of particles confined near the laser focus. We developed an imaging system of light scattering in which a condenser lamp was employed to illuminate the focal plane of the objective lens, and the scattering of the incoherent light was specifically measured to determine the number of confined nanobeads. In contrast to preceding work that used mainly continuous-wave or femtosecond-pulsed lasers, we employed a picosecond-pulsed laser with the half-wavelength of the laser particularly falling within the absorption band of the dopant. Our results show that the number of doped nanobeads held by the laser is significantly greater than that of the bare nanobeads of the same dimension. In striking contrast, the confinement of the nanobeads of the two types was comparable when a continuous-wave laser of the same wavelength and power was employed. The number of confined dye-doped nanobeads increased nonlinearly with the power of the pulsed laser; this dependence was fitted satisfactorily with a second-order polynomial. Supported by theoretical analysis, we attribute the enhanced confinement of doped nanobeads in part to an increased effective refractive index resulting from two-photon resonance between the optical field of the laser and the dopant of the nanobead. We envisage that our findings would evoke applications that benefit from controlled confinement or aggregation of nanomaterials with the employment of near-infrared pulsed lasers. (letter)

  15. NEAR-INFRARED AUTOFLUORESCENCE IN BILATERAL DIFFUSE UVEAL MELANOCYTIC PROLIFERATION ASSOCIATED WITH ESOPHAGEAL CARCINOMA AND CHOROIDAL METASTASIS.

    Science.gov (United States)

    Golshahi, Azadeh; Bornfeld, Norbert; Weinitz, Silke; Kellner, Ulrich

    2016-01-01

    To investigate the advantage of near-infrared autofluorescence (787 nm) for the detection of melanocytic lesions in a patient with bilateral diffuse uveal melanocytic proliferation in association with esophageal carcinoma complicated by most likely unilateral choroidal metastasis. In this retrospective case report, a 55-year-old woman referred for the evaluation of sudden visual loss underwent normal ophthalmological evaluation and, in addition, was examined with near-infrared reflectance, near-infrared autofluorescence, fundus autofluorescence (Heidelberg Retina Angiograph II [HRA2; Heidelberg Engineering]), spectral domain optical coherence tomography (Spectralis OCT; Heidelberg Engineering), and multifocal electroretinography (RetiScan; Roland Consult). The patient had been diagnosed with esophageal carcinoma 3 months before the onset of visual symptoms. The visual acuity was 20/40 in the right eye and 20/20 in the left eye. Bilateral patchy melanocytic proliferation was detected on ophthalmoscopy. The extent of lesions was best detected with near-infrared reflectance and near-infrared autofluorescence, whereas fundus autofluorescence and spectral domain optical coherence tomography did not reveal alterations of the outer retina or retinal pigment epithelium in this early stage of bilateral diffuse uveal melanocytic proliferation. The right eye showed in addition to the findings on the left eye choroidal folds in the fovea and an elevated lesion inferotemporal of the fovea suspicious of a choroidal metastasis. In the B-scan ultrasonography, a homogenous lesion was seen. Spectral domain optical coherence tomography demonstrated a mild accumulation of subretinal fluid adjacent to and over the choroidal metastasis. Transretinal biopsy of this elevated lesion revealed a low differentiated carcinoma of squamous epithelium, compatible with choroidal metastasis of the esophageal carcinoma. The choroidal metastasis increased within 3 months after the first visit. The

  16. Rapid electrostatics-assisted layer-by-layer assembly of near-infrared-active colloidal photonic crystals.

    Science.gov (United States)

    Askar, Khalid; Leo, Sin-Yen; Xu, Can; Liu, Danielle; Jiang, Peng

    2016-11-15

    Here we report a rapid and scalable bottom-up technique for layer-by-layer (LBL) assembling near-infrared-active colloidal photonic crystals consisting of large (⩾1μm) silica microspheres. By combining a new electrostatics-assisted colloidal transferring approach with spontaneous colloidal crystallization at an air/water interface, we have demonstrated that the crystal transfer speed of traditional Langmuir-Blodgett-based colloidal assembly technologies can be enhanced by nearly 2 orders of magnitude. Importantly, the crystalline quality of the resultant photonic crystals is not compromised by this rapid colloidal assembly approach. They exhibit thickness-dependent near-infrared stop bands and well-defined Fabry-Perot fringes in the specular transmission and reflection spectra, which match well with the theoretical calculations using a scalar-wave approximation model and Fabry-Perot analysis. This simple yet scalable bottom-up technology can significantly improve the throughput in assembling large-area, multilayer colloidal crystals, which are of great technological importance in a variety of optical and non-optical applications ranging from all-optical integrated circuits to tissue engineering. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Quantitative Analysis of HER2 Receptor Expression In Vivo by Near-Infrared Optical Imaging

    Directory of Open Access Journals (Sweden)

    Victor Chernomordik

    2010-07-01

    Full Text Available Human epidermal growth factor receptor 2 (HER2 overexpression in breast cancers is associated with poor prognosis and resistance to therapy. Current techniques for estimating this important characteristic use ex vivo assays that require tissue biopsies. We suggest a novel noninvasive method to characterize HER2 expression in vivo, using optical imaging, based on HER2-specific probes (albumin-binding domain–fused-(ZHER2:3422-Cys Affibody molecules [Affibody AB, Solna, Sweden], labeled with Alexa Fluor 750 [Molecular Probes, Invitrogen, Carlsbad, CA] that could be used concomitantly with HER2-targeted therapy. Subcutaneous tumor xenografts, expressing different levels of HER2, were imaged with a near-infrared fluorescence small-animal imaging system at several times postinjection of the probe. The compartmental ligand-receptor model was used to calculate HER2 expression from imaging data. Correlation between HER2 amplification/overexpression in tumor cells and parameters, directly estimated from the sequence of optical images, was observed (eg, experimental data for BT474 xenografts indicate that initial slope, characterizing the temporal dependence of the fluorescence intensity detected in the tumor, linearly depends on the HER2 expression, as measured ex vivo by an enzyme-linked immunosorbent assay for the same tumor. The results obtained from tumors expressing different levels of HER2 substantiate a similar relationship between the initial slope and HER2 amplification/overexpression. This work shows that optical imaging, combined with mathematical modeling, allows noninvasive monitoring of HER2 expression in vivo.

  18. Photometric redshifts for weak lensing tomography from space: the role of optical and near infrared photometry

    Science.gov (United States)

    Abdalla, F. B.; Amara, A.; Capak, P.; Cypriano, E. S.; Lahav, O.; Rhodes, J.

    2008-07-01

    We study in detail the photometric redshift requirements needed for tomographic weak gravitational lensing in order to measure accurately the dark energy equation of state. In particular, we examine how ground-based photometry (u, g, r, i, z, y) can be complemented by space-based near-infrared (near-IR) photometry (J, H), e.g. onboard the planned DUNE satellite. Using realistic photometric redshift simulations and an artificial neural network photo-z method we evaluate the figure of merit for the dark energy parameters (w0, wa). We consider a DUNE-like broad optical filter supplemented with ground-based multiband optical data from surveys like the Dark Energy Survey, Pan-STARRS and LSST. We show that the dark energy figure of merit would be improved by a factor of 1.3-1.7 if IR filters are added onboard DUNE. Furthermore we show that with IR data catastrophic photo-z outliers can be removed effectively. There is an interplay between the choice of filters, the magnitude limits and the removal of outliers. We draw attention to the dependence of the results on the galaxy formation scenarios encoded into the mock galaxies, e.g. the galaxy reddening. For example, very deep u-band data could be as effective as the IR. We also find that about 105-106 spectroscopic redshifts are needed for calibration of the full survey.

  19. Polarimetry and photometry of active quasars at visual and near-infrared wavelengths

    International Nuclear Information System (INIS)

    Smith, P.S.

    1986-01-01

    The optical and near-infrared continua of highly luminous BL Lacertae (BL Lac) objects and optically violent variable (OVV) quasars are studied through simultaneous broad-band photometry and linear polarimetry. Nineteen BL Lacs and OVVs were monitored during a ∼1 1/2-year period, with the major aim of characterizing the wavelength-dependent polarization exhibited by these objects. Optical (UBVRI) observations were conducted at the UCSD/U. Minn. 1.5-m telescope on Mt. Lemmon, Arizona. Simultaneous (within 1 hr.) near-infrared (JHK) measurements were made using the KPNO 2.1-m telescope. Most of the BL Lac objects exhibit large variations in polarization and brightness on time scale of less than a week. The degree of fractional linear polarization (P) is not observed to be related to brightness or optical spectral index. Most BL Lacs did not show a preferred polarization position angle (theta). Wavelength-dependent P and theta are observed in almost all BL Lacs, but not always simultaneously. The OVV quasar 1156 + 295 shows behavior very similar to the BL Lac objects. 3C 345 Exhibited polarization properties that are quite different from those of the BL Lacs. This object showed a clear correlation between brightness and P

  20. Effect of initial chirp on near-infrared supercontinuum generation by a nanosecond pulse in a nonlinear fiber amplifier

    International Nuclear Information System (INIS)

    Song Rui; Hou Jing; Wang Ze-Feng; Lu Qi-Sheng; Xiao Rui

    2013-01-01

    Theoretical and experimental research on the effect of initial chirp on near-infrared supercontinuum generation by a nanosecond pulse in a nonlinear fiber amplifier is carried out. The complex Ginzburg—Landau equation is used to simulate the propagation of the pulse in the fiber amplifier and the results show that pulses with negative initial chirp produce the widest supercontinuum and pulses with positive initial chirp produce the narrowest supercontinuum when the central wavelength of the pump lies in the normal dispersion region of the gain fiber. A self-made line width narrowing system is utilized to control the initial chirp of the nanosecond pump pulse and a four-stage master oscillator power amplifier configuration is adopted to produce a high power near-infrared suppercontinuum. The experimental results are in good agreement with simulations which can provide some guidance on further optimization of the system in future work. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  1. Preliminary tests on a new near-infrared continuous-wave tissue oximeter

    Science.gov (United States)

    Casavola, Claudia; Cicco, Giuseppe; Pirrelli, Anna; Lugara, Pietro M.

    2000-11-01

    We present a preliminary study, in vitro and in vivo, with a novel device for near-infrared tissue oximetry. The light sources used are two quasi-continuous-wave LEDs, emitting at 656 and 851 nm, and the detector is a photodiode. The data are acquired in back-scattering configuration, thus allowing the non-invasive characterization of thick tissues. Stability tests were performed by placing the optical probe on a tissue- like phantom and acquiring data for periods of time ranging from 5 to 40 minutes. No significant drifts in the DC signal were observed after a warm-up period of no more than 10 minutes. We performed reproducibility tests by repositioning the optical probe on the phantom for a number of times. We found a reproducibility better than 5% in the DC signal. We also present the results of a preliminary study conducted in vivo, on the calf muscle of human subjects. We report a comparison of the results obtained with the near-infrared oximeter with the values of blood oxygenation ctO2 measured with conventional chemical tests.

  2. Advanced infrared optically black baffle materials

    International Nuclear Information System (INIS)

    Seals, R.D.; Egert, C.M.; Allred, D.D.

    1990-01-01

    Infrared optically black baffle surfaces are an essential component of many advanced optical systems. All internal surfaces in advanced infrared optical sensors that require stray light management to achieve resolution are of primary concern in baffle design. Current industrial materials need improvements to meet advanced optical sensor systems requirements for optical, survivability, and endurability. Baffles are required to survive and operate in potentially severe environments. Robust diffuse-absorptive black surfaces, which are thermally and mechanically stable to threats of x-ray, launch, and in-flight maneuver conditions, with specific densities to allow an acceptable weight load, handleable during assembly, cleanable, and adaptive to affordable manufacturing, are required as optical baffle materials. In this paper an overview of recently developed advanced infrared optical baffle materials, requirements, manufacturing strategies, and the Optics MODIL (Manufacturing Operations Development and Integration Laboratory) Advanced Baffle Program are discussed

  3. Influence of earlobe thickness on near infrared spectroscopy

    Science.gov (United States)

    Jiang, Jingying; Wang, Tianpei; Li, Si; Li, Lin; Liu, Jiajia; Xu, Kexin

    2017-03-01

    Near-infrared spectroscopy has been recognized as a potential technology for noninvasive blood glucose sensing. However, the detected spectral signal is unstable mainly because of (1) the weak light absorption of glucose itself within NIR range, (2) the influence of temperature and individual differences of biotissue. Our previous results demonstrated that the synergistic effect of both transmittance and reflectance could enhance the strength of the detection signal. In this talk, we design a set of experiments to analyze the effect of earlobe thickness on Near Infrared spectroscopic measurement by using home-made optical fiber probe within the wavelength of 1000-1600nm. Firstly, we made a MC simulation of single-layer skin model and five-layer skin model to get the diffused transmittance spectra and diffused reflectance spectra under different optaical path lengths. And then we obtain the spectra of the earlobes from different volunteers by the same way. The experimental results showed that with the increase of the thickness,the light intensity of diffused transmittance decreases, and the light intensity of diffused reflectance remaines substantially unchanged.

  4. Assessment of quality parameters in grapes during ripening using a miniature fiber-optic near-infrared spectrometer.

    Science.gov (United States)

    Fernández-Novales, Juan; López, María-Isabel; Sánchez, María-Teresa; García-Mesa, José-Antonio; González-Caballero, Virginia

    2009-01-01

    Changes in the chemical properties of wine grapes during ripening were studied using near-infrared (NIR) spectroscopy. A miniature fiber-optic NIR spectrometer system working in transmission mode in the spectral region (700 - 1,060 nm) was evaluated for this purpose. Spectra and analytical data were used to develop partial least square calibration models to quantify changes in the major parameters used to chart ripening in this fruit. NIR spectroscopy provided excellent precision for soluble solid content and for reducing sugars, and good precision for maturity index, while for pH and titratable acidity the miniature NIR spectroscopy instrument proved less accurate. The performance of the instrument in classifying wine grapes by grape type and by irrigation regime was also studied. Percentages of correctly classified samples ranged from 82.7% to 96.2%. The results show that the monitoring of soluble solid content and reducing sugars' changes in wine grape quality parameters during ripening, as well as the classification of grapes, can be performed non-destructively using a miniature fiber-optic NIR spectrometer.

  5. ITO/Au/ITO sandwich structure for near-infrared plasmonics.

    Science.gov (United States)

    Fang, Xu; Mak, Chee Leung; Dai, Jiyan; Li, Kan; Ye, Hui; Leung, Chi Wah

    2014-09-24

    ITO/Au/ITO trilayers with varying gold spacer layer thicknesses were deposited on glass substrates by pulsed laser deposition. Transmission electron microscopy measurements demonstrated the continuous nature of the Au layer down to 2.4 nm. XRD patterns clearly showed an enhanced crystallinity of the ITO films promoted by the insertion of the gold layer. Compared with a single layer of ITO with a carrier concentration of 7.12 × 10(20) cm(-3), the ITO/Au/ITO structure achieved an effective carrier concentration as high as 3.26 × 10(22) cm(-3). Transmittance and ellipsometry measurements showed that the optical properties of ITO/Au/ITO films were greatly influenced by the thickness of the inserted gold layer. The cross-point wavelength of the trilayer samples was reduced with increasing gold layer thickness. Importantly, the trilayer structure exhibited a reduced loss (compared with plain Au) in the near-infrared region, suggesting its potential for plasmonic applications in the near-infrared range.

  6. The DENIS & 2MASS Near Infrared Surveys

    OpenAIRE

    Mamon, Gary

    1996-01-01

    The DENIS and 2MASS near infrared surveys are presented. Their applications in extragalactic astronomy and cosmology are listed. The prospects for a rapid spectroscopic followup survey of a near infrared selected sample of nearly $10^5$ galaxies are illustrated with Monte-Carlo simulations.

  7. Near infrared detection of ammonium minerals.

    Science.gov (United States)

    Krohn, M.D.; Altaner, S.P.

    1987-01-01

    Diagnostic near-infrared spectral features have been identified for minerals with ammonium (NH4+) bound in the crystal structure. Near-infrared detection of NH4-bearing minerals may provide useful information for prospecting for certain ore deposits and may provide a better understanding of the nitrogen cycle within geologic environments.-from Authors

  8. Characterization methods of integrated optics for mid-infrared interferometry

    Science.gov (United States)

    Labadie, Lucas; Kern, Pierre Y.; Schanen-Duport, Isabelle; Broquin, Jean-Emmanuel

    2004-10-01

    his article deals with one of the important instrumentation challenges of the stellar interferometry mission IRSI-Darwin of the European Space Agency: the necessity to have a reliable and performant system for beam combination has enlightened the advantages of an integrated optics solution, which is already in use for ground-base interferometry in the near infrared. Integrated optics provides also interesting features in terms of filtering, which is a main issue for the deep null to be reached by Darwin. However, Darwin will operate in the mid infrared range from 4 microns to 20 microns where no integrated optics functions are available on-the-shelf. This requires extending the integrated optics concept and the undergoing technology in this spectral range. This work has started with the IODA project (Integrated Optics for Darwin) under ESA contract and aims to provide a first component for interferometry. In this paper are presented the guidelines of the characterization work that is implemented to test and validate the performances of a component at each step of the development phase. We present also an example of characterization experiment used within the frame of this work, is theoretical approach and some results.

  9. Optical and Near-infrared Polarimetry of Non-periodic Comet C/2013 US10 (Catalina)

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yuna Grace; Ishiguro, Masateru; Lee, Myung Gyoon [Department of Physics and Astronomy, Seoul National University, 1 Gwanak, Seoul 08826 (Korea, Republic of); Kuroda, Daisuke; Toda, Hiroyuki; Yanagisawa, Kenshi [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, 3037-5 Honjo, Kamogata, Asakuchi, Okayama, 719-0232 (Japan); Hanayama, Hidekazu [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Kawabata, Koji S.; Nakaoka, Tatsuya [Hiroshima Astrophysical Science Center, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan); Akitaya, Hiroshi [Center for Astronomy, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan); Itoh, Ryosuke; Kawai, Nobuyuki [Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan); Ohta, Kouji [Department of Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Yoshida, Michitoshi [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Watanabe, Jun-Ichi, E-mail: ishiguro@astro.snu.ac.kr [National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan)

    2017-10-01

    We present an optical and near-infrared (hereafter NIR) polarimetric study of a comet C/2013 US10 (Catalina) observed on UT 2015 December 17–18 at phase angles of α  = 52.°1–53.°1. Additionally, we obtained an optical spectrum and multi-band images to examine the influence of gas emission. We find that the observed optical signals are significantly influenced by gas emission; that is, the gas-to-total intensity ratio varies from 5 to 30% in the R {sub C} and 3%–18% in the I {sub C} bands, depending on the position in the coma. We derive the “gas-free dust polarization degrees” of 13.8% ± 1.0% in the R {sub C} and 12.5% ± 1.1% in the I {sub C} bands and a gray polarimetric color, i.e., −8.7% ± 9.9% μ m{sup −1} in optical and 1.6% ± 0.9% μ m{sup −1} in NIR. The increments of polarization obtained from the gas correction show that the polarimetric properties of the dust in this low-polarization comet are not different from those in high-polarization comets. In this process, the cometocentric distance dependence of polarization has disappeared. We also find that the R {sub C}-band polarization degree of the southeast dust tail, which consists of large dust particles (100 μ m–1 mm), is similar to that in the outer coma where small and large ones are mixed. Our study confirms that the dichotomy of cometary polarization does not result from the difference of dust properties, but from depolarizing gas contamination. This conclusion can provide a strong support for similarity in origin of comets.

  10. Noninvasive measurement of postocclusive parameters in human forearm blood by near infrared spectroscopy

    Science.gov (United States)

    Rao, K. Prahlad; Radhakrishnan, S.; Reddy, M. Ramasubba

    2005-04-01

    Near infrared (NIR) light in the wavelength range from 700 to 900 nm can pass through skin, bone and other tissues relatively easily. As a result, NIR techniques allow a noninvasive assessment of hemoglobin saturation for a wide range of applications, such as in the study of muscle metabolism, the diagnosis of vascular disorders, brain imaging, and breast cancer detection. Near infrared Spectroscopy (NIRS) is an effective tool to measure the hemoglobin concentration in the tissues, which can discriminate optically the oxy- and deoxy- hemoglobin species because of their different near-infrared absorption spectra. We have developed an NIRS probe consisting of a laser diode of 830 nm wavelength and a PIN photodiode in reflectance mode. We have selected a set of healthy volunteers (mean age 30, range 26-40 years) for the study. The probe is placed on forearm of each subject and the backscattered light intensity is measured by occluding the blood flow at 210, 110 and 85 mmHg pressures. Recovery time, peak time and time after 50% release of the cuff pressure are determined from the optical densities during the post occlusive state of forearm. These parameters are useful for determining the transient increase in blood flow after the release of blood occlusion. Clinically, the functional aspects of blood flow in the limbs could be evaluated noninvasively by NIRS.

  11. Deep and accurate near-infrared photometry of the Galactic globular cluster omega Cen .

    Science.gov (United States)

    Calamida, A.; Bono, G.; Corsi, C. E.; Stetson, P. B.; Prada Moroni, P. G.; Degl'Innocenti, S.; Marchetti, E.; Amico, P.; Ferraro, I.; Iannicola, G.; Monelli, M.; Buonanno, R.; Caputo, F.; Dall'Ora, M.; Freyhammer, L. M.; Koester, D.; Nonino, M.; Piersimoni, A. M.; Pulone, L.; Romaniello, M.

    We present deep and accurate Near-Infrared (NIR) photometry of the Galactic Globular Cluster omega Cen . Data were collected using the Multi-Conjugate Adaptive Optics Demonstrator (MAD) mounted on the VLT (ESO). We combined the NIR photometry with optical space data collected with the Advanced Camera for Surveys (ACS) for the same region of the cluster. Our deep optical-NIR CMD indicates that the spread in age among the different stellar populations in omega Cen is at most of the order of 2 Gyr.

  12. Dynamic Softening or Stiffening a Supramolecular Hydrogel by Ultraviolet or Near-Infrared Light.

    Science.gov (United States)

    Zheng, Zhao; Hu, Jingjing; Wang, Hui; Huang, Junlin; Yu, Yihua; Zhang, Qiang; Cheng, Yiyun

    2017-07-26

    The development of light-responsive hydrogels that exhibit switchable size and mechanical properties with temporal and spatial resolution is of great importance in many fields. However, it remains challenging to prepare smart hydrogels that dramatically change their properties in response to both ultraviolet (UV) and near-infrared (NIR) lights. Here, we designed a dual-light responsive supramolecular gel by integrating UV light-switchable host-guest recognition, temperature responsiveness, and NIR photothermal ability in the gel. The gel could rapidly self-heal and is capable of both softening and stiffening controlled by UV and NIR lights, respectively. Besides stiffness modulation, the bending direction of the gel can be controlled by UV or NIR light irradiation. The smart gel makes it possible to generate dynamic materials that respond to both UV and NIR lights and represents a useful tool that might be used to modulate cellular microenvironments with spatiotemporal resolution.

  13. Voxel-based measurement sensitivity of spatially resolved near-infrared spectroscopy in layered tissues.

    Science.gov (United States)

    Niwayama, Masatsugu

    2018-03-01

    We quantitatively investigated the measurement sensitivity of spatially resolved spectroscopy (SRS) across six tissue models: cerebral tissue, a small animal brain, the forehead of a fetus, an adult brain, forearm muscle, and thigh muscle. The optical path length in the voxel of the model was analyzed using Monte Carlo simulations. It was found that the measurement sensitivity can be represented as the product of the change in the absorption coefficient and the difference in optical path length in two states with different source-detector distances. The results clarified the sensitivity ratio between the surface layer and the deep layer at each source-detector distance for each model and identified changes in the deep measurement area when one of the detectors was close to the light source. A comparison was made with the results from continuous-wave spectroscopy. The study also identified measurement challenges that arise when the surface layer is inhomogeneous. Findings on the measurement sensitivity of SRS at each voxel and in each layer can support the correct interpretation of measured values when near-infrared oximetry or functional near-infrared spectroscopy is used to investigate different tissue structures. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  14. The effects of internal refractive index variation in near-infrared optical tomography: a finite element modelling approach

    International Nuclear Information System (INIS)

    Dehghani, Hamid; Brooksby, Ben; Vishwanath, Karthik; Pogue, Brian W; Paulsen, Keith D

    2003-01-01

    Near-infrared (NIR) tomography is a technique used to measure light propagation through tissue and generate images of internal optical property distributions from boundary measurements. Most popular applications have concentrated on female breast imaging, neonatal and adult head imaging, as well as muscle and small animal studies. In most instances a highly scattering medium with a homogeneous refractive index is assumed throughout the imaging domain. Using these assumptions, it is possible to simplify the model to the diffusion approximation. However, biological tissue contains regions of varying optical absorption and scatter, as well as varying refractive index. In this work, we introduce an internal boundary constraint in the finite element method approach to modelling light propagation through tissue that accounts for regions of different refractive indices. We have compared the results to data from a Monte Carlo simulation and show that for a simple two-layered slab model of varying refractive index, the phase of the measured reflectance data is significantly altered by the variation in internal refractive index, whereas the amplitude data are affected only slightly

  15. Infrared to near-ultraviolet optical response for zigzag-edge silicene nanoribbons under the irradiation of an external electromagnetic field

    Science.gov (United States)

    Liao, Wenhu; Bao, Hairui; Zhang, Xincheng; Zuo, Min; Yang, Hong

    2018-01-01

    We investigate theoretically the width-dependent electronic structure and optical spectrum for intrinsic zigzag-edge silicene nanoribbons with N silicon atoms of the A and B sublattice ( N-ZSiNRs) under the irradiation of an external electromagnetic field at low temperatures. Based on the method of the tight-binding approximation, we have derived a width-dependent dispersion relation and wave function for N-ZSiNRs under the hard-wall boundary condition. By way of the dipole-transition theorem for semiconductors, both the 8- and 16-ZSiNRs have been observed to exhibit broad values (0.30-3.20 eV) of optical conductivity, dielectric function and electron energy loss spectrum in the range of infrared to near-ultraviolet. The optical spectra for 8- and 16-ZSiNRs have been manifested to be transitions between the valence and conduction bands with the same subband indices, as well as the resonances between the edge state and bulk state subbands, while the optical transitions among the different indexed bulk subbands should be forbidden owing to the non-conserved momentum. The obtained results are believed to be of importance in exploring new effects and optoelectronic applications of the silicene-based electron devices.

  16. DISCOVERING BRIGHT QUASARS AT INTERMEDIATE REDSHIFTS BASED ON OPTICAL/NEAR-INFRARED COLORS

    International Nuclear Information System (INIS)

    Wu, Xue-Bing; Zuo, Wenwen; Yang, Jinyi; Yang, Qian; Wang, Feige

    2013-01-01

    The identification of quasars at intermediate redshifts (2.2 < z < 3.5) has been inefficient in most previous quasar surveys since the optical colors of quasars are similar to those of stars. The near-IR K-band excess technique has been suggested to overcome this difficulty. Our recent study also proposed to use optical/near-IR colors for selecting z < 4 quasars. To verify the effectiveness of this method, we selected a list of 105 unidentified bright targets with i ≤ 18.5 from the quasar candidates of SDSS DR6 with both SDSS ugriz optical and UKIDSS YJHK near-IR photometric data, which satisfy our proposed Y – K/g – z criterion and have photometric redshifts between 2.2 and 3.5 estimated from the nine-band SDSS-UKIDSS data. We observed 43 targets with the BFOSC instrument on the 2.16 m optical telescope at Xinglong station of the National Astronomical Observatory of China in the spring of 2012. We spectroscopically identified 36 targets as quasars with redshifts between 2.1 and 3.4. The high success rate of discovering these quasars in the SDSS spectroscopic surveyed area further demonstrates the robustness of both the Y – K/g – z selection criterion and the photometric redshift estimation technique. We also used the above criterion to investigate the possible stellar contamination rate among the quasar candidates of SDSS DR6, and found that the rate is much higher when selecting 3 < z < 3.5 quasar candidates than when selecting lower redshift candidates (z < 2.2). The significant improvement in the photometric redshift estimation when using the nine-band SDSS-UKIDSS data over the five-band SDSS data is demonstrated and a catalog of 7727 unidentified quasar candidates in SDSS DR6 selected with optical/near-IR colors and having photometric redshifts between 2.2 and 3.5 is provided. We also tested the Y – K/g – z selection criterion with the recently released SDSS-III/DR9 quasar catalog and found that 96.2% of 17,999 DR9 quasars with UKIDSS Y- and K

  17. Non-scanning fiber-optic near-infrared beam led to two-photon optogenetic stimulation in-vivo.

    Directory of Open Access Journals (Sweden)

    Kamal R Dhakal

    Full Text Available Stimulation of specific neurons expressing opsins in a targeted region to manipulate brain function has proved to be a powerful tool in neuroscience. However, the use of visible light for optogenetic stimulation is invasive due to low penetration depth and tissue damage owing to larger absorption and scattering. Here, we report, for the first time, in-depth non-scanning fiber-optic two-photon optogenetic stimulation (FO-TPOS of neurons in-vivo in transgenic mouse models. In order to optimize the deep-brain stimulation strategy, we characterized two-photon activation efficacy at different near-infrared laser parameters. The significantly-enhanced in-depth stimulation efficiency of FO-TPOS as compared to conventional single-photon beam was demonstrated both by experiments and Monte Carlo simulation. The non-scanning FO-TPOS technology will lead to better understanding of the in-vivo neural circuitry because this technology permits more precise and less invasive anatomical delivery of stimulation.

  18. Near-infrared II fluorescence for imaging hindlimb vessel regeneration with dynamic tissue perfusion measurement.

    Science.gov (United States)

    Hong, Guosong; Lee, Jerry C; Jha, Arshi; Diao, Shuo; Nakayama, Karina H; Hou, Luqia; Doyle, Timothy C; Robinson, Joshua T; Antaris, Alexander L; Dai, Hongjie; Cooke, John P; Huang, Ngan F

    2014-05-01

    Real-time vascular imaging that provides both anatomic and hemodynamic information could greatly facilitate the diagnosis of vascular diseases and provide accurate assessment of therapeutic effects. Here, we have developed a novel fluorescence-based all-optical method, named near-infrared II (NIR-II) fluorescence imaging, to image murine hindlimb vasculature and blood flow in an experimental model of peripheral arterial disease, by exploiting fluorescence in the NIR-II region (1000-1400 nm) of photon wavelengths. Because of the reduced photon scattering of NIR-II fluorescence compared with traditional NIR fluorescence imaging and thus much deeper penetration depth into the body, we demonstrated that the mouse hindlimb vasculature could be imaged with higher spatial resolution than in vivo microscopic computed tomography. Furthermore, imaging during 26 days revealed a significant increase in hindlimb microvascular density in response to experimentally induced ischemia within the first 8 days of the surgery (Pimaging make it a useful imaging tool for murine models of vascular disease. © 2014 American Heart Association, Inc.

  19. Reststrahlen Band Optics for the Advancement of Far-Infrared Optical Architecture

    Science.gov (United States)

    Streyer, William Henderson

    . Computational models of the emission indicated the samples had significantly higher power efficiency than a blackbody at the same temperature in the same wavelength band. Chapter 5 presents selective thermal emission in the far-infrared from samples of patterned gallium phosphide. The selective absorption of the samples occurs in the material's Reststrahlen band and can be attributed to surface phonon polariton modes. The surfaces of the samples were grated via wet etching to provide the additional momentum necessary for free space photons to couple into and out of the surface phonon polariton modes. Upon heating the samples, selective thermal emission of the surface phonon polariton modes was observed. Chapter 6 investigates a potential means of linking lattice vibrations to free space photons. Lightly doped films of gallium arsenide were grown by molecular beam epitaxy and wet etched with 1D gratings. The light doping served to modify the material's intrinsic permittivity and extend the region of its Reststrahlen band. Though the extension of the region with negative real permittivity was small, it extended beyond the longitudinal optical phonon energy of the material, which stands as the high energy boundary of the unmodified material's Reststrahlen band. Hybrid surface polariton modes were observed at energies near the longitudinal optical phonon energy where they are not supported on the surface of the intrinsic material -- offering a potential bridge between bulk optical phonon populations and free space photons. Chapter 7 presents preliminary results exploring the prospect of exploiting an absorption resonance known as the Berreman mode as a mechanism to link optical phonons to free space photons. The Berreman mode is a strong absorption resonance that occurs near the longitudinal optical phonon energy at moderate angles of incidence in polar semiconductors. Preliminary results demonstrate selective thermal emission consistent with the expected spectral position of the

  20. A robust quantitative near infrared modeling approach for blend monitoring.

    Science.gov (United States)

    Mohan, Shikhar; Momose, Wataru; Katz, Jeffrey M; Hossain, Md Nayeem; Velez, Natasha; Drennen, James K; Anderson, Carl A

    2018-01-30

    This study demonstrates a material sparing Near-Infrared modeling approach for powder blend monitoring. In this new approach, gram scale powder mixtures are subjected to compression loads to simulate the effect of scale using an Instron universal testing system. Models prepared by the new method development approach (small-scale method) and by a traditional method development (blender-scale method) were compared by simultaneously monitoring a 1kg batch size blend run. Both models demonstrated similar model performance. The small-scale method strategy significantly reduces the total resources expended to develop Near-Infrared calibration models for on-line blend monitoring. Further, this development approach does not require the actual equipment (i.e., blender) to which the method will be applied, only a similar optical interface. Thus, a robust on-line blend monitoring method can be fully developed before any large-scale blending experiment is viable, allowing the blend method to be used during scale-up and blend development trials. Copyright © 2017. Published by Elsevier B.V.

  1. Near-field enhanced optical tweezers utilizing femtosecond-laser nanostructured substrates

    Energy Technology Data Exchange (ETDEWEB)

    Kotsifaki, D. G., E-mail: dkotsif@eie.gr; Kandyla, M. [Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vasileos Constantinou Avenue, 11635 Athens (Greece); Lagoudakis, P. G. [Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2015-11-23

    We present experimental evidence of plasmonic-enhanced optical tweezers, of polystyrene beads in deionized water in the vicinity of metal-coated nanostructures. The optical tweezers operate with a continuous wave near-infrared laser. We employ a Cu/Au bilayer that significantly improves dissipation of heat generated by the trapping laser beam and avoid de-trapping from heat convection currents. We investigate the improvement of the optical trapping force and the effective trapping quality factor, and observe an exponential distance dependence of the trapping force from the nanostructures, indicative of evanescent plasmonic enhancement.

  2. Partial loss compensation in dielectric-loaded plasmonic waveguides at near infra-red wavelengths

    DEFF Research Database (Denmark)

    Garcia, Cesar; Coello, Victor; Han, Zhanghua

    2012-01-01

    We report on the fabrication and characterization of straight dielectric-loaded surface plasmon polaritons waveguides doped with lead-sulfide quantum dots as a near infra-red gain medium. A loss compensation of ~33% (an optical gain of ~143 cm^−1) was observed in the guided mode. The mode propaga...

  3. Silicon-Vacancy Color Centers in Nanodiamonds: Cathodoluminescence Imaging Marker in the Near Infrared

    OpenAIRE

    Zhang, Huiliang; Aharonovich, Igor; Glenn, David R.; Schalek, R.; Magyar, Andrew P.; Lichtman, Jeff W.; Hu, Evelyn L.; Walsworth, Ronald L.

    2013-01-01

    We demonstrate that nanodiamonds fabricated to incorporate silicon-vacancy (Si-V) color centers provide bright, spectrally narrow, and stable cathodoluminescence (CL) in the near-infrared. Si-V color centers containing nanodiamonds are promising as non-bleaching optical markers for correlated CL and secondary electron microscopy, including applications to nanoscale bioimaging.

  4. Design of near-infrared fluorescent bioactive conjugated functional iron oxide nanoparticles for optical detection of colon cancer

    Directory of Open Access Journals (Sweden)

    Corem-Salkmon E

    2012-10-01

    Full Text Available Enav Corem-Salkmon, Benny Perlstein, Shlomo MargelThe Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan, IsraelBackground: Colon cancer is one of the major causes of death in the Western world. Early detection significantly improves long-term survival for patients with the disease. Near-infrared (NIR fluorescent nanoparticles hold great promise as contrast agents for tumor detection. NIR offers several advantages for bioimaging compared with fluorescence in the visible spectrum, ie, lower autofluorescence of biological tissues, lower absorbance, and consequently deeper penetration into biomatrices.Methods and results: NIR fluorescent iron oxide nanoparticles with a narrow size distribution were prepared by nucleation, followed by controlled growth of thin iron oxide films onto cyanine NIR dye conjugated gelatin-iron oxide nuclei. For functionalization, and in order to increase the NIR fluorescence intensity, the NIR fluorescent iron oxide nanoparticles obtained were coated with human serum albumin containing cyanine NIR dye. Leakage of the NIR dye from these nanoparticles into phosphate-buffered saline solution containing 4% albumin was not detected. The work presented here is a feasibility study to test the suitability of iron oxide-human serum albumin NIR fluorescent nanoparticles for optical detection of colon cancer. It demonstrates that encapsulation of NIR fluorescent dye within these nanoparticles significantly reduces photobleaching of the dye. Tumor-targeting ligands, peanut agglutinin and anticarcinoembryonic antigen antibodies (αCEA, were covalently conjugated with the NIR fluorescent iron oxide-human serum albumin nanoparticles via a poly(ethylene glycol spacer. Specific colon tumor detection was demonstrated in chicken embryo and mouse models for both nonconjugated and the peanut agglutinin-conjugated or αCEA-conjugated NIR fluorescent iron oxide-human serum albumin

  5. Optical and near-infrared observations of SN 2011dh - The first 100 days

    Science.gov (United States)

    Ergon, M.; Sollerman, J.; Fraser, M.; Pastorello, A.; Taubenberger, S.; Elias-Rosa, N.; Bersten, M.; Jerkstrand, A.; Benetti, S.; Botticella, M. T.; Fransson, C.; Harutyunyan, A.; Kotak, R.; Smartt, S.; Valenti, S.; Bufano, F.; Cappellaro, E.; Fiaschi, M.; Howell, A.; Kankare, E.; Magill, L.; Mattila, S.; Maund, J.; Naves, R.; Ochner, P.; Ruiz, J.; Smith, K.; Tomasella, L.; Turatto, M.

    2014-02-01

    We present optical and near-infrared (NIR) photometry and spectroscopy of the Type IIb supernova (SN) 2011dh for the first 100 days. We complement our extensive dataset with Swift ultra-violet (UV) and Spitzer mid-infrared (MIR) data to build a UV to MIR bolometric lightcurve using both photometric and spectroscopic data. Hydrodynamical modelling of the SN based on this bolometric lightcurve have been presented in Bersten et al. (2012, ApJ, 757, 31). We find that the absorption minimum for the hydrogen lines is never seen below ~11 000 km s-1 but approaches this value as the lines get weaker. This suggests that the interface between the helium core and hydrogen rich envelope is located near this velocity in agreement with the Bersten et al. (2012) He4R270 ejecta model. Spectral modelling of the hydrogen lines using this ejecta model supports the conclusion and we find a hydrogen mass of 0.01-0.04 M⊙ to be consistent with the observed spectral evolution. We estimate that the photosphere reaches the helium core at 5-7 days whereas the helium lines appear between ~10 and ~15 days, close to the photosphere and then move outward in velocity until ~40 days. This suggests that increasing non-thermal excitation due to decreasing optical depth for the γ-rays is driving the early evolution of these lines. The Spitzer 4.5 μm band shows a significant flux excess, which we attribute to CO fundamental band emission or a thermal dust echo although further work using late time data is needed. Thedistance and in particular the extinction, where we use spectral modelling to put further constraints, is discussed in some detail as well as the sensitivity of the hydrodynamical modelling to errors in these quantities. We also provide and discuss pre- and post-explosion observations of the SN site which shows a reduction by ~75 percent in flux at the position of the yellow supergiant coincident with SN 2011dh. The B, V and r band decline rates of 0.0073, 0.0090 and 0.0053 mag day-1

  6. Demonstration of Al:ZnO as a plasmonic component for near-infrared metamaterials

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Liu, Jingjing; Kildishev, Alexander V.

    2012-01-01

    Noble metals such as gold and silver are conventionally used as the primary plasmonic building blocks of optical metamaterials. Making subwavelength-scale structural elements from these metals not only seriously limits the optical performance of a device due to high absorption, it also substantia....... In this letter, we replace a metal with aluminum-doped zinc oxide as a new plasmonic material and experimentally demonstrate negative refraction in an Al:ZnO/ZnO metamaterial in the near-infrared range....

  7. Near infrared photoluminescence properties of porous silicon prepared under the influence of light illumination

    International Nuclear Information System (INIS)

    Hamadeh, H; Naddaf, M; Jazmati, A

    2008-01-01

    Porous silicon (PS) has been prepared by anodic etching of boron doped silicon under the influence of monochromatic light illumination. The optical properties of the PS samples have been investigated using temperature dependent photoluminescence (PL) spectroscopy. An overall enhancement of the infrared luminescence yield is caused by the light illumination. In the visible spectral range, changes at the low energy side of the broad PL band were observed. In the near infrared spectral range, a new PL band at 850 nm, which is strongly correlated with light illumination, was detected. The new PL band disappears once blue light is used, whereas an increase in its intensity is observed, when the etching is performed under the illumination of light with wavelengths close to the band gap. By increasing the temperature, the 850 nm transition band grows at the expense of the main near infrared transition at 1100 nm. The recombination characteristics of this PL band are indicative of its extrinsic nature. The macroscopic morphology shows strong dependence on the wavelength of the illumination light. Photoassisted preparation could provide a tool for the control of the optical and structural properties of PS.

  8. Near infrared photoluminescence properties of porous silicon prepared under the influence of light illumination

    Energy Technology Data Exchange (ETDEWEB)

    Hamadeh, H; Naddaf, M; Jazmati, A [Department of Physics, Atomic Energy Commission of Syria, PO Box 6091, Damascus (Syrian Arab Republic)], E-mail: Scientific8@aec.org.sy

    2008-12-21

    Porous silicon (PS) has been prepared by anodic etching of boron doped silicon under the influence of monochromatic light illumination. The optical properties of the PS samples have been investigated using temperature dependent photoluminescence (PL) spectroscopy. An overall enhancement of the infrared luminescence yield is caused by the light illumination. In the visible spectral range, changes at the low energy side of the broad PL band were observed. In the near infrared spectral range, a new PL band at 850 nm, which is strongly correlated with light illumination, was detected. The new PL band disappears once blue light is used, whereas an increase in its intensity is observed, when the etching is performed under the illumination of light with wavelengths close to the band gap. By increasing the temperature, the 850 nm transition band grows at the expense of the main near infrared transition at 1100 nm. The recombination characteristics of this PL band are indicative of its extrinsic nature. The macroscopic morphology shows strong dependence on the wavelength of the illumination light. Photoassisted preparation could provide a tool for the control of the optical and structural properties of PS.

  9. Near infrared photoluminescence properties of porous silicon prepared under the influence of light illumination

    International Nuclear Information System (INIS)

    Hamadeh, H.; Naddaf, M.; Jazmati, A.

    2009-01-01

    Porous silicon (PS) has been prepared by anodic etching of boron doped silicon under the influence of monochromatic light illumination. The optical properties of the PS samples have been investigated using temperature dependent photoluminescence (PL) spectroscopy. An overall enhancement of the infrared luminescence yield is caused by the light illumination. In the visible spectral range, changes at the low energy side of the broad PL band were observed. In the near infrared spectral range, a new PL band at 850 nm, which is strongly correlated with light illumination, was detected. The new PL band disappears once blue light is used, whereas an increase of its intensity is observed, when the etching is performed under the illumination of light with wavelengths close to the band gap. By increasing the temperature, the 850 nm transition band grows at the expense of the main near infrared transition at 1100 nm. The recombination characteristics of this PL band are indicative of its extrinsic nature. The macroscopic morphology shows strong dependence on the wavelength of the illumination light. Photoassisted preparation could provide a tool for the control of the optical and structural properties of PS. (author)

  10. Near infrared photoluminescence properties of porous silicon prepared under the influence of light illumination

    Science.gov (United States)

    Hamadeh, H.; Naddaf, M.; Jazmati, A.

    2008-12-01

    Porous silicon (PS) has been prepared by anodic etching of boron doped silicon under the influence of monochromatic light illumination. The optical properties of the PS samples have been investigated using temperature dependent photoluminescence (PL) spectroscopy. An overall enhancement of the infrared luminescence yield is caused by the light illumination. In the visible spectral range, changes at the low energy side of the broad PL band were observed. In the near infrared spectral range, a new PL band at 850 nm, which is strongly correlated with light illumination, was detected. The new PL band disappears once blue light is used, whereas an increase in its intensity is observed, when the etching is performed under the illumination of light with wavelengths close to the band gap. By increasing the temperature, the 850 nm transition band grows at the expense of the main near infrared transition at 1100 nm. The recombination characteristics of this PL band are indicative of its extrinsic nature. The macroscopic morphology shows strong dependence on the wavelength of the illumination light. Photoassisted preparation could provide a tool for the control of the optical and structural properties of PS.

  11. Quantum efficiencies of near-infrared emission from Ni2+-doped glass-ceramics

    International Nuclear Information System (INIS)

    Suzuki, Takenobu; Arai, Yusuke; Ohishi, Yasutake

    2008-01-01

    A systematic method to evaluate potentials of Ni 2+ -doped transparent glass-ceramics as a new broadband optical gain media is presented. At first, near-infrared emission of various ceramics were investigated to explore the suitable crystalline phase to be grown in the glass-ceramics. The quantum efficiency of Ni 2+ near-infrared emission estimated by the Struck-Fonger analysis was higher than 95% for spinel-type structure gallate crystals MgGa 2 O 4 and LiGa 5 O 8 at room temperature. Transparent glass-ceramics containing Ni 2+ :LiGa 5 O 8 could be prepared and the quantum efficiency for the glass-ceramics was measured to be about 10%. This value shows a potential of Ni-doped transparent glass-ceramics as a broadband gain media

  12. Towards the mid-infrared optical biopsy

    DEFF Research Database (Denmark)

    Seddon, Angela B.; Benson, Trevor M.; Sujecki, Slawomir

    2016-01-01

    We are establishing a new paradigm in mid-infrared molecular sensing, mapping and imaging to open up the mid-infrared spectral region for in vivo (i.e. in person) medical diagnostics and surgery. Thus, we are working towards the mid-infrared optical biopsy ('opsy' look at, bio the biology) in situ...... in the body for real-time diagnosis. This new paradigm will be enabled through focused development of devices and systems which are robust, functionally designed, safe, compact and cost effective and are based on active and passive mid-infrared optical fibers. In particular, this will enable early diagnosis...... of a bright mid-infrared wideband source in a portable package as a first step for medical fiber-based systems operating in the mid-infrared. Moreover, mid-infrared molecular mapping and imaging is potentially a disruptive technology to give improved monitoring of the environment, energy efficiency, security...

  13. Near-infrared emitting fluorescent nanocrystals-labeled natural killer cells as a platform technology for the optical imaging of immunotherapeutic cells-based cancer therapy

    International Nuclear Information System (INIS)

    Lim, Yong Taik; Cho, Mi Young; Noh, Young-Woock; Chung, Bong Hyun; Chung, Jin Woong

    2009-01-01

    This study describes the development of near-infrared optical imaging technology for the monitoring of immunotherapeutic cell-based cancer therapy using natural killer (NK) cells labeled with fluorescent nanocrystals. Although NK cell-based immunotherapeutic strategies have drawn interest as potent preclinical or clinical methods of cancer therapy, there are few reports documenting the molecular imaging of NK cell-based cancer therapy, primarily due to the difficulty of labeling of NK cells with imaging probes. Human natural killer cells (NK92MI) were labeled with anti-human CD56 antibody-coated quantum dots (QD705) for fluorescence imaging. FACS analysis showed that the NK92MI cells labeled with anti-human CD56 antibody-coated QD705 have no effect on the cell viability. The effect of anti-human CD56 antibody-coated QD705 labeling on the NK92MI cell function was investigated by measuring interferon gamma (IFN- γ) production and cytolytic activity. Finally, the NK92MI cells labeled with anti-human CD56 antibody-coated QD705 showed a therapeutic effect similar to that of unlabeled NK92MI cells. Images of intratumorally injected NK92MI cells labeled with anti-human CD56 antibody-coated could be acquired using near-infrared optical imaging both in vivo and in vitro. This result demonstrates that the immunotherapeutic cells labeled with fluorescent nanocrystals can be a versatile platform for the effective tracking of injected therapeutic cells using optical imaging technology, which is very important in cell-based cancer therapies.

  14. Infrared and optical polarimetry of the radio elliptical IC 5063 (PKS2048-57): discovery of a highly polarized non-thermal nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Hough, J H; Brindle, C; Axon, D J; Bailey, J; Sparks, W B

    1987-02-15

    Two-aperture optical and near-infrared polarization and flux measurements of the radio elliptical galaxy IC 5063 are presented. Analysis of the polarized flux shows that the large infrared excess in the nucleus most likely arises from a steep-spectrum non-thermal source with a polarization of 17 per cent and near-infrared luminosity 6x10/sup 41/ erg s/sup -1/. This result suggests that IC5063 is closely related to the more luminous blazars. The origin of the polarization in the optical is, however, not clear.

  15. Infrared and optical polarimetry of the radio elliptical IC 5063 (PKS2048-57): discovery of a highly polarized non-thermal nucleus

    International Nuclear Information System (INIS)

    Hough, J.H.; Brindle, C.; Axon, D.J.; Bailey, J.; Sparks, W.B.

    1987-01-01

    Two-aperture optical and near-infrared polarization and flux measurements of the radio elliptical galaxy IC 5063 are presented. Analysis of the polarized flux shows that the large infrared excess in the nucleus most likely arises from a steep-spectrum non-thermal source with a polarization of 17 per cent and near-infrared luminosity 6x10 41 erg s -1 . This result suggests that IC5063 is closely related to the more luminous blazars. The origin of the polarization in the optical is, however, not clear. (author)

  16. Discrimination of mineral waters using near infrared spectroscopy and aquaphotomics

    Directory of Open Access Journals (Sweden)

    Munćan Jelena S.

    2014-01-01

    Full Text Available Despite that water is one of the most studied materials today its dynamic properties are still not well understood. Water state in human organism is of high importance for normal healthy functioning of human body. Different kinds of water are usually classified according to its present solutes, and concentrations of these solutes, but though it is known that water molecules can form clusters around present solutes, classification of waters based on types of water molecular organization and present clusters is not present in current literature. In this study we used multivariate analysis for classification of commercial mineral waters based on their near infrared spectra (NIR. Further, we applied Aquaphotomics, a new approach for interpretation of near infrared spectra of water, which gives insight into organization of water molecules in each of these waters.

  17. NEAR-INFRARED SPECTROSCOPY OF POST-AGB STARS

    NARCIS (Netherlands)

    OUDMAIJER, RD; WATERS, LBFM; VANDERVEEN, WECJ; GEBALLE, TR

    The results of a medium resolution near-infrared spectral survey of 18 post-AGB candidate stars are presented. Most of the stars have near-infrared hydrogen lines in absorption, which is normal for their spectral types. Three stars, HD 101584, HD 179821 and HD 170756 have the CO first overtone bands

  18. Development of a near-infrared spectroscopy instrument for applications in urology.

    Science.gov (United States)

    Macnab, Andrew J; Stothers, Lynn

    2008-10-01

    Near infrared spectroscopy (NIRS) is an established technology using photons of light in the near infrared spectrum to monitor changes in tissue of naturally occurring chromophores, including oxygenated and deoxygenated hemoglobin. Technology and methodology have been validated for measurement of a range of physiologic parameters. NIRS has been applied successfully in urology research; however current instruments are designed principally for brain and muscle study. To describe development of a NIRS instrument specifically designed for monitoring changes in chromophore concentration in the bladder detrusor in real time, to facilitate research to establish the role of this non-invasive technology in the evaluation of patients with voiding dysfunction The portable continuous wave NIRS instrument has a 3 laser diode light source (785, 808 and 830 nanometers), fiber optic cables for light transmission, a self adhesive patient interface patch with an emitter and sensor, and software to detect the difference between the light transmitted and received by the instrument. Software incorporated auto-attenuates the optical signals and converts raw optical data into chromophore concentrations displayed graphically. The prototype was designed, tested, and iteratively developed to achieve optimal suprapubic transcutaneous monitoring of the detrusor in human subjects during bladder filling and emptying. Evaluation with simultaneous invasive urodynamic measurement in men and women indicates good specificity and sensitivity of NIRS chromophore concentration changes by receiver operator curve analysis, and correlation between NIRS data and urodynamic pressures. Urological monitoring with this NIRS instrument is feasible and generates data of potential diagnostic value.

  19. OPTICAL/NEAR-INFRARED SELECTION OF RED QUASI-STELLAR OBJECTS: EVIDENCE FOR STEEP EXTINCTION CURVES TOWARD GALACTIC CENTERS?

    Energy Technology Data Exchange (ETDEWEB)

    Fynbo, J. P. U.; Krogager, J.-K.; Vestergaard, M.; Geier, S. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Venemans, B. [Max-Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Noterdaeme, P. [CNRS-UPMC, UMR7095, Institut d' Astrophysique de Paris, 98bis Bd. Arago, F-75014 Paris (France); Moller, P. [European Southern Observatory, Karl-Schwarzschildstrasse 2, D-85748 Garching bei Muenchen (Germany); Ledoux, C. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile)

    2013-01-15

    We present the results of a search for red QSOs using a selection based on optical imaging from the Sloan Digital Sky Survey (SDSS) and near-infrared imaging from UKIDSS. Our main goal with the selection is to search for QSOs reddened by foreground dusty absorber galaxies. For a sample of 58 candidates (including 20 objects fulfilling our selection criteria that already have spectra in the SDSS), 46 (79%) are confirmed to be QSOs. The QSOs are predominantly dust-reddened except for a handful at redshifts z {approx}> 3.5. However, the dust is most likely located in the QSO host galaxies (and for two, the reddening is primarily caused by Galactic dust) rather than in the intervening absorbers. More than half of the QSOs show evidence of associated absorption (BAL absorption). Four (7%) of the candidates turned out to be late-type stars, and another four (7%) are compact galaxies. We could not identify the remaining four objects. In terms of their optical spectra, these QSOs are similar to the QSOs selected in the FIRST-2MASS Red Quasar Survey except they are on average fainter, more distant, and only two are detected in the FIRST survey. As per the usual procedure, we estimate the amount of extinction using the SDSS QSO template reddened by Small-Magellanic-Cloud-(SMC) like dust. It is possible to get a good match to the observed (rest-frame ultraviolet) spectra, but it is not possible to match the observed near-IR photometry from UKIDSS for nearly all the reddened QSOs. The most likely reasons are that the SDSS QSO template is too red at optical wavelengths due to contaminating host galaxy light and because the assumed SMC extinction curve is too shallow. Three of the compact galaxies display old stellar populations with ages of several Gyr and masses of about 10{sup 10} M{sub Sun} (based on spectral energy distribution modeling). The inferred stellar densities in these galaxies exceed 10{sup 10} M{sub Sun} kpc{sup -2}, which is among the highest measured for early

  20. Signal-to-Noise Contribution of Principal Component Loads in Reconstructed Near-Infrared Raman Tissue Spectra

    NARCIS (Netherlands)

    Grimbergen, M. C. M.; van Swol, C. F. P.; Kendall, C.; Verdaasdonk, R. M.; Stone, N.; Bosch, J. L. H. R.

    The overall quality of Raman spectra in the near-infrared region, where biological samples are often studied, has benefited from various improvements to optical instrumentation over the past decade. However, obtaining ample spectral quality for analysis is still challenging due to device

  1. Facile synthesis of CuSe nanoparticles and high-quality single-crystal two-dimensional hexagonal nanoplatelets with tunable near-infrared optical absorption

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yimin [State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Korolkov, Ilia [Laboratory of Glasses and Ceramics, Institute of Chemistry, CNRS-Université de Rennes I, Campus de Beaulieu, 35042 Rennes Cedex (France); Qiao, Xvsheng [State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, Xianghua [Laboratory of Glasses and Ceramics, Institute of Chemistry, CNRS-Université de Rennes I, Campus de Beaulieu, 35042 Rennes Cedex (France); Wan, Jun; Fan, Xianping [State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2016-06-15

    A rapid injection approach is used to synthesize the copper selenide nanoparticles and two-dimensional single crystal nanoplates. This technique excludes the use of toxic or expensive materials, increasing the availability of two-dimensional binary chalcogenide semiconductors. The structure of the nanocrystals has been studied and the possible formation mechanism of the nanoplates has been proposed. The optical absorption showed that the nanoplates demonstrated wide and tuneable absorption band in the visible and near infrared region. These nanoplates could be interesting for converting solar energy and for nanophotonic devices operating in the near infrared. - Graphical abstract: TEM images of the copper selenides nanoparticles and nanoplates synthesized at 180 °C for 0 min, 10 min, 60 min. And the growth mechanism of the copper selenide nanoplates via the “oriented attachment”. Display Omitted - Highlights: • CuSe nanoparticles and nanoplates are synthesized by a rapid injection approach. • CuSe band gap can be widely tuned simply by modifying the synthesized time. • Al{sup 3+} ions have a significant impact on the growth rate of the nanoplates. • Growth mechanism of the CuSe nanoplates is based on the “oriented attachment”.

  2. Quantitative near-infrared spectroscopy on patients with peripheral vascular disease

    OpenAIRE

    Franceschini, MA; Fantini, S; Palumbo, R; Pasqualini, L; Vaudo, G; Franceschini, E; Gratton, E; Palumbo, B; Innocente, S; Mannarino, E

    1997-01-01

    We have used near-infrared spectroscopy to measure the hemoglobin saturation at rest and during exercise on patients affected by peripheral vascular disease (PVD). The instrument used in our study is a frequency-domain tissue oximeter which employs intensity modulated (110 MHz) laser diodes. We examined 9 subjects, 3 of which were controls and 6 were patients affected by stage II PVD. The optical probe was located on the calf muscle of the subjects. The measurement protocol consisted of: (1) ...

  3. Near-Infrared Intraoperative Chemiluminescence Imaging

    KAUST Repository

    Bü chel, Gabriel E.; Carney, Brandon; Shaffer, Travis M.; Tang, Jun; Austin, Christine; Arora, Manish; Zeglis, Brian M.; Grimm, Jan; Eppinger, Jö rg; Reiner, Thomas

    2016-01-01

    Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce4+ in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9pmolcm-2 of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the invivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Near-Infrared Intraoperative Chemiluminescence Imaging

    KAUST Repository

    Büchel, Gabriel E.

    2016-08-03

    Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce4+ in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9pmolcm-2 of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the invivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Non-linear optical studies of adsorbates: Spectroscopy and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiangdong.

    1989-08-01

    In the first part of this thesis, we have established a systematic procedure to apply the surface optical second-harmonic generation (SHG) technique to study surface dynamics of adsorbates. In particular, we have developed a novel technique for studies of molecular surface diffusions. In this technique, the laser-induced desorption with two interfering laser beams is used to produce a monolayer grating of adsorbates. The monolayer grating is detected with diffractions of optical SHG. By monitoring the first-order second-harmonic diffraction, we can follow the time evolution of the grating modulation from which we are able to deduce the diffusion constant of the adsorbates on the surface. We have successfully applied this technique to investigate the surface diffusion of CO on Ni(111). The unique advantages of this novel technique will enable us to readily study anisotropy of a surface diffusion with variable grating orientation, and to investigate diffusion processes of a large dynamic range with variable grating spacings. In the second part of this work, we demonstrate that optical infrared-visible sum-frequency generation (SFG) from surfaces can be used as a viable surface vibrational spectroscopic technique. We have successfully recorded the first vibrational spectrum of a monolayer of adsorbates using optical infrared-visible SFG. The qualitative and quantitative correlation of optical SFG with infrared absorption and Raman scattering spectroscopies are examined and experimentally demonstrated. We have further investigated the possibility to use transient infrared-visible SFG to probe vibrational transients and ultrafast relaxations on surfaces. 146 refs.

  6. Non-linear optical studies of adsorbates: Spectroscopy and dynamics

    International Nuclear Information System (INIS)

    Zhu, Xiangdong.

    1989-08-01

    In the first part of this thesis, we have established a systematic procedure to apply the surface optical second-harmonic generation (SHG) technique to study surface dynamics of adsorbates. In particular, we have developed a novel technique for studies of molecular surface diffusions. In this technique, the laser-induced desorption with two interfering laser beams is used to produce a monolayer grating of adsorbates. The monolayer grating is detected with diffractions of optical SHG. By monitoring the first-order second-harmonic diffraction, we can follow the time evolution of the grating modulation from which we are able to deduce the diffusion constant of the adsorbates on the surface. We have successfully applied this technique to investigate the surface diffusion of CO on Ni(111). The unique advantages of this novel technique will enable us to readily study anisotropy of a surface diffusion with variable grating orientation, and to investigate diffusion processes of a large dynamic range with variable grating spacings. In the second part of this work, we demonstrate that optical infrared-visible sum-frequency generation (SFG) from surfaces can be used as a viable surface vibrational spectroscopic technique. We have successfully recorded the first vibrational spectrum of a monolayer of adsorbates using optical infrared-visible SFG. The qualitative and quantitative correlation of optical SFG with infrared absorption and Raman scattering spectroscopies are examined and experimentally demonstrated. We have further investigated the possibility to use transient infrared-visible SFG to probe vibrational transients and ultrafast relaxations on surfaces. 146 refs

  7. A Method for Quantification of Penetration of Nanoparticles through Skin Layers Using Near-Infrared Optical Imaging

    Directory of Open Access Journals (Sweden)

    Melinda Stees

    2015-07-01

    Full Text Available Our study presents a new method for tracking nanoparticle penetration through different layers of the skin using near-infrared dye-loaded nanoparticles (hydrodynamic diameter = 156 nm and optical imaging. The dye-loaded nanoparticles were mixed in a topical skin cream, applied to human cadaver skin and incubated either for three or 24 h post-application, skin tissue was clipped between glass slides prior to imaging for signal intensity across the skin thickness using an optical imaging system. The data show that nanoparticles penetrate through all the layers of the skin but there is almost an exponential decay in the signal intensity from epidermis to dermis. Depending upon the incubation time, about 55%–59% of the total signal was seen in the epidermis and the remaining through dermis and hypodermis. The advantage of the method is that it allows quantitative analysis of the extent of penetration of nanoparticles through different layers of the skin without interference of any background signal from skin tissue, and without requiring extensive tissue processing. Our method could potentially be used to study the effect of nanoparticle properties and/or the use of different formulation additives on penetration of nanoparticles through different skin layers.

  8. Infrared Spectra and Optical Constants of Astronomical Ices: II. Ethane and Ethylene

    Science.gov (United States)

    Hudson, Reggie L.; Gerakines, Perry A.; Moore, M. H.

    2014-01-01

    Infrared spectroscopic observations have established the presence of hydrocarbon ices on Pluto and other TNOs, but the abundances of such molecules cannot be deduced without accurate optical constants (n, k) and reference spectra. In this paper we present our recent measurements of near- and mid-infrared optical constants for ethane (C2H6) and ethylene (C2H4) in multiple ice phases and at multiple temperatures. As in our recent work on acetylene (C2H2), we also report new measurements of the index of refraction of each ice at 670 nm. Comparisons are made to earlier work where possible, and electronic versions of our new results are made available.

  9. Laser-induced filaments in the mid-infrared

    International Nuclear Information System (INIS)

    Zheltikov, A M

    2017-01-01

    Laser-induced filamentation in the mid-infrared gives rise to unique regimes of nonlinear wave dynamics and reveals in many ways unusual nonlinear-optical properties of materials in this frequency range. The λ 2 scaling of the self-focusing threshold P cr , with radiation wavelength λ , allows the laser powers transmitted by single mid-IR filaments to be drastically increased without the loss of beam continuity and spatial coherence. When extended to the mid-infrared, laser filamentation enables new methods of pulse compression. Often working around the universal physical limitations, it helps generate few-cycle and subcycle field waveforms within an extraordinarily broad range of peak powers, from just a few up to hundreds of P cr . As a part of a bigger picture, laser-induced filamentation in the mid-infrared offers important physical insights into the general properties of the nonlinear-optical response of matter as a function of the wavelength. Unlike their near-infrared counterparts, which can be accurately described within the framework of perturbative nonlinear optics, mid-infrared filaments often entangle perturbative and nonperturbative nonlinear-optical effects, showing clear signatures of strong-field optical physics. With the role of nonperturbative nonlinear-optical phenomena growing, as a general tendency, with the field intensity and the driver wavelength, extension of laser filamentation to even longer driver wavelengths, toward the long-wavelength infrared, promises a hic sunt dracones land. (topical review)

  10. Synchronous photoelectrical observations of flare stars in the visible and near infrared ranges

    International Nuclear Information System (INIS)

    Bruevich, V.V.; Kilyachkov, N.N.; Shevchenko, V.S.; Burnashov, V.I.; Grinin, V.P.; Koryshev, V.V.; Shakhovskaya, N.I.

    1980-01-01

    The results of synchronous photoelectrical observations of the AD Leo and EV Lac flare stars made in 1975 in the Crimea in B-filter and in the near infrared region (i-band, lambdasub(ef) approximately 0.85 μm) and the observations of the UV Cet and EV Lac stars made in 1976 in the Astronomical Institute Uzbek SSR in three passbands: U, isub(TiO)(lambdasub(ef)=0.71 μ) and isub(C)(lambdasub(ef)=0.80μm) are given. Practically all strong flares in the visible spectral range were followed by the IR-flares. In about 70% of the cases the predicted infrared negative preflares were observed. The amplitudes (in erg/s) of the negative flares are comparable with the amplitude of the optical flares. The analysis of the observed data shows that: a) the amplitudes and the energies of the positive IR flares are in average the larger the stronger is the optical flare; b) the amplitudes of the negative IR preflares are on the contrary the smaller the stronger is the optical flare; c) there are infrared flares the main energy out of which takes place in the infrared range of wavelengths; d) The U-i color shows a positive correlation with the amplitude of the flare in U: the stronger is the flare the bluer is its radiation

  11. EDITORIAL: Optical mammography: Imaging and characterization of breast lesions by pulsed near-infrared laser light (OPTIMAMM)

    Science.gov (United States)

    Hebden, Jeremy C.; Rinneberg, Herbert

    2005-06-01

    The Commission of the European Union (EU) conceived its Fifth Framework Programme (FP5) to identify the priorities for the European Union's research, technological development and demonstration activities for the period 1998-2002. By encouraging collaborative research between groups in different member countries, FP5 was intended to help solve problems the EU is facing and respond to major socio-economic challenges. The programme focused on a number of objectives and areas combining technological, industrial, economic, social and cultural aspects. A specific call was made, under its `Quality of Life and Management of Living Resources' section, for proposals which aim to explore improvements in non-invasive methods of imaging for early diagnosis and clinical evaluation of disease. Among the projects successfully funded under the FP5 programme was one entitled `Optical mammography: Imaging and characterization of breast lesions by pulsed near-infrared laser light', known by its acronym OPTIMAMM. The project involved a consortium of nine partners, comprising ten applied science and clinical research groups based in six EU countries, with overall administration and management provided by the Physikalisch-Technische Bundesanstalt, Berlin, Germany. The broad aim of the OPTIMAMM project was to combine multi-disciplinary basic (physics, engineering, mathematics, computer science) and clinical (oncology, histology) research to assess the diagnostic potential of time-domain optical and photoacoustic mammography as novel, non-invasive imaging modalities for the detection and clinical evaluation of breast lesions. Funding for the project, at a total cost of about 1.67 MEuro, began in December 2000 for a period of three years, although a zero-cost extension was granted to enable the ongoing project activities to continue until the end of May 2004. The importance of developing new tools for the detection and diagnosis of breast disease is evident from the very high incidence and

  12. A Retina-Like Dual Band Organic Photosensor Array for Filter-Free Near-Infrared-to-Memory Operations.

    Science.gov (United States)

    Wang, Hanlin; Liu, Hongtao; Zhao, Qiang; Ni, Zhenjie; Zou, Ye; Yang, Jie; Wang, Lifeng; Sun, Yanqiu; Guo, Yunlong; Hu, Wenping; Liu, Yunqi

    2017-08-01

    Human eyes use retina photoreceptor cells to absorb and distinguish photons from different wavelengths to construct an image. Mimicry of such a process and extension of its spectral response into the near-infrared (NIR) is indispensable for night surveillance, retinal prosthetics, and medical imaging applications. Currently, NIR organic photosensors demand optical filters to reduce visible interference, thus making filter-free and anti-visible NIR imaging a challenging task. To solve this limitation, a filter-free and conformal, retina-inspired NIR organic photosensor is presented. Featuring an integration of photosensing and floating-gate memory modules, the device possesses an acute color distinguishing capability. In general, the retina-like photosensor transduces NIR (850 nm) into nonvolatile memory and acts as a dynamic photoswitch under green light (550 nm). In doing this, a filter-free but color-distinguishing photosensor is demonstrated that selectively converts NIR optical signals into nonvolatile memory. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Monitoring of itaconic acid hydrogenation in a trickle bed reactor using fiber-optic coupled near-infrared spectroscopy.

    Science.gov (United States)

    Wood, Joseph; Turner, Paul H

    2003-03-01

    Near-infrared (NIR) spectroscopy has been applied to determine the conversion of itaconic acid in the effluent stream of a trickle bed reactor. Hydrogenation of itaconic to methyl succinic acid was carried out, with the trickle bed operating in recycle mode. For the first time, NIR spectra of itaconic and methyl succinic acids in aqueous solution, and aqueous mixtures withdrawn from the reactor over a range of reaction times, have been recorded using a fiberoptic sampling probe. The infrared spectra displayed a clear isolated absorption band at a wavenumber of 6186 cm(-1) (wavelength 1.617 microm) resulting from the =C-H bonds of itaconic acid, which was found to decrease in intensity with increasing reaction time. The feature could be more clearly observed from plots of the first derivatives of the spectra. A partial least-squares (PLS) model was developed from the spectra of 13 reference samples and was used successfully to calculate the concentration of the two acids in the reactor effluent solution. Itaconic acid conversions of 23-29% were calculated after 360 min of reaction time. The potential of FT-NIR with fiber-optic sampling for remote monitoring of three-phase catalytic reactors and validation of catalytic reactor models is highlighted in the paper.

  14. In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract

    Science.gov (United States)

    Piyawattanametha, Wibool; Ra, Hyejun; Qiu, Zhen; Friedland, Shai; Liu, Jonathan T. C.; Loewke, Kevin; Kino, Gordon S.; Solgaard, Olav; Wang, Thomas D.; Mandella, Michael J.; Contag, Christopher H.

    2012-02-01

    Near-infrared confocal microendoscopy is a promising technique for deep in vivo imaging of tissues and can generate high-resolution cross-sectional images at the micron-scale. We demonstrate the use of a dual-axis confocal (DAC) near-infrared fluorescence microendoscope with a 5.5-mm outer diameter for obtaining clinical images of human colorectal mucosa. High-speed two-dimensional en face scanning was achieved through a microelectromechanical systems (MEMS) scanner while a micromotor was used for adjusting the axial focus. In vivo images of human patients are collected at 5 frames/sec with a field of view of 362×212 μm2 and a maximum imaging depth of 140 μm. During routine endoscopy, indocyanine green (ICG) was topically applied a nonspecific optical contrasting agent to regions of the human colon. The DAC microendoscope was then used to obtain microanatomic images of the mucosa by detecting near-infrared fluorescence from ICG. These results suggest that DAC microendoscopy may have utility for visualizing the anatomical and, perhaps, functional changes associated with colorectal pathology for the early detection of colorectal cancer.

  15. High-power, continuous-wave, single-frequency, all-periodically-poled, near-infrared source.

    Science.gov (United States)

    Devi, Kavita; Chaitanya Kumar, S; Ebrahim-Zadeh, M

    2012-12-15

    We report a high-power, single-frequency, continuous-wave (cw) source tunable across 775-807 nm in the near-infrared, based on internal second harmonic generation (SHG) of a cw singly-resonant optical parametric oscillator (OPO) pumped by a Yb-fiber laser. The compact, all-periodically-poled source employs a 48-mm-long, multigrating MgO doped periodically poled lithium niobate (MgO:PPLN) crystal for the OPO and a 30-mm-long, fan-out grating MgO-doped stoichiometric periodically poled lithium tantalate (MgO:sPPLT) crystal for intracavity SHG, providing as much as 3.7 W of near-infrared power at 793 nm, together with 4 W of idler power at 3232 nm, at an overall extraction efficiency of 28%. Further, the cw OPO is tunable across 3125-3396 nm in the idler, providing as much as 4.3 W at 3133 nm with >3.8  W over 77% of the tuning range together with >3  W of near-infrared power across 56% of SHG tuning range, in high-spatial beam-quality with M2<1.4. The SHG output has an instantaneous linewidth of 8.5 MHz and exhibits a passive power stability better than 3.5% rms over more than 1 min.

  16. Energetic molecular outflow near AFGL 961: millimeter-wave and infrared observations

    International Nuclear Information System (INIS)

    Lada, C.J.; Gautier, T.N. III

    1982-01-01

    We report detailed millimeter-wave and near-infrared spectroscopy of the dynamically active region around the infrared source AFGL 961, near the Rosette nebula. Millimeter-wave 12 CO observations are used to study the high-velocity molecular flow around AFGL 961. These observations show that the high-velocity flow has a maximum extent of at least 6' or 2.9 pc at the distance of AFGL 961. The flow is found to be anisotropic, with redshifted high-velocity emission considerably more extended than blueshifted high-velocity emission. However, the flow does not appear to be as highly collimated as some other sources of high-velocity bipolar outflow. We also find the emission profiles to be asymmetric in velocity such that the integrated intensity of the redshifted high-velocity emission is on average 2.5 times greater than that of the blueshifted emission. The mass of the gas involved in the flow is determined to be approximately 19 M/sub sun/, and the kinetic energy of this gas is estimated to be about 8 x 10 46 ergs. These observations are interpreted as evidence that an energetic bipolar outflow of molecular gas is occurring near AFGL 961. The momentum of the outflowing molecular gas is large, and it is shown that this places strong constraints on possible physical mechanisms which may be driving the outflow. The near-infrared spectrum of AFGL 961 from 1.4-2.4 μm was obtained in order to study the conditions immediately around the infrared source which may be driving the molecular outflow

  17. Feasibility of the optical imaging of thrombus formation in a rotary blood pump by near-infrared light.

    Science.gov (United States)

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu

    2014-09-01

    Blood coagulation is one of the primary concerns when using mechanical circulatory support devices such as blood pumps. Noninvasive detection and imaging of thrombus formation is useful not only for the development of more hemocompatible devices but also for the management of blood coagulation to avoid risk of infarction. The objective of this study is to investigate the use of near-infrared light for imaging of thrombus formation in a rotary blood pump. The optical properties of a thrombus at wavelengths ranging from 600 to 750 nm were analyzed using a hyperspectral imaging (HSI) system. A specially designed hydrodynamically levitated centrifugal blood pump with a visible bottom area was used. In vitro antithrombogenic testing was conducted five times with the pump using bovine whole blood in which the activated blood clotting time was adjusted to 200 s prior to the experiment. Two halogen lights were used for the light sources. The forward scattering through the pump and backward scattering on the pump bottom area were imaged using the HSI system. HSI showed an increase in forward scattering at wavelengths ranging from 670 to 750 nm in the location of thrombus formation. The time at which the thrombus began to form in the impeller rotating at 2780 rpm could be detected. The spectral difference between the whole blood and the thrombus was utilized to image thrombus formation. The results indicate the feasibility of dynamically detecting and imaging thrombus formation in a rotary blood pump. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  18. Near-infrared transillumination photography of intraocular tumours.

    Science.gov (United States)

    Krohn, Jørgen; Ulltang, Erlend; Kjersem, Bård

    2013-10-01

    To present a technique for near-infrared transillumination imaging of intraocular tumours based on the modifications of a conventional digital slit lamp camera system. The Haag-Streit Photo-Slit Lamp BX 900 (Haag-Streit AG) was used for transillumination photography by gently pressing the tip of the background illumination cable against the surface of the patient's eye. Thus the light from the flash unit was transmitted into the eye, leading to improved illumination and image resolution. The modification for near-infrared photography was done by replacing the original camera with a Canon EOS 30D (Canon Inc) converted by Advanced Camera Services Ltd. In this camera, the infrared blocking filter was exchanged for a 720 nm long-pass filter, so that the near-infrared part of the spectrum was recorded by the sensor. The technique was applied in eight patients: three with anterior choroidal melanoma, three with ciliary body melanoma and two with ocular pigment alterations. The good diagnostic quality of the photographs made it possible to evaluate the exact location and extent of the lesions in relation to pigmented intraocular landmarks such as the ora serrata and ciliary body. The photographic procedure did not lead to any complications. We recommend near-infrared transillumination photography as a supplementary diagnostic tool for the evaluation and documentation of anteriorly located intraocular tumours.

  19. Systems engineering and analysis of electro-optical and infrared systems

    CERN Document Server

    Arrasmith, William Wolfgang

    2015-01-01

    Introduction to Electro-optic and Infrared (EO/IR) Systems Engineering?Radiation in the Visible and Infrared Parts of the Electromagnetic SpectrumRadiation SourcesThe Effect of the Atmosphere on Optical PropagationBasic OpticsOptical ModulationThe Detection of Optical RadiationNoise in the Optical Detection ProcessTechnical Performance Measures and Metrics of Optical DetectorsModern Detectors and their Measures of PerformanceThe Effects of Cooling on Optical Detector NoiseSignal and Image ProcessingElectro-Optic and Infrared Systems AnalysisLaser Imaging Systems?Spectral Imaging?LIDAR and LADA

  20. Near field ice detection using infrared based optical imaging technology

    Science.gov (United States)

    Abdel-Moati, Hazem; Morris, Jonathan; Zeng, Yousheng; Corie, Martin Wesley; Yanni, Victor Garas

    2018-02-01

    If not detected and characterized, icebergs can potentially pose a hazard to oil and gas exploration, development and production operations in arctic environments as well as commercial shipping channels. In general, very large bergs are tracked and predicted using models or satellite imagery. Small and medium bergs are detectable using conventional marine radar. As icebergs decay they shed bergy bits and growlers, which are much smaller and more difficult to detect. Their low profile above the water surface, in addition to occasional relatively high seas, makes them invisible to conventional marine radar. Visual inspection is the most common method used to detect bergy bits and growlers, but the effectiveness of visual inspections is reduced by operator fatigue and low light conditions. The potential hazard from bergy bits and growlers is further increased by short detection range (<1 km). As such, there is a need for robust and autonomous near-field detection of such smaller icebergs. This paper presents a review of iceberg detection technology and explores applications for infrared imagers in the field. Preliminary experiments are performed and recommendations are made for future work, including a proposed imager design which would be suited for near field ice detection.

  1. Optical polarimetric and near-infrared photometric study of the RCW95 Galactic H II region

    Science.gov (United States)

    Vargas-González, J.; Roman-Lopes, A.; Santos, F. P.; Franco, G. A. P.; Santos, J. F. C.; Maia, F. F. S.; Sanmartim, D.

    2018-02-01

    We carried out an optical polarimetric study in the direction of the RCW 95 star-forming region in order to probe the sky-projected magnetic field structure by using the distribution of linear polarization segments which seem to be well aligned with the more extended cloud component. A mean polarization angle of θ = 49.8° ± 7.7°7 was derived. Through the spectral dependence analysis of polarization it was possible to obtain the total-to-selective extinction ratio (RV) by fitting the Serkowski function, resulting in a mean value of RV = 2.93 ± 0.47. The foreground polarization component was estimated and is in agreement with previous studies in this direction of the Galaxy. Further, near-infrared (NIR) images from Vista Variables in the Via Láctea (VVV) survey were collected to improve the study of the stellar population associated with the H II region. The Automated Stellar Cluster Analysis algorithm was employed to derive structural parameters for two clusters in the region, and a set of PAdova and TRieste Stellar Evolution Code (PARSEC) isochrones was superimposed on the decontaminated colour-magnitude diagrams to estimate an age of about 3 Myr for both clusters. Finally, from the NIR photometry study combined with spectra obtained with the Ohio State Infrared Imager and Spectrometer mounted at the Southern Astrophysics Research Telescope we derived the spectral classification of the main ionizing sources in the clusters associated with IRAS 15408-5356 and IRAS 15412-5359, both objects classified as O4V stars.

  2. Near-infrared spectroscopic tissue imaging for medical applications

    Science.gov (United States)

    Demos, Stavros [Livermore, CA; Staggs, Michael C [Tracy, CA

    2006-12-12

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  3. Infrared Spectra and Optical Constants of Elusive Amorphous Methane

    Science.gov (United States)

    Gerakines, Perry A.; Hudson, Reggie L.

    2015-01-01

    New and accurate laboratory results are reported for amorphous methane (CH4) ice near 10 K for the study of the interstellar medium (ISM) and the outer Solar System. Near- and mid-infrared (IR) data, including spectra, band strengths, absorption coefficients, and optical constants, are presented for the first time for this seldom-studied amorphous solid. The apparent IR band strength near 1300 cm(exp -1) (7.69 micrometer) for amorphous CH4 is found to be about 33% higher than the value long used by IR astronomers to convert spectral observations of interstellar CH4 into CH4 abundances. Although CH4 is most likely to be found in an amorphous phase in the ISM, a comparison of results from various laboratory groups shows that the earlier CH4 band strength at 1300 cm(exp -1) (7.69 micrometer) was derived from IR spectra of ices that were either partially or entirely crystalline CH4 Applications of the new amorphous-CH4 results are discussed, and all optical constants are made available in electronic form.

  4. Near-infrared oxygen airglow from the Venus nightside

    Science.gov (United States)

    Crisp, D.; Meadows, V. S.; Allen, D. A.; Bezard, B.; Debergh, C.; Maillard, J.-P.

    1992-01-01

    Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen airglow emission from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The airglow is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) airglow. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus.

  5. Spectroscopy and near infrared upconversion of Er{sup 3+}-doped TZNT glasses

    Energy Technology Data Exchange (ETDEWEB)

    Venkata Krishnaiah, K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Marques-Hueso, J. [Institute of Sensors, Signals and Systems & Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Suresh, K.; Venkataiah, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Richards, B.S. [Light Technology Institute (LTI), Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe (Germany); Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Jayasankar, C.K., E-mail: ckjaya@yahoo.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

    2016-01-15

    In this paper we report on the near infrared (NIR) upconversion (UC) and spectroscopic properties of erbium (Er{sup 3+})-doped TeO{sub 2}–ZnO–Nb{sub 2}O{sub 5}–TiO{sub 2} (TZNT) oxide glasses. Judd–Ofelt theory has been applied to investigate the intensity parameters (Ω{sub λ}, λ=2, 4 and 6) which are used to derive radiative properties of the fluorescent levels. The different glasses present high refractive indices, low dispersion and Abbe numbers, as determined by variable angle spectroscopic ellipsometry. Under 980 nm excitation, the NIR emission profile and full width at half maximum have been studied in a broad range of Er{sup 3+} concentrations (0.01–3.0 mol%). On the other side, NIR UC has been obtained by exciting at 1523 nm, showing an increase of the intensity with Er{sup 3+} ion density in the studied range. The decay curves of the {sup 4}I{sub 13/2} level exhibit single exponential nature for all the different concentrations. The lifetime of the {sup 4}I{sub 13/2} level has been found to decrease (3.73–1.20 ms) after an initial increase (3.65–3.73 ms) with increasing of Er{sup 3+} ion concentration. The TZNT samples show broadband UC emission at 1.0 µm, which match with the band gap of silicon. This reveals that the investigated glasses could find application in photonics, for example non-linear optics and photovoltaic’s. - Highlights: • The Er{sup 3+}:TZNT glasses have been synthesized and optically characterized. • Refractive index and Abbe number of the TZNT glasses were measured by Ellipsometry. • Near infrared emission (1400–1600 nm) has been obtained under 980 nm excitation. • Near infrared upconversion at 980 nm has been investigated under 1523 nm excitation.

  6. Near-infrared observations of the far-infrared source V region in NGC 6334

    International Nuclear Information System (INIS)

    Fischer, J.; Joyce, R.R.; Simon, M.; Simon, T.

    1982-01-01

    We have observed a very red near-infrared source at the center of NGC 6334 FIRS V, a far-infrared source suspected of variability by McBreen et al. The near-infrared source has deep ice and silicate absorption bands, and its half-power size at 20 μm is approx.15'' x 10''. Over the past 2 years we have observed no variability in the near-infrared flux. We have also detected an extended source of H 2 line emission in this region. The total luminosity in the H 2 v-1--0 S(1) line, uncorrected for extinction along the line of sight, is 0.3 L/sub sun/. Detection of emission in high-velocity wings of the J = 1--0 12 CO line suggests that the H 2 emission is associated with a supersonic gas flow

  7. Near-Infrared Fluorescent Nanoprobes for Revealing the Role of Dopamine in Drug Addiction.

    Science.gov (United States)

    Feng, Peijian; Chen, Yulei; Zhang, Lei; Qian, Cheng-Gen; Xiao, Xuanzhong; Han, Xu; Shen, Qun-Dong

    2018-02-07

    Brain imaging techniques enable visualizing the activity of central nervous system without invasive neurosurgery. Dopamine is an important neurotransmitter. Its fluctuation in brain leads to a wide range of diseases and disorders, like drug addiction, depression, and Parkinson's disease. We designed near-infrared fluorescence dopamine-responsive nanoprobes (DRNs) for brain activity imaging during drug abuse and addiction process. On the basis of light-induced electron transfer between DRNs and dopamine and molecular wire effect of the DRNs, we can track the dynamical change of the neurotransmitter level in the physiological environment and the releasing of the neurotransmitter in living dopaminergic neurons in response to nicotine stimulation. The functional near-infrared fluorescence imaging can dynamically track the dopamine level in the mice midbrain under normal or drug-activated condition and evaluate the long-term effect of addictive substances to the brain. This strategy has the potential for studying neural activity under physiological condition.

  8. NEAR-INFRARED VARIABILITY IN YOUNG STARS IN CYGNUS OB7

    Energy Technology Data Exchange (ETDEWEB)

    Rice, Thomas S. [Department of Astronomy, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Wolk, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Aspin, Colin [Institute for Astronomy, University of Hawaii at Manoa, 640 N Aohoku Pl, Hilo, HI 96720 (United States)

    2012-08-10

    We present the first results from a 124 night J, H, K near-infrared monitoring campaign of the dark cloud L 1003 in Cygnus OB7, an active star-forming region. Using three seasons of UKIRT observations spanning 1.5 years, we obtained high-quality photometry on 9200 stars down to J = 17 mag, with photometric uncertainty better than 0.04 mag. On the basis of near-infrared excesses from disks, we identify 30 pre-main-sequence stars, including 24 which are newly discovered. We analyze those stars and find that the NIR excesses are significantly variable. All 9200 stars were monitored for photometric variability; among the field star population, {approx}160 exhibited near-infrared variability (1.7% of the sample). Of the 30 young stellar objects (YSOs), 28 of them (93%) are variable at a significant level. Of the 30 YSOs, twenty-five have near-infrared excess consistent with simple disk-plus-star classical T Tauri models. Nine of these (36%) drift in color space over the course of these observations and/or since Two Micron All Sky Survey observations such that they cross the boundary defining the NIR excess criteria; effectively, they have a transient near-infrared excess. Thus, time-series JHK observations can be used to obtain a more complete sample of disk-bearing stars than single-epoch JHK observations. About half of the YSOs have color-space variations parallel to either the classical T Tauri star locus or a hybrid track which includes the dust reddening trajectory. This indicates that the NIR variability in YSOs that possess accretion disks arises from a combination of variable extinction and changes in the inner accretion disk: either in accretion rate, central hole size, and/or the inclination of the inner disk. While some variability may be due to stellar rotation, the level of variability on the individual stars can exceed a magnitude. This is a strong empirical suggestion that protoplanetary disks are quite dynamic and exhibit more complex activity on short

  9. Near-infrared water vapour self-continuum at close to room temperature

    International Nuclear Information System (INIS)

    Ptashnik, I.V.; Petrova, T.M.; Ponomarev, Yu.N.; Shine, K.P.; Solodov, A.A.; Solodov, A.M.

    2013-01-01

    The gaseous absorption of solar radiation within near-infrared atmospheric windows in the Earth's atmosphere is dominated by the water vapour continuum. Recent measurements by Baranov et al. (2011) [17] in 2500 cm −1 (4 μm) window and by Ptashnik et al. (2011) [18] in a few near-infrared windows revealed that the self-continuum absorption is typically an order of magnitude stronger than given by the MT C KD continuum model prior to version 2.5. Most of these measurements, however, were made at elevated temperatures, which makes their application to atmospheric conditions difficult. Here we report new laboratory measurements of the self-continuum absorption at 289 and 318 K in the near-infrared spectral region 1300–8000 cm −1 , using a multipass 30 m base cell with total optical path 612 m. Our results confirm the main conclusions of the previous measurements both within bands and in windows. Of particular note is that we present what we believe to be the first near-room temperature measurement using Fourier Transform Spectrometry of the self-continuum in the 6200 cm −1 (1.6 μm) window, which provides tentative evidence that, at such temperatures, the water vapour continuum absorption may be as strong as it is in 2.1 μm and 4 μm windows and up to 2 orders of magnitude stronger than the MT C KD-2.5 continuum. We note that alternative methods of measuring the continuum in this window have yielded widely differing assessment of its strength, which emphasises the need for further measurements. -- Highlights: ► New lab measurements of the near-infrared water vapour self-continuum absorption. ► First room-temperature data on the self-continuum in the 1.6 μm window. ► In the 1.6 μm window the new data exceed MT C KD-2.5 model by 2 orders of magnitude

  10. Gastric cancer differentiation using Fourier transform near-infrared spectroscopy with unsupervised pattern recognition

    Science.gov (United States)

    Yi, Wei-song; Cui, Dian-sheng; Li, Zhi; Wu, Lan-lan; Shen, Ai-guo; Hu, Ji-ming

    2013-01-01

    The manuscript has investigated the application of near-infrared (NIR) spectroscopy for differentiation gastric cancer. The 90 spectra from cancerous and normal tissues were collected from a total of 30 surgical specimens using Fourier transform near-infrared spectroscopy (FT-NIR) equipped with a fiber-optic probe. Major spectral differences were observed in the CH-stretching second overtone (9000-7000 cm-1), CH-stretching first overtone (6000-5200 cm-1), and CH-stretching combination (4500-4000 cm-1) regions. By use of unsupervised pattern recognition, such as principal component analysis (PCA) and cluster analysis (CA), all spectra were classified into cancerous and normal tissue groups with accuracy up to 81.1%. The sensitivity and specificity was 100% and 68.2%, respectively. These present results indicate that CH-stretching first, combination band and second overtone regions can serve as diagnostic markers for gastric cancer.

  11. An extraordinary directive radiation based on optical antimatter at near infrared.

    Science.gov (United States)

    Mocella, Vito; Dardano, Principia; Rendina, Ivo; Cabrini, Stefano

    2010-11-22

    In this paper we discuss and experimentally demonstrate that in a quasi- zero-average-refractive-index (QZAI) metamaterial, in correspondence of a divergent source in near infrared (λ = 1.55 μm) the light scattered out is extremely directive (Δθ(out) = 0.06°), coupling with diffraction order of the alternating complementary media grating. With a high degree of accuracy the measurements prove also the excellent vertical confinement of the beam even in the air region of the metamaterial, in absence of any simple vertical confinement mechanism. This extremely sensitive device works on a large contact area and open news perspective to integrated spectroscopy.

  12. Infrared and optical observations of Nova Mus 1983

    International Nuclear Information System (INIS)

    Whitelock, P.A.; Carter, B.S.; Feast, M.W.; Glass, I.S.; Laney, D.; Menzies, J.W.

    1984-01-01

    Extensive optical (UBVRI) and infrared (JHKL) photometry of Nova Mus 1983 obtained over a period of 300 days is tabulated. Infrared and optical spectra are described. Although by classical definition this was a fast nova its later development was slower than for typical objects of this class. Surprisingly the development of infrared thermal dust emission did not occur. Throughout the period covered, the infrared emission was characteristic of a bound-free plus free-free plasma continuum with emission lines. (author)

  13. Optical field emission from resonant gold nanorods driven by femtosecond mid-infrared pulses

    Energy Technology Data Exchange (ETDEWEB)

    Kusa, F. [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei Tokyo 184-8588 (Japan); Institute of Industrial Science, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Echternkamp, K. E.; Herink, G.; Ropers, C. [4th Physical Institute – Solids and Nanostructures, University of Göttingen, 37077 Göttingen (Germany); Ashihara, S., E-mail: ashihara@iis.u-tokyo.ac.jp [Institute of Industrial Science, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2015-07-15

    We demonstrate strong-field photoelectron emission from gold nanorods driven by femtosecond mid-infrared optical pulses. The maximum photoelectron yield is reached at the localized surface plasmon resonance, indicating that the photoemission is governed by the resonantly-enhanced optical near-field. The wavelength- and field-dependent photoemission yield allows for a noninvasive determination of local field enhancements, and we obtain intensity enhancement factors close to 1300, in good agreement with finite-difference time domain computations.

  14. Near Infrared Spectroscopy as a Hemodynamic Monitor in Critical Illness.

    Science.gov (United States)

    Ghanayem, Nancy S; Hoffman, George M

    2016-08-01

    The objectives of this review are to discuss the technology and clinical interpretation of near infrared spectroscopy oximetry and its clinical application in patients with congenital heart disease. MEDLINE and PubMed. Near infrared spectroscopy provides a continuous noninvasive assessment of tissue oxygenation. Over 20 years ago, near infrared spectroscopy was introduced into clinical practice for monitoring cerebral oxygenation during cardiopulmonary bypass in adults. Since that time, the utilization of near infrared spectroscopy has extended into the realm of pediatric cardiac surgery and is increasingly being used in the cardiac ICU to monitor tissue oxygenation perioperatively.

  15. The Stellar Populations of Two Ultra-diffuse Galaxies from Optical and Near-infrared Photometry

    Science.gov (United States)

    Pandya, Viraj; Romanowsky, Aaron J.; Laine, Seppo; Brodie, Jean P.; Johnson, Benjamin D.; Glaccum, William; Villaume, Alexa; Cuillandre, Jean-Charles; Gwyn, Stephen; Krick, Jessica; Lasker, Ronald; Martín-Navarro, Ignacio; Martinez-Delgado, David; van Dokkum, Pieter

    2018-05-01

    We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospector fully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (≳7.7 Gyr) and surprisingly metal-poor ([Z/Z ⊙] ≲ ‑1.0) stellar population, even after marginalizing over uncertainties on diffuse interstellar dust. In contrast, the field UDG DGSAT I shows evidence of being younger than the Virgo UDG, with an extended star formation history and an age posterior extending down to ∼3 Gyr. The stellar metallicity of DGSAT I is sub-solar but higher than that of the Virgo UDG, with [Z/{Z}ȯ ]=-{0.63}-0.62+0.35; in the case of exactly zero diffuse interstellar dust, DGSAT I may even have solar metallicity. With VCC 1287 and several Coma UDGs, a general picture is emerging where cluster UDGs may be “failed” galaxies, but the field UDG DGSAT I seems more consistent with a stellar feedback-induced expansion scenario. In the future, our approach can be applied to a large and diverse sample of UDGs down to faint surface brightness limits, with the goal of constraining their stellar ages, stellar metallicities, and circumstellar and diffuse interstellar dust content.

  16. Mid-infrared optical parametric oscillator pumped by an amplified random fiber laser

    Science.gov (United States)

    Shang, Yaping; Shen, Meili; Wang, Peng; Li, Xiao; Xu, Xiaojun

    2017-01-01

    Recently, the concept of random fiber lasers has attracted a great deal of attention for its feature to generate incoherent light without a traditional laser resonator, which is free of mode competition and insure the stationary narrow-band continuous modeless spectrum. In this Letter, we reported the first, to the best of our knowledge, optical parametric oscillator (OPO) pumped by an amplified 1070 nm random fiber laser (RFL), in order to generate stationary mid-infrared (mid-IR) laser. The experiment realized a watt-level laser output in the mid-IR range and operated relatively stable. The use of the RFL seed source allowed us to take advantage of its respective stable time-domain characteristics. The beam profile, spectrum and time-domain properties of the signal light were measured to analyze the process of frequency down-conversion process under this new pumping condition. The results suggested that the near-infrared (near-IR) signal light `inherited' good beam performances from the pump light. Those would be benefit for further develop about optical parametric process based on different pumping circumstances.

  17. Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus.

    Science.gov (United States)

    Walther, L E; Asenov, D R; Di Martino, E

    2011-04-01

    Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

  18. On-Line Monitoring of Fermentation Processes by Near Infrared and Fluorescence Spectroscopy

    DEFF Research Database (Denmark)

    Svendsen, Carina

    Monitoring and control of fermentation processes is important to ensure high product yield, product quality and product consistency. More knowledge on on-line analytical techniques such as near infrared and fluorescence spectroscopy is desired in the fermentation industry to increase the efficiency...... of on-line monitoring systems. The primary aim of this thesis is to elucidate and explore the dynamics in fermentation processes by spectroscopy. Though a number of successful on-line lab-scale monitoring systems have been reported, it seems that several challenges are still met, which limits the number...... of full-scale systems implemented in industrial fermentation processes. This thesis seeks to achieve a better understanding of the techniques near infrared and fluorescence spectroscopy and thereby to solve some of the challenges that are encountered. The thesis shows the advantages of applying real...

  19. Sub-nanosecond time-resolved near-field scanning magneto-optical microscope.

    Science.gov (United States)

    Rudge, J; Xu, H; Kolthammer, J; Hong, Y K; Choi, B C

    2015-02-01

    We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 μm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.

  20. Medium-resolution near-infrared spectroscopy of massive young stellar objects

    Science.gov (United States)

    Pomohaci, R.; Oudmaijer, R. D.; Lumsden, S. L.; Hoare, M. G.; Mendigutía, I.

    2017-12-01

    We present medium-resolution (R ∼ 7000) near-infrared echelle spectroscopic data for 36 massive young stellar objects (MYSOs) drawn from the Red MSX Source survey. This is the largest sample observed at this resolution at these wavelengths of MYSOs to date. The spectra are characterized mostly by emission from hydrogen recombination lines and accretion diagnostic lines. One MYSO shows photospheric H I absorption, a comparison with spectral standards indicates that the star is an A-type star with a low surface gravity, implying that the MYSOs are probably swollen, as also suggested by evolutionary calculations. An investigation of the Brγ line profiles shows that most are in pure emission, while 13 ± 5 per cent display P Cygni profiles, indicative of outflow, while less than 8 ± 4 per cent have inverse P Cygni profiles, indicative of infall. These values are comparable with investigations into the optically bright Herbig Be stars, but not with those of Herbig Ae and T Tauri stars, consistent with the notion that the more massive stars undergo accretion in a different fashion than lower mass objects that are undergoing magnetospheric accretion. Accretion luminosities and rates as derived from the Br γ line luminosities agree with results for lower mass sources, providing tentative evidence for massive star formation theories based on scaling of low-mass scenarios. We present Br γ/Br12 line profile ratios exploiting the fact that optical depth effects can be traced as a function of Doppler shift across the lines. These show that the winds of MYSOs in this sample are nearly equally split between constant, accelerating and decelerating velocity structures. There are no trends between the types of features we see and bolometric luminosities or near-infrared colours.

  1. A NEAR-INFRARED SPECTROSCOPIC STUDY OF YOUNG FIELD ULTRACOOL DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Allers, K. N. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Liu, Michael C., E-mail: k.allers@bucknell.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2013-08-01

    We present a near-infrared (0.9-2.4 {mu}m) spectroscopic study of 73 field ultracool dwarfs having spectroscopic and/or kinematic evidence of youth ( Almost-Equal-To 10-300 Myr). Our sample is composed of 48 low-resolution (R Almost-Equal-To 100) spectra and 41 moderate-resolution spectra (R {approx}> 750-2000). First, we establish a method for spectral typing M5-L7 dwarfs at near-IR wavelengths that is independent of gravity. We find that both visual and index-based classification in the near-IR provides consistent spectral types with optical spectral types, though with a small systematic offset in the case of visual classification at J and K band. Second, we examine features in the spectra of {approx}10 Myr ultracool dwarfs to define a set of gravity-sensitive indices based on FeH, VO, K I, Na I, and H-band continuum shape. We then create an index-based method for classifying the gravities of M6-L5 dwarfs that provides consistent results with gravity classifications from optical spectroscopy. Our index-based classification can distinguish between young and dusty objects. Guided by the resulting classifications, we propose a set of low-gravity spectral standards for the near-IR. Finally, we estimate the ages corresponding to our gravity classifications.

  2. High-resolution optical coherence tomography, autofluorescence, and infrared reflectance imaging in Sjögren reticular dystrophy.

    Science.gov (United States)

    Schauwvlieghe, Pieter-Paul; Torre, Kara Della; Coppieters, Frauke; Van Hoey, Anneleen; De Baere, Elfride; De Zaeytijd, Julie; Leroy, Bart P; Brodie, Scott E

    2013-01-01

    To describe the phenotype of three cases of Sjögren reticular dystrophy in detail, including high-resolution optical coherence tomography, autofluorescence imaging, and near-infrared reflectance imaging. Two unrelated teenagers were independently referred for ophthalmologic evaluation. Both underwent a full ophthalmologic workup, including electrophysiologic and extensive imaging with spectral-domain optical coherence tomography, autofluorescence imaging, and near-infrared reflectance imaging. In addition, mutation screening of ABCA4, PRPH2, and the mitochondrial tRNA gene was performed in Patient 1. Subsequently, the teenage sister of Patient 2 was examined. Strikingly similar phenotypes were present in these three patients. Fundoscopy showed bilateral foveal pigment alterations, and a lobular network of deep retinal, pigmented deposits throughout the posterior pole, tapering toward the midperiphery, with relative sparing of the immediate perifoveal macula and peripapillary area. This network is mildly to moderately hyperautofluorescent on autofluorescence and bright on near-infrared reflectance imaging. Optical coherence tomography showed abnormalities of the retinal pigment epithelium-Bruch membrane complex, photoreceptor outer segments, and photoreceptor inner/outer segment interface. The results of retinal function test were entirely normal. No molecular cause was detected in Patient 1. Imaging suggested that the lobular network of deep retinal deposits in Sjögren reticular dystrophy is the result of accumulation of both pigment and lipofuscin between photoreceptors and retinal pigment epithelium, as well as within the retinal pigment epithelium.

  3. Near-infrared radiation absorption properties of covellite (CuS using first-principles calculations

    Directory of Open Access Journals (Sweden)

    Lihua Xiao

    2016-08-01

    Full Text Available First-principles density functional theory was used to investigate the electronic structure, optical properties and the origin of the near-infrared (NIR absorption of covellite (CuS. The calculated lattice constant and optical properties are found to be in reasonable agreement with experimental and theoretical findings. The electronic structure reveals that the valence and conduction bands of covellite are determined by the Cu 3d and S 3p states. By analyzing its optical properties, we can fully understand the potential of covellite (CuS as a NIR absorbing material. Our results show that covellite (CuS exhibits NIR absorption due to its metal-like plasma oscillation in the NIR range.

  4. Cryogenic optical systems for the rapid infrared imager/spectrometer (RIMAS)

    Science.gov (United States)

    Capone, John I.; Content, David A.; Kutyrev, Alexander S.; Robinson, Frederick D.; Lotkin, Gennadiy N.; Toy, Vicki L.; Veilleux, Sylvain; Moseley, Samuel H.; Gehrels, Neil A.; Vogel, Stuart N.

    2014-07-01

    The Rapid Infrared Imager/Spectrometer (RIMAS) is designed to perform follow-up observations of transient astronomical sources at near infrared (NIR) wavelengths (0.9 - 2.4 microns). In particular, RIMAS will be used to perform photometric and spectroscopic observations of gamma-ray burst (GRB) afterglows to compliment the Swift satellite's science goals. Upon completion, RIMAS will be installed on Lowell Observatory's 4.3 meter Discovery Channel Telescope (DCT) located in Happy Jack, Arizona. The instrument's optical design includes a collimator lens assembly, a dichroic to divide the wavelength coverage into two optical arms (0.9 - 1.4 microns and 1.4 - 2.4 microns respectively), and a camera lens assembly for each optical arm. Because the wavelength coverage extends out to 2.4 microns, all optical elements are cooled to ~70 K. Filters and transmission gratings are located on wheels prior to each camera allowing the instrument to be quickly configured for photometry or spectroscopy. An athermal optomechanical design is being implemented to prevent lenses from loosing their room temperature alignment as the system is cooled. The thermal expansion of materials used in this design have been measured in the lab. Additionally, RIMAS has a guide camera consisting of four lenses to aid observers in passing light from target sources through spectroscopic slits. Efforts to align these optics are ongoing.

  5. Photoacoustic determination of glucose concentration in whole blood by a near-infrared laser diode

    Science.gov (United States)

    Zhao, Zuomin; Myllylae, Risto A.

    2001-06-01

    The near-infrared photoacoustic technique is recognized as a potential method for the non-invasive determination of human glucose, because near-infrared light can incident a few millimeters into human tissue, where it produces an acoustic wave capable of carrying information about the composition of the tissue. This paper demonstrates a photoacoustic glucose measurement in a blood sample as a step toward a non-invasive measurement. The experimental apparatus consists of a near-infrared laser diode operating with 4 micro joules pulse energy at 905 nm, a roller pump connected to a silicon plastic tube and a cuvette for circulating the blood sample. In addition, the apparatus comprises a PZT piezoelectric transducer integrated with a battery-powered preamplifier to receive the photoacoustic signal. During the experiment, a glucose solution is mixed into a human blood sample to change its concentration. Although the absorption coefficient of glucose is much smaller than that of blood in the near-infrared region, the osmotic and hydrophilic properties of glucose decrease the reduced scattering coefficient of blood caused by the dissolved glucose surrounding the blood cells. This changes the distribution of the absorbed optical energy in blood, which, in turn, produces a change in the photoacoustic signal. Our experiment demonstrates that signal amplitudes in fresh and stored blood samples in crease about 7% and 10%, respectively, when the glucose concentration reaches the upper limit of the physiological region (500 mg/dl).

  6. A correlated-k model of radiative transfer in the near-infrared windows of Venus

    International Nuclear Information System (INIS)

    Tsang, C.C.C.; Irwin, P.G.J.; Taylor, F.W.; Wilson, C.F.

    2008-01-01

    We present a correlated-k-based model for generating synthetic spectra in the near-infrared window regions, from 1.0 to 2.5 μm, emitted from the deep atmosphere of Venus on the nightside. This approach is applicable for use with any near-infrared instrument, ground-based and space-borne, for analysis of the thermal emissions in this spectral range. We also approach this work with the view of using the model, in conjunction with a retrieval algorithm, to retrieve minor species from the Venus Express/VIRTIS instrument. An existing radiative-transfer model was adapted for Venusian conditions to deal with the prevailing high pressures and temperatures and other conditions. A comprehensive four-modal cloud structure model based on Pollack et al. [Near-infrared light from venus' nightside: a spectroscopic analysis. Icarus 1993;103:1-42], using refractive indices for a 75% H 2 SO 4 25% H 2 O mixture from Palmer and Williams [Optical constants of sulfuric acid; application to the clouds of Venus? Appl Opt 1975;14(1):208-19], was also implemented. We then utilized a Mie scattering algorithm to account for the multiple scattering effect between cloud and haze layers that occur in the Venusian atmosphere. The correlated-k model is shown to produce good agreement with ground-based spectra of Venus in the near infrared, and to match the output from a line-by-line radiative-transfer model to better than 10%

  7. A review: Functional near infrared spectroscopy evaluation in muscle tissues using Monte Carlo simulation

    Science.gov (United States)

    Halim, A. A. A.; Laili, M. H.; Salikin, M. S.; Rusop, M.

    2018-05-01

    Monte Carlo Simulation has advanced their quantification based on number of the photon counting to solve the propagation of light inside the tissues including the absorption, scattering coefficient and act as preliminary study for functional near infrared application. The goal of this paper is to identify the optical properties using Monte Carlo simulation for non-invasive functional near infrared spectroscopy (fNIRS) evaluation of penetration depth in human muscle. This paper will describe the NIRS principle and the basis for its proposed used in Monte Carlo simulation which focused on several important parameters include ATP, ADP and relate with blow flow and oxygen content at certain exercise intensity. This will cover the advantages and limitation of such application upon this simulation. This result may help us to prove that our human muscle is transparent to this near infrared region and could deliver a lot of information regarding to the oxygenation level in human muscle. Thus, this might be useful for non-invasive technique for detecting oxygen status in muscle from living people either athletes or working people and allowing a lots of investigation muscle physiology in future.

  8. Study of atmospheric air AC glow discharge using optical emission spectroscopy and near infrared diode laser cavity ringdown spectroscopy

    Science.gov (United States)

    Srivastava, Nimisha; Wang, Chuji; Dibble, Theodore S.

    2008-11-01

    AC glow discharges were generated in atmospheric pressure by applying high voltage AC in the range of 3500-15000 V to a pair of stainless steel electrodes separated by an air gap. The discharges were characterized by optical emission spectroscopy (OES) and continuous wave cavity ringdown spectroscopy (cw-CRDS). The electronic (Tex), vibrational (Tv), and rotational (Tr) temperatures were measured. Spectral stimulations of the emission spectra of several vibronic bands of the 2^nd positive system of N2, the 1^st negative system of N2^+, the (0,1,2,3-0) bands of NO (A-X), and the (0-0) band of OH (A-X), which were obtained under various plasma operating conditions, show that Tr, Tv, and Tex are in the ranges of 2000 - 3800, 3500 - 5000, and 6000 - 10500^ K, respectively. Emission spectra show that OH concentration increases while NO concentration decreases with an increase of electrode spacing. The absorption spectra of H2O and OH overtone in the near infrared (NIR) were measured by the cw-CRDS with a telecommunications diode laser at wavelength near 1515 nm.

  9. Near-infrared and optical studies of the highly obscured nova V1831 Aquilae (Nova Aquilae 2015)

    Science.gov (United States)

    Banerjee, D. P. K.; Srivastava, Mudit K.; Ashok, N. M.; Munari, U.; Hambsch, F.-J.; Righetti, G. L.; Maitan, A.

    2018-01-01

    Near-infrared (NIR) and optical photometry and spectroscopy are presented for the nova V1831 Aquilae, covering the early decline and dust-forming phases during the first ∼90 d after its discovery. The nova is highly reddened due to interstellar extinction. Based solely on the nature of the NIR spectrum, we are able to classify the nova to be of the Fe II class. The distance and extinction to the nova are estimated to be 6.1 ± 0.5 kpc and Av ∼ 9.02, respectively. Lower limits of the electron density, emission measure and ionized ejecta mass are made from a Case B analysis of the NIR Brackett lines, while the neutral gas mass is estimated from the optical [O I] lines. We discuss the cause of the rapid strengthening of the He I 1.0830-μm line during the early stages. V1831 Aql formed a modest amount of dust fairly early (∼19.2 d after discovery); the dust shell is not seen to be optically thick. Estimates of the dust temperature, dust mass and grain size are made. Dust formation commences around day 19.2 at a condensation temperature of 1461 ± 15 K, suggestive of a carbon composition, following which the temperature is seen to decrease gradually to 950 K. The dust mass shows a rapid initial increase, which we interpret as being due to an increase in the number of grains, followed by a period of constancy, suggesting the absence of grain destruction processes during this latter time. A discussion of the evolution of these parameters is made, including certain peculiarities seen in the grain radius evolution.

  10. Determination of true optical absorption and scattering coefficient of wooden cell wall substance by time-of-flight near infrared spectroscopy.

    Science.gov (United States)

    Kitamura, Ryunosuke; Inagaki, Tetsuya; Tsuchikawa, Satoru

    2016-02-22

    The true absorption coefficient (μa) and reduced scattering coefficient (μ´s) of the cell wall substance in Douglas fir were determined using time-of-flight near infrared spectroscopy. Samples were saturated with hexane, toluene or quinolone to minimize the multiple reflections of light on the boundary between pore-cell wall substance in wood. μ´s exhibited its minimum value when the wood was saturated with toluene because the refractive index of toluene is close to that of the wood cell wall substance. The optical parameters of the wood cell wall substance calculated were μa = 0.030 mm(-1) and μ´s= 18.4 mm(-1). Monte Carlo simulations using these values were in good agreement with the measured time-resolved transmittance profiles.

  11. Far-IR transparency and dynamic infrared signature control with novel conducting polymer systems

    Science.gov (United States)

    Chandrasekhar, Prasanna; Dooley, T. J.

    1995-09-01

    Materials which possess transparency, coupled with active controllability of this transparency in the infrared (IR), are today an increasingly important requirement, for varied applications. These applications include windows for IR sensors, IR-region flat panel displays used in camouflage as well as in communication and sight through night-vision goggles, coatings with dynamically controllable IR-emissivity, and thermal conservation coatings. Among stringent requirements for these applications are large dynamic ranges (color contrast), 'multi-color' or broad-band characteristics, extended cyclability, long memory retention, matrix addressability, small area fabricability, low power consumption, and environmental stability. Among materials possessing the requirements for variation of IR signature, conducting polymers (CPs) appear to be the only materials with dynamic, actively controllable signature and acceptable dynamic range. Conventional CPs such as poly(alkyl thiophene), poly(pyrrole) or poly(aniline) show very limited dynamic range, especially in the far-IR, while also showing poor transparency. We have developed a number of novel CP systems ('system' implying the CP, the selected dopant, the synthesis method, and the electrolyte) with very wide dynamic range (up to 90% in both important IR regions, 3 - 5 (mu) and 8 - 12 (mu) ), high cyclability (to 105 cycles with less than 10% optical degradation), nearly indefinite optical memory retention, matrix addressability of multi-pixel displays, very wide operating temperature and excellent environmental stability, low charge capacity, and processability into areas from less than 1 mm2 to more than 100 cm2. The criteria used to design and arrive at these CP systems, together with representative IR signature data, are presented in this paper.

  12. Near-infrared scintillation of xenon by 63Ni beta decay

    Science.gov (United States)

    Yoshimizu, Norimasa; Lal, Amit; Pollock, Clifford R.

    2006-07-01

    The near-infrared scintillation of xenon gas by the β decay of 37MBq of Ni63 was studied, in the interest of its use in integrated devices for applications such as optical beacons and wavelength calibration. The emission was imaged and analyzed using Spencer's theory of electron penetration using xenon scattering cross sections derived from Thomas-Fermi theory. The total emission was approximately 2×105photons/s at 20kPa and 1×105photons/s at 100kPa. Spectral data show three dominant peaks at 823, 828, and 882nm as well as the formation of metastable states.

  13. Near-Infrared Spectroscopic Study of Chlorite Minerals

    OpenAIRE

    Min Yang; Meifang Ye; Haihui Han; Guangli Ren; Ling Han; Zhuan Zhang

    2018-01-01

    The mineral chemistry of twenty chlorite samples from the United States Geological Survey (USGS) spectral library and two other regions, having a wide range of Fe and Mg contents and relatively constant Al and Si contents, was studied via infrared (IR) spectroscopy, near-infrared (NIR) spectroscopy, and X-ray fluorescence (XRF) analysis. Five absorption features of the twenty samples near 4525, 4440, 4361, 4270, and 4182 cm−1 were observed, and two diagnostic features at 4440 and 4280 cm−1 we...

  14. Development of a real-time and quantitative thrombus sensor for an extracorporeal centrifugal blood pump by near-infrared light.

    Science.gov (United States)

    Sakota, Daisuke; Fujiwara, Tatsuki; Ohuchi, Katsuhiro; Kuwana, Katsuyuki; Yamazaki, Hiroyuki; Kosaka, Ryo; Nishida, Masahiro; Mizuno, Tomohiro; Arai, Hirokuni; Maruyama, Osamu

    2018-01-01

    We developed an optical thrombus sensor for a monopivot extracorporeal centrifugal blood pump. In this study, we investigated its quantitative performance for thrombus detection in acute animal experiments of left ventricular assist using the pump on pathogen-free pigs. Optical fibers were set in the driver unit of the pump. The incident light at the near-infrared wavelength of 810 nm was aimed at the pivot bearing, and the resulting scattered light was guided to the optical fibers. The detected signal was analyzed to obtain the thrombus formation level. As a result, real-time and quantitative monitoring of the thrombus surface area on the pivot bearing was achieved with an accuracy of 3.6 ± 2.3 mm 2 . In addition, the sensing method using the near-infrared light was not influenced by changes in the oxygen saturation and the hematocrit. It is expected that the developed sensor will be useful for optimal anticoagulation management for long-term extracorporeal circulation therapies.

  15. CROSS-CORRELATION BETWEEN X-RAY AND OPTICAL/NEAR-INFRARED BACKGROUND INTENSITY FLUCTUATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell-Wynne, Ketron; Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Xue, Yongquan [CAS Key Laboratory for Researches in Galaxies and Cosmology, Center for Astrophysics, Department of Astronomy, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui 230026 (China); Luo, Bin [School of Astronomy and Space Science, Nanjing University, Nanjing, 210093 (China); Brandt, William [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA, 16802 (United States); Koekemoer, Anton [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2016-12-01

    Angular power spectra of optical and infrared background anisotropies at wavelengths between 0.5 and 5 μ m are a useful probe of faint sources present during reionization, in addition to faint galaxies and diffuse signals at low redshift. The cross-correlation of these fluctuations with backgrounds at other wavelengths can be used to separate some of these signals. A previous study on the cross-correlation between X-ray and Spitzer fluctuations at 3.6 μ m and 4.5 μ m has been interpreted as evidence for direct collapse black holes present at z  > 12. Here we return to this cross-correlation and study its wavelength dependence from 0.5 to 4.5 μ m using Hubble and Spitzer data in combination with a subset of the 4 Ms Chandra observations in GOODS-S/ECDFS. Our study involves five Hubble bands at 0.6, 0.7, 0.85, 1.25, and 1.6 μ m, and two Spitzer -IRAC bands at 3.6 μ m and 4.5 μ m. We confirm the previously seen cross-correlation between 3.6 μ m (4.5 μ m) and X-rays with 3.7 σ (4.2 σ ) and 2.7 σ (3.7 σ ) detections in the soft [0.5–2] keV and hard [2–8] keV X-ray bands, respectively, at angular scales above 20 arcsec. The cross-correlation of X-rays with Hubble is largely anticorrelated, ranging between the levels of 1.4 σ –3.5 σ for all the Hubble and X-ray bands. This lack of correlation in the shorter optical/NIR bands implies the sources responsible for the cosmic infrared background at 3.6 and 4.5 μ m are at least partly dissimilar to those at 1.6 μ m and shorter.

  16. Interstitial near-infrared photoimmunotherapy: effective treatment areas and light doses needed for use with fiber optic diffusers.

    Science.gov (United States)

    Okuyama, Shuhei; Nagaya, Tadanobu; Sato, Kazuhide; Ogata, Fusa; Maruoka, Yasuhiro; Choyke, Peter L; Kobayashi, Hisataka

    2018-02-16

    Near-infrared photoimmunotherapy (NIR-PIT), a promising cancer therapy utilizing an antibody-photoabsorber conjugate (APC) and NIR light, which induces rapid necrotic cell death only in APC-bound cells. Effective NIR-PIT in mouse models has been achieved using superficial light illumination (SLI) with light emitting diodes (LEDs) or lasers, but in the clinical setting, fiber optic diffusers have been employed to deliver light to deeper tumors. However, the performance of NIR light in tissue delivered by fiber optic diffusers is poorly understood. Here, we investigated NIR-PIT using a cylindrical fiber optic diffuser in a mouse model of A431 tumors. NIR-PIT with 100 J/cm, the same light dose used in clinical trials of NIR-PIT, was applied after insertion of the diffuser within the tumor bed, and then both bioluminescence and fluorescence imaging were analyzed to assess the therapeutic efficacy. The diffuser can deliver adequate NIR light dose for effective NIR-PIT to the A431 tumor at a distance of approximately 1 cm around the light source at 100 J/cm. At 50 J/cm NIR light effective NIR-PIT was reduced to a distance of 5 - 7 mm diameter around the light source. These results indicate that the energy of interstitial light (measured in Joules/cm) administered via a fiber diffuser determines the depth of effective NIR-PIT around the diffuser and determines the spacing at which such diffusers should be placed to entirely cover the tumor. Thermal measurements demonstrate that interstitial light for NIR-PIT does not cause damage to the skin overlying the diffuser.

  17. Near-Infrared Quantum Cutting Long Persistent Luminescence

    OpenAIRE

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-01-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called ?near-infrared quantum cutting long persistent luminescence (NQPL)?, which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr3+,Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy ...

  18. Optical to near-infrared transit observations of super-Earth GJ 1214b: water-world or mini-Neptune?

    Science.gov (United States)

    de Mooij, E. J. W.; Brogi, M.; de Kok, R. J.; Koppenhoefer, J.; Nefs, S. V.; Snellen, I. A. G.; Greiner, J.; Hanse, J.; Heinsbroek, R. C.; Lee, C. H.; van der Werf, P. P.

    2012-02-01

    Context. GJ 1214b, the 6.55 Earth-mass transiting planet recently discovered by the MEarth team, has a mean density of ~35% of that of the Earth. It is thought that this planet is either a mini-Neptune, consisting of a rocky core with a thick, hydrogen-rich atmosphere, or a planet with a composition dominated by water. Aims: In the case of a hydrogen-rich atmosphere, molecular absorption and scattering processes may result in detectable radius variations as a function of wavelength. The aim of this paper is to measure these variations. Methods: We have obtained observations of the transit of GJ 1214b in the r- and I-band with the Isaac Newton Telescope (INT), in the g-, r-, i- and z-bands with the 2.2 m MPI/ESO telescope, in the Ks-band with the Nordic Optical Telescope (NOT), and in the Kc-band with the William Herschel Telescope (WHT). By comparing the transit depth between the the different bands, which is a measure for the planet-to-star size ratio, the atmosphere is investigated. Results: We do not detect clearly significant variations in the planet-to-star size ratio as function of wavelength. Although the ratio at the shortest measured wavelength, in g-band, is 2σ larger than in the other bands. The uncertainties in the Ks and Kc bands are large, due to systematic features in the light curves. Conclusions: The tentative increase in the planet-to-star size ratio at the shortest wavelength could be a sign of an increase in the effective planet-size due to Rayleigh scattering, which would require GJ 1214b to have a hydrogen-rich atmosphere. If true, then the atmosphere has to have both clouds, to suppress planet-size variations at red optical wavelengths, as well as a sub-solar metallicity, to suppress strong molecular features in the near- and mid-infrared. However, star spots, which are known to be present on the host-star's surface, can (partly) cancel out the expected variations in planet-to-star size ratio, because the lower surface temperature of the

  19. Dynamic array of dark optical traps

    DEFF Research Database (Denmark)

    Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

    2004-01-01

    A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase......-encoded coherent light source. Two-dimensional input phase distributions corresponding to the trapping patterns are encoded using a computer-programmable spatial light modulator, enabling each trap to be shaped and moved arbitrarily within the plane of observation. We demonstrate the generation of multiple dark...... optical traps for simultaneous manipulation of hollow "air-filled" glass microspheres suspended in an aqueous medium. (C) 2004 American Institute of Physics....

  20. Prediction of valid acidity in intact apples with Fourier transform near infrared spectroscopy*

    OpenAIRE

    Liu, Yan-de; Ying, Yi-bin; Fu, Xia-ping

    2005-01-01

    To develop nondestructive acidity prediction for intact Fuji apples, the potential of Fourier transform near infrared (FT-NIR) method with fiber optics in interactance mode was investigated. Interactance in the 800 nm to 2619 nm region was measured for intact apples, harvested from early to late maturity stages. Spectral data were analyzed by two multivariate calibration techniques including partial least squares (PLS) and principal component regression (PCR) methods. A total of 120 Fuji appl...

  1. Emergence of two near-infrared windows for in vivo and intraoperative SERS.

    Science.gov (United States)

    Lane, Lucas A; Xue, Ruiyang; Nie, Shuming

    2018-04-06

    Two clear windows in the near-infrared (NIR) spectrum are of considerable current interest for in vivo molecular imaging and spectroscopic detection. The main rationale is that near-infrared light can penetrate biological tissues such as skin and blood more efficiently than visible light because these tissues scatter and absorb less light at longer wavelengths. The first clear window, defined as light wavelengths between 650nm and 950nm, has been shown to be far superior for in vivo and intraoperative optical imaging than visible light. The second clear window, operating in the wavelength range of 1000-1700nm, has been reported to further improve detection sensitivity, spatial resolution, and tissue penetration because tissue photon scattering and background interference are further reduced at longer wavelengths. Here we discuss recent advances in developing biocompatible plasmonic nanoparticles for in vivo and intraoperative surface-enhanced Raman scattering (SERS) in both the first and second NIR windows. In particular, a new class of 'broad-band' plasmonic nanostructures is well suited for surface Raman enhancement across a broad range of wavelengths allowing a direct comparison of detection sensitivity and tissue penetration between the two NIR window. Also, optimized and encoded SERS nanoparticles are generally nontoxic and are much brighter than near-infrared quantum dots (QDs), raising new possibilities for ultrasensitive detection of microscopic tumors and image-guided precision surgery. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Near-infrared dichroism of a mesogenic transition metal complex and its solubility in nematic hosts

    International Nuclear Information System (INIS)

    Marshall, K.L.; Jacobs, S.D.

    1987-01-01

    A transition metal complex possessing the nematic phase, bis (p-n-butylstyryl-1, 2-dithiolato) nickel, was synthesized and its optical properties and solubility in the nematic hosts K15 and MBBA were investigated. The metal complex displayed a high solubility in both host materials (up to 10% wt/wt) and a strong near-infrared absorption band centered at 860 nm. A blocking extinction of greater than OD = 3 was obtained with a 100 micron pathlength of a 0.5% wt/wt mixture of the nematic metal complex in K15, suggesting its usefulness for passive blocking of near infrared radiation. A 24 micron thick, homogeneously aligned guest-host cell containing a 1% wt/wt mixture of the metal complex in K15 possessed a contrast ratio of nearly 5:1 and a blocking extinction of OD = 3.5 at 860 nm, demonstrating for the first time the existence of near-infrared dichroism in this class of materials. The solubility and blocking extinction of the mesogenic metal complex in K15 was considerably superior to the non-mesogenic near ir laser dye bis(dimethylaminodithiobenzil) nickel in the same host. An interaction of the nematic metal complex in mixtures with MBBA which resulted in the creation of a new absorption band at 1050 nm was also observed. 21 refs., 9 figs

  3. Rapid assessment of selected free amino acids during Edam cheese ripening by near infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Jiří Mlček

    2013-01-01

    Full Text Available The study focuses on rapid determination of free amino acids produced during the ripening of cheese, by using near infrared spectroscopy. Analyses of 96 samples of Edam cheese (30% and 45% of fat in dry matter were performed at monthly intervals up to the ripening age of 6 months. In total, 19 amino acids were analysed with infrared spectrometer using two different methods, either in the regime of reflectance in the integrating sphere of the apparatus or using a fibre optic apparatus with the fibre optic probe. Reference data based on high-performance liquid chromatography were used for calibration of the spectrophotometer. Calibration models were developed using a partial least square algorithm and tested by means of cross-validation. When measured with the integrating sphere and with the probe, the values of correlation coefficients ranged from 0.835 to 0.993 and from 0.739 to 0.995, respectively. Paired t-test did not show significant differences between the reference and predicted values (P < 0.05. The results of this new calibration method showed the possibility of near infrared technology for fast determination of free amino acids, which occur during the ripening of Edam cheese. The content of free amino acids allow us to prepare Edam cheese quickly and efficiently for sale or to prepare the material for processed cheese.

  4. Molecular Imaging of β-Amyloid Plaques with Near-Infrared Boron Dipyrromethane (BODIPY-Based Fluorescent Probes

    Directory of Open Access Journals (Sweden)

    Hiroyuki Watanabe

    2013-07-01

    Full Text Available The formation of β-amyloid (Aβ plaques is a critical neurodegenerative change in Alzheimer disease (AD. We designed and synthesized novel boron dipyrromethane (BODIPY-based Aβ probes (BAPs and evaluated their utility for near-infrared fluorescence imaging of Aβ plaques in the brain. In binding experiments in vitro, BAPs showed high affinity for synthetic Aβ aggregates (Kd = 18–149 nM. Furthermore, BAPs clearly stained Aβ plaques in sections of Tg2576 mice. In mouse brain tissue, BAPs showed sufficient uptake for optical imaging. In addition, ex vivo fluorescent staining of brain sections from Tg2576 mice after the injection of BAP-2 showed selective binding of Aβ plaques with little nonspecific binding. BAPs may be useful as a near-infrared fluorescent probe for imaging Aβ plaques.

  5. OPTICAL CONSTANTS AND BAND STRENGTHS OF CH4:C2H6 ICES IN THE NEAR- AND MID-INFRARED

    International Nuclear Information System (INIS)

    Molpeceres, Germán; Ortigoso, Juan; Escribano, Rafael; Maté, Belén; Satorre, Miguel Angel; Millán, Carlos

    2016-01-01

    We present a spectroscopic study of methane–ethane ice mixtures. We have grown CH 4 :C 2 H 6 mixtures with ratios 3:1, 1:1, and 1:3 at 18 and 30 K, plus pure methane and ethane ices, and have studied them in the near-infrared (NIR) and mid-infrared (MIR) ranges. We have determined densities of all species mentioned above. For amorphous ethane grown at 18 and 30 K we have obtained a density of 0.41 and 0.54 g cm −3 , respectively, lower than a previous measurement of the density of the crystalline species, 0.719 g cm −3 . As far as we know this is the first determination of the density of amorphous ethane ice. We have measured band shifts of the main NIR methane and ethane features in the mixtures with respect to the corresponding values in the pure ices. We have estimated band strengths of these bands in the NIR and MIR ranges. In general, intensity decay in methane modes was detected in the mixtures, whereas for ethane no clear tendency was observed. Optical constants of the mixtures at 30 and 18 K have also been evaluated. These values can be used to trace the presence of these species in the surface of trans-Neptunian objects. Furthermore, we have carried out a theoretical calculation of these ice mixtures. Simulation cells for the amorphous solids have been constructed using a Metropolis Monte Carlo procedure. Relaxation of the cells and prediction of infrared spectra have been carried out at density functional theory level.

  6. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

    International Nuclear Information System (INIS)

    Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

    2013-01-01

    We performed a near-infrared spectroscopic survey toward an area of ∼10 deg 2 of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R ∼ 20) spectra in 2-5 μm for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 μm, and 67% of the sources also have photometric data up to 24 μm. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 μm can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near-infrared

  7. Near-Infrared Imaging for Spatial Mapping of Organic Content in Petroleum Source Rocks

    Science.gov (United States)

    Mehmani, Y.; Burnham, A. K.; Vanden Berg, M. D.; Tchelepi, H.

    2017-12-01

    Natural gas from unconventional petroleum source rocks (shales) plays a key role in our transition towards sustainable low-carbon energy production. The potential for carbon storage (in adsorbed state) in these formations further aligns with efforts to mitigate climate change. Optimizing production and development from these resources requires knowledge of the hydro-thermo-mechanical properties of the rock, which are often strong functions of organic content. This work demonstrates the potential of near-infrared (NIR) spectral imaging in mapping the spatial distribution of organic content with O(100µm) resolution on cores that can span several hundred feet in depth (Mehmani et al., 2017). We validate our approach for the immature oil shale of the Green River Formation (GRF), USA, and show its applicability potential in other formations. The method is a generalization of a previously developed optical approach specialized to the GRF (Mehmani et al., 2016a). The implications of this work for spatial mapping of hydro-thermo-mechanical properties of excavated cores, in particular thermal conductivity, are discussed (Mehmani et al., 2016b). References:Mehmani, Y., A.K. Burnham, M.D. Vanden Berg, H. Tchelepi, "Quantification of organic content in shales via near-infrared imaging: Green River Formation." Fuel, (2017). Mehmani, Y., A.K. Burnham, M.D. Vanden Berg, F. Gelin, and H. Tchelepi. "Quantification of kerogen content in organic-rich shales from optical photographs." Fuel, (2016a). Mehmani, Y., A.K. Burnham, H. Tchelepi, "From optics to upscaled thermal conductivity: Green River oil shale." Fuel, (2016b).

  8. Creation of near-infrared emitting optical center related to nickel–silicon impurity complex in nanodiamond grains

    International Nuclear Information System (INIS)

    Tóth, S.; Himics, L.; Koós, M.

    2016-01-01

    Nanodiamond grains having intensive light emission in the near-infrared region even at room temperature carry an important application potential. Advantages of light emitting optical centers formed in nanodiamond grains are the emission concentrated into a narrow band and that they are mostly single photon emitter. Transition metal related impurity centers formed in nanodiamond grains exhibit these favorable properties. In this work we report on the creation of Ni–Si impurity related complex defect center in nanodiamond grains under microwave plasma assisted chemical vapor deposition (MW CVD) growth process. This complex center accounts for the previously undocumented fluorescence system with zero phonon line (ZPL) emission at 865 nm (1.433 eV) and band width of 1.5 nm (2.4 meV) at room temperature. By varying deposition conditions the Ni–Si impurity related complex defect center was formed in nanodiamond grains of 80–200 nm average sizes. Some variation of ZPL peak position and line width have been detected in nanodiamond grains prepared at different conditions, as well as in numerous nanodiamond grains prepared at the same conditions. The variations of local stress field may explain the spread of ZPL spectral parameters.

  9. Creation of near-infrared emitting optical center related to nickel–silicon impurity complex in nanodiamond grains

    Energy Technology Data Exchange (ETDEWEB)

    Tóth, S., E-mail: toth.sara@wigner.mta.hu; Himics, L.; Koós, M.

    2016-08-15

    Nanodiamond grains having intensive light emission in the near-infrared region even at room temperature carry an important application potential. Advantages of light emitting optical centers formed in nanodiamond grains are the emission concentrated into a narrow band and that they are mostly single photon emitter. Transition metal related impurity centers formed in nanodiamond grains exhibit these favorable properties. In this work we report on the creation of Ni–Si impurity related complex defect center in nanodiamond grains under microwave plasma assisted chemical vapor deposition (MW CVD) growth process. This complex center accounts for the previously undocumented fluorescence system with zero phonon line (ZPL) emission at 865 nm (1.433 eV) and band width of 1.5 nm (2.4 meV) at room temperature. By varying deposition conditions the Ni–Si impurity related complex defect center was formed in nanodiamond grains of 80–200 nm average sizes. Some variation of ZPL peak position and line width have been detected in nanodiamond grains prepared at different conditions, as well as in numerous nanodiamond grains prepared at the same conditions. The variations of local stress field may explain the spread of ZPL spectral parameters.

  10. Zinc Phthalocyanine Labelled Polyethylene Glycol: Preparation, Characterization, Interaction with Bovine Serum Albumin and Near Infrared Fluorescence Imaging in Vivo

    Directory of Open Access Journals (Sweden)

    Tianjun Liu

    2012-05-01

    Full Text Available Zinc phthalocyanine labelled polyethylene glycol was prepared to track and monitor the in vivo fate of polyethylene glycol. The chemical structures were characterized by nuclear magnetic resonance and infrared spectroscopy. Their light stability and fluorescence quantum yield were evaluated by UV-Visible and fluorescence spectroscopy methods. The interaction of zinc phthalocyanine labelled polyethylene glycol with bovine serum albumin was evaluated by fluorescence titration and isothermal titration calorimetry methods. Optical imaging in vivo, organ aggregation as well as distribution of fluorescence experiments for tracking polyethylene glycol were performed with zinc phthalocyanine labelled polyethylene glycol as fluorescent agent. Results show that zinc phthalocyanine labelled polyethylene glycol has good optical stability and high emission ability in the near infrared region. Imaging results demonstrate that zinc phthalocyanine labelled polyethylene glycol can track and monitor the in vivo process by near infrared fluorescence imaging, which implies its potential in biomaterials evaluation in vivo by a real-time noninvasive method.

  11. Spot fat reduction by red and near infrared LED phototherapy

    Science.gov (United States)

    Lim, Sungkyoo; Park, Eal-Whan

    2018-02-01

    Low level light therapy (LLLT) using light from red and near infrared LEDs or Lasers have been reported effective as noninvasive methods for reducing spot fat. A total of 55 subjects were randomly divided into test groups and control groups for abdominal fat reduction clinical trial using red and near infrared LED phototherapy devices. Red and near infrared light with irradiance of 10 mW/cm2 were irradiated over the abdominal area to the test group for 30 minutes followed by 30 minutes of aerobic exercise, 3 times a week for 4 weeks. Control group used sham devices for 30 minutes and followed by 30 minutes of aerobic exercise. It is expected that red and near infrared LED phototherapy combined with aerobic exercise would be effective and safe for abdominal fat reduction without any side effects.

  12. Near-infrared Thermal Emission Detections of a Number of Hot Jupiters and the Systematics of Ground-based Near-infrared Photometry

    Science.gov (United States)

    Croll, Bryce; Albert, Loic; Jayawardhana, Ray; Cushing, Michael; Moutou, Claire; Lafreniere, David; Johnson, John Asher; Bonomo, Aldo S.; Deleuil, Magali; Fortney, Jonathan

    2015-03-01

    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K CONT-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations. Based on observations obtained with WIRCam, a joint project of Canada-France-Hawaii Telescope (CFHT), Taiwan, Korea, Canada, France, at the CFHT, which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

  13. A brief review on the history of human functional near-infrared spectroscopy (fNIRS) development and fields of application.

    Science.gov (United States)

    Ferrari, Marco; Quaresima, Valentina

    2012-11-01

    This review is aimed at celebrating the upcoming 20th anniversary of the birth of human functional near-infrared spectroscopy (fNIRS). After the discovery in 1992 that the functional activation of the human cerebral cortex (due to oxygenation and hemodynamic changes) can be explored by NIRS, human functional brain mapping research has gained a new dimension. fNIRS or optical topography, or near-infrared imaging or diffuse optical imaging is used mainly to detect simultaneous changes in optical properties of the human cortex from multiple measurement sites and displays the results in the form of a map or image over a specific area. In order to place current fNIRS research in its proper context, this paper presents a brief historical overview of the events that have shaped the present status of fNIRS. In particular, technological progresses of fNIRS are highlighted (i.e., from single-site to multi-site functional cortical measurements (images)), introduction of the commercial multi-channel systems, recent commercial wireless instrumentation and more advanced prototypes. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Transcranial red and near infrared light transmission in a cadaveric model.

    Directory of Open Access Journals (Sweden)

    Jared R Jagdeo

    Full Text Available BACKGROUND AND OBJECTIVE: Low level light therapy has garnered significant interest within the past decade. The exact molecular mechanisms of how red and near infrared light result in physiologic modulation are not fully understood. Heme moieties and copper within cells are red and near infrared light photoreceptors that induce the mitochondrial respiratory chain component cytochrome C oxidase, resulting in a cascade linked to cytoprotection and cellular metabolism. The copper centers in cytochrome C oxidase have a broad absorption range that peaks around 830 nm. Several in vitro and in vivo animal and human models exist that have demonstrated the benefits of red light and near infrared light for various conditions. Clinical applications for low level light therapy are varied. One study in particular demonstrated improved durable functional outcomes status post-stroke in patients treated with near infrared low level light therapy compared to sham treatment [1]. Despite previous data suggesting the beneficial effect in treating multiple conditions, including stroke, with low level light therapy, limited data exists that measures transmission in a human model. STUDY DESIGN/MATERIALS AND METHODS: To investigate this idea, we measured the transmission of near infrared light energy, using red light for purposes of comparison, through intact cadaver soft tissue, skull bones, and brain using a commercially available LED device at 830 nm and 633 nm. RESULTS: Our results demonstrate that near infrared measurably penetrates soft tissue, bone and brain parenchyma in the formalin preserved cadaveric model, in comparison to negligible red light transmission in the same conditions. CONCLUSION: These findings indicate that near infrared light can penetrate formalin fixed soft tissue, bone and brain and implicate that benefits observed in clinical studies are potentially related to direct action of near infrared light on neural tissue.

  15. Effectiveness of near-infrared transillumination in early caries diagnosis

    Directory of Open Access Journals (Sweden)

    Mirela Marinova-Takorova

    2016-11-01

    Full Text Available Early caries detection is essential for minimal intervention dentistry, since it could give the opportunity to reverse the process and eliminate or at least postpone the surgical treatment. The aim of the present study was to evaluate the effectiveness of near-infrared transillumination in early caries diagnosis for both occlusal and proximal lesions. Thirty-eight adult patients were included in the study. The results from the visual, radiological and near-infrared transillumination examination for proximal caries lesions were compared. The diagnostic abilities of these methods for occlusal lesions were assayed on 60 teeth. The three methods showed a very high level of correlation when there were caries lesions involving the enamel and dentin. Concerning proximal caries involving only the enamel, the visual--tactile diagnosis proved to be insufficiently sensitive even with the use of magnification. Radiographic examination and near-infrared transillumination correlated significantly, but the latter was more sensitive. Radiographic examination proved to be insufficiently sensitive for occlusal lesions. The results obtained with the near-infrared fluorescence correlated most with the visual–tactile examination. These results suggest that near-infrared transillumination is an effective method for diagnosis of lesions both involving only the enamel and involving the enamel and dentin. It could be used for both occlusal and proximal caries lesions and it could eventually substitute radiographic bitewings, especially in children and pregnant women, due to its efficiency as a diagnostic tool and the absence of radiation.

  16. Search for near-infrared counterparts of IRAS embedded sources in the M17 SW giant molecular cloud

    International Nuclear Information System (INIS)

    Elmegreen, D.M.; Phillips, J.; Beck, K.; Thomas, H.; Howard, J.

    1988-01-01

    Wide-field near-infrared and blue band plates of the region containing the M17 giant molecular cloud complex have been blinked to locate bright near-infrared stars that may be embedded in the M17 SW giant molecular cloud. Twenty such stars coincided with the positions of IRAS point sources that appeared embedded based on color-color diagrams. Some of these stars may be the sources of the infrared luminosities. Of the 20 stars, seven were too faint to appear on the B band plate. The optical magnitudes and colors determined from the plate image diameters were measured for the other 13 coincident stars; they are most likely upper main-sequence or pre-main-sequence stars with extinctions of 7 mag. The IRAS luminosity-temperature diagram indicates that the embedded sources in M17 are more massive than those in the Orion cloud. 35 references

  17. Photoacoustic contrast imaging of biological tissues with nanodiamonds fabricated for high near-infrared absorbance.

    Science.gov (United States)

    Zhang, Ti; Cui, Huizhong; Fang, Chia-Yi; Su, Long-Jyun; Ren, Shenqiang; Chang, Huan-Cheng; Yang, Xinmai; Forrest, M Laird

    2013-02-01

    Radiation-damaged nanodiamonds (DNDs) are potentially ideal optical contrast agents for photoacoustic (PA) imaging in biological tissues due to their low toxicity and high optical absorbance. PA imaging contrast agents have been limited to quantum dots and gold particles, since most existing carbon-based nanoparticles, including fluorescent nanodiamonds, do not have sufficient optical absorption in the near-infrared (NIR) range. A new DND by He+ ion beam irradiation with very high NIR absorption was synthesized. These DNDs produced a 71-fold higher PA signal on a molar basis than similarly dimensioned gold nanorods, and 7.1 fmol of DNDs injected into rodents could be clearly imaged 3 mm below the skin surface with PA signal enhancement of 567% using an 820-nm laser wavelength.

  18. Infrared Supercontinuum Generation in Optical Fibres

    DEFF Research Database (Denmark)

    Dupont, Sune Vestergaard Lund

    During my PhD studies I have worked with intense lasers and optical fibres. In our conceptual universe the colour of light (wavelength) does not depend on the material in which it propagates. At high intensities however, nonlinear effects change the behaviour of light and rise of new wavelength...... with laser-like intensity is obtained, which otherwise is impossible without the use of more complicated equipment. Until recently, supercontinuum covering the mid-infrared was not possible due to absorption in the silica glass optical fibres are made of. In our project infrared transparent materials...... such as ZBLAN and chalcogenide have been investigated. Using ZBLAN it has been possible to generated a supercontinuum stretching beyond 4200 nm. Supercontinuum generation requires knowledge about the physical properties of the optical fibre in which the pulse-broadening takes place. Consequently thorough...

  19. Near-infrared photometry of HDE 245770 (A 0535 + 26)

    International Nuclear Information System (INIS)

    Persi, P.; Ferrari-Toniolo, M.; Spada, G.; Conti, G.; Di Benedetto, P.; Tanzi, E.G.; Tarenghi, M.

    1979-01-01

    A derivation is presented of the optical-infrared energy distribution of the OBe star HDE 245770, the optical counterpart of the transient X-ray source A 0535 + 26, using infrared observations made in the period 1976 November - 1977 March and UBV photometry obtained by other workers in 1976 November. An infrared excess is evident with flux density Ssub(ν) varies as νsup(approximately 0.6). The excess is explained in terms of thermal free-free emission from an ionized gaseous envelope around the OBe star. Assuming a matter outflow through the envelope with uniform velocity of a few hundred km/s, a value is obtained for the mass loss rate in HDE 245770 of about 10 -6 solar masses/yr. (author)

  20. Angular selectivity asymmetry of holograms recorded in near infrared sensitive liquid crystal photopolymerizable materials

    Science.gov (United States)

    Harbour, Steven; Galstian, Tigran; Akopyan, Rafik; Galstyan, Artur

    2004-08-01

    We have experimentally observed and theoretically explained the angular selectivity asymmetry in polymer dispersed liquid crystal holograms. Experiments are conducted in compounds with near infrared sensitivity. The coupled-wave theory is used to describe the diffraction properties of obtained anisotropic holographic gratings. Furthermore, the comparison of theory and experiments provides information about the optical axis direction that is defined by the average molecular orientation of the liquid crystal in the polymer matrix.

  1. Near-infrared spectral tomography integrated with digital breast tomosynthesis: Effects of tissue scattering on optical data acquisition design

    Energy Technology Data Exchange (ETDEWEB)

    Michaelsen, Kelly; Krishnaswamy, Venkat; Pogue, Brian W.; Poplack, Steven P.; Paulsen, Keith D. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Department of Diagnostic Radiology, Dartmouth Medical School, Lebanon, New Hampshire 03756 (United States); Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 and Department of Diagnostic Radiology, Dartmouth Medical School, Lebanon, New Hampshire 03756 (United States)

    2012-07-15

    Purpose: Design optimization and phantom validation of an integrated digital breast tomosynthesis (DBT) and near-infrared spectral tomography (NIRST) system targeting improvement in sensitivity and specificity of breast cancer detection is presented. Factors affecting instrumentation design include minimization of cost, complexity, and examination time while maintaining high fidelity NIRST measurements with sufficient information to recover accurate optical property maps. Methods: Reconstructed DBT slices from eight patients with abnormal mammograms provided anatomical information for the NIRST simulations. A limited frequency domain (FD) and extensive continuous wave (CW) NIRST system was modeled. The FD components provided tissue scattering estimations used in the reconstruction of the CW data. Scattering estimates were perturbed to study the effects on hemoglobin recovery. Breast mimicking agar phantoms with inclusions were imaged using the combined DBT/NIRST system for comparison with simulation results. Results: Patient simulations derived from DBT images show successful reconstruction of both normal and malignant lesions in the breast. They also demonstrate the importance of accurately quantifying tissue scattering. Specifically, 20% errors in optical scattering resulted in 22.6% or 35.1% error in quantification of total hemoglobin concentrations, depending on whether scattering was over- or underestimated, respectively. Limited frequency-domain optical signal sampling provided two regions scattering estimates (for fat and fibroglandular tissues) that led to hemoglobin concentrations that reduced the error in the tumor region by 31% relative to when a single estimate of optical scattering was used throughout the breast volume of interest. Acquiring frequency-domain data with six wavelengths instead of three did not significantly improve the hemoglobin concentration estimates. Simulation results were confirmed through experiments in two-region breast mimicking

  2. Near-infrared spectral tomography integrated with digital breast tomosynthesis: Effects of tissue scattering on optical data acquisition design

    International Nuclear Information System (INIS)

    Michaelsen, Kelly; Krishnaswamy, Venkat; Pogue, Brian W.; Poplack, Steven P.; Paulsen, Keith D.

    2012-01-01

    Purpose: Design optimization and phantom validation of an integrated digital breast tomosynthesis (DBT) and near-infrared spectral tomography (NIRST) system targeting improvement in sensitivity and specificity of breast cancer detection is presented. Factors affecting instrumentation design include minimization of cost, complexity, and examination time while maintaining high fidelity NIRST measurements with sufficient information to recover accurate optical property maps. Methods: Reconstructed DBT slices from eight patients with abnormal mammograms provided anatomical information for the NIRST simulations. A limited frequency domain (FD) and extensive continuous wave (CW) NIRST system was modeled. The FD components provided tissue scattering estimations used in the reconstruction of the CW data. Scattering estimates were perturbed to study the effects on hemoglobin recovery. Breast mimicking agar phantoms with inclusions were imaged using the combined DBT/NIRST system for comparison with simulation results. Results: Patient simulations derived from DBT images show successful reconstruction of both normal and malignant lesions in the breast. They also demonstrate the importance of accurately quantifying tissue scattering. Specifically, 20% errors in optical scattering resulted in 22.6% or 35.1% error in quantification of total hemoglobin concentrations, depending on whether scattering was over- or underestimated, respectively. Limited frequency-domain optical signal sampling provided two regions scattering estimates (for fat and fibroglandular tissues) that led to hemoglobin concentrations that reduced the error in the tumor region by 31% relative to when a single estimate of optical scattering was used throughout the breast volume of interest. Acquiring frequency-domain data with six wavelengths instead of three did not significantly improve the hemoglobin concentration estimates. Simulation results were confirmed through experiments in two-region breast mimicking

  3. [Near infrared light irradiator using halogen lamp].

    Science.gov (United States)

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  4. Activatable Optical Imaging with a Silica-Rhodamine Based Near Infrared (SiR700) Fluorophore: A comparison with cyanine based dyes

    Science.gov (United States)

    McCann, Thomas E.; Kosaka, Nobuyuki; Koide, Yuichiro; Mitsunaga, Makoto; Choyke, Peter L.; Nagano, Tetsuo; Urano, Yasuteru; Kobayashi, Hisataka

    2011-01-01

    Optical imaging is emerging as an important tool to visualize tumors. However, there are many potential choices among the available fluorophores. Optical imaging probes that emit in the visible range can image superficial tumors with high quantum yields, however, if deeper imaging is needed then near infrared (NIR) fluorophores are necessary. Most commercially available NIR fluorophores are cyanine based and are prone to non-specific binding and relatively limited photostability. Silica-containing rhodamine (SiR) fluorophores represent a new class of NIR fluorophores, which permit photoactivation via H-dimer formation as well as demonstrate improved photostability. This permits higher tumor-to-background ratios (TBRs) to be achieved over longer periods of time. Here, we compared an avidin conjugated with SiR700 (Av-SiR700) to similar compounds based on cyanine dyes (Av-Cy5.5 and Av-Alexa Fluor 680) in a mouse tumor model of ovarian cancer metastasis. We found that the Av-SiR700 probe demonstrated superior quenching enabling activation after binding-internalization to the target cell. As a result, Av-SiR700 had higher TBRs compared to Av-Cy5.5, and better biostability compared to Av-Alexa Fluor 680. PMID:22034863

  5. Characterization and Predictive Value of Near Infrared 2-Deoxyglucose Optical Imaging in Severe Acute Pancreatitis.

    Directory of Open Access Journals (Sweden)

    Cristiane de Oliveira

    , which were not predicted by the blood parameters.In-vivo fluorescent imaging of a non-radioactive near infrared 2-DG optical probe can predict the AP severity early during the disease.

  6. In situ sensing of subsurface contamination--part I: near-infrared spectral characterization of alkanes, aromatics, and chlorinated hydrocarbons.

    Science.gov (United States)

    Klavarioti, Maria; Kostarelos, Konstantinos; Pourjabbar, Anahita; Ghandehari, Masoud

    2014-05-01

    There is an imperative need for a chemical sensor capable of remote, in situ, long-term monitoring of chemical species at sites containing toxic chemical spills, specifically at chemical waste dumps, landfills, and locations with underground storage tanks. In the current research, a series of experiments were conducted measuring the near-infrared optical absorption of alkanes, aromatics, and chlorinated hydrocarbons. A spectral library was then developed to characterize the optical spectra of liquid hydrocarbons. Near-infrared analysis was chosen due to compatibility with optical fibers. The goal was to differentiate between classes of hydrocarbons and to also discriminate between compounds within a class of similar molecular structures. It was observed that unique absorption spectra can be obtained for each hydrocarbon, and this uniqueness can be used to discriminate between hydrocarbons from different families. Statistical analyses, namely, principal component analysis (PCA) and correlation coefficient (Spearman and Pearson methods), were attempted to match absorption spectra from an unknown hydrocarbon with the database with limited success. An algorithm was subsequently written to identify the characteristic peaks of each hydrocarbon that could be used to match data from an unknown chemical species with the database.

  7. Thermal Infrared and Visible to Near-Infrared Spectral Analysis of Chert and Amorphous Silica

    Science.gov (United States)

    McDowell, M. L.; Hamilton, V. E.; Cady, S. L.; Knauth, P.

    2009-03-01

    We look in detail at the thermal infrared and visible to near-infrared spectra of various forms of chert and amorphous silica and compare the spectral variations between samples with variations in physical and chemical characteristics.

  8. Combined optimal-pathlengths method for near-infrared spectroscopy analysis

    International Nuclear Information System (INIS)

    Liu Rong; Xu Kexin; Lu Yanhui; Sun Huili

    2004-01-01

    Near-infrared (NIR) spectroscopy is a rapid, reagent-less and nondestructive analytical technique, which is being increasingly employed for quantitative application in chemistry, pharmaceutics and food industry, and for the optical analysis of biological tissue. The performance of NIR technology greatly depends on the abilities to control and acquire data from the instrument and to calibrate and analyse data. Optical pathlength is a key parameter of the NIR instrument, which has been thoroughly discussed in univariate quantitative analysis in the presence of photometric errors. Although multiple wavelengths can provide more chemical information, it is difficult to determine a single pathlength that is suitable for each wavelength region. A theoretical investigation of a selection procedure for multiple pathlengths, called the combined optimal-pathlengths (COP) method, is identified in this paper and an extensive comparison with the single pathlength method is also performed on simulated and experimental NIR spectral data sets. The results obtained show that the COP method can greatly improve the prediction accuracy in NIR spectroscopy quantitative analysis

  9. Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials

    International Nuclear Information System (INIS)

    Wolf, Omri; Ma, Xuedan; Brener, Igal; Allerman, Andrew A.; Wendt, Joel R.; Shaner, Eric A.; Song, Alex Y.

    2015-01-01

    We use planar metamaterial resonators to enhance by more than two orders of magnitude the near infrared second harmonic generation obtained from intersubband transitions in III-Nitride heterostructures. The improvement arises from two factors: employing an asymmetric double quantum well design and aligning the resonators' cross-polarized resonances with the intersubband transition energies. The resulting nonlinear metamaterial operates at wavelengths where single photon detection is available, and represents a different class of sources for quantum photonics related phenomena

  10. UNVEILING THE σ-DISCREPANCY IN INFRARED-LUMINOUS MERGERS. I. DUST AND DYNAMICS

    International Nuclear Information System (INIS)

    Rothberg, Barry; Fischer, Jacqueline

    2010-01-01

    Mergers in the local universe present a unique opportunity for studying the transformations of galaxies in detail. Presented here are recent results, based on multi-wavelength, high-resolution imaging and medium resolution spectroscopy, which demonstrate how star formation and the presence of red supergiants and/or asymptotic giant branch stars have led to a serious underestimation of the dynamical masses of infrared-bright galaxies. The dominance of a nuclear disk of young stars in the near-infrared bands, where dust obscuration does not block their signatures, can severely bias the global properties measured in a galaxy, including mass. This explains why past studies of gas-rich luminous infrared galaxies (LIRGs) and ultraluminous infrared galaxies, which have measured dynamical masses using the 1.62 or 2.29 μm CO band heads, have found that these galaxies are forming m m* ellipticals. Moreover, merger remnants, including LIRGs, are placed on the I-band fundamental plane for the first time and appear to be virtually indistinguishable from elliptical galaxies.

  11. Nonlinear optics in germanium mid-infrared fiber material: Detuning oscillations in femtosecond mid-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    M. Ordu

    2017-09-01

    Full Text Available Germanium optical fibers hold great promise in extending semiconductor photonics into the fundamentally important mid-infrared region of the electromagnetic spectrum. The demonstration of nonlinear response in fabricated Ge fiber samples is a key step in the development of mid-infrared fiber materials. Here we report the observation of detuning oscillations in a germanium fiber in the mid-infrared region using femtosecond dispersed pump-probe spectroscopy. Detuning oscillations are observed in the frequency-resolved response when mid-infrared pump and probe pulses are overlapped in a fiber segment. The oscillations arise from the nonlinear frequency resolved nonlinear (χ(3 response in the germanium semiconductor. Our work represents the first observation of coherent oscillations in the emerging field of germanium mid-infrared fiber optics.

  12. Optical detection of ultrasound using an apertureless near-field scanning optical microscopy system

    Science.gov (United States)

    Ahn, Phillip; Zhang, Zhen; Sun, Cheng; Balogun, Oluwaseyi

    2013-01-01

    Laser ultrasonics techniques are power approaches for non-contact generation and detection of high frequency ultrasound on a local scale. In these techniques, optical diffraction limits the spatial information that can be accessed from a measurement. In order to improve the lateral spatial resolution, we incorporate an apertureless near-field scanning optical microscope (aNSOM) into laser ultrasonics setup for local detection of laser generated ultrasound. The aNSOM technique relies on the measurement of a weak backscattered near-field light intensity resulting from the oblique illumination of a nanoscale probe-tip positioned close to a sample surface. We enhance the optical near-field intensity by coupling light to surface plasmon polaritons (SPPs) on the shaft of an atomic force microscopy (AFM) cantilever. The SPPs propagate down the AFM shaft, localize at the tip apex, and are backscattered to the far-field when the separation distance between the probe tip and the sample surface is comparable to the probe-tip radius. The backscattered near-field intensity is dynamically modulated when an ultrasonic wave arrives at the sample surface leading to a transient change in the tip-sample separation distance. We present experimental results detailing measurement of broadband and narrowband laser generated ultrasound in solids with frequencies reaching up to 180 MHz range.

  13. Near-infrared emitting In-rich InGaN layers grown directly on Si: Towards the whole composition range

    Energy Technology Data Exchange (ETDEWEB)

    Aseev, Pavel, E-mail: pavel.aseev@upm.es; Rodriguez, Paul E. D. Soto; Gómez, Víctor J.; Alvi, Naveed ul Hassan; Calleja, Enrique [Instituto de Sistemas Optoelectrónicos y Microtecnología, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Mánuel, José M.; Jiménez, Juan J.; García, Rafael [Departamente Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, Puerto Real, 11510 Cádiz (Spain); Morales, Francisco M. [Departamente Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, Puerto Real, 11510 Cádiz (Spain); IMEYMAT: Institute of Research on Electron Microscopy and Materials of the University of Cádiz, 11510 Cádiz (Spain); Senichev, Alexander [Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Germany); Lienau, Christoph [Institute of Physics and Center of Interface Science, Carl von Ossietzky Universität Oldenburg, Ammerländer Heerstr. 114-118, 26129 Oldenburg (Germany); and others

    2015-02-16

    The authors report compact and chemically homogeneous In-rich InGaN layers directly grown on Si (111) by plasma-assisted molecular beam epitaxy. High structural and optical quality is evidenced by transmission electron microscopy, near-field scanning optical microscopy, and X-ray diffraction. Photoluminescence emission in the near-infrared is observed up to room temperature covering the important 1.3 and 1.55 μm telecom wavelength bands. The n-InGaN/p-Si interface is ohmic due to the absence of any insulating buffer layers. This qualitatively extends the application fields of III-nitrides and allows their integration with established Si technology.

  14. Near-infrared emitting In-rich InGaN layers grown directly on Si: Towards the whole composition range

    International Nuclear Information System (INIS)

    Aseev, Pavel; Rodriguez, Paul E. D. Soto; Gómez, Víctor J.; Alvi, Naveed ul Hassan; Calleja, Enrique; Mánuel, José M.; Jiménez, Juan J.; García, Rafael; Morales, Francisco M.; Senichev, Alexander; Lienau, Christoph

    2015-01-01

    The authors report compact and chemically homogeneous In-rich InGaN layers directly grown on Si (111) by plasma-assisted molecular beam epitaxy. High structural and optical quality is evidenced by transmission electron microscopy, near-field scanning optical microscopy, and X-ray diffraction. Photoluminescence emission in the near-infrared is observed up to room temperature covering the important 1.3 and 1.55 μm telecom wavelength bands. The n-InGaN/p-Si interface is ohmic due to the absence of any insulating buffer layers. This qualitatively extends the application fields of III-nitrides and allows their integration with established Si technology

  15. Wave-guided Optical Waveguides tracked and coupled using dynamic diffractive optics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Villangca, Mark Jayson; Bañas, Andrew Rafael

    With light’s miniscule momentum, shrinking robotics down to the micro- and nano-scale regime creates opportunities for exploiting optical forces and near-field light delivery in advanced actuation and control atthe smallest physical dimensions. Advancing light-driven nano- or micro-actuation requ......With light’s miniscule momentum, shrinking robotics down to the micro- and nano-scale regime creates opportunities for exploiting optical forces and near-field light delivery in advanced actuation and control atthe smallest physical dimensions. Advancing light-driven nano- or micro...... waveguides (WOWs) [2]. As the WOWs are optically trapped and maneuvered in 3D-space, it is important to maintain efficient light-coupling through these free-standing waveguides within their operating volume [3]. We propose the use ofdynamic diffractive techniques to create focal spots that will track...... and couple to the WOWs during full volume operation. This is done by using a spatial light modulator to encode the necessary diffractive phase patterns to generate the multiple and dynamic coupling spots. The method is initially tested for a single WOW and we have experimentally demonstrated dynamic tracking...

  16. Temperature-dependent infrared optical properties of 3C-, 4H- and 6H-SiC

    Science.gov (United States)

    Tong, Zhen; Liu, Linhua; Li, Liangsheng; Bao, Hua

    2018-05-01

    The temperature-dependent optical properties of cubic (3C) and hexagonal (4H and 6H) silicon carbide are investigated in the infrared range of 2-16 μm both by experimental measurements and numerical simulations. The temperature in experimental measurement is up to 593 K, while the numerical method can predict the optical properties at elevated temperatures. To investigate the temperature effect, the temperature-dependent damping parameter in the Lorentz model is calculated based on anharmonic lattice dynamics method, in which the harmonic and anharmonic interatomic force constants are determined from first-principles calculations. The infrared phonon modes of silicon carbide are determined from first-principles calculations. Based on first-principles calculations, the Lorentz model is parameterized without any experimental fitting data and the temperature effect is considered. In our investigations, we find that the increasing temperature induces a small reduction of the reflectivity in the range of 10-13 μm. More importantly, it also shows that our first-principles calculations can predict the infrared optical properties at high-temperature effectively which is not easy to be obtained through experimental measurements.

  17. Multiwavelength Observations of the 2002 Outburst of GX 339-4: Two Patterns of X-Ray-Optical/Near-Infrared Behavior

    Science.gov (United States)

    Homan, Jeroen; Buxton, Michelle; Markoff, Sera; Bailyn, Charles D.; Nespoli, Elisa; Belloni, Tomaso

    2005-05-01

    We report on quasi-simultaneous Rossi X-Ray Timing Explorer and optical/near-infrared (NIR) observations of the black hole candidate X-ray transient GX 339-4. Our observations were made over a time span of more than 8 months in 2002 and cover the initial rise and transition from a hard to a soft spectral state in X-rays. Two distinct patterns of correlated X-ray-optical/NIR behavior were found. During the hard state, the optical/NIR and X-ray fluxes correlated well, with a NIR versus X-ray flux power-law slope similar to that of the correlation found between X-ray and radio fluxes in previous studies of GX 339-4 and other black hole binaries. As the source went through an intermediate state, the optical/NIR fluxes decreased rapidly, and once it had entered the spectrally soft state, the optical/NIR spectrum of GX 339-4 was much bluer, and the ratio of X-ray to NIR flux was higher by a factor of more than 10 compared to the hard state. In the spectrally soft state, changes in the NIR preceded those in the soft X-rays by more than 2 weeks, indicating a disk origin of the NIR emission and providing a measure of the viscous timescale. A sudden onset of NIR flaring of ~0.5 mag on a timescale of 1 day was also observed during this period. We present spectral energy distributions, including radio data, and discuss possible sources for the optical/NIR emission. We conclude that, in the hard state, this emission probably originates in the optically thin part of a jet and that in none of the X-ray states is X-ray reprocessing the dominant source of optical/NIR emission. Finally, comparing the light curves from the all-sky monitor (ASM) and Proportional Counter Array (PCA) instruments, we find that the X-ray/NIR delay depends critically on the sensitivity of the X-ray detector, with the delay inferred from the PCA (if present at all) being a factor of 3-6 times shorter than the delay inferred from the ASM; this may be important in interpreting previously reported X-ray-optical

  18. Preparation and Optical Properties of Infrared Transparent 3Y-TZP Ceramics

    Directory of Open Access Journals (Sweden)

    Chuanfeng Wang

    2017-04-01

    Full Text Available In the present study, a tough tetragonal zirconia polycrystalline (Y-TZP material was developed for use in high-speed infrared windows and domes. The influence of the preparation procedure and the microstructure on the material’s optical properties was evaluated by SEM and FT-IR spectroscopy. It was revealed that a high transmittance up to 77% in the three- to five-micrometer IR region could be obtained when the sample was pre-sintered at 1225 °C and subjected to hot isostatic pressing (HIP at 1275 °C for two hours. The infrared transmittance and emittance at elevated temperature were also examined. The in-line transmittance remained stable as the temperature increased to 427 °C, with degradation being observed only near the infrared cutoff edge. Additionally, the emittance property of 3Y-TZP ceramic at high temperature was found to be superior to those of sapphire and spinel. Overall, the results indicate that Y-TZP ceramic is a potential candidate for high-speed infrared windows and domes.

  19. Near-Infrared Keck Interferometer and IOTA Closure Phase Observations of Wolf-Rayet stars

    Science.gov (United States)

    Rajagopal, J.; Wallace, D.; Barry, R.; Richardson, L. J.; Traub, W.; Danchi, W. C.

    We present first results from observations of a small sample of IR-bright Wolf-Rayet stars with the Keck Interferometer in the near-infrared, and with the IONIC beam three-telescope beam combiner at the Infrared and Optical Telescope Array (IOTA) observatory. The former results were obtained as part of shared-risk observations in commissioning the Keck Interferometer and form a subset of a high-resolution study of dust around Wolf-Rayet stars using multiple interferometers in progress in our group. The latter results are the first closure phase observations of these stars in the near-infrared in a separated telescope interferometer. Earlier aperture-masking observations with the Keck-I telescope provide strong evidence that dust-formation in late-type WC stars are a result of wind-wind collision in short-period binaries.Our program with the Keck interferometer seeks to further examine this paradigm at much higher resolution. We have spatially resolved the binary in the prototypical dusty WC type star WR 140. WR 137, another episodic dust-producing star, has been partially resolved for the first time, providing the first direct clue to its possible binary nature.We also include WN stars in our sample to investigate circumstellar dust in this other main sub-type of WRs. We have been unable to resolve any of these, indicating a lack of extended dust.Complementary observations using the MIDI instrument on the VLTI in the mid-infrared are presented in another contribution to this workshop.

  20. Imaging of solid tumor using near-infrared emitting purple bacteria

    International Nuclear Information System (INIS)

    Moon, Sung Min; Min, Jung Joon; Kim, Sun A; Choy, Hyon E.; Bom, Hee Seung

    2005-01-01

    Rhodobacter sphaeroides 2.4.1 is α-3 purple nonsulfur eubacterium with an extensive metabolism. Under anaerobic conditions, it is able to grow by photosynthesis, respiration and fermentation. When grown photosynthetically, it uses wavelengths of light in the near-infrared and contains a reaction center that is the peripheral light-harvesting (LH2) complex. These molecules absorb and emit near-infrared light. Using this near-infrared fluorescent bacterial we investigated its targeting capacity of solid tumor in small animals. R. sphaeroides 2.4.1 strains were cultured in sistrons minimal medium A (SIS) at 32 C. Xenograft tumor model has been established by subcutaneous injection of CT26 mouse colon cancer cell line. 1X10 8 Rhodobacter sphaeroides cells suspended in 100 ul of PBS were injected via tail vein with 1-cc insulin syringe into tumor bearing mouse. In vivo fluorescence imaging has been done after 20 min to 30 days of purple bacteria using indocyanine (ICG) emission filter (Em=810∼835 nm). Near-infrared imaging signal from Rhodobacter sphaeroides was initially detected at liver for 3 days but at the necrotic region of tumor mass thereafter. Total photon flux measured 5.5X10 8 (p/s/cm 2 /sr) at Day 1. Also it was increased to 7.8X10 8 (p/s/cm 2 /sr) at 12 day. One of important characteristic is that the signal appeared only at central necrosis area. It has been monitored for 36 day. We successfully imaged cancer with near-infrared fluorescence bacteria. Our result indicate that near-infrared fluorescence purple bacteria are able to be used to monitor bacterial trafficking in living tumor models

  1. Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

    Science.gov (United States)

    Soller, Babs R.; Idwasi, Patrick O.; Balaguer, Jorge; Levin, Steven; Simsir, Sinan A.; Vander Salm, Thomas J.; Collette, Helen; Heard, Stephen O.

    2003-01-01

    OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and

  2. Crossing the Resolution Limit in Near-Infrared Imaging of Silicon Chips: Targeting 10-nm Node Technology

    Directory of Open Access Journals (Sweden)

    Krishna Agarwal

    2015-05-01

    Full Text Available The best reported resolution in optical failure analysis of silicon chips is 120-nm half pitch demonstrated by Semicaps Private Limited, whereas the current and future industry requirement for 10-nm node technology is 100-nm half pitch. We show the first experimental evidence for resolution of features with 100-nm half pitch buried in silicon (λ/10.6, thus fulfilling the industry requirement. These results are obtained using near-infrared reflection-mode imaging using a solid immersion lens. The key novel feature of our approach is the choice of an appropriately sized collection pinhole. Although it is usually understood that, in general, resolution is improved by using the smallest pinhole consistent with an adequate signal level, it is found that in practice for silicon chips there is an optimum pinhole size, determined by the generation of induced currents in the sample. In failure analysis of silicon chips, nondestructive imaging is important to avoid disturbing the functionality of integrated circuits. High-resolution imaging techniques like SEM or TEM require the transistors to be exposed destructively. Optical microscopy techniques may be used, but silicon is opaque in the visible spectrum, mandating the use of near-infrared light and thus poor resolution in conventional optical microscopy. We expect our result to change the way semiconductor failure analysis is performed.

  3. Effects of Mo-doping on microstructure and near-infrared shielding performance of hydrothermally prepared tungsten bronzes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qingjuan; Li, Can; Xu, Wenai; Zhao, Xiaolin; Zhu, Jingxin [Laboratory of Green Energy Materials and Storage Systems, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Jiang, Haiwei, E-mail: tyjmx@163.com [Laboratory of Green Energy Materials and Storage Systems, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Kang, Litao, E-mail: kangltxy@163.com [Laboratory of Green Energy Materials and Storage Systems, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences (China); Zhao, Zhe [School of Materials Science & Engineering, Shanghai Institute of Technology, Shanghai 201418 (China)

    2017-03-31

    Highlights: • Mo-doped tungsten bronzes were hydrothermally synthesized at 80 °C. • Samples transformed from hexagonal to monoclinic structure with Mo-content increase. • 1.5% Mo-doped samples show the best near-infrared shielding performance. • High Mo-doping weakens localized surface plasmon resonance (LSPR) absorption and thus NIR shielding performance. • Small polaron absorption seems to be less affected by Mo-doping. - Abstract: Both Mo and W belong to VIB-sub-group, and possess similar ionic radii, electronegativity and oxide lattice configuration. Herein, Mo-doped (0–80 at.%) tungsten bronzes, M{sub x}WO{sub 3}, were hydrothermally prepared to systematically explore the influence of Mo-doping on their micro-structure and optical performance. The products adopted a hexagonal structure within 6 at.% Mo-doping, and transformed into a monoclinic phase with higher Mo-doping content. Further tests suggested that 1.5 at.% Mo-doping is beneficial for the formation of pure hexagonal phase and uniform nano-rod morphology. Optical measures showed that all samples exhibited high and comparable visible transmittance (70–80%), but a very different near infrared (NIR) shielding ability. The sample doped with 1.5 at.% Mo demonstrated the best NIR shielding ability with a transmittance minimum of 20% at 1300 nm. Further increase of Mo-doping dosage remarkably deteriorated NIR shielding ability by depressing the absorption of localized surface plasmon resonance (LSPR). However, the optical absorption from small-polaron was less influenced by the introduction of Mo. As a result, Mo-doping caused an evident blue shift of the infrared absorption peaks from 1350 to 750 nm.

  4. Experimental realization of optical lumped nanocircuits at infrared wavelengths.

    Science.gov (United States)

    Sun, Yong; Edwards, Brian; Alù, Andrea; Engheta, Nader

    2012-01-29

    The integration of radiofrequency electronic methodologies on micro- as well as nanoscale platforms is crucial for information processing and data-storage technologies. In electronics, radiofrequency signals are controlled and manipulated by 'lumped' circuit elements, such as resistors, inductors and capacitors. In earlier work, we theoretically proposed that optical nanostructures, when properly designed and judiciously arranged, could behave as nanoscale lumped circuit elements--but at optical frequencies. Here, for the first time we experimentally demonstrate a two-dimensional optical nanocircuit at mid-infrared wavelengths. With the guidance of circuit theory, we design and fabricate arrays of Si3N4 nanorods with specific deep subwavelength cross-sections, quantitatively evaluate their equivalent impedance as lumped circuit elements in the mid-infrared regime, and by Fourier transform infrared spectroscopy show that these nanostructures can indeed function as two-dimensional optical lumped circuit elements. We further show that the connections among nanocircuit elements, in particular whether they are in series or in parallel combination, can be controlled by the polarization of impinging optical signals, realizing the notion of 'stereo-circuitry' in metatronics-metamaterials-inspired optical circuitry.

  5. Inverted cones grating for flexible metafilter at optical and infrared frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Brückner, Jean-Baptiste; Le Rouzo, Judikaël; Escoubas, Ludovic [Aix-Marseille Université, IM2NP, CNRS-UMR 7334, Domaine Universitaire de Saint-Jérôme, Service 231, 13397 Marseille Cedex 20 (France); Brissonneau, Vincent; Dubarry, Christophe [CEA-LITEN DTNM, 17 Avenue des Martyrs, 38054 Grenoble cedex 9 (France); Ferchichi, Abdelkerim; Gourgon, Cécile [LTM CNRS, Laboratoire des Technologies de la Microélectronique 17 Avenue des Martyrs, 38054 Grenoble cedex 9 (France); Berginc, Gérard [Thales Optronique S.A., 2 Avenue Gay Lussac, 78990 Elancourt (France)

    2014-02-24

    By combining the antireflective properties from gradual changes in the effective refractive index and cavity coupling from cone gratings and the efficient optical behavior of a tungsten film, a flexible filter showing very broad antireflective properties from the visible to short wavelength infrared region and, simultaneously, a mirror-like behavior in the mid-infrared wavelength region and long-infrared wavelength region has been conceived. Nanoimprint technology has permitted the replication of inverted cone patterns on a large scale on a flexible polymer, afterwards coated with a thin tungsten film. This optical metafilter is of great interest in the stealth domain where optical signature reduction from the optical to short wavelength infrared region is an important matter. As it also acts as selective thermal emitter offering a good solar-absorption/infrared-emissivity ratio, interests are found as well for solar heating applications.

  6. Effect of multiple circular holes Fraunhofer diffraction for the infrared optical imaging

    Science.gov (United States)

    Lu, Chunlian; Lv, He; Cao, Yang; Cai, Zhisong; Tan, Xiaojun

    2014-11-01

    With the development of infrared optics, infrared optical imaging systems play an increasingly important role in modern optical imaging systems. Infrared optical imaging is used in industry, agriculture, medical, military and transportation. But in terms of infrared optical imaging systems which are exposed for a long time, some contaminations will affect the infrared optical imaging. When the contamination contaminate on the lens surface of the optical system, it would affect diffraction. The lens can be seen as complementary multiple circular holes screen happen Fraunhofer diffraction. According to Babinet principle, you can get the diffraction of the imaging system. Therefore, by studying the multiple circular holes Fraunhofer diffraction, conclusions can be drawn about the effect of infrared imaging. This paper mainly studies the effect of multiple circular holes Fraunhofer diffraction for the optical imaging. Firstly, we introduce the theory of Fraunhofer diffraction and Point Spread Function. Point Spread Function is a basic tool to evaluate the image quality of the optical system. Fraunhofer diffraction will affect Point Spread Function. Then, the results of multiple circular holes Fraunhofer diffraction are given for different hole size and hole spacing. We choose the hole size from 0.1mm to 1mm and hole spacing from 0.3mm to 0.8mm. The infrared wavebands of optical imaging are chosen from 1μm to 5μm. We use the MATLAB to simulate light intensity distribution of multiple circular holes Fraunhofer diffraction. Finally, three-dimensional diffraction maps of light intensity are given to contrast.

  7. Development of an optical resonator with high-efficient output coupler for the JAERI far-infrared free-electron laser

    International Nuclear Information System (INIS)

    Nagai, Ryoji; Hajima, Ryoichi; Nishimori, Nobuyuki; Sawamura, Masaru; Kikuzawa, Nobuhiro; Shizuma, Toshiyuki; Minehara, Eisuke

    2001-01-01

    An optical resonator with a high-efficient output coupler was developed for the JAERI far-infrared free-electron laser. The optical resonator is symmetrical near-concentric geometry with an insertable scraper output coupler. As a result of the development of the optical resonator, the JAERI-FEL has been successfully, lased with averaged power over 1 kW. Performance of the optical resonator with the output coupler was evaluated at optical wavelength of 22 μm by using an optical mode calculation code. The output coupling and diffractive loss with a dominant eigen-mode of the resonator were calculated using an iterative computation called Fox-Li procedure. An efficiency factor of the optical resonator was introduced for the evaluation of the optical resonator performance. The efficiency factor was derived by the amount of the output coupling and diffractive loss of the optical resonator. It was found that the optical resonator with the insertable scraper coupler was the most suitable to a high-power and high-efficient far-infrared free-electron laser. (author)

  8. Optical/Infrared Signatures for Space-Based Remote Sensing

    National Research Council Canada - National Science Library

    Picard, R. H; Dewan, E. M; Winick, J. R; O'Neil, R. R

    2007-01-01

    This report describes work carried out under the Air Force Research Laboratory's basic research task in optical remote-sensing signatures, entitled Optical / Infrared Signatures for Space-Based Remote Sensing...

  9. Near Infrared Spectroscopic Identification of Alkyl Aromatic Esters and Phenyl Ketones

    Science.gov (United States)

    Nelyubov, D. V.; Vazhenin, D. A.; Kudriavtsev, A. A.; Buzolina, A. Yu.

    2018-03-01

    Bands characterizing the content of carbon atoms in alkyl (7177-7205 cm-1) and phenyl structural fragments (9175-9192 cm-1) in organic molecules were revealed by studying the near infrared spectra of such compounds. The optical density at the maxima of these absorption bands was shown to depend strongly on the fraction of carbon atoms in the corresponding fragments. The developed models proved to be adequate for determining the fraction of carbon atoms in alkyl aromatic esters and phenyl ketones. The feasibility of modeling the molecular structure of alkyl aromatic esters using regression models was demonstrated for the product of the condensation of oleic acid and benzyl alcohol.

  10. WTS: A near-infrared transit survey

    Directory of Open Access Journals (Sweden)

    Hodgkin Simon

    2013-04-01

    Full Text Available The WFCAM Transit Survey is a transiting planet survey running on the United Kingdom Infrared Telescope targeting M dwarf stars in the near infrared. The survey has been operating since 2007 and gathering photometric time series of about 15000 M dwarf stars brighter than J = 17 mag. We identified and followed-up planet candidates from the most complete field and found two hot Jupiters around non-M dwarf hosts (WTS-1b & WTS-2b but found no planets around the M dwarfs.

  11. Tunable Fano resonator using multilayer graphene in the near-infrared region

    Science.gov (United States)

    Zhou, Chaobiao; Liu, Guoqin; Ban, Guoxun; Li, Shiyu; Huang, Qingzhong; Xia, Jinsong; Wang, Yi; Zhan, Mingsheng

    2018-03-01

    Fano resonance (FR) holds promising applications for high performance optoelectronic devices due to its strong enhancement of light-matter interactions. In this work, we experimentally demonstrate a tunable FR in a photonic crystal nanoresonator (PCR), including the effects of structural parameters and graphene nanosheets with different layer numbers. The results show that the intensity and position of Fano peaks can be tuned via altering the lattice constant and the hole radius of PCR due to the variation of the effective refractive index. More importantly, we experimentally study the interaction between sharp FR with multilayer graphene. The results indicate that the FR transmission spectrum can be efficiently adjusted with the layer number of graphene, and the largest change in transmission (˜44%) is achieved with three-layer graphene because of high conductivity. These consequences may lead to efficient and tunable electro-optical modulators, biosensors, and optical switches in the near-infrared region.

  12. Probing evolutionary population synthesis models in the near infrared with early-type galaxies

    Science.gov (United States)

    Dahmer-Hahn, Luis Gabriel; Riffel, Rogério; Rodríguez-Ardila, Alberto; Martins, Lucimara P.; Kehrig, Carolina; Heckman, Timothy M.; Pastoriza, Miriani G.; Dametto, Natacha Z.

    2018-06-01

    We performed a near-infrared (NIR; ˜1.0 -2.4 μm) stellar population study in a sample of early-type galaxies. The synthesis was performed using five different evolutionary population synthesis libraries of models. Our main results can be summarized as follows: low-spectral-resolution libraries are not able to produce reliable results when applied to the NIR alone, with each library finding a different dominant population. The two newest higher resolution models, on the other hand, perform considerably better, finding consistent results to each other and to literature values. We also found that optical results are consistent with each other even for lower resolution models. We also compared optical and NIR results and found out that lower resolution models tend to disagree in the optical and in the NIR, with higher fraction of young populations in the NIR and dust extinction ˜1 mag higher than optical values. For higher resolution models, optical and NIR results tend to agree much better, suggesting that a higher spectral resolution is fundamental to improve the quality of the results.

  13. Emission characteristics of the Yb3+-sensitized Tm3+-doped optical fiber upon pumping with infrared LED

    International Nuclear Information System (INIS)

    Htein, Lin; Fan, Weiwei; Han, Won-Taek

    2014-01-01

    Near infrared emissions at 975, 1040 and 1450 nm of the Yb 3+ -sensitized Tm 3+ -doped optical fiber were obtained upon simultaneous excitation of Yb 3+ and Tm 3+ ions using the infrared LED. -- Highlights: • A novel pumping scheme for 1450 nm emission from 3 H 4 → 3 F 4 transition of Tm was demonstrated. • The absorption bands of Yb and Tm located within 690–970 nm were simultaneously excited with the IR LED. • Near infrared emissions at 975, 1040 and 1450 nm were obtained. • The Yb 3+ /Tm 3+ -codoped fiber showed the good spectroscopic quality and the increase of radiative lifetime of 3 H 4 level. • This LED pumping scheme can be useful for low-cost S-band fiber laser/amplifier applications

  14. The Kepler and K2 Near-Infrared Transit Survey (KNITS)

    Science.gov (United States)

    Colon, Knicole; Rodriguez, Joseph E.; Barentsen, Geert; Cardoso, Jose Vinicius de Miranda; Vanderburg, Andrew

    2018-01-01

    NASA's Kepler mission discovered a plethora of transiting exoplanets after observing a single region of the Galaxy for four years. After a second reaction wheel failed, NASA's Kepler spacecraft was repurposed as K2 to observe different fields along the ecliptic in ~80 day campaigns. To date, K2 has discovered ~130 exoplanets along with another ~400 candidates. The exoplanets that have been confirmed or validated from Kepler and K2 have been primarily subject to spectroscopic observations, high-resolution imaging, or statistical methods. However, most of these, along with all the remaining candidate exoplanets, have had no follow-up transit photometry. In addition, recent studies have shown that for single-planet systems, statistical validation alone can be unreliable and additional follow-up observations are required to reveal the true nature of the system. I will present the latest results from an ongoing program to use the 3.5-meter WIYN telescope at Kitt Peak National Observatory for near-infrared transit photometry of Kepler and K2 exoplanets and candidates. Our program of high-precision, high-cadence, high-spatial-resolution near-infrared transit photometry is providing new measurements of the transit ephemerides and planetary radii as well as weeding out false positives lurking within the candidate lists. To date, 25 K2 and 5 Kepler targets have been observed with WIYN. I will also describe upcoming observations with WIYN that will take place in January 2018 as part of a campaign to observe exoplanet transits in the near-infrared simultaneously with the Kepler spacecraft during K2 Campaign 16. Our program ultimately provides a vetted sample of exoplanets that could be targeted in the future by NASA’s James Webb Space Telescope (JWST) and also demonstrates WIYN’s capabilities for observations of exoplanets to be discovered by NASA's all-sky Transiting Exoplanet Survey Satellite (TESS).Data presented herein were obtained at the WIYN Observatory from

  15. Near-infrared reflectance analysis by Gauss-Jordan linear algebra

    International Nuclear Information System (INIS)

    Honigs, D.E.; Freelin, J.M.; Hieftje, G.M.; Hirschfeld, T.B.

    1983-01-01

    Near-infrared reflectance analysis is an analytical technique that uses the near-infrared diffuse reflectance of a sample at several discrete wavelengths to predict the concentration of one or more of the chemical species in that sample. However, because near-infrared bands from solid samples are both abundant and broad, the reflectance at a given wavelength usually contains contributions from several sample components, requiring extensive calculations on overlapped bands. In the present study, these calculations have been performed using an approach similar to that employed in multi-component spectrophotometry, but with Gauss-Jordan linear algebra serving as the computational vehicle. Using this approach, correlations for percent protein in wheat flour and percent benzene in hydrocarbons have been obtained and are evaluated. The advantages of a linear-algebra approach over the common one employing stepwise regression are explored

  16. NEAR-INFRARED POLARIMETRY OF A NORMAL SPIRAL GALAXY VIEWED THROUGH THE TAURUS MOLECULAR CLOUD COMPLEX

    International Nuclear Information System (INIS)

    Clemens, Dan P.; Cashman, L. R.; Pavel, M. D.

    2013-01-01

    Few normal galaxies have been probed using near-infrared polarimetry, even though it reveals magnetic fields in the cool interstellar medium better than either optical or radio polarimetry. Deep H-band (1.6 μm) linear imaging polarimetry toward Taurus serendipitously included the galaxy 2MASX J04412715+2433110 with adequate sensitivity and resolution to map polarization across nearly its full extent. The observations revealed the galaxy to be a steeply inclined (∼75°) disk type with a diameter, encompassing 90% of the Petrosian flux, of 4.2 kpc at a distance of 53 Mpc. Because the sight line passes through the Taurus Molecular Cloud complex, the foreground polarization needed to be measured and removed. The foreground extinction A V of 2.00 ± 0.10 mag and reddening E(H – K) of 0.125 ± 0.009 mag were also assessed and removed, based on analysis of Two Micron All Sky Survey, UKIRT Infrared Deep Sky Survey, Spitzer, and Wide-field Infrared Survey Explorer photometry using the Near-Infrared Color Excess, NICE-Revisited, and Rayleigh-Jeans Color Excess methods. Corrected for the polarized foreground, the galaxy polarization values range from 0% to 3%. The polarizations are dominated by a disk-parallel magnetic field geometry, especially to the northeast, while either a vertical field or single scattering of bulge light produces disk-normal polarizations to the southwest. The multi-kiloparsec coherence of the magnetic field revealed by the infrared polarimetry is in close agreement with short-wavelength radio synchrotron observations of edge-on galaxies, indicating that both cool and warm interstellar media of disk galaxies may be threaded by common magnetic fields.

  17. Early tumor detection afforded by in vivo imaging of near-infrared II fluorescence.

    Science.gov (United States)

    Tao, Zhimin; Dang, Xiangnan; Huang, Xing; Muzumdar, Mandar D; Xu, Eric S; Bardhan, Neelkanth Manoj; Song, Haiqin; Qi, Ruogu; Yu, Yingjie; Li, Ting; Wei, Wei; Wyckoff, Jeffrey; Birrer, Michael J; Belcher, Angela M; Ghoroghchian, P Peter

    2017-07-01

    Cell-intrinsic reporters such as luciferase (LUC) and red fluorescent protein (RFP) have been commonly utilized in preclinical studies to image tumor growth and to monitor therapeutic responses. While extrinsic reporters that emit near infrared I (NIR-I: 650-950 nm) or near-infrared II (NIR-II: 1000-1700 nm) optical signals have enabled minimization of tissue autofluorescence and light scattering, it has remained unclear as to whether their use has afforded more accurate tumor imaging in small animals. Here, we developed a novel optical imaging construct comprised of rare earth lanthanide nanoparticles coated with biodegradable diblock copolymers and doped with organic fluorophores, generating NIR-I and NIR-II emissive bands upon optical excitation. Simultaneous injection of multiple spectrally-unique nanoparticles into mice bearing tumor implants established via intraperitoneal dissemination of LUC + /RFP + OVCAR-8 ovarian cancer cells enabled direct comparisons of imaging with extrinsic vs. intrinsic reporters, NIR-II vs. NIR-I signals, as well as targeted vs. untargeted exogenous contrast agents in the same animal and over time. We discovered that in vivo optical imaging at NIR-II wavelengths facilitates more accurate detection of smaller and earlier tumor deposits, offering enhanced sensitivity, improved spatial contrast, and increased depths of tissue penetration as compared to imaging with visible or NIR-I fluorescent agents. Our work further highlights the hitherto underappreciated enhancements in tumor accumulation that may be achieved with intraperitoneal as opposed to intravenous administration of nanoparticles. Lastly, we found discrepancies in the fidelity of tumor uptake that could be obtained by utilizing small molecules for in vivo as opposed to in vitro targeting of nanoparticles to disseminated tumors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. High-Resolution Near-Infrared Spectroscopy of FU Orionis Objects

    Science.gov (United States)

    Hartmann, Lee; Hinkle, Kenneth; Calvet, Nuria

    2004-07-01

    We present an analysis of recent near-infrared, high-resolution spectra of the variable FU Ori objects. During a phase of rapid fading in optical brightness during 1997, V1057 Cyg exhibited shell absorption in first-overtone (v''-v'=2-0) CO lines, blueshifted by about 50 km s-1 from the system velocity. This shell component had not been seen previously, nor was it present in 1999, although some blueshifted absorption asymmetry is seen at the latter epoch. The appearance of this CO absorption shell is connected with the roughly contemporaneous appearance of blueshifted, low-excitation optical absorption lines with comparable low velocities; we suggest that this shell was also responsible for some of the peculiar emission features seen in red-optical spectra of V1057 Cyg. FU Ori continues to exhibit broad CO lines, with some evidence for the double-peaked profiles characteristic of an accretion disk; the line profiles are consistent with previous observations. Both FU Ori and V1057 Cyg continue to exhibit lower rotational broadening at 2.3 μm than at optical wavelengths, in agreement with the prediction of differentially rotating disk models; we have a marginal detection of the same effect in V1515 Cyg. The relative population of the first-overtone CO rotational levels in the FU Ori objects suggests low excitation temperatures. We compare disk models to the observations and find agreement with overall line strengths and rotational broadening, but the observed line profiles are generally less double-peaked than predicted. We suggest that the discrepancy in line profiles is due to turbulent motions in FU Ori disks, an effect qualitatively predicted by recent simulations of the magnetorotational instability in vertically stratified accretion disks. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under a cooperative agreement with the NSF, on behalf of the Gemini

  19. Near-infrared branding efficiently correlates light and electron microscopy.

    Science.gov (United States)

    Bishop, Derron; Nikić, Ivana; Brinkoetter, Mary; Knecht, Sharmon; Potz, Stephanie; Kerschensteiner, Martin; Misgeld, Thomas

    2011-06-05

    The correlation of light and electron microscopy of complex tissues remains a major challenge. Here we report near-infrared branding (NIRB), which facilitates such correlation by using a pulsed, near-infrared laser to create defined fiducial marks in three dimensions in fixed tissue. As these marks are fluorescent and can be photo-oxidized to generate electron contrast, they can guide re-identification of previously imaged structures as small as dendritic spines by electron microscopy.

  20. The Araucaria Project. The Distance to the Sculptor Group Galaxy NGC 7793 from Near-infrared Photometry of Cepheid Variables

    Energy Technology Data Exchange (ETDEWEB)

    Zgirski, Bartlomiej; Pietrzyński, Grzegorz; Wielgorski, Piotr; Narloch, Weronika; Graczyk, Dariusz [Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warsaw (Poland); Gieren, Wolfgang; Gorski, Marek [Universidad de Concepcion, Departamento de Astronomia, Casilla 160-C, Concepcion (Chile); Karczmarek, Paulina [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478, Warsaw (Poland); Kudritzki, Rolf-Peter; Bresolin, Fabio, E-mail: bzgirski@camk.edu.pl, E-mail: pietrzyn@camk.edu.pl, E-mail: pwielgor@camk.edu.pl, E-mail: wnarloch@camk.edu.pl, E-mail: darek@astro-udec.cl, E-mail: mgorski@astrouw.edu.pl, E-mail: wgieren@astro-udec.cl, E-mail: pkarczmarek@astrouw.edu.pl, E-mail: kud@ifa.hawaii.edu, E-mail: bresolin@ifa.hawaii.edu [Institute for Astronomy, University of Hawaii at Manoa, 2680 Woodlawn Drive, Honolulu HI 96822 (United States)

    2017-10-01

    Following the earlier discovery of classical Cepheid variables in the Sculptor Group spiral galaxy NGC 7793 from an optical wide-field imaging survey, we have performed deep near-infrared J - and K -band follow-up photometry of a subsample of these Cepheids to derive the distance to this galaxy with a higher accuracy than what was possible from optical photometry alone, by minimizing the effects of reddening and metallicity on the distance result. Combining our new near-infrared period–luminosity relations with previous optical photometry, we obtain a true distance modulus to NGC 7793 of (27.66 ± 0.04) mag (statistical) ±0.07 mag (systematic), i.e., a distance of (3.40 ± 0.17) Mpc. We also determine the mean reddening affecting the Cepheids to be E(B − V) = (0.08 ± 0.02) mag, demonstrating that there is significant dust extinction intrinsic to the galaxy in addition to the small foreground extinction. A comparison of the new, improved Cepheid distance to earlier distance determinations of NGC 7793 from the Tully–Fisher and TRGB methods is in agreement within the reported uncertainties of these previous measurements.

  1. Dispersion properties and low infrared optical losses in epitaxial AlN on sapphire substrate in the visible and infrared range

    International Nuclear Information System (INIS)

    Soltani, A.; Stolz, A.; Gerbedoen, J.-C.; Rousseau, M.; Bourzgui, N.; De Jaeger, J.-C.; Charrier, J.; Mattalah, M.; Barkad, H. A.; Mortet, V.; BenMoussa, A.

    2014-01-01

    Optical waveguiding properties of a thick wurtzite aluminum nitride highly [002]-textured hetero-epitaxial film on (001) basal plane of sapphire substrate are studied. The physical properties of the film are determined by X-ray diffraction, atomic force microscopy, microRaman, and photocurrent spectroscopy. The refractive index and the thermo-optic coefficients are determined by m-lines spectroscopy using the classical prism coupling technique. The optical losses of this planar waveguide are also measured in the spectral range of 450–1553 nm. The lower value of optical losses is equal to 0.7 dB/cm at 1553 nm. The optical losses due to the surface scattering are simulated showing that the contribution is the most significant at near infrared wavelength range, whereas the optical losses are due to volume scattering and material absorption in the visible range. The good physical properties and the low optical losses obtained from this planar waveguide are encouraging to achieve a wide bandgap optical guiding platform from these aluminum nitride thin films

  2. Dispersion properties and low infrared optical losses in epitaxial AlN on sapphire substrate in the visible and infrared range

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, A., E-mail: ali.soltani@iemn.univ-lille1.fr; Stolz, A.; Gerbedoen, J.-C.; Rousseau, M.; Bourzgui, N.; De Jaeger, J.-C. [Institut d' Électronique, Microélectronique et Nanotechnologie, UMR-CNRS 8520, PRES Université Lille Nord de France, Cité Scientifique, Avenue Poincaré, CS 60069, 59652 Villeneuve d' Ascq Cedex (France); Charrier, J. [Fonctions Optiques pour les Technologies de l' informatiON, UMR-CNRS 6082, ENSSAT 6, rue de Kerampont, CS 80518, 22305 Lannion Cedex (France); Mattalah, M. [Laboratoire de Microélectronique, Université Djilali Liabes, 22000 Sidi Bel Abbes (Algeria); Barkad, H. A. [Institut Universitaire Technologique Industriel, Université de Djibouti, Avenue Georges Clémenceau, BP 1904 Djibouti (Djibouti); Mortet, V. [Institute of Physics of Academy of Sciences of Czech Republic, Fyzikální ústav AV CR, v.v.i., Na Slovance 1999/2 (Czech Republic); BenMoussa, A. [Solar Terrestrial Center of Excellence, Royal Observatory of Belgium, Circular 3, B-1180 Brussels (Belgium)

    2014-04-28

    Optical waveguiding properties of a thick wurtzite aluminum nitride highly [002]-textured hetero-epitaxial film on (001) basal plane of sapphire substrate are studied. The physical properties of the film are determined by X-ray diffraction, atomic force microscopy, microRaman, and photocurrent spectroscopy. The refractive index and the thermo-optic coefficients are determined by m-lines spectroscopy using the classical prism coupling technique. The optical losses of this planar waveguide are also measured in the spectral range of 450–1553 nm. The lower value of optical losses is equal to 0.7 dB/cm at 1553 nm. The optical losses due to the surface scattering are simulated showing that the contribution is the most significant at near infrared wavelength range, whereas the optical losses are due to volume scattering and material absorption in the visible range. The good physical properties and the low optical losses obtained from this planar waveguide are encouraging to achieve a wide bandgap optical guiding platform from these aluminum nitride thin films.

  3. Stabilization and operation of porous silicon photonic structures from near-ultraviolet to near-infrared using high-pressure water vapor annealing

    International Nuclear Information System (INIS)

    Gelloz, Bernard; Koshida, Nobuyoshi

    2010-01-01

    The effects of high-pressure water vapor annealing (HWA), electrochemical oxidation, and substrate resistivity on the properties of porous silicon Bragg mirrors and photoluminescent cavities have been investigated. The photonic structures treated by HWA show very good stability upon ageing in air whereas as-formed structures exhibit significant drifts in their optical properties. Using HWA with lightly doped porous silicon, the structure transparency is enhanced sufficiently to enable the possible photonic operation in the near-ultraviolet. However, the index contrast achievable with these structures is very low in the visible and near-infrared. Useful index contrasts in this range can be achieved with either lightly doped porous silicon treated by electrochemical oxidation and HWA or heavily doped porous silicon treated by HWA.

  4. THE MID-INFRARED AND NEAR-ULTRAVIOLET EXCESS EMISSIONS OF QUIESCENT GALAXIES ON THE RED SEQUENCE

    International Nuclear Information System (INIS)

    Ko, Jongwan; Lee, Jong Chul; Hwang, Ho Seong; Sohn, Young-Jong

    2013-01-01

    We study the mid-infrared (IR) and near-ultraviolet (UV) excess emissions of spectroscopically selected quiescent galaxies on the optical red sequence. We use the Wide-field Infrared Survey Explorer mid-IR and Galaxy Evolution Explorer near-UV data for a spectroscopic sample of galaxies in the Sloan Digital Sky Survey Data Release 7 to study the possible connection between quiescent red-sequence galaxies with and without mid-IR/near-UV excess. Among 648 12 μm detected quiescent red-sequence galaxies without Hα emission, 26% and 55% show near-UV and mid-IR excess emissions, respectively. When we consider only bright (M r n 4000 than those without mid-IR and near-UV excess emissions. We also find that mid-IR weighted mean stellar ages of quiescent red-sequence galaxies with mid-IR excess are larger than those with near-UV excess, and smaller than those without mid-IR and near-UV excess. The environmental dependence of the fraction of quiescent red-sequence galaxies with mid-IR and near-UV excess seems strong even though the trends of quiescent red-sequence galaxies with near-UV excess differ from those with mid-IR excess. These results indicate that the recent star formation traced by near-UV (∼< 1 Gyr) and mid-IR (∼< 2 Gyr) excess is not negligible among nearby, quiescent, red, early-type galaxies. We suggest a possible evolutionary scenario of quiescent red-sequence galaxies from quiescent red-sequence galaxies with near-UV excess to those with mid-IR excess to those without near-UV and mid-IR excess.

  5. Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots.

    Science.gov (United States)

    Geiregat, Pieter; Houtepen, Arjan J; Sagar, Laxmi Kishore; Infante, Ivan; Zapata, Felipe; Grigel, Valeriia; Allan, Guy; Delerue, Christophe; Van Thourhout, Dries; Hens, Zeger

    2018-01-01

    Colloidal quantum dots (QDs) raise more and more interest as solution-processable and tunable optical gain materials. However, especially for infrared active QDs, optical gain remains inefficient. Since stimulated emission involves multifold degenerate band-edge states, population inversion can be attained only at high pump power and must compete with efficient multi-exciton recombination. Here, we show that mercury telluride (HgTe) QDs exhibit size-tunable stimulated emission throughout the near-infrared telecom window at thresholds unmatched by any QD studied before. We attribute this unique behaviour to surface-localized states in the bandgap that turn HgTe QDs into 4-level systems. The resulting long-lived population inversion induces amplified spontaneous emission under continuous-wave optical pumping at power levels compatible with solar irradiation and direct current electrical pumping. These results introduce an alternative approach for low-threshold QD-based gain media based on intentional trap states that paves the way for solution-processed infrared QD lasers and amplifiers.

  6. Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots

    Science.gov (United States)

    Geiregat, Pieter; Houtepen, Arjan J.; Sagar, Laxmi Kishore; Infante, Ivan; Zapata, Felipe; Grigel, Valeriia; Allan, Guy; Delerue, Christophe; van Thourhout, Dries; Hens, Zeger

    2018-01-01

    Colloidal quantum dots (QDs) raise more and more interest as solution-processable and tunable optical gain materials. However, especially for infrared active QDs, optical gain remains inefficient. Since stimulated emission involves multifold degenerate band-edge states, population inversion can be attained only at high pump power and must compete with efficient multi-exciton recombination. Here, we show that mercury telluride (HgTe) QDs exhibit size-tunable stimulated emission throughout the near-infrared telecom window at thresholds unmatched by any QD studied before. We attribute this unique behaviour to surface-localized states in the bandgap that turn HgTe QDs into 4-level systems. The resulting long-lived population inversion induces amplified spontaneous emission under continuous-wave optical pumping at power levels compatible with solar irradiation and direct current electrical pumping. These results introduce an alternative approach for low-threshold QD-based gain media based on intentional trap states that paves the way for solution-processed infrared QD lasers and amplifiers.

  7. Synthesis and Properties of Sulfhydryl-Reactive Near-Infrared Cyanine Fluorochromes for Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Yuhui Lin

    2003-04-01

    Full Text Available Near-infrared fluorochromes (NIRF are useful compounds for diverse biotechnology applications and for in vivo biomedical imaging. Such NIRF must have high quantum yield, be biocompatible, and be conjugatable to a wide variety of proteins, peptides, and other affinity ligands. Here, we describe the synthesis of four new nonsymmetrical sulfhydryl-reactive cyanine NIRF with excellent optical and chemical properties. Each fluorochrome was designed to contain an iodoacetamido group that reacts specifically with sulfhydryl-containing molecules. The synthesized fluorochromes were used to label model peptides and sulfhydryl-containing biomolecules.

  8. Near-infrared deep brain stimulation via upconversion nanoparticle–mediated optogenetics

    Science.gov (United States)

    Chen, Shuo; Weitemier, Adam Z.; Zeng, Xiao; He, Linmeng; Wang, Xiyu; Tao, Yanqiu; Huang, Arthur J. Y.; Hashimotodani, Yuki; Kano, Masanobu; Iwasaki, Hirohide; Parajuli, Laxmi Kumar; Okabe, Shigeo; Teh, Daniel B. Loong; All, Angelo H.; Tsutsui-Kimura, Iku; Tanaka, Kenji F.; Liu, Xiaogang; McHugh, Thomas J.

    2018-02-01

    Optogenetics has revolutionized the experimental interrogation of neural circuits and holds promise for the treatment of neurological disorders. It is limited, however, because visible light cannot penetrate deep inside brain tissue. Upconversion nanoparticles (UCNPs) absorb tissue-penetrating near-infrared (NIR) light and emit wavelength-specific visible light. Here, we demonstrate that molecularly tailored UCNPs can serve as optogenetic actuators of transcranial NIR light to stimulate deep brain neurons. Transcranial NIR UCNP-mediated optogenetics evoked dopamine release from genetically tagged neurons in the ventral tegmental area, induced brain oscillations through activation of inhibitory neurons in the medial septum, silenced seizure by inhibition of hippocampal excitatory cells, and triggered memory recall. UCNP technology will enable less-invasive optical neuronal activity manipulation with the potential for remote therapy.

  9. Dynamics of polaritons in semiconductor microcavities near instability thresholds

    International Nuclear Information System (INIS)

    He, Peng-Bin

    2012-01-01

    A theoretical study is presented on the dynamics of polaritons in semiconductor microcavities near parametric instability thresholds. With upward or downward ramp of optical pump, different instability modes emerge in parameter space defined by damping and detuning. According to these modes, stationary short-wave, stationary periodic, oscillatory periodic, and oscillatory uniform parametric instabilities are distinguished. By multiple scale expansion, the dynamics near threshold can be described by a critical mode with a slowly varying amplitude for the last three instabilities. Furthermore, it is found that the evolutions of their amplitudes are governed by real or complex Ginzburg–Landau equations. -- Highlights: ► Phase diagrams for different instability in extended parameter space. ► Different instability modes near thresholds. ► Different envelop equations near thresholds obtained by multi-scale expansion.

  10. Micro- and nano-scale optical devices for high density photonic integrated circuits at near-infrared wavelengths

    Science.gov (United States)

    Chatterjee, Rohit

    In this research work, we explore fundamental silicon-based active and passive photonic devices that can be integrated together to form functional photonic integrated circuits. The devices which include power splitters, switches and lenses are studied starting from their physics, their design and fabrication techniques and finally from an experimental standpoint. The experimental results reveal high performance devices that are compatible with standard CMOS fabrication processes and can be easily integrated with other devices for near infrared telecom applications. In Chapter 2, a novel method for optical switching using nanomechanical proximity perturbation technique is described and demonstrated. The method which is experimentally demonstrated employs relatively low powers, small chip footprint and is compatible with standard CMOS fabrication processes. Further, in Chapter 3, this method is applied to develop a hitless bypass switch aimed at solving an important issue in current wavelength division multiplexing systems namely hitless switching of reconfigurable optical add drop multiplexers. Experimental results are presented to demonstrate the application of the nanomechanical proximity perturbation technique to practical situations. In Chapter 4, a fundamental photonic component namely the power splitter is described. Power splitters are important components for any photonic integrated circuits because they help split the power from a single light source to multiple devices on the same chip so that different operations can be performed simultaneously. The power splitters demonstrated in this chapter are based on multimode interference principles resulting in highly compact low loss and highly uniform power splitting to split the power of the light from a single channel to two and four channels. These devices can further be scaled to achieve higher order splitting such as 1x16 and 1x32 power splits. Finally in Chapter 5 we overcome challenges in device

  11. High-Contrast Near-Infrared Imaging Polarimetry of the Protoplanetary Disk around RY Tau

    Science.gov (United States)

    Takami, Michihiro; Karr, Jennifer L.; Hashimoto, Jun; Kim, Hyosun; Wisenewski, John; Henning, Thomas; Grady, Carol; Kandori, Ryo; Hodapp, Klaus W.; Kudo, Tomoyuki; hide

    2013-01-01

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at H-band at a high resolution (approx. 0.05) for the first time, using Subaru-HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with: (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk.

  12. HIGH-CONTRAST NEAR-INFRARED IMAGING POLARIMETRY OF THE PROTOPLANETARY DISK AROUND RY TAU

    Energy Technology Data Exchange (ETDEWEB)

    Takami, Michihiro; Karr, Jennifer L.; Kim, Hyosun; Chou, Mei-Yin [Institute of Astronomy and Astrophysics, Academia Sinica. P.O. Box 23-141, Taipei 10617, Taiwan (China); Hashimoto, Jun; Kandori, Ryo; Kusakabe, Nobuhiko; Kwon, Jungmi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Wisniewski, John [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States); Henning, Thomas; Brandner, Wolfgang [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Hodapp, Klaus W. [Institute for Astronomy, University of Hawaii, 640 North A' ohoku Place, Hilo, HI 96720 (United States); Kudo, Tomoyuki [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Itoh, Yoichi [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo, Hyogo 679-5313 (Japan); Momose, Munetake [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan); Mayama, Satoshi [The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan); Currie, Thayne [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON (Canada); Follette, Katherine B. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson AZ 85721 (United States); Abe, Lyu, E-mail: hiro@asiaa.sinica.edu.tw [Laboratoire Lagrange (UMR 7293), Universite de Nice-Sophia Antipolis, CNRS, Observatoire de la Cote d' Azur, 28 Avenue Valrose, F-06108 Nice Cedex 2 (France); and others

    2013-08-01

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at the H band at a high resolution ({approx}0.''05) for the first time, using Subaru/HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk.

  13. Vibrational Spectroscopy of Intramolecular Hydrogen Bonds in the Infrared and Near-Infrared Regions

    DEFF Research Database (Denmark)

    Schrøder, Sidsel Dahl

    and 1,4-diaminobutane). Experimentally, the hydrogen bonds have been studied with vibrational spectroscopy in the infrared and near-infrared regions. The focus is primarily on spectra recorded in the near-infrared regions, which in these studies are dominated by O-H and N-H stretching overtones....... Overtone spectra have been recorded with intracavity laser photoacoustic laser spectroscopy and conventional long path absorption spectroscopy. Theoretically, a combination of electronic structure calculations and local mode models have been employed to guide the assignment of bands in the vibrational......,4-diaminobutane, no sign of intramolecular N-H···N hydrogen bonds were identified in the overtone spectra. However, theoretical analyzes indicate that intramolecular N-H···N hydrogen bonds are present in all three diamines if two hydrogen atoms on one of the methylene groups are substituted with triuoromethyl...

  14. Near-infrared mapping of spiral barred galaxies

    International Nuclear Information System (INIS)

    Gallais, P.; Rouan, D.; Lacombe, F.

    1990-01-01

    The results presented were obtained with a 32 x 32 InSb charge injection device (CID) array cooled at 4K, at the f/36 cassegrain focus of the 3m60 Canada-France-Hawaii telescope with a spatial resolution of 0.5 inches per pixel. The objects presented are spiral barred galaxies mapped at J(1.25 microns), H(1.65 microns) and K(2.2 microns). The non-axisymetric potential due to the presence of a bar induces dynamical processes leading to the confinement of matter and peculiar morphologies. Infrared imaging is used to study the link between various components. Correlations with other wavelengths ranges and 2-colors diagrams ((J-H), (H-K)) lead to the identification of star forming regions, nucleus. Maps show structures connected to the central core. The question is, are they flowing away or toward the nucleus. Observations of M83 lead to several conclusions. The star forming region, detected in the visible and the infrared cannot be very compact and must extend to the edge of the matter concentration. The general shape of the near-infrared emission and the location of radio and 10 micron peaks suggest the confinement of matter between the inner Linblad resonances localized from CO measurements about 100 and 400 pc. The distribution of color indices in the arc from southern part to the star forming region suggests an increasing amount of gas and a time evolution eventually triggered by supernova explosions. Close to the direction of the bar, a bridge-like structure connects the arc to the nucleus with peculiar color indices

  15. Athermalization of infrared dual field optical system based on wavefront coding

    Science.gov (United States)

    Jiang, Kai; Jiang, Bo; Liu, Kai; Yan, Peipei; Duan, Jing; Shan, Qiu-sha

    2017-02-01

    Wavefront coding is a technology which combination of the optical design and digital image processing. By inserting a phase mask closed to the pupil plane of the optical system the wavefront of the system is re-modulated. And the depth of focus is extended consequently. In reality the idea is same as the athermalization theory of infrared optical system. In this paper, an uncooled infrared dual field optical system with effective focal as 38mm/19mm, F number as 1.2 of both focal length, operating wavelength varying from 8μm to 12μm was designed. A cubic phase mask was used at the pupil plane to re-modulate the wavefront. Then the performance of the infrared system was simulated with CODEV as the environment temperature varying from -40° to 60°. MTF curve of the optical system with phase mask are compared with the outcome before using phase mask. The result show that wavefront coding technology can make the system not sensitive to thermal defocus, and then realize the athermal design of the infrared optical system.

  16. Optical monitoring of kidney oxygenation and hemodynamics using a miniaturized near-infrared sensor

    Science.gov (United States)

    Shadgan, Babak; Macnab, Andrew; Nigro, Mark; Nguan, Christopher

    2017-02-01

    Background: Following human renal allograft transplant primary graft dysfunction can occur early in the postoperative period as a result of acute tubular necrosis, acute rejection, drug toxicity, and vascular complications. Successful treatment of graft dysfunction requires early detection and accurate diagnosis so that disease-specific medical and/or surgical intervention can be provided promptly. However, current diagnostic methods are not sensitive or specific enough, so that identifying the cause of graft dysfunction is problematic and often delayed. Near-infrared spectroscopy (NIRS) is an established optical method that monitors changes in tissue hemodynamics and oxygenation in real time. We report the feasibility of directly monitoring kidney the kidney in an animal model using NIRS to detect renal ischemia and hypoxia. Methods: In an anesthetized pig, a customized continuous wave spatially resolved (SR) NIRS sensor was fixed directly to the surface of the surgically exposed kidney. Changes in the concentration of oxygenated (O2Hb) deoxygenated (HHb) and total hemoglobin (THb) were monitored before, during and after renal artery clamping and reperfusion, and the resulting fluctuations in chromophore concentration from baseline used to measure variations in renal perfusion and oxygenation. Results: On clamping the renal artery THb and O2Hb concentrations declined progressively while HHb rose. With reperfusion after releasing the artery clamp O2Hb and THb rose while HHb fell with all parameters returning to its baseline. This pattern was similar in all three trials. Conclusion: This pilot study indicates that a miniaturized NIRS sensor applied directly to the surface of a kidney in an animal model can detect the onset of renal ischemia and tissue hypoxia. With modification, our NIRS-based method may contribute to early detection of renal vascular complications and graft dysfunction following renal transplant.

  17. GNIRS-DQS: A Gemini Near Infrared Spectrograph Distant Quasar Survey

    Science.gov (United States)

    Matthews, Brandon; Shemmer, Ohad; Brotherton, Michael S.; Andruchow, Ileana; Boroson, Todd A.; Brandt, W. Niel; Cellone, Sergio; Ferrero, Gabriel; Gallagher, Sarah; Green, Richard F.; Hennawi, Joseph F.; Lira, Paulina; Myers, Adam D.; Plotkin, Richard; Richards, Gordon T.; Runnoe, Jessie; Schneider, Donald P.; Shen, Yue; Strauss, Michael A.; Willott, Chris J.; Wills, Beverley J.

    2018-06-01

    We describe an ongoing three-year Gemini survey, launched in 2017, that will obtain near-infrared spectroscopy of 416 Sloan Digital Sky Survey (SDSS) quasars between redshifts of 1.5 and 3.5 in the ~1.0-2.5 μm band. These spectra will cover critical diagnostic emission lines, such as Mg II, Hβ, and [O III], in each source. This project will more than double the existing inventory of near-infrared spectra of luminous quasars at these redshifts, including the era of fast quasar growth. Additional rest frame ultraviolet coverage of at least the C IV emission line is provided by the SDSS spectrum of each source. We will utilize the spectroscopic inventory to determine the most accurate and precise quasar black hole masses, accretion rates, and redshifts, and use the results to derive improved prescriptions for UV-based proxies for these parameters. The improved redshifts will establish velocities of quasar outflows that interact with the host galaxies, and will help constrain how imprecise distance estimates bias quasar clustering measurements. Furthermore, our measurements will facilitate a more complete understanding of how the rest-frame UV-optical spectral properties depend on redshift and luminosity, and test whether the physical properties of the quasar central engine evolve over cosmic time. We will make our data immediately available to the public, provide reduced spectra via a dedicated website, and produce a catalog of measurements and fundamental quasar properties.

  18. Optical analysis and alignment applications using the infrared Smartt interferometer

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Bolen, P.D.; Liberman, I.; Seery, B.D.

    1981-01-01

    The possibility of using the infrared Smartt interferometer for optical analysis and alignment of infrared laser systems has been discussed previously. In this paper, optical analysis of the Gigawatt Test Facility at Los Alamos, as well as a deformable mirror manufactured by Rocketdyne, are discussed as examples of the technique. The possibility of optically characterizing, as well as aligning, pulsed high energy laser systems like Helios and Antares is discussed in some detail

  19. Tumour oxygen dynamics measured simultaneously by near-infrared spectroscopy and 19F magnetic resonance imaging in rats

    International Nuclear Information System (INIS)

    Xia Mengna; Kodibagkar, Vikram; Liu Hanli; Mason, Ralph P

    2006-01-01

    Simultaneous near-infrared spectroscopy (NIRS) and magnetic resonance imaging (MRI) were used to investigate the correlation between tumour vascular oxygenation and tissue oxygen tension dynamics in rat breast 13762NF tumours with respect to hyperoxic gas breathing. NIRS directly detected global variations in the oxygenated haemoglobin concentration (Δ[HbO 2 ]) within tumours and oxygen tension (pO 2 ) maps were achieved using 19 F MRI of the reporter molecule hexafluorobenzene. Multiple correlations were examined between rates and magnitudes of vascular (Δ[HbO 2 ]) and tissue (pO 2 ) responses. Significant correlations were found between response to oxygen and carbogen breathing using either modality. Comparison of results for the two methods showed a correlation between the vascular perfusion rate ratio and the mean pO 2 values (R 2 > 0.7). The initial rates of increase of Δ[HbO 2 ] and the slope of dynamic pO 2 response, d(pO 2 )/dt, of well-oxygenated voxels in response to hyperoxic challenge were also correlated. These results demonstrate the feasibility of simultaneous measurements using NIRS and MRI. As expected, the rate of pO 2 response to oxygen is primarily dependent upon the well perfused rather than poorly perfused vasculature

  20. Reversible and Dynamic Fluorescence Imaging of Cellular Redox Self-Regulation Using Fast-Responsive Near-Infrared Ge-Pyronines.

    Science.gov (United States)

    Nie, Hailiang; Jing, Jing; Tian, Yong; Yang, Wen; Zhang, Rubo; Zhang, Xiaoling

    2016-04-13

    Cellular self-regulation of reactive oxygen species (ROS) stress via glutathione (GSH) antioxidant repair plays a crucial role in maintaining redox balance, which affects various physiological and pathological pathways. In this work, we developed a simple yet effective strategy for reversible, dynamic, and real-time fluorescence imaging of ROS stress and GSH repair, based on novel Ge-pyronine dyes (GePs). Unlike the current O-pyronine (OP) dye, the fluorescence of GePs can be quenched in GSH reduction and then greatly restored by ROS (e.g., ClO(-), ONOO(-), and HO(•)) oxidation because of their unique affinity toward thiols. The "on-off" and "off-on" fluorescence switch can complete in 10 and 20 s, respectively, and exhibit excellent reversibility in vitro and in cells. GePs also show excitation in the long wavelength from the deep-red to near-infrared (NIR) (621-662 nm) region, high fluorescence quantum yield (Φ(fl) = 0.32-0.44) in aqueous media, and excellent cell permeability. Our results demonstrated that GePs can be used for real-time monitoring of the reversible and dynamic interconversion between ROS oxidation and GSH reduction in living cells. GePs might be a useful tool for investigating various redox-related physiological and pathological pathways.

  1. Near infrared spectroscopy based monitoring of extraction processes of raw material with the help of dynamic predictive modeling

    Science.gov (United States)

    Wang, Haixia; Suo, Tongchuan; Wu, Xiaolin; Zhang, Yue; Wang, Chunhua; Yu, Heshui; Li, Zheng

    2018-03-01

    The control of batch-to-batch quality variations remains a challenging task for pharmaceutical industries, e.g., traditional Chinese medicine (TCM) manufacturing. One difficult problem is to produce pharmaceutical products with consistent quality from raw material of large quality variations. In this paper, an integrated methodology combining the near infrared spectroscopy (NIRS) and dynamic predictive modeling is developed for the monitoring and control of the batch extraction process of licorice. With the spectra data in hand, the initial state of the process is firstly estimated with a state-space model to construct a process monitoring strategy for the early detection of variations induced by the initial process inputs such as raw materials. Secondly, the quality property of the end product is predicted at the mid-course during the extraction process with a partial least squares (PLS) model. The batch-end-time (BET) is then adjusted accordingly to minimize the quality variations. In conclusion, our study shows that with the help of the dynamic predictive modeling, NIRS can offer the past and future information of the process, which enables more accurate monitoring and control of process performance and product quality.

  2. GEMINI NEAR INFRARED FIELD SPECTROGRAPH OBSERVATIONS OF THE SEYFERT 2 GALAXY MRK 573: IN SITU ACCELERATION OF IONIZED AND MOLECULAR GAS OFF FUELING FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Travis C.; Straughn, A. N. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Machuca, C.; Crenshaw, D. M.; Baron, F.; Revalski, M.; Pope, C. L. [Department of Physics and Astronomy, Georgia State University, Astronomy Offices, 25 Park Place, Suite 605, Atlanta, GA 30303 (United States); Diniz, M. R.; Riffel, R. A. [Departamento de Física, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil); Kraemer, S. B. [Institute for Astrophysics and Computational Sciences, Department of Physics, The Catholic University of America, Washington, DC 20064 (United States); Schmitt, H. R. [Naval Research Laboratory, Washington, DC 20375 (United States); Storchi-Bergmann, T., E-mail: travis.c.fischer@nasa.gov [Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, IF, CP 15051, 91501-970 Porto Alegre, RS (Brazil)

    2017-01-01

    We present near-infrared and optical emission-line and stellar kinematics of the Seyfert 2 galaxy Mrk 573 using the Near-Infrared Field Spectrograph (NIFS) at Gemini North and Dual Imaging Spectrograph at Apache Point Observatory, respectively. By obtaining full kinematic maps of the infrared ionized and molecular gas and stellar kinematics in a ∼700 × 2100 pc{sup 2} circumnuclear region of Mrk 573, we find that kinematics within the Narrow-Line Region are largely due to a combination of both rotation and in situ acceleration of material originating in the host disk. Combining these observations with large-scale, optical long-slit spectroscopy that traces ionized gas emission out to several kpcs, we find that rotation kinematics dominate the majority of the gas. We find that outflowing gas extends to distances less than 1 kpc, suggesting that outflows in Seyfert galaxies may not be powerful enough to evacuate their entire bulges.

  3. Gemini Near Infrared Field Spectrograph Observations of the Seyfert 2 Galaxy MRK 573: In Situ Acceleration of Ionized and Molecular Gas Off Fueling Flows

    Science.gov (United States)

    Fischer, Travis C.; Machuca, C.; Diniz, M. R.; Crenshaw, D. M.; Kraemer, S. B.; Riffel, R. A.; Schmitt, H. R.; Baron, F.; Storchi-Bergmann, T.; Straughn, A. N.; hide

    2016-01-01

    We present near-infrared and optical emission-line and stellar kinematics of the Seyfert 2 galaxy Mrk 573 using the Near-Infrared Field Spectrograph (NIFS) at Gemini North and Dual Imaging Spectrograph at Apache Point Observatory, respectively. By obtaining full kinematic maps of the infrared ionized and molecular gas and stellar kinematics in approximately 700 x 2100 pc(exp 2) circumnuclear region of Mrk 573, we find that kinematics within the Narrow-Line Region are largely due to a combination of both rotation and in situ acceleration of material originating in the host disk. Combining these observations with large-scale, optical long-slit spectroscopy that traces ionized gas emission out to several kpcs, we find that rotation kinematics dominate the majority of the gas. We find that outflowing gas extends to distances less than 1 kpc, suggesting that outflows in Seyfert galaxies may not be powerful enough to evacuate their entire bulges.

  4. Near-infrared sub-bandgap all-silicon photodetectors: state of the art and perspectives.

    Science.gov (United States)

    Casalino, Maurizio; Coppola, Giuseppe; Iodice, Mario; Rendina, Ivo; Sirleto, Luigi

    2010-01-01

    Due to recent breakthroughs, silicon photonics is now the most active discipline within the field of integrated optics and, at the same time, a present reality with commercial products available on the market. Silicon photodiodes are excellent detectors at visible wavelengths, but the development of high-performance photodetectors on silicon CMOS platforms at wavelengths of interest for telecommunications has remained an imperative but unaccomplished task so far. In recent years, however, a number of near-infrared all-silicon photodetectors have been proposed and demonstrated for optical interconnect and power-monitoring applications. In this paper, a review of the state of the art is presented. Devices based on mid-bandgap absorption, surface-state absorption, internal photoemission absorption and two-photon absorption are reported, their working principles elucidated and their performance discussed and compared.

  5. Near-Infrared Sub-Bandgap All-Silicon Photodetectors: State of the Art and Perspectives

    Directory of Open Access Journals (Sweden)

    Luigi Sirleto

    2010-11-01

    Full Text Available Due to recent breakthroughs, silicon photonics is now the most active discipline within the field of integrated optics and, at the same time, a present reality with commercial products available on the market. Silicon photodiodes are excellent detectors at visible wavelengths, but the development of high-performance photodetectors on silicon CMOS platforms at wavelengths of interest for telecommunications has remained an imperative but unaccomplished task so far. In recent years, however, a number of near-infrared all-silicon photodetectors have been proposed and demonstrated for optical interconnect and power-monitoring applications. In this paper, a review of the state of the art is presented. Devices based on mid-bandgap absorption, surface-state absorption, internal photoemission absorption and two-photon absorption are reported, their working principles elucidated and their performance discussed and compared.

  6. Prefrontal cerebral blood volume patterns while playing video games--a near-infrared spectroscopy study.

    Science.gov (United States)

    Nagamitsu, Shinichiro; Nagano, Miki; Yamashita, Yushiro; Takashima, Sachio; Matsuishi, Toyojiro

    2006-06-01

    Video game playing is an attractive form of entertainment among school-age children. Although this activity reportedly has many adverse effects on child development, these effects remain controversial. To investigate the effect of video game playing on regional cerebral blood volume, we measured cerebral hemoglobin concentrations using near-infrared spectroscopy in 12 normal volunteers consisting of six children and six adults. A Hitachi Optical Topography system was used to measure hemoglobin changes. For all subjects, the video game Donkey Kong was played on a Game Boy device. After spectroscopic probes were positioned on the scalp near the target brain regions, the participants were asked to play the game for nine periods of 15s each, with 15-s rest intervals between these task periods. Significant increases in bilateral prefrontal total-hemoglobin concentrations were observed in four of the adults during video game playing. On the other hand, significant decreases in bilateral prefrontal total-hemoglobin concentrations were seen in two of the children. A significant positive correlation between mean oxy-hemoglobin changes in the prefrontal region and those in the bilateral motor cortex area was seen in adults. Playing video games gave rise to dynamic changes in cerebral blood volume in both age groups, while the difference in the prefrontal oxygenation patterns suggested an age-dependent utilization of different neural circuits during video game tasks.

  7. Recent advances in mid- and near-infrared spectroscopy with applications for research and teaching, focusing on petrochemistry and biotechnology relevant products

    Science.gov (United States)

    Heise, H. M.; Fritzsche, J.; Tkatsch, H.; Waag, F.; Karch, K.; Henze, K.; Delbeck, S.; Budde, J.

    2013-11-01

    Mid- and near-infrared spectroscopy is introduced as a versatile analytical method for characterizing liquid and solid chemicals as obtained from petrochemistry and biotechnology processes. Besides normal transmission measurements, special equipment with silver halide fiber-optic probes allowing efficient analysis based on mid-infrared attenuated total reflection, and an accessory for near-infrared diffuse reflection measurements, are presented. The latter technique can be used advantageously for powdered samples such as microalgae biomass and polysaccharides, as well as for different tissues such as meat samples. The advantages and disadvantages of both methods, which can be used for industrial process monitoring and chemical quality control applications, are discussed, and have been used in several research projects of BSc students within their degree course of bio- and nano-technologies of our University of Applied Sciences.

  8. Recent advances in mid- and near-infrared spectroscopy with applications for research and teaching, focusing on petrochemistry and biotechnology relevant products

    International Nuclear Information System (INIS)

    Heise, H M; Fritzsche, J; Tkatsch, H; Waag, F; Karch, K; Henze, K; Delbeck, S; Budde, J

    2013-01-01

    Mid- and near-infrared spectroscopy is introduced as a versatile analytical method for characterizing liquid and solid chemicals as obtained from petrochemistry and biotechnology processes. Besides normal transmission measurements, special equipment with silver halide fiber-optic probes allowing efficient analysis based on mid-infrared attenuated total reflection, and an accessory for near-infrared diffuse reflection measurements, are presented. The latter technique can be used advantageously for powdered samples such as microalgae biomass and polysaccharides, as well as for different tissues such as meat samples. The advantages and disadvantages of both methods, which can be used for industrial process monitoring and chemical quality control applications, are discussed, and have been used in several research projects of BSc students within their degree course of bio- and nano-technologies of our University of Applied Sciences. (paper)

  9. Noninvasive imaging of multiple myeloma using near infrared fluorescent molecular probe

    Science.gov (United States)

    Hathi, Deep; Zhou, Haiying; Bollerman-Nowlis, Alex; Shokeen, Monica; Akers, Walter J.

    2016-03-01

    Multiple myeloma is a plasma cell malignancy characterized by monoclonal gammopathy and osteolytic bone lesions. Multiple myeloma is most commonly diagnosed in late disease stages, presenting with pathologic fracture. Early diagnosis and monitoring of disease status may improve quality of life and long-term survival for multiple myeloma patients from what is now a devastating and fatal disease. We have developed a near-infrared targeted fluorescent molecular probe with high affinity to the α4β1 integrin receptor (VLA-4)overexpressed by a majority of multiple myeloma cells as a non-radioactive analog to PET/CT tracer currently being developed for human diagnostics. A near-infrared dye that emits about 700 nm was conjugated to a high affinity peptidomimmetic. Binding affinity and specificity for multiple myeloma cells was investigated in vitro by tissue staining and flow cytometry. After demonstration of sensitivity and specificity, preclinical optical imaging studies were performed to evaluate tumor specificity in murine subcutaneous and metastatic multiple myeloma models. The VLA-4-targeted molecular probe showed high affinity for subcutaneous MM tumor xenografts. Importantly, tumor cells specific accumulation in the bone marrow of metastatic multiple myeloma correlated with GFP signal from transfected cells. Ex vivo flow cytometry of tumor tissue and bone marrow further corroborated in vivo imaging data, demonstrating the specificity of the novel agent and potential for quantitative imaging of multiple myeloma burden in these models.

  10. Shot-Noise-Limited Dual-Beam Detector for Atmospheric Trace-Gas Monitoring with Near-Infrared Diode Lasers

    Science.gov (United States)

    Durry, Georges; Pouchet, Ivan; Amarouche, Nadir; Danguy, Théodore; Megie, Gerard

    2000-10-01

    A dual-beam detector is used to measure atmospheric trace species by differential absorption spectroscopy with commercial near-infrared InGaAs laser diodes. It is implemented on the Spectrom tre Diodes Laser Accordables, a balloonborne tunable diode laser spectrometer devoted to the in situ monitoring of CH 4 and H 2 O. The dual-beam detector is made of simple analogical subtractor circuits combined with InGaAs photodiodes. The detection strategy consists in taking the balanced analogical difference between the reference and the sample signals detected at the input and the output of an open optical multipass cell to apply the full dynamic range of the measurements (16 digits) to the weak molecular absorption information. The obtained sensitivity approaches the shot-noise limit. With a 56-m optical cell, the detection limit obtained when the spectra is recorded within 8 ms is 10 4 (expressed in absorbance units). The design and performances of both a simple substractor and an upgraded feedback substractor circuit are discussed with regard to atmospheric in situ CH 4 absorption spectra measured in the 1.653- m region. Mixing ratios are obtained from the absorption spectra by application of a nonlinear least-squares fit to the full molecular line shape in conjunction with in situ P and T measurements.

  11. Chalcogenide Glass Optical Waveguides for Infrared Biosensing

    Directory of Open Access Journals (Sweden)

    Bruno Bureau

    2009-09-01

    Full Text Available Due to the remarkable properties of chalcogenide (Chg glasses, Chg optical waveguides should play a significant role in the development of optical biosensors. This paper describes the fabrication and properties of chalcogenide fibres and planar waveguides. Using optical fibre transparent in the mid-infrared spectral range we have developed a biosensor that can collect information on whole metabolism alterations, rapidly and in situ. Thanks to this sensor it is possible to collect infrared spectra by remote spectroscopy, by simple contact with the sample. In this way, we tried to determine spectral modifications due, on the one hand, to cerebral metabolism alterations caused by a transient focal ischemia in the rat brain and, in the other hand, starvation in the mouse liver. We also applied a microdialysis method, a well known technique for in vivo brain metabolism studies, as reference. In the field of integrated microsensors, reactive ion etching was used to pattern rib waveguides between 2 and 300 μm wide. This technique was used to fabricate Y optical junctions for optical interconnections on chalcogenide amorphous films, which can potentially increase the sensitivity and stability of an optical micro-sensor. The first tests were also carried out to functionalise the Chg planar waveguides with the aim of using them as (biosensors.

  12. Virus-resembling nano-structures for near infrared fluorescence imaging of ovarian cancer HER2 receptors

    Science.gov (United States)

    Guerrero, Yadir A.; Bahmani, Baharak; Singh, Sheela P.; Vullev, Valentine I.; Kundra, Vikas; Anvari, Bahman

    2015-10-01

    Ovarian cancer remains the dominant cause of death due to malignancies of the female reproductive system. The capability to identify and remove all tumors during intraoperative procedures may ultimately reduce cancer recurrence, and lead to increased patient survival. The objective of this study is to investigate the effectiveness of an optical nano-structured system for targeted near infrared (NIR) imaging of ovarian cancer cells that over-express the human epidermal growth factor receptor 2 (HER2), an important biomarker associated with ovarian cancer. The nano-structured system is comprised of genome-depleted plant-infecting brome mosaic virus doped with NIR chromophore, indocyanine green, and functionalized at the surface by covalent attachment of monoclonal antibodies against the HER2 receptor. We use absorption and fluorescence spectroscopy, and dynamic light scattering to characterize the physical properties of the constructs. Using fluorescence imaging and flow cytometry, we demonstrate the effectiveness of these nano-structures for targeted NIR imaging of HER2 receptors in vitro. These functionalized nano-materials may provide a platform for NIR imaging of ovarian cancer.

  13. Virus-resembling nano-structures for near infrared fluorescence imaging of ovarian cancer HER2 receptors

    International Nuclear Information System (INIS)

    Guerrero, Yadir A; Bahmani, Baharak; Vullev, Valentine I; Anvari, Bahman; Singh, Sheela P; Kundra, Vikas

    2015-01-01

    Ovarian cancer remains the dominant cause of death due to malignancies of the female reproductive system. The capability to identify and remove all tumors during intraoperative procedures may ultimately reduce cancer recurrence, and lead to increased patient survival. The objective of this study is to investigate the effectiveness of an optical nano-structured system for targeted near infrared (NIR) imaging of ovarian cancer cells that over-express the human epidermal growth factor receptor 2 (HER2), an important biomarker associated with ovarian cancer. The nano-structured system is comprised of genome-depleted plant-infecting brome mosaic virus doped with NIR chromophore, indocyanine green, and functionalized at the surface by covalent attachment of monoclonal antibodies against the HER2 receptor. We use absorption and fluorescence spectroscopy, and dynamic light scattering to characterize the physical properties of the constructs. Using fluorescence imaging and flow cytometry, we demonstrate the effectiveness of these nano-structures for targeted NIR imaging of HER2 receptors in vitro. These functionalized nano-materials may provide a platform for NIR imaging of ovarian cancer. (paper)

  14. Imaging of phase change materials below a capping layer using correlative infrared near-field microscopy and electron microscopy

    Science.gov (United States)

    Lewin, M.; Hauer, B.; Bornhöfft, M.; Jung, L.; Benke, J.; Michel, A.-K. U.; Mayer, J.; Wuttig, M.; Taubner, T.

    2015-10-01

    Phase Change Materials (PCM) show two stable states in the solid phase with significantly different optical and electronic properties. They can be switched reversibly between those two states and are promising candidates for future non-volatile memory applications. The development of phase change devices demands characterization tools, yielding information about the switching process at high spatial resolution. Scattering-type Scanning Near-field Optical Microscopy (s-SNOM) allows for spectroscopic analyses of the different optical properties of the PCMs on the nm-scale. By correlating the optical s-SNOM images with transmission electron microscopy images of the same sample, we unambiguously demonstrate the correlation of the infrared optical contrast with the structural state of the phase change material. The investigated sample consists of sandwiched amorphous and crystalline regions of Ag 4 In 3 Sb 67 Te 26 below a 100 nm thick ( ZnS ) 80 - ( SiO2 ) 20 capping layer. Our results demonstrate the sensitivity of s-SNOM to small dielectric near-field contrasts even below a comparably thick capping layer ( 100 nm ).

  15. The Munich Near-Infrared Cluster Survey - IX. Galaxy evolution to z ~ 2 from optically selected catalogues†‡

    Science.gov (United States)

    Feulner, Georg; Goranova, Yuliana; Hopp, Ulrich; Gabasch, Armin; Bender, Ralf; Botzler, Christine S.; Drory, Niv

    2007-06-01

    We present B-, R- and I-band-selected galaxy catalogues based on the Munich Near-Infrared Cluster Survey (MUNICS) which, together with the previously used K-selected sample, serve as an important probe of galaxy evolution in the redshift range 0 Karl-Schwarzschild Strasse 2, D-85748, Garching bei München, Germany.

  16. 77 FR 27081 - II-VI, Incorporated, Infrared Optics-Saxonburg Division, Saxonburg, Pennsylvania; Notice of...

    Science.gov (United States)

    2012-05-08

    ..., Infrared Optics--Saxonburg Division, Saxonburg, Pennsylvania; Notice of Affirmative Determination Regarding... Assistance (TAA) applicable to workers and former workers of II-VI, Incorporated, Infrared Optics--Saxonburg...). The workers were engaged in employment related to the production of infrared and CO 2 laser optics...

  17. Optical and Near-infrared Radial Velocity Content of M Dwarfs: Testing Models with Barnard’s Star

    Science.gov (United States)

    Artigau, Étienne; Malo, Lison; Doyon, René; Figueira, Pedro; Delfosse, Xavier; Astudillo-Defru, Nicola

    2018-05-01

    High-precision radial velocity (RV) measurements have been central in the study of exoplanets during the last two decades, from the early discovery of hot Jupiters, to the recent mass measurements of Earth-sized planets uncovered by transit surveys. While optical RV is now a mature field, there is currently a strong effort to push the technique into the near-infrared domain (chiefly Y, J, H, and K bandpasses) to probe planetary systems around late-type stars. The combined lower mass and luminosity of M dwarfs leads to an increased reflex RV signal for planets in the habitable zone compared to Sun-like stars. The estimates on the detectability of planets rely on various instrumental characteristics but also on a prior knowledge of the stellar spectrum. While the overall properties of M dwarf spectra have been extensively tested against observations, the same is not true for their detailed line profiles, which leads to significant uncertainties when converting a given signal-to-noise ratio to a corresponding RV precision as attainable on a given spectrograph. By combining archival CRIRES and HARPS data with ESPaDOnS data of Barnard’s star, we show that state-of-the-art atmosphere models over-predict the Y- and J-band RV content by more than a factor of ∼2, while under-predicting the H- and K-band content by half.

  18. Characterization of Articular Cartilage Recovery and Its Correlation with Optical Response in the Near-Infrared Spectral Range.

    Science.gov (United States)

    Afara, Isaac Oluwaseun; Singh, Sanjleena; Moody, Hayley; Zhang, Lihai; Oloyede, Adekunle

    2017-07-01

    In this study, we examine the capacity of a new parameter, based on the recovery response of articular cartilage, to distinguish between healthy and damaged tissues. We also investigate whether or not this new parameter correlates with the near-infrared (NIR) optical response of articular cartilage. Normal and artificially degenerated (proteoglycan-depleted) bovine cartilage samples were nondestructively probed using NIR spectroscopy. Subsequently they were subjected to a load and unloading protocol, and the recovery response was logged during unloading. The recovery parameter, elastic rebound ( E R ), is based on the strain energy released as the samples underwent instantaneous elastic recovery. Our results reveal positive relationship between the rebound parameter and cartilage proteoglycan content (normal samples: 2.20 ± 0.10 N mm; proteoglycan-depleted samples: 0.50 ± 0.04 N mm for 1 hour of enzymatic treatment and 0.13 ± 0.02 N mm for 4 hours of enzymatic treatment). In addition, multivariate analysis using partial least squares regression was employed to investigate the relationship between E R and NIR spectral data. The results reveal significantly high correlation ( R 2 cal = 98.35% and R 2 val = 79.87%; P cartilage in the combined NIR regions 5,450 to 6,100 cm -1 and 7,500 to 12,500 cm -1 . We conclude that E R can indicate the mechanical condition and state of health of articular cartilage. The correlation of E R with cartilage optical response in the NIR range could facilitate real-time evaluation of the tissue's integrity during arthroscopic surgery and could also provide an important tool for cartilage assessment in tissue engineering and regeneration research.

  19. Near-Infrared Mapping Spectrometer for investigation of Jupiter and its satellites

    International Nuclear Information System (INIS)

    Aptaker, I.M.

    1988-01-01

    The Near-Infrared-Mapping Spectrometer (NIMS) is one of the science instruments in the Galileo mission, which will explore Jupiter and its satellites in the mid-1990's. The NIMS experiment will map geological units on the surfaces of the Jovian satellites and characterize their mineral content; and, for the atmosphere of Jupiter, investigate cloud properties and the spatial and temporal variability of molecular abundances. The optics are gold-coated reflective and consist of a telescope and a grating spectrometer. The balance of the instrument includes a 17-detector (silicon and indium antimonide) focal plane array, a tuning fork chopper, microprocessor-controlled electronics, and a passive radiative cooler. A wobbling secondary mirror in the telescope provides 20 pixels in one dimension of spatial scanning in a pushbroom mode with 0.5 mr x 0.5 mr instantaneous field of view. The spectral range is 0.7-5.2 microns; resolution is 0.025 micron. NIMS is the first infrared experiment to combine both spatial and spectral mapping capability in one instrument

  20. In vivo type 2 cannabinoid receptor-targeted tumor optical imaging using a near infrared fluorescent probe.

    Science.gov (United States)

    Zhang, Shaojuan; Shao, Pin; Bai, Mingfeng

    2013-11-20

    The type 2 cannabinoid receptor (CB2R) plays a vital role in carcinogenesis and progression and is emerging as a therapeutic target for cancers. However, the exact role of CB2R in cancer progression and therapy remains unclear. This has driven the increasing efforts to study CB2R and cancers using molecular imaging tools. In addition, many types of cancers overexpress CB2R, and the expression levels of CB2R appear to be associated with tumor aggressiveness. Such upregulation of the receptor in cancer cells provides opportunities for CB2R-targeted imaging with high contrast and for therapy with low side effects. In the present study, we report the first in vivo tumor-targeted optical imaging using a novel CB2R-targeted near-infrared probe. In vitro cell fluorescent imaging and a competitive binding assay indicated specific binding of NIR760-mbc94 to CB2R in CB2-mid delayed brain tumor (DBT) cells. NIR760-mbc94 also preferentially labeled CB2-mid DBT tumors in vivo, with a 3.7-fold tumor-to-normal contrast enhancement at 72 h postinjection, whereas the fluorescence signal from the tumors of the mice treated with NIR760 free dye was nearly at the background level at the same time point. SR144528, a CB2R competitor, significantly inhibited tumor uptake of NIR760-mbc94, indicating that NIR760-mbc94 binds to CB2R specifically. In summary, NIR760-mbc94 specifically binds to CB2R in vitro and in vivo and appears to be a promising molecular tool that may have great potential for use in diagnostic imaging of CB2R-positive cancers and therapeutic monitoring as well as in elucidating the role of CB2R in cancer progression and therapy.

  1. An Application for the Quantitative Analysis of Pharmaceutical Tablets Using a Rapid Switching System Between a Near-Infrared Spectrometer and a Portable Near-Infrared Imaging System Equipped with Fiber Optics.

    Science.gov (United States)

    Murayama, Kodai; Ishikawa, Daitaro; Genkawa, Takuma; Ozaki, Yukihiro

    2018-04-01

    We present a rapid switching system between a newly developed near-infrared (NIR) spectrometer and its imaging system to select the spot size of a diffuse reflectance (DR) probe. In a previous study, we developed a portable NIR imaging system, known as D-NIRs, which has significant advantages over other systems. Its high speed, high spectral resolution, and portability are particularly useful in the process of monitoring pharmaceutical tablets. However, the spectral accuracies relating to the changes in the formulation of the pharmaceutical tablets have not been fully discussed. Therefore, we improved the rapid optical switching system and present a new model of D-NIRs (ND-NIRs) here. This system can automatically switch the optical paths of the DR and NIR imaging probes, greatly contributing to the simultaneous measurement of both the imaging and spot. The NIR spectra of the model tablets, including 0-10% ascorbic acid, were measured and simultaneous NIR images of the tablets were obtained. The predicted results using spot sizes for the DR probe of 1 and 5 mm diameter, resulted in concentrations of R2 = 0.79 and 0.94, with root mean square errors (RMSE) of 1.78 and 0.89, respectively. For tablets with a high concentration of ascorbic acid, the NIR imaging results showed inhomogeneity in concentration. However, the predicted values for the low concentration samples appeared higher than the known concentration of the tablets, although the homogeneity of the concentration was confirmed. In addition, the optimal spot size using NIR imaging data was estimated to be 5-7 mm. The results obtained in this study show that the spot size of the fiber probe, attached to a spectrometer, is important in developing a highly reliable model to determine the component concentration of a tablet.

  2. Research on capability of detecting ballistic missile by near space infrared system

    Science.gov (United States)

    Lu, Li; Sheng, Wen; Jiang, Wei; Jiang, Feng

    2018-01-01

    The infrared detection technology of ballistic missile based on near space platform can effectively make up the shortcomings of high-cost of traditional early warning satellites and the limited earth curvature of ground-based early warning radar. In terms of target detection capability, aiming at the problem that the formula of the action distance based on contrast performance ignores the background emissivity in the calculation process and the formula is only valid for the monochromatic light, an improved formula of the detecting range based on contrast performance is proposed. The near space infrared imaging system parameters are introduced, the expression of the contrastive action distance formula based on the target detection of the near space platform is deduced. The detection range of the near space infrared system for the booster stage ballistic missile skin, the tail nozzle and the tail flame is calculated. The simulation results show that the near-space infrared system has the best effect on the detection of tail-flame radiation.

  3. Visible and Mid-Infrared Gypsum Optical Constants for Modeling of Martian Deposits

    Science.gov (United States)

    Roush, Ted L.; Esposito, Francesca; Rossmann, George R.; Colangeli, Luigi

    2007-08-01

    .g. 12-16]. All the mid-infrared spectra exhibit distinct spectral features near 4.5 μm that are attributed to the sulfate anion [12,16]. Yet no sign of this feature is present in the infrared data used to determine the optical constants. This discrepancy, and lack of optical constants in the visible and mid-infrared prompted us to undertake an effort to estimate k-values at these wavelengths. Data Used: On-line spectral libraries are available at RELAB (http://lf314- rlds.geo.brown.edu/) and ASTER (http://speclib.jpl.nasa.gov/). Both contain spectral data and information regarding sample acquisition, characterization, preparation, and spectral measurements. The RELAB gypsum samples used here are Fink, U. and S. Burk 1971 Comm. Lunar. Planet. Lab., 185, 8 [15] Salisbury, J. et al. 1991 Infrared (2.1-25 mm) spectra of Minerals, John Hopkins U. Press [16] Blaney, D. and T. McCord 1995 JGR., 100, 14433 [17] Shkuratov, Y. and Y. Grynko 2005 Icarus, 173, 16 [18] Hapke, B. and E. Wells 1981 JGR., 96, 3055 [19] Clark, R. and T. Roush 1984 JGR., 89, 6329 [20] Hapke, B. 1981 JGR, 96, 3039 [21] Hapke, B. 1986 Icarus, 67, 264 [22] Hapke, B. 1993 Theory of Reflectance and Emittance Spectroscopy, Cambridge Press [23] Poulet, F. and S. Erard JGR, 109, E02009 [24] Shkuratov, Y et al. 1999 Icarus, 137, 235 [25] Bohren, C. and D. Huffman 1983 Absorption and Scattering of Light by Small Particles, Wiley [26] Heavens, O. 1970 Thin Film Physics, Methuen [27] Roush, T. 2005 Icarus 179, 259.

  4. A NEAR-INFRARED SEARCH FOR SILICATES IN JOVIAN TROJAN ASTEROIDS

    International Nuclear Information System (INIS)

    Yang Bin; Jewitt, David

    2011-01-01

    We obtained near-infrared (NIR; 0.8-2.5 μm) spectra of seven Jovian Trojan asteroids that have been formerly reported to show silicate-like absorption features near 1 μm. Our sample includes the Trojan (1172) Aneas, which is one of the three Trojans known to possess a comet-like 10 μm emission feature, indicative of fine-grained silicates. Our observations show that all seven Trojans appear featureless in high signal-to-noise ratio spectra. The simultaneous absence of the 1 μm band and the presence of the 10 μm emission can be understood if the silicates on (1172) Aneas are iron-poor. In addition, we present NIR observations of five optically gray Trojans, including three objects from the collisionally produced Eurybates family. The five gray Trojans appear featureless in the NIR with no diagnostic absorption features. The NIR spectrum of Eurybates can be best fitted with the spectrum of a CM2 carbonaceous chondrite, which hints that the C-type Eurybates family members may have experienced aqueous alteration.

  5. Progress in nano-electro optics characterization of nano-optical materials and optical near-field interactions

    CERN Document Server

    Ohtsu, Motoichi

    2005-01-01

    This volume focuses on the characterization of nano-optical materials and optical-near field interactions. It begins with the techniques for characterizing the magneto-optical Kerr effect and continues with methods to determine structural and optical properties in high-quality quantum wires with high spatial uniformity. Further topics include: near-field luminescence mapping in InGaN/GaN single quantum well structures in order to interpret the recombination mechanism in InGaN-based nano-structures; and theoretical treatment of the optical near field and optical near-field interactions, providing the basis for investigating the signal transport and associated dissipation in nano-optical devices. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  6. The origin of the near-infrared emission in Palomar Green Quasars - The case for hot dust

    International Nuclear Information System (INIS)

    Berriman, G.

    1990-01-01

    This paper uses the variation with redshift of the near-infrared colors of the Palomar Green Bright Quasars as the basis for an analysis of the origin of their infrared light. Comparison of the data with simple models of the continuum, appropriately redshifted, show that the flux ratios start to decline when blue optical emission is redshifted into the infrared bandpasses. The rise in vFv(2.2 microns)/vFv(1.65 microns) is attributable to the declining importance of starlight. The range of vFv(2.2 microns)/vFv(1.65 microns) at maximum is attributable to a nonthermal emission only if it has an unusually steep range of spectra, with alpha = -1.7 on average and alpha = -2.2 in the extreme. At the same time, this emission does not vary and is unpolarized. Such a combination of properties has not been seen in any known nonthermal source. Emission from hot dust, probably from a broad range of temperatures centered near 1000 K, is a much simpler interpretation. It supplies on average 25 percent of the total 2.2 microns light at z = 0 and 35 percent in the extreme. 42 refs

  7. Near-infrared Mueller matrix imaging for colonic cancer detection

    Science.gov (United States)

    Wang, Jianfeng; Zheng, Wei; Lin, Kan; Huang, Zhiwei

    2016-03-01

    Mueller matrix imaging along with polar decomposition method was employed for the colonic cancer detection by polarized light in the near-infrared spectral range (700-1100 nm). A high-speed (colonic tissues (i.e., normal and caner) were acquired. Polar decomposition was further implemented on the 16 images to derive the diattentuation, depolarization, and the retardance images. The decomposed images showed clear margin between the normal and cancerous colon tissue samples. The work shows the potential of near-infrared Mueller matrix imaging for the early diagnosis and detection of malignant lesions in the colon.

  8. Infrared and Optical Spectroscopy of Type Ia Supernovae in the Nebular Phase

    OpenAIRE

    Bowers, E. J. C.; Meikle, W. P. S.; Geballe, T. R.; Walton, N. A.; Pinto, P. A.; Dhillon, V. S.; Howell, S. B.; Harrop-Allin, M. K.

    1997-01-01

    We present near-infrared (NIR) spectra for Type Ia supernovae at epochs of 13 to 338 days after maximum blue light. Some contemporary optical spectra are also shown. All the NIR spectra exhibit considerable structure throughout the J-, H- and K-bands. In particular they exhibit a flux `deficit' in the J-band which persists as late as 175 days. This is responsible for the well-known red J-H colour. To identify the emission features and test the $^{56}$Ni hypothesis for the explosion and subseq...

  9. The fabrication and visible-near-infrared optical modulation of vanadium dioxide/silicon dioxide composite photonic crystal structure

    Science.gov (United States)

    Liang, Jiran; Li, Peng; Song, Xiaolong; Zhou, Liwei

    2017-12-01

    We demonstrated a visible and near-infrared light tunable photonic nanostructure, which is composed of vanadium dioxide (VO2) thin film and silicon dioxide (SiO2) ordered nanosphere arrays. The vanadium films were sputtered on two-dimensional (2D) SiO2 sphere arrays. VO2 thin films were prepared by rapid thermal annealing (RTA) method with different oxygen flow rates. The close-packed VO2 shell formed a continuous surface, the composition of VO2 films in the structure changed when the oxygen flow rates increased. The 2D VO2/SiO2 composite photonic crystal structure exhibited transmittance trough tunability and near-infrared (NIR) transmittance modulation. When the oxygen flow rate increased from 3 slpm to 4 slpm, the largest transmittance trough can be regulated from 904 to 929 nm at low temperature, the transmittance troughs also appear blue shift when the VO2 phase changes from insulator to metal. The composite nanostructure based on VO2 films showed visible transmittance tunability, which would provide insights into the glass color changing in smart windows.

  10. Diverse Near-Infrared Resonant Gold Nanostructures for Biomedical Applications

    KAUST Repository

    Huang, Jianfeng

    2015-12-08

    The ability of near-infrared (NIR) light to penetrate tissues deeply and to target malignant sites with high specificity via precise temporal and spatial control of light illumination makes it useful for diagnosing and treating diseases. Owing to their unique biocompatibility, surface chemistry and optical properties, gold nanostructures offer advantages as in vivo NIR photosensitizers. This chapter describes the recent progress in the varied use of NIR-resonant gold nanostructures for NIR-light-mediated diagnostic and therapeutic applications. We begin by describing the unique biological, chemical and physical properties of gold nanostructures that make them excellent candidates for biomedical applications. From here, we make an account of the basic principles involved in the diagnostic and therapeutic applications where gold nanostructures have set foot. Finally, we review recent developments in the fabrication and use of diverse NIR-resonant gold nanostructures for cancer imaging and cancer therapy.

  11. The near-infrared broad emission line region of active galactic nuclei - II. The 1-μm continuum

    Science.gov (United States)

    Landt, Hermine; Elvis, Martin; Ward, Martin J.; Bentz, Misty C.; Korista, Kirk T.; Karovska, Margarita

    2011-06-01

    We use quasi-simultaneous near-infrared (near-IR) and optical spectroscopy from four observing runs to study the continuum around 1 μm in 23 well-known broad emission line active galactic nuclei (AGN). We show that, after correcting the optical spectra for host galaxy light, the AGN continuum around this wavelength can be approximated by the sum of mainly two emission components, a hot dust blackbody and an accretion disc. The accretion disc spectrum appears to dominate the flux at ˜ 1 μm, which allows us to derive a relation for estimating AGN black hole masses based on the near-IR virial product. This result also means that a near-IR reverberation programme can determine the AGN state independent of simultaneous optical spectroscopy. On average we derive hot dust blackbody temperatures of ˜1400 K, a value close to the sublimation temperature of silicate dust grains, and relatively low hot dust covering factors of ˜7 per cent. Our preliminary variability studies indicate that in most sources, the hot dust emission responds to changes in the accretion disc flux with the expected time lag; however, a few sources show a behaviour that can be attributed to dust destruction.

  12. Near infrared and visible face recognition based on decision fusion of LBP and DCT features

    Science.gov (United States)

    Xie, Zhihua; Zhang, Shuai; Liu, Guodong; Xiong, Jinquan

    2018-03-01

    Visible face recognition systems, being vulnerable to illumination, expression, and pose, can not achieve robust performance in unconstrained situations. Meanwhile, near infrared face images, being light- independent, can avoid or limit the drawbacks of face recognition in visible light, but its main challenges are low resolution and signal noise ratio (SNR). Therefore, near infrared and visible fusion face recognition has become an important direction in the field of unconstrained face recognition research. In order to extract the discriminative complementary features between near infrared and visible images, in this paper, we proposed a novel near infrared and visible face fusion recognition algorithm based on DCT and LBP features. Firstly, the effective features in near-infrared face image are extracted by the low frequency part of DCT coefficients and the partition histograms of LBP operator. Secondly, the LBP features of visible-light face image are extracted to compensate for the lacking detail features of the near-infrared face image. Then, the LBP features of visible-light face image, the DCT and LBP features of near-infrared face image are sent to each classifier for labeling. Finally, decision level fusion strategy is used to obtain the final recognition result. The visible and near infrared face recognition is tested on HITSZ Lab2 visible and near infrared face database. The experiment results show that the proposed method extracts the complementary features of near-infrared and visible face images and improves the robustness of unconstrained face recognition. Especially for the circumstance of small training samples, the recognition rate of proposed method can reach 96.13%, which has improved significantly than 92.75 % of the method based on statistical feature fusion.

  13. Persistent Luminescence Nanophosphor Involved Near-Infrared Optical Bioimaging for Investigation of Foodborne Probiotics Biodistribution in Vivo: A Proof-of-Concept Study.

    Science.gov (United States)

    Liu, Yaoyao; Liu, Jing-Min; Zhang, Dongdong; Ge, Kun; Wang, Peihua; Liu, Huilin; Fang, Guozhen; Wang, Shuo

    2017-09-20

    Probiotics has attracted great attention in food nutrition and safety research field, but thus far there are limited analytical techniques for visualized and real-time monitoring of the probiotics when they are ingested in vivo. Herein, the optical bioimaging technique has been introduced for investigation of foodborne probiotics biodistribution in vivo, employing the near-infrared (NIR) emitting persistent luminescence nanophosphors (PLNPs) of Cr 3+ -doped zinc gallogermanate (ZGGO) as the contrast nanoprobes. The ultrabrightness, super long afterglow, polydispersed size, low toxicity, and excellent photostability and biocompatibility of PLNPs were demonstrated to be qualified as a tracer for labeling probiotics via antibody (anti-Gram positive bacteria LTA antibody) recognition as well as contrast agent for long-term bioimaging the probiotics. In vivo optical bioimaging assay showed that the LTA antibody functionalized ZGGO nanoprobes that could be efficiently tagged to the probiobics were successfully applied for real-time monitoring and nondamaged probing of the biodistribution of probiotics inside the living body after oral administration. This work presents a proof-of-concept that exploited the bioimaging methodology for real-time and nondamaged researching the foodborne probiotics behaviors in vivo, which would open up a novel way of food safety detection and nutrition investigation.

  14. Rapid Visualization of Human Tumor Xenografts through Optical Imaging with a Near-Infrared Fluorescent Anti–Epidermal Growth Factor Receptor Nanobody

    Directory of Open Access Journals (Sweden)

    Sabrina Oliveira

    2012-01-01

    Full Text Available Given that overexpression of the epidermal growth factor receptor (EGFR is found in many types of human epithelial cancers, noninvasive molecular imaging of this receptor is of great interest. A number of studies have employed monoclonal antibodies as probes; however, their characteristic long half-life in the bloodstream has encouraged the development of smaller probes. In this study, an anti-EGFR nanobody-based probe was developed and tested in comparison with cetuximab for application in optical molecular imaging. To this aim, the anti-EGFR nanobody 7D12 and cetuximab were conjugated to the near-infrared fluorophore IRDye800CW. 7D12-IR allowed the visualization of tumors as early as 30 minutes postinjection, whereas with cetuximab-IR, no signal above background was observed at the tumor site. Quantification of the IR-conjugated proteins in the tumors revealed ≈ 17% of injected dose per gram 2 hours after injection of 7D12-IR, which was significantly higher than the tumor uptake obtained 24 hours after injection of cetuximab-IR. This difference is associated with the superior penetration and distribution of 7D12-IR within the tumor. These results demonstrate that this anti-EGFR nanobody conjugated to the NIR fluorophore has excellent properties for rapid preclinical optical imaging, which holds promise for its future use as a complementary diagnostic tool in humans.

  15. Rheo-optical near-infrared (NIR) spectroscopy study of partially miscible polymer blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG)

    Science.gov (United States)

    Shinzawa, Hideyuki; Mizukado, Junji

    2018-03-01

    Tensile deformations of a partially miscible blend of polymethyl methacrylate (PMMA) and polyethylene glycol (PEG) is studied by a rheo-optical characterization near-infrared (NIR) technique to probe deformation behavior during tensile deformation. Sets of NIR spectra of the polymer samples were collected by using an acousto-optic tunable filter (AOTF) NIR spectrometer coupled with a tensile testing machine as an excitation device. While deformations of the samples were readily captured as strain-dependent NIR spectra, the entire feature of the spectra was overwhelmed with the baseline fluctuation induced by the decrease in the sample thickness and subsequent change in the light scattering. Several pretreatment techniques, including multiplicative scatter collection (MSC) and null-space projection, are subjected to the NIR spectra prior to the determination of the sequential order of the spectral intensity changes by two-dimensional (2D) correlation analysis. The comparison of the MSC and null-space projection provided an interesting insight into the system, especially deformation-induced variation of light scattering observed during the tensile testing of the polymer sample. In addition, the sequential order determined with the 2D correlation spectra revealed that orientation of a specific part of PMMA chain occurs before that of the others because of the interaction between Cdbnd O group of PMMA and terminal sbnd OH group of PEG.

  16. Near infrared fluorescent chlorophyll nanoscale liposomes for sentinel lymph node mapping

    Science.gov (United States)

    Fan, Lina; Wu, Qiang; Chu, Maoquan

    2012-01-01

    Background Sentinel lymph node (SLN) mapping using in vivo near infrared fluorescence imaging has attracted great attention during the past few years. Here we report on the early use of poorly water-soluble chlorophyll with near infrared fluorescence extracted from the leaf of Chimonanthus salicifolius, for mouse axillary SLN mapping. Methods and results To improve the water solubility and SLN targeting of the chlorophyll, we encapsulated the chlorophyll in nanoscale liposomes. The liposome-coated chlorophyll nanocomposites obtained were spherical in shape and had an average diameter of 21.7 ± 6.0 nm. The nanocomposites dispersed well in water, and in aqueous suspension they exhibited brighter near infrared fluorescence than chlorophyll alone. After incubation of the nanocomposites with normal liver cells (QSG-7701) and macrophage cells (Ana-1) for no more than 48 hours, there was no obvious reduction in cell viability. When the nanocomposites were injected intradermally into the paw of a mouse, the axillary SLN was found to be strongly fluorescent and was easily visualized in real time without a requirement for surgery. The intensity of the near infrared fluorescence emitted by the SLN was obviously brighter than that emitted by the SLN of another mouse that had been intradermally injected with chlorophyll alone. Conclusion Our data show that the liposome-coated chlorophyll nanocomposites could have great potential for clinical SLN mapping due to their lack of toxicity, bright near infrared fluorescence, and small diameter. PMID:22787402

  17. A near-infrared confocal scanner

    International Nuclear Information System (INIS)

    Lee, Seungwoo; Yoo, Hongki

    2014-01-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface. (paper)

  18. Observation of near-infrared surface brightness of the large Magellanic cloud

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Koizumi, Yutaka; Matsumoto, Toshio; Murakami, Hiroshi; Uyama, Kiichiro.

    1981-01-01

    The near-infrared surface brightness of the large Magellanic cloud was observed by an infrared telescope carried by a balloon. The balloon flight was made at Australian Balloon Launching Station. The brightness distribution of 2.4 Mu m radiation was obtained. A part of Bar was bright, and the expansion of the contour at the east end of Bar corresponded to the 30 Dor region. Many near-infrared sources distribute in this region. Discussions on the color and brightness of the center of Bar and the 30 Dor region are presented. (Kato, T.)

  19. Near-infrared spectroscopy during peripheral vascular surgery

    DEFF Research Database (Denmark)

    Eiberg, J P; Schroeder, T V; Vogt, K C

    1997-01-01

    Near-infrared spectroscopy was performed perioperatively on the dorsum of the foot in 14 patients who underwent infrainguinal bypass surgery using a prosthesis or the greater saphenous vein. Dual-wavelength continuous light spectroscopy was used to assess changes in tissue saturation before, duri...

  20. New applications of near infrared spectroscopy in the food industry

    Energy Technology Data Exchange (ETDEWEB)

    Groenewald, C.A. (Peter Rassloff Instruments and Services, Norwood, South Africa)

    The near infrared spectroscopic method of analysis was initially developed for rapid analyses of protein in wheat. A brief explanation of the theory and history of near infrared spectroscopic analysis will be given. Research was done on the application of near infrared spectroscopic (NIR) in the food industry. Especially exciting was the breakthrough achieved in applying NIR to determine the dry solid content of bread. Such application could revolutionise the baking industry. Results will also be presented of research done on the application of NIR techniques for the determination of protein and fat in bread based on dry matter; hardness in wheat; absorption and sedimentation in pasta products; and use in process control in snack products manufacture. The limitations that were found in the application of NIR analysis will also be covered. The developments in NIR technology may result in these methods becoming standard practice in many food laboratories.

  1. New applications of near infrared spectroscopy in the food industry

    International Nuclear Information System (INIS)

    Groenewald, C.A.

    1984-01-01

    The near infrared spectroscopic method of analysis was initially developed for rapid analyses of protein in wheat. A brief explanation of the theory and history of near infrared spectroscopic analysis will be given. Research was done on the application of near infrared spectroscopic (NIR) in the food industry. Especially exciting was the breakthrough achieved in applying NIR to determine the dry solid content of bread. Such application could revolutionise the baking industry. Results will also be presented of research done on the application of NIR techniques for the determination of protein and fat in bread based on dry matter; hardness in wheat; absorption and sedimentation in pasta products; and use in process control in snack products manufacture. The limitations that were found in the application of NIR analysis will also be covered. The developments in NIR technology may result in these methods becoming standard practice in many food laboratories

  2. Imperial College near infrared spectroscopy neuroimaging analysis framework.

    Science.gov (United States)

    Orihuela-Espina, Felipe; Leff, Daniel R; James, David R C; Darzi, Ara W; Yang, Guang-Zhong

    2018-01-01

    This paper describes the Imperial College near infrared spectroscopy neuroimaging analysis (ICNNA) software tool for functional near infrared spectroscopy neuroimaging data. ICNNA is a MATLAB-based object-oriented framework encompassing an application programming interface and a graphical user interface. ICNNA incorporates reconstruction based on the modified Beer-Lambert law and basic processing and data validation capabilities. Emphasis is placed on the full experiment rather than individual neuroimages as the central element of analysis. The software offers three types of analyses including classical statistical methods based on comparison of changes in relative concentrations of hemoglobin between the task and baseline periods, graph theory-based metrics of connectivity and, distinctively, an analysis approach based on manifold embedding. This paper presents the different capabilities of ICNNA in its current version.

  3. Space imaging infrared optical guidance for autonomous ground vehicle

    Science.gov (United States)

    Akiyama, Akira; Kobayashi, Nobuaki; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu

    2008-08-01

    We have developed the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle based on the uncooled infrared camera and focusing technique to detect the objects to be evaded and to set the drive path. For this purpose we made servomotor drive system to control the focus function of the infrared camera lens. To determine the best focus position we use the auto focus image processing of Daubechies wavelet transform technique with 4 terms. From the determined best focus position we transformed it to the distance of the object. We made the aluminum frame ground vehicle to mount the auto focus infrared unit. Its size is 900mm long and 800mm wide. This vehicle mounted Ackerman front steering system and the rear motor drive system. To confirm the guidance ability of the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle we had the experiments for the detection ability of the infrared auto focus unit to the actual car on the road and the roadside wall. As a result the auto focus image processing based on the Daubechies wavelet transform technique detects the best focus image clearly and give the depth of the object from the infrared camera unit.

  4. Noninvasive observation of skeletal muscle contraction using near-infrared time-resolved reflectance and diffusing-wave spectroscopy

    Science.gov (United States)

    Belau, Markus; Ninck, Markus; Hering, Gernot; Spinelli, Lorenzo; Contini, Davide; Torricelli, Alessandro; Gisler, Thomas

    2010-09-01

    We introduce a method for noninvasively measuring muscle contraction in vivo, based on near-infrared diffusing-wave spectroscopy (DWS). The method exploits the information about time-dependent shear motions within the contracting muscle that are contained in the temporal autocorrelation function g(1)(τ,t) of the multiply scattered light field measured as a function of lag time, τ, and time after stimulus, t. The analysis of g(1)(τ,t) measured on the human M. biceps brachii during repetitive electrical stimulation, using optical properties measured with time-resolved reflectance spectroscopy, shows that the tissue dynamics giving rise to the speckle fluctuations can be described by a combination of diffusion and shearing. The evolution of the tissue Cauchy strain e(t) shows a strong correlation with the force, indicating that a significant part of the shear observed with DWS is due to muscle contraction. The evolution of the DWS decay time shows quantitative differences between the M. biceps brachii and the M. gastrocnemius, suggesting that DWS allows to discriminate contraction of fast- and slow-twitch muscle fibers.

  5. 77 FR 21586 - II-VI, Incorporated, Infrared Optics-Saxonburg Division, Saxonburg, PA; Notice of Affirmative...

    Science.gov (United States)

    2012-04-10

    ..., Infrared Optics--Saxonburg Division, Saxonburg, PA; Notice of Affirmative Determination Regarding... Assistance (TAA) applicable to workers and former workers of II-VI, Incorporated, Infrared Optics--Saxonburg...). The workers were engaged in employment related to the production of infrared and CO 2 laser optics...

  6. Dual stacked partial least squares for analysis of near-infrared spectra

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Yiming [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Xie, Qiong, E-mail: yimbi@163.com [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie [Institute of Automation, Chinese Academy of Sciences, 100190 Beijing (China); Zhao, Yuhui [School of Economics and Business, Northeastern University at Qinhuangdao, 066000 Qinhuangdao City (China); Li, Changwen [Food Research Institute of Tianjin Tasly Group, 300410 Tianjin (China)

    2013-08-20

    Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications.

  7. Dual stacked partial least squares for analysis of near-infrared spectra

    International Nuclear Information System (INIS)

    Bi, Yiming; Xie, Qiong; Peng, Silong; Tang, Liang; Hu, Yong; Tan, Jie; Zhao, Yuhui; Li, Changwen

    2013-01-01

    Graphical abstract: -- Highlights: •Dual stacking steps are used for multivariate calibration of near-infrared spectra. •A selective weighting strategy is introduced that only a subset of all available sub-models is used for model fusion. •Using two public near-infrared datasets, the proposed method achieved competitive results. •The method can be widely applied in many fields, such as Mid-infrared spectra data and Raman spectra data. -- Abstract: A new ensemble learning algorithm is presented for quantitative analysis of near-infrared spectra. The algorithm contains two steps of stacked regression and Partial Least Squares (PLS), termed Dual Stacked Partial Least Squares (DSPLS) algorithm. First, several sub-models were generated from the whole calibration set. The inner-stack step was implemented on sub-intervals of the spectrum. Then the outer-stack step was used to combine these sub-models. Several combination rules of the outer-stack step were analyzed for the proposed DSPLS algorithm. In addition, a novel selective weighting rule was also involved to select a subset of all available sub-models. Experiments on two public near-infrared datasets demonstrate that the proposed DSPLS with selective weighting rule provided superior prediction performance and outperformed the conventional PLS algorithm. Compared with the single model, the new ensemble model can provide more robust prediction result and can be considered an alternative choice for quantitative analytical applications

  8. Polarised infrared cathodoluminescence from platelet defects in natural diamonds

    International Nuclear Information System (INIS)

    Kiflawi, I.; Lang, A.R.

    1977-01-01

    It is reported that the large platelet defects occasionally found in natural diamonds emit polarised cathodoluminescence in the near infrared. There is much uncertainty regarding the composition and structure of the platelets. New findings on the optical properties of the platelets are discussed. The discovery that cathodoluminescence from giant platelets can be seen in the near infrared using an image converter was followed up by photographic recording with Kodak high speed infrared films, and it was found that the infrared emission from the platelets is polarised in the platelet plane with a considerably higher polarisation ratio than in the case of their visible emissions. In order to assess the degree of polarisation of the infrared emission a Polaroid Type HR linear polariser was used, which is very effective at the longest wavelengths recorded by the Kodak high speed infrared film. The high degree of polarisation of the platelet infrared emission constitutes a well defined optical characteristic that any model for platelet structure, and for optical processes associated with platelets, must satisfactorily accommodate. (U.K.)

  9. Characterization of herbal powder blends homogeneity using near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Wenlong Li

    2014-11-01

    Full Text Available Homogeneity of powder blend is essential to obtain uniform contents for the tablets and capsules. Near-infrared (NIR spectroscopy with fiber-optic probe was used as an on-line technique for monitoring the homogeneity of pharmaceutical blend during the blending process instead of the traditional techniques, such as high performance liquid chromatograph (HPLC method. In this paper NIRS with a SabIR diffuse reflectance fiber-optic probe was used to monitor the blending process of coptis powder and lactose (excipient with different contents, and further qualitative methods, like similarity, moving block of standard deviation and mean square were used for calculation purposes with the collected spectra after the pretreatment of multiplicative signal correction (MSC and second derivative. Correlation spectrum was used for the wavelength selection. Four different coptis were blended with lactose separately to validate the proposed method, and the blending process of "liu wei di huang" pill was also simulated in bottles to verify this method on multiple herbal blends. The overall results suggest that NIRS is a simple, effective and noninvasive technique can be successfully applied to the determination of homogeneity in the herbal blend.

  10. The application of Near Infrared Reflectance Spectroscopy (NIRS) for the quantitative analysis of hydrocortisone in primary materials

    OpenAIRE

    A. PITTAS; C. SERGIDES; K. NIKOLICH

    2001-01-01

    Near Infrared Reflectance Spectroscopy (NIRS), coupled with fiber optic probes, has been shown to be a quick and reliable analytical tool for quality assurance and quality control in the pharmaceutical industry, both for verifications of raw materials and quantification of the active ingredients in final products. In this paper, a typical pharmaceutical product, hydrocortisone sodium succinate, is used as an example for the application of NIR spectroscopy for quality control. In order to deve...

  11. Real time near-infrared Raman spectroscopy for the diagnosis of nasopharyngeal cancer.

    Science.gov (United States)

    Ming, Lim Chwee; Gangodu, Nagaraja Rao; Loh, Thomas; Zheng, Wei; Wang, Jianfeng; Lin, Kan; Zhiwei, Huang

    2017-07-25

    Near-infrared (NIR) Raman spectroscopy has been investigated as a tool to differentiate nasopharyngeal cancer (NPC) from normal nasopharyngeal tissue in an ex-vivo setting. Recently, we have miniaturized the fiber-optic Raman probe to investigate its utility in real time in-vivo surveillance of NPC patients. A posterior probability model using partial linear square (PLS) mathematical technique was constructed to verify the sensitivity and specificity of Raman spectroscopy in diagnosing NPC from post-irradiated and normal tissue using a diagnostic algorithm from three significant latent variables. NIR-Raman signals of 135 sites were measured from 79 patients with either newly diagnosed NPC (N = 12), post irradiated nasopharynx (N = 37) and normal nasopharynx (N = 30). The mean Raman spectra peaks identified differences at several Raman peaks at 853 cm-1, 940 cm-1, 1078 cm-1, 1335 cm-1, 1554 cm-1, 2885 cm-1 and 2940 cm-1 in the three different nasopharyngeal conditions. The sensitivity and specificity of distinguishing Raman signatures among normal nasopharynx versus NPC and post-irradiated nasopharynx versus NPC were 91% and 95%; and 77% and 96% respectively. Real time near-infrared Raman spectroscopy has a high specificity in distinguishing malignant from normal nasopharyngeal tissue in vivo, and may be investigated as a novel non-invasive surveillance tool in patients with nasopharyngeal cancer.

  12. Spectral classification by the near infrared photometric parameters

    International Nuclear Information System (INIS)

    Tignanelli, H.L.; Feinstein, A.

    1985-01-01

    From the analysis of the measurements of KM-type stars done in the near infrared (1 to 3.5 microns: the JHKL bands of Johnsons's system), with an 83 cm reflector and a PbS detector at La Plata Observatory, we try to establish a new photometric classification system that discriminates luminosity class by means of certain parameters defined by infrared colours and infrared magnitudes. Data compiled and homogenized by J.Koornneef of southern bright stars in those bands were also included. The results give us information about the spectral types and reddening of those stars. We also indicate how to calculate the radiation excess that those stars could have. (author)

  13. The fabrication and visible-near-infrared optical modulation of vanadium dioxide/silicon dioxide composite photonic crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Jiran; Li, Peng; Song, Xiaolong; Zhou, Liwei [Tianjin University, School of Microelectronics, Tianjin (China)

    2017-12-15

    We demonstrated a visible and near-infrared light tunable photonic nanostructure, which is composed of vanadium dioxide (VO{sub 2}) thin film and silicon dioxide (SiO{sub 2}) ordered nanosphere arrays. The vanadium films were sputtered on two-dimensional (2D) SiO{sub 2} sphere arrays. VO{sub 2} thin films were prepared by rapid thermal annealing (RTA) method with different oxygen flow rates. The close-packed VO{sub 2} shell formed a continuous surface, the composition of VO{sub 2} films in the structure changed when the oxygen flow rates increased. The 2D VO{sub 2}/SiO{sub 2} composite photonic crystal structure exhibited transmittance trough tunability and near-infrared (NIR) transmittance modulation. When the oxygen flow rate increased from 3 slpm to 4 slpm, the largest transmittance trough can be regulated from 904 to 929 nm at low temperature, the transmittance troughs also appear blue shift when the VO{sub 2} phase changes from insulator to metal. The composite nanostructure based on VO{sub 2} films showed visible transmittance tunability, which would provide insights into the glass color changing in smart windows. (orig.)

  14. Characterisation of olive fruit for the milling process by using visible/near infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Roberto Beghi

    2013-10-01

    Full Text Available Increasing consumption of olive oil and table olives has recently determined an expansion of olive tree cultivation in the world. This trend is supported by the documented nutritional value of the Mediterranean diet. The aim of this work was to test a portable visible/ near infrared (vis/NIR system (400-1000 nm for the analysis of physical-chemical parameters, such as olive soluble solid content (SSC and texture before the olive oil extraction process. The final goal is to provide the sector with post-harvest methods and sorting systems for a quick evaluation of important properties of olive fruit. In the present study, a total of 109 olives for oil production were analysed. Olive spectra registered with the optical device and values obtained with destructive analysis in the laboratory were analysed. Specific statistical models were elaborated to study correlations between optical and laboratory analysis, and to evaluate predictions of reference parameters obtained through the analysis of the visible-near infrared range. Statistical models were processed using chemometric techniques to extract maximum data information. Principal component analysis (PCA was performed on vis/NIR spectra to examine sample groupings and identify outliers, while partial least square (PLS regression algorithm was used to correlate samples spectra and physical- chemical properties. Results are encouraging. PCA showed a significant sample grouping among different ranges of SSC and texture. PLS models gave fairly good predictive capabilities in validation for SSC (R2=0.67 and RMSECV%=7.5% and texture (R2=0.68 and RMSECV%=8.2%.

  15. Rapid infrared and optical variability in the bright quasar 3C273

    International Nuclear Information System (INIS)

    Courvoisier, T.J.-L.; Robson, E.I.; Hughes, D.H.; Bouchet, P.; Schwarz, H.E.; Krisciunas, K.

    1988-01-01

    We have observed variations by a factor of two in the infrared flux from the bright quasar 3C273 on a timescale as short as one day. In February 1988, the behaviour of the source changed from having a stable infrared flux and slow optical variations to a state characterized by recurrent infrared and optical flaring. The optical variations were of several per cent per day, changing from increase to decrease approximately every week. The amplitude of the repeated optical flares was 30-40%. The data are consistent with re-injection/acceleration of electrons followed by rapid cooling. The inferred magnetic field is 0.7 gauss and the data are marginally consistent with no relativistic beaming. (author)

  16. Near infrared spectral polarization imaging of prostate cancer tissues using Cybesin: a receptor-targeted contrast agent

    Science.gov (United States)

    Pu, Yang; Wang, W. B.; Tang, G. C.; Liang, Kexian; Achilefu, S.; Alfano, R. R.

    2013-03-01

    Cybesin, a smart contrast agent to target cancer cells, was investigated using a near infrared (NIR) spectral polarization imaging technique for prostate cancer detection. The approach relies on applying a contrast agent that can target cancer cells. Cybesin, as a small ICG-derivative dye-peptide, emit fluorescence between 750 nm and 900 nm, which is in the "tissue optical window". Cybesin was reported targeting the over-expressed bombesin receptors in cancer cells in animal model and the human prostate cancers over-expressing bombesin receptors. The NIR spectral polarization imaging study reported here demonstrated that Cybesin can be used as a smart optical biomarker and as a prostate cancer receptor targeted contrast agent.

  17. NIRAC: Near Infrared Airglow Camera for the International Space Station

    Science.gov (United States)

    Gelinas, L. J.; Rudy, R. J.; Hecht, J. H.

    2017-12-01

    NIRAC is a space based infrared airglow imager that will be deployed to the International Space Station in late 2018, under the auspices of the Space Test Program. NIRAC will survey OH airglow emissions in the 1.6 micron wavelength regime, exploring the spatial and temporal variability of emission intensities at latitudes from 51° south to 51° north. Atmospheric perturbations in the 80-100 km altitude range, including those produced by atmospheric gravity waves (AGWs), are observable in the OH airglow. The objective of the NIRAC experiment is to make near global measurement of the OH airglow and airglow perturbations. These emissions also provide a bright source of illumination at night, allowing for nighttime detection of clouds and surface characteristics. The instrument, developed by the Aerospace Space Science Applications Laboratory, employs a space-compatible FPGA for camera control and data collection and a novel, custom optical system to eliminate image smear due to orbital motion. NIRAC utilizes a high-performance, large format infrared focal plane array, transitioning technology used in the existing Aerospace Corporation ground-based airglow imager to a space based platform. The high-sensitivity, four megapixel imager has a native spatial resolution of 100 meters at ISS altitudes. The 23° x 23° FOV sweeps out a 150 km swath of the OH airglow layer as viewed from the ISS, and is sensitive to OH intensity perturbations down to 0.1%. The detector has a 1.7 micron cutoff that precludes the need for cold optics and reduces cooling requirements (to 180 K). Detector cooling is provided by a compact, lightweight cryocooler capable of reaching 120K, providing a great deal of margin.

  18. Near-infrared image guidance in cancer surgery

    NARCIS (Netherlands)

    Schaafsma, B.E.

    2017-01-01

    Intraoperative imaging using near-infrared (NIR) fluorescence is a fast developing imaging modality as it provides real-time visual information during surgery (Chapter 1). The ability to detect lymph nodes and tumours that need to be resected can assist the surgeon to improve surgery by reducing

  19. Preparation and near-infrared absorption of nano-SnO{sub 2}/SiO{sub 2} assemblies with doping and without doping

    Energy Technology Data Exchange (ETDEWEB)

    Hai Shujie [Faculty of Material Science and Chemical Engineering, China University of Geosciences, Lu Mo Road 388, Wuhan 430074 (China); Yan Chunjie, E-mail: chjyan2005@126.co [Engineering Research Center of Nano-Geomaterials, Ministry of Education, China University of Geosciences, Lu Mo Road 388, Wuhan 430074 (China); Yu Hongjie; Xiao Guoqi; Wang Duo [Faculty of Material Science and Chemical Engineering, China University of Geosciences, Lu Mo Road 388, Wuhan 430074 (China)

    2009-11-20

    The assemblies of nano-SnO{sub 2}/SiO{sub 2} and Sb- or Pd-doped nano-SnO{sub 2}/SiO{sub 2}, in which the nano-SnO{sub 2} particles are located in the pores of mesoporous SiO{sub 2} dry gels, were synthesized. Only for the Sb-doped nano-SnO{sub 2}/SiO{sub 2} assemblies, a broad near-infrared absorption step occurs in the optical absorption spectrum of the wavelength range from 300 to 1500 nm. The near-infrared absorption phenomenon is attributed to electronic transitions from the ground states to the excitation states of the impurity energy levels, which are formed by Sb doping in SnO{sub 2}. With increasing the weight ratio of SnO{sub 2}:SiO{sub 2} or the annealing temperature, the near-infrared absorption step slope side exhibits 'red shift', which is caused by the quantum confinement effect weakening due to the increased SnO{sub 2} crystalline diameter.

  20. Functional connectivity in the prefrontal cortex measured by near-infrared spectroscopy during ultrarapid object recognition

    Science.gov (United States)

    Medvedev, Andrei V.; Kainerstorfer, Jana M.; Borisov, Sergey V.; Vanmeter, John

    2011-01-01

    Near-infrared spectroscopy (NIRS) is a developing technology for low-cost noninvasive functional brain imaging. With multichannel optical instruments, it becomes possible to measure not only local changes in hemoglobin concentrations but also temporal correlations of those changes in different brain regions which gives an optical analog of functional connectivity traditionally measured by fMRI. We recorded hemodynamic activity during the Go-NoGo task from 11 right-handed subjects with probes placed bilaterally over prefrontal areas. Subjects were detecting animals as targets in natural scenes pressing a mouse button. Data were low-pass filtered right versus left hemisphere. Intra- and interhemispheric functional connectivity was also significantly stronger during the task compared to baseline. Functional connectivity between the inferior and the middle frontal regions was significantly stronger in the right hemisphere. Our results demonstrate that optical methods can be used to detect transient changes in functional connectivity during rapid cognitive processes.

  1. Near-opposition martian limb-darkening: Quantification and implication for visible-near-infrared bidirectional reflectance studies.

    Science.gov (United States)

    de Grenier, Muriel; Pinet, Patrick C.

    1995-06-01

    A nearly global coverage of the martian eastern hemisphere, acquired under small phase angles and varying observational geometries conditions, has been produced from 1988 opposition by spectral (0.5-1 μm) imaging data obtained at the Pic du Midi Observatory in France. From this data set, the methodology presented here permits a systematic analysis of martian photometric behavior at a regional scale of 100-300 km in the visible and near-infrared. The quantification of limb-darkening as a function of wavelength and surface albedo gives access in martian regional properties as a function of wavelength and surface albedo and results in the production of visible and near-infrared geometric albedo maps. A linear relation between the limb darkening parameter k and geometric albedo exists in the near infrared. Based on laboratory studies, it suggests a spectral response of particulate type for the martian soil. Conversely, in the visible, the value of k parameter is 0.6 independent of albedo and is consistent with a single scattering photometric behavior in the surface layer. However, the observed change in the martian photometry from single to multiple scattering may be partially due to a large contribution of atmospheric scattering above 0.7 μm. In the absence of a multitemporal dataset analysis, it must be emphasized that the present results are a priori only pertinent to the atmospheric and surface conditions existing on Mars at the time of observation. However, this analysis may contribute to characterize some physical properties, such as surface roughness. In the near-infrared, for bright terrains, k tends to 0.8 and agrees with the presence of very fine particulate materials. Photometry of dark areas is more irregular (0.48 duricrust. Finally, we evaluate the influence of reflectance geometrical effects on the multispectral and spectroscopic data of the martian surface.

  2. Pairing of near-ultraviolet solar cells with electrochromic windows for smart management of the solar spectrum

    Science.gov (United States)

    Davy, Nicholas C.; Sezen-Edmonds, Melda; Gao, Jia; Lin, Xin; Liu, Amy; Yao, Nan; Kahn, Antoine; Loo, Yueh-Lin

    2017-08-01

    Current smart window technologies offer dynamic control of the optical transmission of the visible and near-infrared portions of the solar spectrum to reduce lighting, heating and cooling needs in buildings and to improve occupant comfort. Solar cells harvesting near-ultraviolet photons could satisfy the unmet need of powering such smart windows over the same spatial footprint without competing for visible or infrared photons, and without the same aesthetic and design constraints. Here, we report organic single-junction solar cells that selectively harvest near-ultraviolet photons, produce open-circuit voltages eclipsing 1.6 V and exhibit scalability in power generation, with active layers (10 cm2) substantially larger than those typical of demonstration organic solar cells (0.04-0.2 cm2). Integration of these solar cells with a low-cost, polymer-based electrochromic window enables intelligent management of the solar spectrum, with near-ultraviolet photons powering the regulation of visible and near-infrared photons for natural lighting and heating purposes.

  3. Near-infrared light emitting device using semiconductor nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Supran, Geoffrey J.S.; Song, Katherine W.; Hwang, Gyuweon; Correa, Raoul Emile; Shirasaki, Yasuhiro; Bawendi, Moungi G.; Bulovic, Vladimir; Scherer, Jennifer

    2018-04-03

    A near-infrared light emitting device can include semiconductor nanocrystals that emit at wavelengths beyond 1 .mu.m. The semiconductor nanocrystals can include a core and an overcoating on a surface of the core.

  4. Near-infrared quantum dots for HER2 localization and imaging of cancer cells.

    Science.gov (United States)

    Rizvi, Sarwat B; Rouhi, Sepideh; Taniguchi, Shohei; Yang, Shi Yu; Green, Mark; Keshtgar, Mo; Seifalian, Alexander M

    2014-01-01

    Quantum dots are fluorescent nanoparticles with unique photophysical properties that allow them to be used as diagnostic, therapeutic, and theranostic agents, particularly in medical and surgical oncology. Near-infrared-emitting quantum dots can be visualized in deep tissues because the biological window is transparent to these wavelengths. Their small sizes and free surface reactive groups that can be conjugated to biomolecules make them ideal probes for in vivo cancer localization, targeted chemotherapy, and image-guided cancer surgery. The human epidermal growth factor receptor 2 gene (HER2/neu) is overexpressed in 25%-30% of breast cancers. The current methods of detection for HER2 status, including immunohistochemistry and fluorescence in situ hybridization, are used ex vivo and cannot be used in vivo. In this paper, we demonstrate the application of near-infrared-emitting quantum dots for HER2 localization in fixed and live cancer cells as a first step prior to their in vivo application. Near-infrared-emitting quantum dots were characterized and their in vitro toxicity was established using three cancer cell lines, ie, HepG2, SK-BR-3 (HER2-overexpressing), and MCF7 (HER2-underexpressing). Mouse antihuman anti-HER2 monoclonal antibody was conjugated to the near-infrared-emitting quantum dots. In vitro toxicity studies showed biocompatibility of SK-BR-3 and MCF7 cell lines with near-infrared-emitting quantum dots at a concentration of 60 μg/mL after one hour and 24 hours of exposure. Near-infrared-emitting quantum dot antiHER2-antibody bioconjugates successfully localized HER2 receptors on SK-BR-3 cells. Near-infrared-emitting quantum dot bioconjugates can be used for rapid localization of HER2 receptors and can potentially be used for targeted therapy as well as image-guided surgery.

  5. A NEW GAS CELL FOR HIGH-PRECISION DOPPLER MEASUREMENTS IN THE NEAR-INFRARED

    International Nuclear Information System (INIS)

    Valdivielso, L.; Esparza, P.; MartIn, E. L.; Maukonen, D.; Peale, R. E.

    2010-01-01

    High-resolution spectroscopy in the near-infrared could become the leading method for discovering extra-solar planets around very low mass stars and brown dwarfs. In order to help to achieve an accuracy of ∼m s -1 , we are developing a gas cell which consists of a mixture of gases whose absorption spectral lines span all over the near-infrared region. We present the most promising mixture, made of acetylene, nitrous oxide, ammonia, chloromethanes, and hydrocarbons. The mixture is contained in a small size 13 cm long gas cell and covers most of the H and K bands. It also shows small absorptions in the J band, but they are few and not sharp enough for near-infrared wavelength calibration. We describe the working method and experiments, and compare our results with the state of the art for near-infrared gas cells.

  6. The Large UV/Optical/Infrared Surveyor (LUVOIR): Decadal Mission concept design update

    Science.gov (United States)

    Bolcar, Matthew R.; Aloezos, Steve; Bly, Vincent T.; Collins, Christine; Crooke, Julie; Dressing, Courtney D.; Fantano, Lou; Feinberg, Lee D.; France, Kevin; Gochar, Gene; Gong, Qian; Hylan, Jason E.; Jones, Andrew; Linares, Irving; Postman, Marc; Pueyo, Laurent; Roberge, Aki; Sacks, Lia; Tompkins, Steven; West, Garrett

    2017-09-01

    In preparation for the 2020 Astrophysics Decadal Survey, NASA has commissioned the study of four large mission concepts, including the Large Ultraviolet / Optical / Infrared (LUVOIR) Surveyor. The LUVOIR Science and Technology Definition Team (STDT) has identified a broad range of science objectives including the direct imaging and spectral characterization of habitable exoplanets around sun-like stars, the study of galaxy formation and evolution, the epoch of reionization, star and planet formation, and the remote sensing of Solar System bodies. NASA's Goddard Space Flight Center (GSFC) is providing the design and engineering support to develop executable and feasible mission concepts that are capable of the identified science objectives. We present an update on the first of two architectures being studied: a 15- meter-diameter segmented-aperture telescope with a suite of serviceable instruments operating over a range of wavelengths between 100 nm to 2.5 μm. Four instruments are being developed for this architecture: an optical / near-infrared coronagraph capable of 10-10 contrast at inner working angles as small as 2 λ/D the LUVOIR UV Multi-object Spectrograph (LUMOS), which will provide low- and medium-resolution UV (100 - 400 nm) multi-object imaging spectroscopy in addition to far-UV imaging; the High Definition Imager (HDI), a high-resolution wide-field-of-view NUV-Optical-IR imager; and a UV spectro-polarimeter being contributed by Centre National d'Etudes Spatiales (CNES). A fifth instrument, a multi-resolution optical-NIR spectrograph, is planned as part of a second architecture to be studied in late 2017.

  7. Gastric cancer target detection using near-infrared hyperspectral imaging with chemometrics

    Science.gov (United States)

    Yi, Weisong; Zhang, Jian; Jiang, Houmin; Zhang, Niya

    2014-09-01

    Gastric cancer is one of the leading causes of cancer death in the world due to its high morbidity and mortality. Hyperspectral imaging (HSI) is an emerging, non-destructive, cutting edge analytical technology that combines conventional imaging and spectroscopy in one single system. The manuscript has investigated the application of near-infrared hyperspectral imaging (900-1700 nm) (NIR-HSI) for gastric cancer detection with algorithms. Major spectral differences were observed in three regions (950-1050, 1150-1250, and 1400-1500 nm). By inspecting cancerous mean spectrum three major absorption bands were observed around 975, 1215 and 1450 nm. Furthermore, the cancer target detection results are consistent and conformed with histopathological examination results. These results suggest that NIR-HSI is a simple, feasible and sensitive optical diagnostic technology for gastric cancer target detection with chemometrics.

  8. A near-infrared survey for pre-main sequence stars in Taurus

    Science.gov (United States)

    Gomez, Mercedes; Kenyon, Scott J.; Hartmann, Lee

    1994-01-01

    We present a near-infrared survey of approximately 2 sq deg covering parts of L1537, L1538, and Heiles cloud 2 in the Taurus-Auriga molecular cloud. Although this study is more sensitive than previous attempts to identify pre-main sequence stars in Taurus-Auriga, our survey regions contain only one new optically visible, young star. We did find several candidate embedded protostars; additional 10 micrometer photometry is necessary to verify the pre-main sequence nature of these sources. Our results--combined with those of previous surveys--show that the L1537/L1538 clouds contain no pre-main sequence stars. These two clouds are less dense than the active star formation sites in Taurus-Auriga, which suggests a cloud must achieve a threshold density to form stars.

  9. THE OPTICAL AND NEAR-INFRARED TRANSMISSION SPECTRUM OF THE SUPER-EARTH GJ 1214b: FURTHER EVIDENCE FOR A METAL-RICH ATMOSPHERE

    International Nuclear Information System (INIS)

    Bean, Jacob L.; Désert, Jean-Michel; Stalder, Brian; Berta, Zachory K.; Kabath, Petr; Seager, Sara; Miller-Ricci Kempton, Eliza; Homeier, Derek; Walsh, Shane; Seifahrt, Andreas

    2011-01-01

    We present an investigation of the transmission spectrum of the 6.5 M ⊕ planet GJ 1214b based on new ground-based observations of transits of the planet in the optical and near-infrared, and on previously published data. Observations with the VLT + FORS and Magellan + MMIRS using the technique of multi-object spectroscopy with wide slits yielded new measurements of the planet's transmission spectrum from 0.61 to 0.85 μm, and in the J, H, and K atmospheric windows. We also present a new measurement based on narrow-band photometry centered at 2.09 μm with the VLT + HAWKI. We combined these data with results from a reanalysis of previously published FORS data from 0.78 to 1.00 μm using an improved data reduction algorithm, and previously reported values based on Spitzer data at 3.6 and 4.5 μm. All of the data are consistent with a featureless transmission spectrum for the planet. Our K-band data are inconsistent with the detection of spectral features at these wavelengths reported by Croll and collaborators at the level of 4.1σ. The planet's atmosphere must either have at least 70% H 2 O by mass or optically thick high-altitude clouds or haze to be consistent with the data.

  10. Near infrared spectra of Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Bappu, M.K.V.; Ganesh, K.S.; Scaria, K.K.

    1977-01-01

    The near-infrared spectra of three Wolf-Rayet stars of the carbon sequence and five of the nitrogen sequence have been studied. Wavelength identifications and intensity scans are presented to show the emission line characteristics of these objects in the 6800 A to 8200 A domain of the spectrum. (author)

  11. Scanning Near-Field Optical Microscopy

    Directory of Open Access Journals (Sweden)

    Dušan Vobornik

    2008-02-01

    Full Text Available An average human eye can see details down to 0,07 mm in size. The ability to see smaller details of the matter is correlated with the development of the science and the comprehension of the nature. Today’s science needs eyes for the nano-world. Examples are easily found in biology and medical sciences. There is a great need to determine shape, size, chemical composition, molecular structure and dynamic properties of nano-structures. To do this, microscopes with high spatial, spectral and temporal resolution are required. Scanning Near-field Optical Microscopy (SNOM is a new step in the evolution of microscopy. The conventional, lens-based microscopes have their resolution limited by diffraction. SNOM is not subject to this limitation and can offer up to 70 times better resolution.

  12. Scanning near-field optical microscopy.

    Science.gov (United States)

    Vobornik, Dusan; Vobornik, Slavenka

    2008-02-01

    An average human eye can see details down to 0,07 mm in size. The ability to see smaller details of the matter is correlated with the development of the science and the comprehension of the nature. Today's science needs eyes for the nano-world. Examples are easily found in biology and medical sciences. There is a great need to determine shape, size, chemical composition, molecular structure and dynamic properties of nano-structures. To do this, microscopes with high spatial, spectral and temporal resolution are required. Scanning Near-field Optical Microscopy (SNOM) is a new step in the evolution of microscopy. The conventional, lens-based microscopes have their resolution limited by diffraction. SNOM is not subject to this limitation and can offer up to 70 times better resolution.

  13. [Study on predicting sugar content and valid acidity of apples by near infrared diffuse reflectance technique].

    Science.gov (United States)

    Liu, Yan-de; Ying, Yi-bin; Fu, Xia-ping

    2005-11-01

    The nondestructive method for quantifying sugar content (SC) and available acid (VA) of intact apples using diffuse near infrared reflectance and optical fiber sensing techniques were explored in the present research. The standard sample sets and prediction models were established by partial least squares analysis (PLS). A total of 120 Shandong Fuji apples were tested in the wave number of 12,500 - 4000 cm(-1) using Fourier transform near infrared spectroscopy. The results of the research indicated that the nondestructive quantification of SC and VA, gave a high correlation coefficient 0.970 and 0.906, a low root mean square error of prediction (RMSEP) 0.272 and 0.056 2, a low root mean square error of calibration (RMSEC) 0.261 and 0.0677, and a small difference between RMSEP and RMSEC 0.011 a nd 0.0115. It was suggested that the diffuse nearinfrared reflectance technique be feasible for nondestructive determination of apple sugar content in the wave number range of 10,341 - 5461 cm(-1) and for available acid in the wave number range of 10,341 - 3818 cm(-1).

  14. Highly transparent conductive AZO/Zr50Cu50/AZO films in wide range of visible and near infrared wavelength grown by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Jingyun Cheng

    Full Text Available Novel AZO/Zr50Cu50/AZO tri-layer transparent conductive films with excellent transmittance in both visible and near infrared region were successfully prepared by pulsed laser deposition on glass substrates. The electrical and optical properties were investigated at various Zr50Cu50 thicknesses. As the AZO thickness was fixed at 50 nm and Zr50Cu50 thickness was varied between 1 and 18 nm, it was found that AZO (50 nm/Zr50Cu50/AZO (50 nm tri-layer films exhibited good conductivity and high transmittance in both visible and near infrared wavelength. Additionally, both the electrical and optical properties of AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm tri-layer films were found to be sensitive to the growth temperature. In this work, the lowest sheet resistance (43 Ω/□ and relatively high transmittance (∼80% in the range of 400–2000 nm were achieved while the growth temperature was 350 °C. Furthermore, the AZO (50 nm/Zr50Cu50 (2 nm/AZO (50 nm thin film deposited at 350 °C exhibits the highest figure of merit of 1.42 × 10−3 Ω−1, indicating that the multilayer is promising for coated glasses and thin film solar cells. Keywords: Transparent conductive oxide, AZO, Zr50Cu50, Electrical and optical properties, Visible and near infrared transmittance

  15. Quantitative near-infrared spectroscopy on patients with peripheral vascular disease

    Science.gov (United States)

    Franceschini, Maria-Angela; Fantini, Sergio; Palumbo, Renato; Pasqualini, Leonella; Vaudo, Gaetano; Franceschini, Edoardo; Gratton, Enrico; Palumbo, Barbara; Innocente, Salvatore; Mannarino, Elmo

    1998-01-01

    We have used near-infrared spectroscopy to measure the hemoglobin saturation at rest and during exercise on patients affected by peripheral vascular disease (PVD). The instrument used in our study is a frequency-domain tissue oximeter which employs intensity modulated (110 MHz) laser diodes. We examined 9 subjects, 3 of which were controls and 6 were patients affected by stage II PVD. The optical probe was located on the calf muscle of the subjects. The measurement protocol consisted of: (1) baseline (approximately 5 min); (2) stationary bicycle exercise (approximately 5 min); (3) recovery (approximately 15 min). The change in hemoglobin saturation during exercise ((Delta) Y) and the recovery time after exercise (trec) were significantly greater in the PVD patients ((Delta) Y equals -21 +/- 3%, trec equals 5.9 +/- 3.8 min) than in the control subjects ((Delta) Y equals 2 +/- 3%, trec equals 0.6 +/- 0.1 min).

  16. Imitation-tumor targeting based on continuous-wave near-infrared tomography.

    Science.gov (United States)

    Liu, Dan; Liu, Xin; Zhang, Yan; Wang, Qisong; Lu, Jingyang; Sun, Jinwei

    2017-12-01

    Continuous-wave Near-Infrared (NIR) optical spectroscopy has shown great diagnostic capability in the early tumor detection with advantages of low-cost, portable, non-invasive, and non-radiative. In this paper, Modified Lambert-Beer Theory is deployed to address the low-resolution issues of the NIR technique and to design the tumor detecting and imaging system. Considering that tumor tissues have features such as high blood flow and hypoxia, the proposed technique can detect the location, size, and other information of the tumor tissues by comparing the absorbance between pathological and normal tissues. Finally, the tumor tissues can be imaged through tomographic method. The simulation experiments prove that the proposed technique and designed system can efficiently detect the tumor tissues, achieving imaging precision within 1 mm. The work of the paper has shown great potential in the diagnosis of tumor close to body surface.

  17. Multi-channel near infrared spectroradiometer

    International Nuclear Information System (INIS)

    Joseph, G.B.; Biddles, B.J.; D'silva, R.A.; Picot, A.J.; Ackerman, M.J.

    1988-01-01

    A multichannel spectroradiometer has been developed by Sira Ltd. for the study of rapidly varying events in the near infrared. The instrument is being used in the examination of gun flashes, rocket motor exhaust efflux analysis and ordnance or pyrotechnic flash studies. The spectral range of about 1.4 to 5.2 microns is covered in two bands with the first order dispersion from a pair of ruled blazed gratings being imaged onto a pair of detector arrays. Data may be logged at a rate of 1000 complete spectra per second

  18. Analysis of Leucaena mimosine, Acacia tannins and total phenols by near infrared reflectance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M N.V. [Hyderabad Univ. (India). Dept. of Plant Sciences

    1995-11-01

    The mimosine contents of Leucaena foliage, Acacia tannins and total phenols from leaf, bark and pod were analyzed by a near infrared relectance spectrophotometer (Compscan 3000). A calibration equation (linear summation regression) was developed with near infrared spectral analysis software, using 30 spectra from old and young leaves of Leucaena and 23 spectra from different samples of Acacia. The near infrared analyzer calculated that the percentages of mimosine, total phenols and tannins are closely comparable to laboratory results. (author)

  19. Near infrared face recognition: A literature survey

    Czech Academy of Sciences Publication Activity Database

    Farokhi, Sajad; Flusser, Jan; Sheikh, U. U.

    2016-01-01

    Roč. 21, č. 1 (2016), s. 1-17 ISSN 1574-0137 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Literature survey * Biometrics * Face recognition * Near infrared * Illumination invariant Subject RIV: JD - Computer Applications, Robotics http://library.utia.cas.cz/separaty/2016/ZOI/flusser-0461834.pdf

  20. Large Magellanic Cloud Near-infrared Synoptic Survey. V. Period–Luminosity Relations of Miras

    International Nuclear Information System (INIS)

    Yuan, Wenlong; Macri, Lucas M.; He, Shiyuan; Huang, Jianhua Z.; Kanbur, Shashi M.; Ngeow, Chow-Choong

    2017-01-01

    We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK s . We use densely sampled I -band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period–Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K s . We study the Period–Luminosity–Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.

  1. Near-infrared mapping of ARP 299 (IC 694-NGC 3690) - colliding galaxies unveiled

    International Nuclear Information System (INIS)

    Telesco, C.M.; Decher, R.; Gatley, I.; Edinburgh Royal Observatory, England)

    1985-01-01

    Near-infrared maps and multicolor photometry of the interacting galaxies IC 694 and NGC 3690 which form Arp 299 (= Markarian 171) are presented. These data reveal for the first time the distribution of nuclei and old red stars in a cataclysmically interacting system. The nuclei are considerably offset from the visual centroids of the galaxies but not from the mass centroids. The near-infrared colors of the most active regions are strongly affected by extinction, emission form hot dust, and bremsstrahlung. Near-infrared emission is also identified with secondary regions of star formation, probably resulting from the galaxies interaction. 24 references

  2. Infrared emission from protostars

    International Nuclear Information System (INIS)

    Adams, F.C.; Shu, F.H.

    1985-01-01

    The emergent spectral energy distribution at infrared to radio wavelengths is calculated for the simplest theoretical construct of a low-mass protostar. It is shown that the emergent spectrum in the infrared is insensitive to the details assumed for the temperature profile as long as allowance is made for a transition from optically thick to optically thin conditions and luminosity conservation isenforced at the inner and outer shells. The radiation in the far infrared and submillimeter wavelengths depends on the exact assumptions made for grain opacities at low frequencies. An atlas of emergent spectral energy distributions is presented for a grid of values of the instantaneous mass of the protostar and the mass infall rate. The attenuated contribution of the accretion shock to the near-infrared radiation is considered. 50 references

  3. Time-resolved ultraviolet near-field scanning optical microscope for characterizing photoluminescence lifetime of light-emitting devices.

    Science.gov (United States)

    Park, Kyoung-Duck; Jeong, Hyun; Kim, Yong Hwan; Yim, Sang-Youp; Lee, Hong Seok; Suh, Eun-Kyung; Jeong, Mun Seok

    2013-03-01

    We developed a instrument consisting of an ultraviolet (UV) near-field scanning optical microscope (NSOM) combined with time-correlated single photon counting, which allows efficient observation of temporal dynamics of near-field photoluminescence (PL) down to the sub-wavelength scale. The developed time-resolved UV NSOM system showed a spatial resolution of 110 nm and a temporal resolution of 130 ps in the optical signal. The proposed microscope system was successfully demonstrated by characterizing the near-field PL lifetime of InGaN/GaN multiple quantum wells.

  4. Energy modulation of nonrelativistic electrons in an optical near field on a metal microslit

    Science.gov (United States)

    Ishikawa, R.; Bae, J.; Mizuno, K.

    2001-04-01

    Energy modulation of nonrelativistic electrons with a laser beam using a metal microslit as an interaction circuit has been investigated. An optical near field is induced in the proximity of the microslit by illumination of the laser beam. The electrons passing close to the slit are accelerated or decelerated by an evanescent wave contained in the near field whose phase velocity is equal to the velocity of the electrons. The electron-evanescent wave interaction in the microslit has been analyzed theoretically and experimentally. The theory has predicted that electron energy can be modulated at optical frequencies. Experiments performed in the infrared region have verified theoretical predictions. The electron-energy changes of more than ±5 eV with a 10 kW CO2 laser pulse at the wavelength of 10.6 μm has been successfully observed for an electron beam with an energy of less than 80 keV.

  5. Near infrared spectroscopy based brain-computer interface

    Science.gov (United States)

    Ranganatha, Sitaram; Hoshi, Yoko; Guan, Cuntai

    2005-04-01

    A brain-computer interface (BCI) provides users with an alternative output channel other than the normal output path of the brain. BCI is being given much attention recently as an alternate mode of communication and control for the disabled, such as patients suffering from Amyotrophic Lateral Sclerosis (ALS) or "locked-in". BCI may also find applications in military, education and entertainment. Most of the existing BCI systems which rely on the brain's electrical activity use scalp EEG signals. The scalp EEG is an inherently noisy and non-linear signal. The signal is detrimentally affected by various artifacts such as the EOG, EMG, ECG and so forth. EEG is cumbersome to use in practice, because of the need for applying conductive gel, and the need for the subject to be immobile. There is an urgent need for a more accessible interface that uses a more direct measure of cognitive function to control an output device. The optical response of Near Infrared Spectroscopy (NIRS) denoting brain activation can be used as an alternative to electrical signals, with the intention of developing a more practical and user-friendly BCI. In this paper, a new method of brain-computer interface (BCI) based on NIRS is proposed. Preliminary results of our experiments towards developing this system are reported.

  6. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Marion, G. H.; Kirshner, R. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Burns, C. R.; Freedman, W. L.; Persson, S. E. [Carnegie Observatories, 813 Santa Barbara St, Pasadena, CA 91101 (United States); Winge, C. [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile); Kromer, M.; Gall, E. E. E. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching bei Muenchen (Germany); Gerardy, C. L.; Hoeflich, P. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Im, M.; Jeon, Y. [CEOU/Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of); Nugent, P. E. [Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94611 (United States); Pignata, G. [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Stanishev, V., E-mail: hsiao@lco.cl [CENTRA - Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  7. Near-infrared light absorption by brown carbon in the ambient atmosphere

    Science.gov (United States)

    Chung, C.; Hoffer, A.; Beres, N. D.; Moosmüller, H.; Liu, C.; Green, M.; Kim, S. W.; Engelbrecht, J. P.; Gelencser, A.

    2017-12-01

    Organic aerosols have been assumed to have little-to-no absorption in the red and near-infrared spectral regions of solar radiation, even though a class of organic aerosols were shown to absorb significantly in these spectral regions. Here, we show that ambient atmospheric data from commonly-used 7-wavelength aethalometers contain evidence of abundant near-infrared light absorption by organic aerosol. This evidence comes from the absorption Ångström exponent over 880 950 nm, which often exceeds values explainable by fresh or coated black carbon, or mineral dust. This evidence is not due to an artifact from the instrument random errors or biases, either. The best explanation for these large 880/950 nm absorption Ångström exponent values in the aethalometer data is near-infrared light absorption by tar balls. Tar balls are among common particles from forest fire.

  8. [Near infrared spectroscopy study on water content in turbine oil].

    Science.gov (United States)

    Chen, Bin; Liu, Ge; Zhang, Xian-Ming

    2013-11-01

    Near infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for determination of water content in turbine oil. Through the 57 samples of different water content in turbine oil scanned applying near infrared (NIR) spectroscopy, with the water content in the turbine oil of 0-0.156%, different pretreatment methods such as the original spectra, first derivative spectra and differential polynomial least squares fitting algorithm Savitzky-Golay (SG), and successive projections algorithm (SPA) were applied for the extraction of effective wavelengths, the correlation coefficient (R) and root mean square error (RMSE) were used as the model evaluation indices, accordingly water content in turbine oil was investigated. The results indicated that the original spectra with different water content in turbine oil were pretreated by the performance of first derivative + SG pretreatments, then the selected effective wavelengths were used as the inputs of least square support vector machine (LS-SVM). A total of 16 variables selected by SPA were employed to construct the model of SPA and least square support vector machine (SPA-LS-SVM). There is 9 as The correlation coefficient was 0.975 9 and the root of mean square error of validation set was 2.655 8 x 10(-3) using the model, and it is feasible to determine the water content in oil using near infrared spectroscopy and SPA-LS-SVM, and an excellent prediction precision was obtained. This study supplied a new and alternative approach to the further application of near infrared spectroscopy in on-line monitoring of contamination such as water content in oil.

  9. IS THE LATE NEAR-INFRARED BUMP IN SHORT-HARD GRB 130603B DUE TO THE LI-PACZYNSKI KILONOVA?

    International Nuclear Information System (INIS)

    Jin, Zhi-Ping; Fan, Yi-Zhong; Wei, Da-Ming; Xu, Dong; Wu, Xue-Feng

    2013-01-01

    Short-hard gamma-ray bursts (GRBs) are widely believed to be produced by the merger of two binary compact objects, specifically by two neutron stars or by a neutron star orbiting a black hole. According to the Li-Paczynski kilonova model, the merger would launch sub-relativistic ejecta and a near-infrared/optical transient would then occur, lasting up to days, which is powered by the radioactive decay of heavy elements synthesized in the ejecta. The detection of a late bump using the Hubble Space Telescope (HST) in the near-infrared afterglow light curve of the short-hard GRB 130603B is indeed consistent with such a model. However, as shown in this Letter, the limited HST near-infrared light curve behavior can also be interpreted as the synchrotron radiation of the external shock driven by a wide mildly relativistic outflow. In such a scenario, the radio emission is expected to peak with a flux of ∼100 μJy, which is detectable for current radio arrays. Hence, the radio afterglow data can provide complementary evidence on the nature of the bump in GRB 130603B. It is worth noting that good spectroscopy during the bump phase in short-hard bursts can test the validity of either model above, analogous to spectroscopy of broad-lined Type Ic supernova in long-soft GRBs

  10. The Development of Novel Near-Infrared (NIR Tetraarylazadipyrromethene Fluorescent Dyes

    Directory of Open Access Journals (Sweden)

    Young-Tae Chang

    2013-05-01

    Full Text Available Novel structures of an near-infrared (NIR tetraarylazadipyrromethene (aza-BODIPY series have been prepared. We designed the core structure containing two amido groups at the para-position of the aromatic rings. The amido group was incorporated to secure insensitivity to pH and to ensure a bathochromic shift to the NIR region. Forty members of aza-BODIPY compounds were synthesized by substitution of the acetyl group with commercial amines on the alpha bromide. The physicochemical properties and photostability were investigated and the fluorescence emission maxima (745~755 nm were found to be in the near infrared (NIR range of fluorescence.

  11. Short wavelength infrared optical windows for evaluation of benign and malignant tissues

    Science.gov (United States)

    Sordillo, Diana C.; Sordillo, Laura A.; Sordillo, Peter P.; Shi, Lingyan; Alfano, Robert R.

    2017-04-01

    There are three short wavelength infrared (SWIR) optical windows outside the conventionally used first near-infrared (NIR) window (650 to 950 nm). They occur in the 1000- to 2500-nm range and may be considered second, third, and fourth NIR windows. The second (1100 to 1350 nm) and third windows (1600 to 1870 nm) are now being explored through label-free linear and multiphoton imaging. The fourth window (2100 to 2350 nm) has been mostly ignored because of water absorption and the absence of sensitive detectors and ultrafast lasers. With the advent of new technology, use of window IV is now possible. Absorption and scattering properties of light through breast and prostate cancer, bone, lipids, and intralipid solutions at these windows were investigated. We found that breast and prostate cancer and bone have longer total attenuation lengths at NIR windows III and IV, whereas fatty tissues and intralipid have longest lengths at windows II and III. Since collagen is the major chromophore at 2100 and 2350 nm, window IV could be especially valuable in evaluating cancers and boney tissues, whereas windows II and III may be more useful for tissues with high lipid content. SWIR windows may be utilized as additional optical tools for the evaluation of collagen in tissues.

  12. In vivo near infrared (NIRS) sensor attachment using fibrin bioadhesive

    Science.gov (United States)

    Macnab, Andrew; Pagano, Roberto; Kwon, Brian; Dumont, Guy; Shadgan, Babak

    2018-02-01

    Background: `Tisseel' (Baxter Healthcare, Deerfield, IL) is a fibrin-based sealant that is commonly used during spine surgery to augment dural repairs. We wish to intra-operatively secure a near infrared spectroscopy (NIRS) sensor to the dura in order to monitor the tissue hemodynamics of the underlying spinal cord. To determine if `Tisseel' sealant adversely attenuates NIR photon transmission. Methods: We investigated `Tisseel' in both an in vitro and in vivo paradigm. For in vitro testing, we used a 1 mm pathlength cuvette containing either air or `Tisseel' interposed between a NIR light source (760 and 850 nm) and a photodiode detector and compared transmittance. For in vivo testing, a continuous wave (760 and 850 nm) spatiallyresolved NIRS device was placed over the triceps muscle using either conventional skin apposition (overlying adhesive bandage) or bioadhesion with `Tisseel'. Raw optical data and tissue saturation index (TSI%) collected at rest were compared. Results: In-vitro NIR light absorption by `Tisseel' was very high, with transmittance reduced by 95% compared to air. In-vivo muscle TSI% values were 80% with conventional attachment and 20% using fibrin glue. Conclusion: The optical properties of `Tisseel' significantly attenuate NIR light during in-vitro transmittance and critically compromise photon transmission in-vivo.

  13. Gold/Chitosan Nanocomposites with Specific Near Infrared Absorption for Photothermal Therapy Applications

    Directory of Open Access Journals (Sweden)

    Guandong Zhang

    2012-01-01

    Full Text Available Gold/chitosan nanocomposites were synthesized and evaluated as a therapeutic agent for the photothermal therapy. Gold nanoparticles (Au NPs with controllable optical absorption in the near infrared (NIR region were prepared by the reaction of chloroauric acid and sodium thiosulfate. To apply these particles to cancer therapy, the bare Au NPs were coated with chitosan (CS, O-carboxymethyl chitosan (CMCS, and a blend of CS and CMCS for utilizations in physiologic conditions. The surface properties, optical stability, and photothermal ablation efficiency on hepatocellular carcinoma cells (HepG2 and human dermal fibroblast cells (HDF demonstrate that these gold nanocomposites have great potential as a therapeutic agent in in vitro tests. The CS-coated nanocomposites show the highest efficiency for the photo-ablation on the HepG2 cells, and the CS and CMCS blended coated particles show the best discrimination between the cancer cell and normal cells. The well-controlled NIR absorption and the biocompatible surface of these nanocomposites allow low-power NIR laser activation and low-dosage particle injection for the cancer cell treatment.

  14. Characterization of near-field optical probes

    DEFF Research Database (Denmark)

    Vohnsen, Brian; Bozhevolnyi, Sergey I.

    1999-01-01

    Radiation and collection characteristics of four different near-field optical-fiber probes, namely, three uncoated probes and an aluminium-coated small-aperture probe, are investigated and compared. Their radiation properties are characterized by observation of light-induced topography changes...... in a photo-sensitive film illuminated with the probes, and it is confirmed that the radiated optical field is unambigiously confined only for the coated probe. Near-field optical imaging of a standing evanescent-wave pattern is used to compare the detection characteristics of the probes, and it is concluded...... that, for the imaging of optical-field intensity distributions containing predominantly evanescent-wave components, a sharp uncoated tip is the probe of choice. Complementary results obtained with optical phase-conjugation experiments with he uncoated probes are discussed in relation to the probe...

  15. Scanning near-field infrared microscopy on semiconductor structures

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Rainer

    2011-01-15

    Near-field optical microscopy has attracted remarkable attention, as it is the only technique that allows the investigation of local optical properties with a resolution far below the diffraction limit. Especially, the scattering-type near-field optical microscopy allows the nondestructive examination of surfaces without restrictions to the applicable wavelengths. However, its usability is limited by the availability of appropriate light sources. In the context of this work, this limit was overcome by the development of a scattering-type near-field microscope that uses a widely tunable free-electron laser as primary light source. In the theoretical part, it is shown that an optical near-field contrast can be expected when materials with different dielectric functions are combined. It is derived that these differences yield different scattering cross-sections for the coupled system of the probe and the sample. Those cross-sections define the strength of the near-field signal that can be measured for different materials. Hence, an optical contrast can be expected, when different scattering cross-sections are probed. This principle also applies to vertically stacked or even buried materials, as shown in this thesis experimentally for two sample systems. In the first example, the different dielectric functions were obtained by locally changing the carrier concentration in silicon by the implantation of boron. It is shown that the concentration of free charge-carriers can be deduced from the near-field contrast between implanted and pure silicon. For this purpose, two different experimental approaches were used, a non-interferometric one by using variable wavelengths and an interferometric one with a fixed wavelength. As those techniques yield complementary information, they can be used to quantitatively determine the effective carrier concentration. Both approaches yield consistent results for the carrier concentration, which excellently agrees with predictions from

  16. Scanning near-field infrared microscopy on semiconductor structures

    International Nuclear Information System (INIS)

    Jacob, Rainer

    2011-01-01

    Near-field optical microscopy has attracted remarkable attention, as it is the only technique that allows the investigation of local optical properties with a resolution far below the diffraction limit. Especially, the scattering-type near-field optical microscopy allows the nondestructive examination of surfaces without restrictions to the applicable wavelengths. However, its usability is limited by the availability of appropriate light sources. In the context of this work, this limit was overcome by the development of a scattering-type near-field microscope that uses a widely tunable free-electron laser as primary light source. In the theoretical part, it is shown that an optical near-field contrast can be expected when materials with different dielectric functions are combined. It is derived that these differences yield different scattering cross-sections for the coupled system of the probe and the sample. Those cross-sections define the strength of the near-field signal that can be measured for different materials. Hence, an optical contrast can be expected, when different scattering cross-sections are probed. This principle also applies to vertically stacked or even buried materials, as shown in this thesis experimentally for two sample systems. In the first example, the different dielectric functions were obtained by locally changing the carrier concentration in silicon by the implantation of boron. It is shown that the concentration of free charge-carriers can be deduced from the near-field contrast between implanted and pure silicon. For this purpose, two different experimental approaches were used, a non-interferometric one by using variable wavelengths and an interferometric one with a fixed wavelength. As those techniques yield complementary information, they can be used to quantitatively determine the effective carrier concentration. Both approaches yield consistent results for the carrier concentration, which excellently agrees with predictions from

  17. Au-Nanomaterials as a Superior Choice for Near-Infrared Photothermal Therapy

    Directory of Open Access Journals (Sweden)

    Fahmida Jabeen

    2014-12-01

    Full Text Available Photothermal therapy (PPT is a platform to fight cancer by using multiplexed interactive plasmonic nanomaterials as probes in combination with the excellent therapeutic performance of near-infrared (NIR light. With recent rapid developments in optics and nanotechnology, plasmonic materials have potential in cancer diagnosis and treatment, but there are some concerns regarding their clinical use. The primary concerns include the design of plasmonic nanomaterials which are taken up by the tissues, perform their function and then clear out from the body. Gold nanoparticles (Au NPs can be developed in different morphologies and functionalized to assist the photothermal therapy in a way that they have clinical value. This review outlines the diverse Au morphologies, their distinctive characteristics, concerns and limitations to provide an idea of the requirements in the field of NIR-based therapeutics.

  18. A prototype stationary Fourier transform spectrometer for near-infrared absorption spectroscopy.

    Science.gov (United States)

    Li, Jinyang; Lu, Dan-feng; Qi, Zhi-mei

    2015-09-01

    A prototype stationary Fourier transform spectrometer (FTS) was constructed with a fiber-coupled lithium niobate (LiNbO3) waveguide Mach-Zehnder interferometer (MZI) for the purpose of rapid on-site spectroscopy of biological and chemical measurands. The MZI contains push-pull electrodes for electro-optic modulation, and its interferogram as a plot of intensity against voltage was obtained by scanning the modulating voltage from -60 to +60 V in 50 ms. The power spectrum of input signal was retrieved by Fourier transform processing of the interferogram combined with the wavelength dispersion of half-wave voltage determined for the MZI used. The prototype FTS operates in the single-mode wavelength range from 1200 to 1700 nm and allows for reproducible spectroscopy. A linear concentration dependence of the absorbance at λmax = 1451 nm for water in ethanolic solution was obtained using the prototype FTS. The near-infrared spectroscopy of solid samples was also implemented, and the different spectra obtained with different materials evidenced the chemical recognition capability of the prototype FTS. To make this prototype FTS practically applicable, work on improving its spectral resolution by increasing the maximum optical path length difference is in progress.

  19. Large Magellanic Cloud Near-infrared Synoptic Survey. V. Period–Luminosity Relations of Miras

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Wenlong; Macri, Lucas M. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); He, Shiyuan; Huang, Jianhua Z. [Department of Statistics, Texas A and M University, College Station, TX 77843 (United States); Kanbur, Shashi M. [Department of Physics, The State University of New York at Oswego, Oswego, NY 13126 (United States); Ngeow, Chow-Choong, E-mail: lmacri@tamu.edu [Graduate Institute of Astronomy, National Central University, Jhongli 32001, Taiwan (China)

    2017-10-01

    We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK{sub s}. We use densely sampled I -band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period–Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K{sub s}. We study the Period–Luminosity–Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.

  20. Near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Virendra Jain

    2015-01-01

    Full Text Available Tissue ischaemia can be a significant contributor to increased morbidity and mortality. Conventional oxygenation monitoring modalities measure systemic oxygenation, but regional tissue oxygenation is not monitored. Near-infrared spectroscopy (NIRS is a non-invasive monitor for measuring regional oxygen saturation which provides real-time information. There has been increased interest in the clinical application of NIRS following numerous studies that show improved outcome in various clinical situations especially cardiac surgery. Its use has shown improved neurological outcome and decreased postoperative stay in cardiac surgery. Its usefulness has been investigated in various high risk surgeries such as carotid endarterectomy, thoracic surgeries, paediatric population and has shown promising results. There is however, limited data supporting its role in neurosurgical population. We strongly feel, it might play a key role in future. It has significant advantages over other neuromonitoring modalities, but more technological advances are needed before it can be used more widely into clinical practice.

  1. Light distribution analysis of optical fibre probe-based near-field optical tweezers using FDTD

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B H; Yang, L J; Wang, Y [School of Mechanical and Electrical Engineering, Harbin Institute of Technology, Heilongjiang, Harbin, 150001 (China)], E-mail: richelaw@163.com

    2009-09-01

    Optical fibre probe-based near-field optical tweezers overcomes the diffraction limit of conventional optical tweezers, utilizing strong mechanical forces and torque associated with highly enhanced electric fields to trap and manipulate nano-scale particles. Near-field evanescent wave generated at optical fibre probe decays rapidly with the distance that results a significant reduced trapping volume, thus it is necessary to analyze the near-field distribution of optical fibre probe. The finite difference time domain (FDTD) method is applied to characterize the near-field distribution of optical fibre probe. In terms of the distribution patterns, depolarization and polarization, the near-field distributions in longitudinal sections and cross-sections of tapered metal-coated optical fibre probe are calculated. The calculation results reveal that the incident polarized wave becomes depolarized after exiting from the nano-scale aperture of probe. The near-field distribution of the probe is unsymmetrical, and the near-field distribution in the cross-section vertical to the incident polarized wave is different from that in the cross-section parallel to the incident polarized wave. Moreover, the polarization of incident wave has a great impact on the light intensity distribution.

  2. NanoComposite Polymers for High Resolution Near Infrared Detectors

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop nanocomposite materials with tuned refractive index in the near infra red spectral range as an index-matched immersion lens for high resolution infra-red...

  3. Increased prefrontal hemodynamic change after atomoxetine administration in pediatric attention-deficit/hyperactivity disorder as measured by near-infrared spectroscopy.

    Science.gov (United States)

    Ota, Toyosaku; Iida, Junzo; Nakanishi, Yoko; Sawada, Satomi; Matsuura, Hiroki; Yamamuro, Kazuhiko; Ueda, Shotaro; Uratani, Mitsuhiro; Kishimoto, Naoko; Negoro, Hideki; Kishimoto, Toshifumi

    2015-03-01

    Atomoxetine, approved in Japan for the treatment of pediatric attention-deficit/hyperactivity disorder (ADHD) in April 2009, is a nonstimulant that is thought to act presynaptically via the inhibition of norepinephrine reuptake. Near-infrared spectroscopy is a non-invasive optical tool that can be used to study oxygenation and hemodynamic changes in the cerebral cortex. The present study examined the effects of a clinical dose of atomoxetine on changes in prefrontal hemodynamic activity in children with ADHD, as measured by near-infrared spectroscopy using the Stroop Color-Word Task. Ten children with ADHD participated in the present study. We used 24-channel near-infrared spectroscopy to measure the relative concentrations of oxyhemoglobin in the frontal lobes of participants in the drug-naïve condition and those who had received atomoxetine for 8 weeks. Measurements were conducted every 0.1 s during the Stroop Color-Word Task. We used the ADHD Rating Scale-IV-Japanese version (Home Version) to evaluate ADHD symptoms. We found a significant decrease in ADHD Rating Scale-IV-Japanese version scores, from 30.7 to 22.6 (P=0.003). During the Stroop Color-Word Task, we found significantly higher levels of oxyhemoglobin changes in the prefrontal cortex of participants in the atomoxetine condition compared with those in the drug-naïve condition. This increase in oxyhemoglobin changes might indicate an intensified prefrontal hemodynamic response induced by atomoxetine. Near-infrared spectroscopy is a sensitive tool for measuring the pharmacological effects of atomoxetine in children with ADHD. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

  4. Prediction of tablets disintegration times using near-infrared diffuse reflectance spectroscopy as a nondestructive method.

    Science.gov (United States)

    Donoso, M; Ghaly, Evone S

    2005-01-01

    The goals of this study are to user near-infrared reflectance (NIR) spectroscopy to measure the disintegration time of a series of tablets compacted at different compressional forces, calibrate NIR data vs. laboratory equipment data, develop a model equation, validate the model, and test the model's predictive ability. Seven theophylline tablet formulations of the same composition but with different disintegration time values (0.224, 1.141, 2.797, 5.492, 9.397, 16.8, and 30.092 min) were prepared along with five placebo tablet formulations with different disintegration times. Laboratory disintegration time was compared to near-infrared diffuse reflectance data. Linear regression, quadratic, cubic, and partial least square techniques were used to determine the relationship between disintegration time and near-infrared spectra. The results demonstrated that an increase in disintegration time produced an increase in near-infrared absorbance. Series of model equations, which depended on the mathematical technique used for regression, were developed from the calibration of disintegration time using laboratory equipment vs. the near-infrared diffuse reflectance for each formulation. The results of NIR disintegration time were similar to laboratory tests. The near-infrared diffuse reflectance spectroscopy method is an alternative nondestructive method for measurement of disintegration time of tablets.

  5. ULTRA-DEEP GEMINI NEAR-INFRARED OBSERVATIONS OF THE BULGE GLOBULAR CLUSTER NGC 6624

    Energy Technology Data Exchange (ETDEWEB)

    Saracino, S.; Dalessandro, E.; Ferraro, F. R.; Lanzoni, B.; Miocchi, P. [Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Geisler, D.; Mauro, F.; Cohen, R. E.; Villanova, S. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Origlia, L. [INAF—Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Bidin, C. Moni, E-mail: sara.saracino@unibo.it [Instituto de Astronomía, Universidad Católica del Norte, Av. Angamos 0610, Antofagasta (Chile)

    2016-11-20

    We used ultra-deep J and K {sub s} images secured with the near-infrared (NIR) GSAOI camera assisted by the multi-conjugate adaptive optics system GeMS at the GEMINI South Telescope in Chile, to obtain a ( K {sub s} , J - K {sub s} ) color–magnitude diagram (CMD) for the bulge globular cluster NGC 6624. We obtained the deepest and most accurate NIR CMD from the ground for this cluster, by reaching K {sub s} ∼ 21.5, approximately 8 mag below the horizontal branch level. The entire extension of the Main Sequence (MS) is nicely sampled and at K {sub s} ∼ 20 we detected the so-called MS “knee” in a purely NIR CMD. By taking advantage of the exquisite quality of the data, we estimated the absolute age of NGC 6624 ( t {sub age} = 12.0 ± 0.5 Gyr), which turns out to be in good agreement with previous studies in the literature. We also analyzed the luminosity and mass functions of MS stars down to M ∼ 0.45 M{sub ⊙}, finding evidence of a significant increase of low-mass stars at increasing distances from the cluster center. This is a clear signature of mass segregation, confirming that NGC 6624 is in an advanced stage of dynamical evolution.

  6. The application of near infrared spectroscopy in nutritional intervention studies

    Directory of Open Access Journals (Sweden)

    Philippa A Jackson

    2013-08-01

    Full Text Available Functional near infrared spectroscopy (NIRS is a non-invasive optical imaging technique used to monitor cerebral blood flow (CBF and by proxy neuronal activation. The use of NIRS in nutritional intervention studies is a relatively novel application of this technique, with only a small, but growing, number of trials published to date. These trials—in which the effects on CBF following administration of dietary components such as caffeine, polyphenols and omega-3 polyunsaturated fatty acids are assessed—have successfully demonstrated NIRS as a sensitive measure of change in haemodynamic response during cognitive tasks in both acute and chronic treatment intervention paradigms. The existent research in this area has been limited by the constraints of the technique itself however advancements in the measurement technology, paired with studies endeavouring increased sophistication in number and locations of channels over the head should render the use of NIRS in nutritional interventions particularly valuable in advancing our understanding of the effects of nutrients and dietary components on the brain.

  7. Rheo-optical two-dimensional (2D) near-infrared (NIR) correlation spectroscopy for probing strain-induced molecular chain deformation of annealed and quenched Nylon 6 films

    Science.gov (United States)

    Shinzawa, Hideyuki; Mizukado, Junji

    2018-04-01

    A rheo-optical characterization technique based on the combination of a near-infrared (NIR) spectrometer and a tensile testing machine is presented here. In the rheo-optical NIR spectroscopy, tensile deformations are applied to polymers to induce displacement of ordered or disordered molecular chains. The molecular-level variation of the sample occurring on short time scales is readily captured as a form of strain-dependent NIR spectra by taking an advantage of an acousto-optic tunable filter (AOTF) equipped with the NIR spectrometer. In addition, the utilization of NIR with much less intense absorption makes it possible to measure transmittance spectra of relatively thick samples which are often required for conventional tensile testing. An illustrative example of the rheo-optical technique is given with annealed and quenched Nylon 6 samples to show how this technique can be utilized to derive more penetrating insight even from the seemingly simple polymers. The analysis of the sets of strain-dependent NIR spectra suggests the presence of polymer structures undergoing different variations during the tensile elongation. For instance, the tensile deformation of the semi-crystalline Nylon 6 involves a separate step of elongation of the rubbery amorphous chains and subsequent disintegration of the rigid crystalline structure. Excess amount of crystalline phase in Nylon 6, however, results in the retardation of the elastic deformation mainly achieved by the amorphous structure, which eventually leads to the simultaneous orientation of both amorphous and crystalline structures.

  8. Tunable magnetization of infrared epsilon-near-zero media via field-effect modulation

    Science.gov (United States)

    Salary, Mohammad Mahdi; Mosallaei, Hossein

    2018-04-01

    In this letter, we demonstrate that field effect modulation enables electrical tuning of the effective permeability of epsilon-near-zero (ENZ) media at infrared frequencies. In particular, hexagonal silicon carbide (6H-SiC) is incorporated as an epsilon-near-zero host in a gated 6H-SiC/SiO2/Si heterostructure. The change in the applied voltage leads to a change in the carrier concentration of the accumulation layer formed at the interface of 6H-SiC and SiO2 which can alter the effective permeability of the heterostructure by virtue of the photonic doping effect. We will rigorously model and analyze the structure by linking charge transport and electromagnetic models. The presented mechanism allows for tuning the impedance and magnetization of ENZ materials in real-time while capturing extreme cases of epsilon-and-mu-near-zero and magnetic conductor. As such, it can be used for various applications such as real-time engineering of thermal emission, dynamic switching, reconfigurable tunneling, and holography.

  9. Turbid Media Extinction Coefficient for Near-Infrared Laser Radiation

    International Nuclear Information System (INIS)

    Dreischuh, T; Gurdev, L; Vankov, O; Stoyanov, D; Avramov, L

    2015-01-01

    In this work, extended investigations are performed of the extinction coefficient of Intralipid-20% dilutions in distilled water depending on the Intralipid concentration, for laser radiation wavelengths in the red and near-infrared regions covering the so-called tissue optical window. The extinction is measured by using an approach we have developed recently based on the features of the spatial intensity distribution of laser-radiation beams propagating through semi-infinite turbid media. The measurements are conducted using separately two dilution- containing plexiglass boxes of different sizes and volumes, in order to prove the appropriateness of the assumption of semi-infinite turbid medium. The experimental results for the extinction are in agreement with our previous results and with empiric formulae found by other authors concerning the wavelength dependence of the scattering coefficient of Intralipid – 10% and Intralipid – 20%. They are also in agreement with known data of the water absorptance. It is estimated as well that the wavelengths around 1320 nm would be advantageous for deep harmless sensing and diagnostics of tissues

  10. Near-Field Optical Microscopy of Fractal Structures

    DEFF Research Database (Denmark)

    Coello, Victor; Bozhevolnyi, Sergey I.

    1999-01-01

    Using a photon scanning tunnelling microscope combined with a shear-force feedback system, we image both topographical and near-field optical images (at the wavelengths of 633 and 594 nm) of silver colloid fractals. Near-field optical imaging is calibrated with a standing evanescent wave pattern...

  11. The near-infrared waveguide properties of an LGS crystal formed by swift Kr8+ ion irradiation

    Science.gov (United States)

    Zhou, Yu-Fan; Liu, Peng; Liu, Tao; Zhang, Lian; Sun, Jian-Rong; Wang, Zhi-Guang; Wang, Xue-Lin

    2013-11-01

    In this work, we report on the optical properties in the near-infrared region of a LGS crystal planar waveguide formed by swift heavy ion irradiation. The planar optical waveguide in a LGS crystal was fabricated by 330 MeV Kr8+-ion implantation at a fluence of 1 × 1012 cm-2. The initial beam had an energy of 2.1 GeV and was slowed down by passing it through a 259 μm thick Al foil. The guided mode was measured using a prism coupler at a wavelength of 1539 nm. The near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. The FD-BPM was used to simulate the guided mode profile. The lattice damage induced by SHI irradiation in the LGS crystal was studied using micro-Raman spectroscopy. The Raman spectra are consistent with the stopping power distributions of the Kr8+ ions simulated by SRIM and with the micro-photograph of the waveguide taken by a microscope using polarized light.

  12. The near-infrared waveguide properties of an LGS crystal formed by swift Kr8+ ion irradiation

    International Nuclear Information System (INIS)

    Zhou, Yu-Fan; Liu, Peng; Liu, Tao; Zhang, Lian; Sun, Jian-Rong; Wang, Zhi-Guang; Wang, Xue-Lin

    2013-01-01

    In this work, we report on the optical properties in the near-infrared region of a LGS crystal planar waveguide formed by swift heavy ion irradiation. The planar optical waveguide in a LGS crystal was fabricated by 330 MeV Kr 8+ -ion implantation at a fluence of 1 × 10 12 cm −2 . The initial beam had an energy of 2.1 GeV and was slowed down by passing it through a 259 μm thick Al foil. The guided mode was measured using a prism coupler at a wavelength of 1539 nm. The near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. The FD-BPM was used to simulate the guided mode profile. The lattice damage induced by SHI irradiation in the LGS crystal was studied using micro-Raman spectroscopy. The Raman spectra are consistent with the stopping power distributions of the Kr 8+ ions simulated by SRIM and with the micro-photograph of the waveguide taken by a microscope using polarized light

  13. CR-39 (PADC) Reflection and Transmission of Light in the Ultraviolet-Near-Infrared (UV-NIR) Range.

    Science.gov (United States)

    Traynor, Nathan B J; McLauchlin, Christopher; Dodge, Kenneth; McGarrah, James E; Padalino, Stephen J; McCluskey, Michelle; Sangster, T C; McLean, James G

    2018-04-01

    The spectral reflection (specular and diffuse) and transmission of Columbia Resin 39 (CR-39) were measured for incoherent light with wavelengths in the range of 200-2500 nm. These results will be of use for the optical characterization of CR-39, as well as in investigations of the chemical modifications of the polymer caused by ultraviolet (UV) exposure. A Varian Cary 5000 was used to perform spectroscopy on several different thicknesses of CR-39. With proper analysis for the interdependence of reflectance and transmittance, results are consistent across all samples. The reflectivity from each CR-39-air boundary reveals an increase in the index of refraction in the near-UV. Absorption observations are consistent with the Beer-Lambert law. Strong absorption of UV light of wavelength shorter than 350 nm suggests an optical band gap of 3.5 eV, although the standard analysis is not conclusive. Absorption features observed in the near infrared are assigned to molecular vibrations, including some that are new to the literature.

  14. Infrared polarimetry of the reflection nebula near L 1551 IRS 5

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Tetsuya; Yamashita, Takuya; Sato, Shuji; Suzuki, Hiro; Hough, J H; Garden, R; Gatley, I

    1986-11-01

    The K-band polarization has been measured in the region extending 30 arcsec to the SW of L 1551 IRS5. The degree of polarization is exceptionally high, reaching approx. 67 per cent. The large polarizations and the azimuthal pattern of the position angles are attributed to scattering of infrared radiation from IRS5 by dust grains. The infrared brightness distribution resembles that of the optical nebulosity. It is proposed that infrared scattering occurs at the 'walls' of a cavity formed by the interaction of stellar winds with the ambient cloud.

  15. 77 FR 36579 - II-VI, Inc., Infrared Optics-Saxonburg Division, Saxonburg, PA; Leased Workers From Adecco, Carol...

    Science.gov (United States)

    2012-06-19

    ...., Infrared Optics-Saxonburg Division, Saxonburg, PA; Leased Workers From Adecco, Carol Harris, Unlimited Staffing, and Staffmark, Working On-Site at II-VI, Inc., Infrared Optics-Saxonburg Division, Saxonburg, PA... workers and former workers of II-VI, Inc., Infrared Optics-Saxonburg Division, Saxonburg, Pennsylvania...

  16. Characterization of long-range plasmonic waveguides at visible to near-infrared regime

    Directory of Open Access Journals (Sweden)

    Sheng-Ting Huang

    2017-12-01

    Full Text Available Long-range surface plasmon polariton waveguides composed with thin gold stripes embedded in SU-8 polymer cladding with various stripe widths were fabricated. Material properties of the polymer cladding layer, gold thin film, and the device structures were discussed. Optical properties based on modal propagation were characterized at visible to near-infrared wavelengths. The measured propagation losses of waveguide widths from 3 to 9 μm at 633, 785, and 1550 nm are 7.5-18.8, 6.8-12.5, and 1.9-3.9 dB/mm, respectively. Guiding mode properties such as overlap integrals between the simulated and the measured fields and the polarization extinction ratios of the waveguides with different stripe widths were investigated at the telecommunication wavelength. Good accordance between the measurement and simulation results was presented.

  17. N-Annulated perylene-substituted and fused porphyrin dimers with intense near-infrared one-photon and two-photon absorption

    KAUST Repository

    Luo, Jie

    2015-01-21

    Fusion of two N-annulated perylene (NP) units with a fused porphyrin dimer along the S0-S1 electronic transition moment axis has resulted in new near-infrared (NIR) dyes 1a/1b with very intense absorption (ε>1.3×105M-1cm-1) beyond 1250nm. Both compounds displayed moderate NIR fluorescence with fluorescence quantum yields of 4.4×10-6 and 6.0×10-6 for 1a and 1b, respectively. The NP-substituted porphyrin dimers 2a/2b have also been obtained by controlled oxidative coupling and cyclodehydrogenation, and they showed superimposed absorptions of the fused porphyrin dimer and the NP chromophore. The excited-state dynamics of all of these compounds have been studied by femtosecond transient absorption measurements, which revealed porphyrin dimer-like behaviour. These new chromophores also exhibited good nonlinear optical susceptibility with large two-photon absorption cross-sections in the NIR region due to extended π-conjugation. Time-dependent density functional theory calculations have been performed to aid our understanding of their electronic structures and absorption spectra.

  18. Near infrared spectroscopy of human muscles

    Science.gov (United States)

    Gasbarrone, R.; Currà, A.; Cardillo, A.; Bonifazi, G.; Serranti, S.

    2018-02-01

    Optical spectroscopy is a powerful tool in research and industrial applications. Its properties of being rapid, non-invasive and not destructive make it a promising technique for qualitative as well as quantitative analysis in medicine. Recent advances in materials and fabrication techniques provided portable, performant, sensing spectrometers readily operated by user-friendly cabled or wireless systems. We used such a system to test whether infrared spectroscopy techniques, currently utilized in many areas as primary/secondary raw materials sector, cultural heritage, agricultural/food industry, environmental remote and proximal sensing, pharmaceutical industry, etc., could be applied in living humans to categorize muscles. We acquired muscles infrared spectra in the Vis-SWIR regions (350-2500 nm), utilizing an ASD FieldSpec 4 Standard-Res Spectroradiometer with a spectral sampling capability of 1.4 nm at 350-1000 nm and 1.1 nm at 1001-2500 nm. After a preliminary spectra pre-processing (i.e. signal scattering reduction), Principal Component Analysis (PCA) was applied to identify similar spectral features presence and to realize their further grouping. Partial Least-Squares Discriminant Analysis (PLS-DA) was utilized to implement discrimination/prediction models. We studied 22 healthy subjects (age 25-89 years, 11 females), by acquiring Vis-SWIR spectra from the upper limb muscles (i.e. biceps, a forearm flexor, and triceps, a forearm extensor). Spectroscopy was performed in fixed limb postures (elbow angle approximately 90‡). We found that optical spectroscopy can be applied to study human tissues in vivo. Vis-SWIR spectra acquired from the arm detect muscles, distinguish flexors from extensors.

  19. The optical + infrared L dwarf spectral sequence of young planetary-mass objects in the Upper Scorpius association

    Science.gov (United States)

    Lodieu, N.; Zapatero Osorio, M. R.; Béjar, V. J. S.; Peña Ramírez, K.

    2018-01-01

    We present the results of photometric and spectroscopic follow-ups of the lowest mass member candidates in the nearest OB association, Upper Scorpius (∼5-10 Myr; 145 ± 17 pc), with the Gran Telescopio de Canarias (GTC) and European Southern Observatory (ESO) Very Large Telescope (VLT). We confirm the membership of the large majority (>80 per cent) of candidates originally selected photometrically and astrometrically based on their spectroscopic features, weak equivalent widths of gravity-sensitive doublets and radial velocities. Confirmed members follow a sequence over a wide magnitude range (J = 17.0-19.3 mag) in several colour-magnitude diagrams with optical, near- and mid-infrared photometry and have near-infrared spectral types in the L1-L7 interval with likely masses below 15 Jupiter masses. We find that optical spectral types tend to be earlier than near-infrared spectral types by a few subclasses for spectral types later than M9. We investigate the behaviour of spectral indices, defined in the literature as a function of spectral type and gravity, by comparison with values reported in the literature for young and old dwarfs. We also derive effective temperatures in the 1900-1600 K range from fits of synthetic model-atmosphere spectra to the observed photometry, but we caution that the procedure carries large uncertainties. We determine bolometric corrections for young L dwarfs with ages of ∼5-10 Myr (Upper Sco association) and find them to be similar in the J band but larger by 0.1-0.4 mag in the K band with respect to field L dwarfs. Finally, we discover two faint young L dwarfs, Visible and Infrared Survey Telescope for Astronomy (VISTA) J1607-2146 (L4.5) and VISTA J1611-2215 (L5), that have Hα emission and possible flux excesses at 4.5 μm, pointing to the presence of accretion from a disc on to the central objects of mass below ∼15MJup at an age of 5-10 Myr.

  20. Optical properties of phosphorene

    International Nuclear Information System (INIS)

    Yang, Jiong; Lu Yuerui

    2017-01-01

    Phosphorene is a two-dimensional semiconductor with layers-dependent bandgap in the near-infrared range and it has attracted a great deal of attention due to its high anisotropy and carrier mobility. The highly anisotropic nature of phosphorene has been demonstrated through Raman and polarization photoluminescence measurements. Photoluminescence spectroscopy has also revealed the layers-dependent bandgap of phosphorene. Furthermore, due to the reduced dimensionality and screening in phosphorene, excitons and trions can stably exist at elevated temperatures and have large binding energies. The exciton and trion dynamics are thus detected by applying electrical bias or optical injection to the phosphorene system. Finally, various optical and optoelectronic applications based on phosphorene have been demonstrated and discussed. (topical reviews)

  1. Utilization of Infrared Fiber Optic in the Automotive Industry

    Science.gov (United States)

    Tucker, Dennis S.; Brantley, Lott W. (Technical Monitor)

    2001-01-01

    Fiber optics are finding a place in the automotive industry. Illumination is the primary application today. Soon, however, fiber optics will be used for data communications and sensing applications. Silica fiber optics and plastic fibers are sufficient for illumination and communication applications however, sensing applications involving high temperature measurement and remote gas analysis would benefit from the use of infrared fiber optics. Chalcogonide and heavy metal fluoride glass optical fibers are two good candidates for these applications. Heavy metal fluoride optical fibers are being investigated by NASA for applications requiring transmission in the infrared portion of the electromagnetic spectrum. Zirconium-Barium-Lanthanum-Aluminum-Sodium-Fluoride (ZBLAN) is one such material which has been investigated. This material has a theoretical attenuation coefficient 100 times lower than that of silica and transmits into the mid-IR. However, the measured attenuation coefficient is higher than silica due to impurities and crystallization. Impurities can be taken care of by utilizing cleaner experimental protocol. It has been found that crystallization can be suppressed by processing in reduced gravity. Fibers processed in reduced gravity on the KC135 reduced gravity aircraft were found to be free of crystals while those processed on the ground were found to have crystals. These results will be presented along with plans for producing continuous lengths of ZBLAN optical fiber on board the International Space Station.

  2. Partial Least Square with Savitzky Golay Derivative in Predicting Blood Hemoglobin Using Near Infrared Spectrum

    Directory of Open Access Journals (Sweden)

    Mohd Idrus Mohd Nazrul Effendy

    2018-01-01

    Full Text Available Near infrared spectroscopy (NIRS is a reliable technique that widely used in medical fields. Partial least square was developed to predict blood hemoglobin concentration using NIRS. The aims of this paper are (i to develop predictive model for near infrared spectroscopic analysis in blood hemoglobin prediction, (ii to establish relationship between blood hemoglobin and near infrared spectrum using a predictive model, (iii to evaluate the predictive accuracy of a predictive model based on root mean squared error (RMSE and coefficient of determination rp2. Partial least square with first order Savitzky Golay (SG derivative preprocessing (PLS-SGd1 showed the higher performance of predictions with RMSE = 0.7965 and rp2= 0.9206 in K-fold cross validation. Optimum number of latent variable (LV and frame length (f were 32 and 27 nm, respectively. These findings suggest that the relationship between blood hemoglobin and near infrared spectrum is strong, and the partial least square with first order SG derivative is able to predict the blood hemoglobin using near infrared spectral data.

  3. Optical changes of dentin in the near-IR as a function of mineral content

    Science.gov (United States)

    Berg, Rhett A.; Simon, Jacob C.; Fried, Daniel; Darling, Cynthia L.

    2017-02-01

    The optical properties of human dentin can change markedly due to aging, friction from opposing teeth, and acute trauma, resulting in the formation of transparent or sclerotic dentin with increased mineral density. The objective of this study was to determine the optical attenuation coefficient of human dentin tissues with different mineral densities in the near-infrared (NIR) spectral regions from 1300-2200 nm using NIR transillumination and optical coherence tomography (OCT). N=50 dentin samples of varying opacities were obtained by sectioning whole extracted teeth into 150 μm transverse sections at the cemento-enamel junction or the apical root. Transillumination images were acquired with a NIR camera and attenuation measurements were acquired at various NIR wavelengths using a NIR sensitive photodiode. Samples were imaged with transverse microradiography (gold standard) in order to determine the mineral density of each sample.

  4. Focal plane optics in far-infrared and submillimeter astronomy

    Science.gov (United States)

    Hildebrand, R. H.

    1985-01-01

    The construction of airborne observatories, high mountain-top observatories, and space observatories designed especially for infrared and submillimeter astronomy has opened fields of research requiring new optical techniques. A typical far-IR photometric study involves measurement of a continuum spectrum in several passbands between approx 30 microns and 1000 microns and diffraction-limited mapping of the source. At these wavelengths, diffraction effects strongly influence the design of the field optics systems which couple the incoming flux to the radiation sensors (cold bolometers). The Airy diffraction disk for a typical telescope at submillimeter wavelengths approx 100 microns-1000 microns is many millimeters in diameter; the size of the field stop must be comparable. The dilute radiation at the stop is fed through a Winston nonimaging concentrator to a small cavity containing the bolometer. The purpose of this paper is to review the principles and techniques of infrared field optics systems, including spectral filters, concentrators, cavities, and bolometers (as optical elements), with emphasis on photometric systems for wavelengths longer than 60 microns.

  5. Focal plane optics in far-infrared and submillimeter astronomy

    Science.gov (United States)

    Hildebrand, R. H.

    1986-02-01

    The construction of airborne observatories, high mountain-top observatories, and space observatories designed especially for infrared and submillimeter astronomy has opened fields of research requiring new optical techniques. A typical far-IR photometric study involves measurement of a continuum spectrum in several passbands between approx 30 microns and 1000 microns and diffraction-limited mapping of the source. At these wavelengths, diffraction effects strongly influence the design of the field optics systems which couple the incoming flux to the radiation sensors (cold bolometers). The Airy diffraction disk for a typical telescope at submillimeter wavelengths approx 100 microns-1000 microns is many millimeters in diameter; the size of the field stop must be comparable. The dilute radiation at the stop is fed through a Winston nonimaging concentrator to a small cavity containing the bolometer. The purpose of this paper is to review the principles and techniques of infrared field optics systems, including spectral filters, concentrators, cavities, and bolometers (as optical elements), with emphasis on photometric systems for wavelengths longer than 60 microns.

  6. Near-infrared scintillation of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, T. [Fermilab; Escobar, C. O. [Campinas State U.; Lippincott, W. H. [Fermilab; Rubinov, P. [Fermilab

    2016-03-03

    Since the 1970s it has been known that noble gases scintillate in the near infrared (NIR) region of the spectrum (0.7 $\\mu$m < $\\lambda$; < 1.5$\\mu$m). More controversial has been the question of the NIR light yield for condensed noble gases. We first present the motivation for using the NIR scintillation in liquid argon detectors, then briefly review early as well as more recent efforts and finally show encouraging preliminary results of a test performed at Fermilab.

  7. Electrowetting Variable Optics for Visible and Infrared Applications

    Science.gov (United States)

    Watson, Alexander Maxwell

    Miniaturized variable optical devices are important for the fields of medical technology, optical communication, and consumer imaging devices. Areas ranging from endoscopy and optogenetics to atomic clocks and imaging all benefit from versatile optical systems. These applications all require precise and rapid control of imaging focal depth and lateral scanning. Electrowetting variable optics is one emergent technology that has the capability to provide focus tuning, beam steering, and even phase modulation in a small and robust package which requires no moving parts. Furthermore, electrowetting based devices there are attractive due to their transmissive nature, polarization insensitivity, low insertion loss, low electrical power requirements, and high optical quality. These features mean that electrowetting adaptive optical components are an attractive solution, compared with MEMS and liquid crystal optical components. Electrowetting is a technique that enables control of the shape of a liquid droplet with applied voltage. A conductive droplet on a dielectric surface alters its contact angle due to charges that build up between an underlying electrode and the surface of the droplet. This effect can be used to tune the curvature and tilt of liquids within cavities. The liquid boundary creates a high quality surface to use for lensing or steering applications. This thesis will focus on the development of electrowetting based lenses and prisms and applications in imaging for both visible and infrared wavelengths. Within this dissertation is the first demonstration of electrowetting lenses for phase control, as well as the investigation of non-aqueous electrowetting lens liquids for electrowetting lenses operation in the infrared. Key considerations that affect the performance and reliability are dielectric material and thickness, liquid selection and source of ionic conduction. The optical devices presented herein utilize judicious selection of dielectric material

  8. ‘Green’-synthesized near-infrared PbS quantum dots with silica-PEG dual-layer coating: ultrastable and biocompatible optical probes for in vivo animal imaging

    Science.gov (United States)

    Wang, D.; Qian, J.; Cai, F.; He, S.; Han, S.; Mu, Y.

    2012-06-01

    In this paper, PbS semiconductor quantum dots (QDs) with near-infrared (NIR) photoluminescence were synthesized in oleic acid and paraffin liquid mixture by using an easily handled and ‘green’ approach. Surface functionalization of the QDs was accomplished with a silica and polyethylene glycol (PEG) phospholipid dual-layer coating and the excellent chemical stability of the nanoparticles is demonstrated. We then successfully applied the ultrastable PbS QDs to in vivo sentinel lymph node (SLN) mapping of mice. Histological analyses were also carried out to ensure that the intravenously injected nanoparticles did not produce any toxicity to the organism of mice. These experimental results suggested that our ultrastable NIR PbS QDs can serve as biocompatible and efficient probes for in vivo optical bioimaging and has great potentials for disease diagnosis and clinical therapies in the future.

  9. ‘Green’-synthesized near-infrared PbS quantum dots with silica–PEG dual-layer coating: ultrastable and biocompatible optical probes for in vivo animal imaging

    International Nuclear Information System (INIS)

    Wang, D; Qian, J; Cai, F; He, S; Han, S; Mu, Y

    2012-01-01

    In this paper, PbS semiconductor quantum dots (QDs) with near-infrared (NIR) photoluminescence were synthesized in oleic acid and paraffin liquid mixture by using an easily handled and ‘green’ approach. Surface functionalization of the QDs was accomplished with a silica and polyethylene glycol (PEG) phospholipid dual-layer coating and the excellent chemical stability of the nanoparticles is demonstrated. We then successfully applied the ultrastable PbS QDs to in vivo sentinel lymph node (SLN) mapping of mice. Histological analyses were also carried out to ensure that the intravenously injected nanoparticles did not produce any toxicity to the organism of mice. These experimental results suggested that our ultrastable NIR PbS QDs can serve as biocompatible and efficient probes for in vivo optical bioimaging and has great potentials for disease diagnosis and clinical therapies in the future. (paper)

  10. NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

    International Nuclear Information System (INIS)

    Zapatero Osorio, M. R.; Bejar, V. J. S.; Rebolo, R.; Acosta-Pulido, J. A.; Manchado, A.; Pena Ramirez, K.; Goldman, B.; Caballero, J. A.

    2011-01-01

    We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust clouds, anomalous red infrared colors, or low-gravity atmospheres. The polarimetric data were acquired with the LIRIS instrument on the William Herschel Telescope. We also provide mid-infrared photometry in the interval 3.4-24 μm for some targets obtained with Spitzer and WISE, which has allowed us to confirm the peculiar red colors of five sources in the sample. We can impose modest upper limits of 0.9% and 1.8% on the linear polarization degree for seven targets with a confidence of 99%. Only one source, 2MASS J02411151-0326587 (L0), appears to be strongly polarized (P ∼ 3%) in the J band with a significance level of P/σ P ∼ 10. The likely origin of its linearly polarized light and rather red infrared colors may reside in a surrounding disk with an asymmetric distribution of grains. Given its proximity (66 ± 8 pc), this object becomes an excellent target for the direct detection of the disk.

  11. Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy

    Science.gov (United States)

    We present near-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36 healthy elderly (mean age, 85 ± 6 years) and 19 young adults (mean age, 28 ± 4 years). Non-invasive measurements were obtained on the forehead using a commercially a...

  12. Surface roughness and gloss study of prints: application of specular reflection at near infrared

    International Nuclear Information System (INIS)

    Silfsten, P; Dutta, R; Pääkkönen, P; Peiponen, K-E; Tåg, C-M; Gane, P A C

    2012-01-01

    Absolute reflectance data were measured with a spectrophotometer in the visible and near infrared (NIR) spectral range. The specular reflectance data in the NIR were used for the assessment of the surface roughness of magenta, yellow, cyan and black prints on paper. In addition, surface roughness data obtained from the prints with a mechanical diamond stylus, an optical profiling system and the spectrophotometer are compared with each other. The surface roughness obtained with the aid of the spectrophotometer data suggests a smoother surface than when measured with the diamond stylus and the optical profiling system. The gloss of the prints can be obtained from the absolute specular reflectance spectra in the spectral region of visible light. It is shown that specular reflection data at a fixed wavelength in the NIR are useful also in the interpretation of gloss in the visible spectral range, but using an unconventional grazing angle of incidence. (paper)

  13. Pure Electric and Pure Magnetic Resonances in Near-Infrared Metal Double-Triangle Metamaterial Arrays

    International Nuclear Information System (INIS)

    Cao Zhi-Shen; Pan Jian; Chen Zhuo; Zhan Peng; Min Nai-Ben; Wang Zhen-Lin

    2011-01-01

    We experimentally and numerically investigate the optical properties of metamaterial arrays composed of double partially-overlapped metallic nanotriangles fabricated by an angle-resolved nanosphere lithography. We demonstrate that each double-triangle can be viewed as an artificial magnetic element analogous to the conventional metal split-ring-resonator. It is shown that under normal-incidence conditions, individual double-triangle can exhibit a strong local magnetic resonance, but the collective response of the metamaterial arrays is purely electric because magnetic resonances of the two double-triangles in a unit cell having opposite openings are out of phase. For oblique incidences the metamaterial arrays are shown to support a pure magnetic response at the same frequency band. Therefore, switchable electric and magnetic resonances are achieved in double-triangle arrays. Moreover, both the electric and magnetic resonances are shown to allow for a tunability over a large spectral range down to near-infrared. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  14. Largely Improved Near-Infrared Silicon-Photosensing by the Piezo-Phototronic Effect.

    Science.gov (United States)

    Dai, Yejing; Wang, Xingfu; Peng, Wenbo; Zou, Haiyang; Yu, Ruomeng; Ding, Yong; Wu, Changsheng; Wang, Zhong Lin

    2017-07-25

    Although silicon (Si) devices are the backbone of modern (opto-)electronics, infrared Si-photosensing suffers from low-efficiency due to its limitation in light-absorption. Here, we demonstrate a large improvement in the performance, equivalent to a 366-fold enhancement in photoresponsivity, of a Si-based near-infrared (NIR) photodetector (PD) by introducing the piezo-phototronic effect via a deposited CdS layer. By externally applying a -0.15‰ compressive strain to the heterojunction, carrier-dynamics modulation at the local junction can be induced by the piezoelectric polarization, and the photoresponsivity and detectivity of the PD exhibit an enhancement of two orders of magnitude, with the peak values up to 19.4 A/W and 1.8 × 10 12 cm Hz 1/2 /W, respectively. The obtained maximum responsivity is considerably larger than those of commercial Si and InGaAs PDs in the NIR waveband. Meanwhile, the rise time and fall time are reduced by 84.6% and 76.1% under the external compressive strain. This work provides a cost-effective approach to achieve high-performance NIR photosensing by the piezo-phototronic effect for high-integration Si-based optoelectronic systems.

  15. Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry.

    Science.gov (United States)

    Merlo, Sabina; Poma, Paolo; Crisà, Eleonora; Faralli, Dino; Soldo, Marco

    2017-02-25

    In this work, we have applied optical low-coherence reflectometry (OLCR), implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis) as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time.

  16. Scanning near-field optical microscopy and near-field optical probes: properties, fabrication, and control of parameters

    International Nuclear Information System (INIS)

    Dryakhlushin, V F; Veiko, V P; Voznesenskii, N B

    2007-01-01

    A brief review of modern applications of scanning near-field optical (SNO) devices in microscopy, spectroscopy, and lithography is presented in the introduction. The problem of the development of SNO probes, as the most important elements of SNO devices determining their resolution and efficiency, is discussed. Based on the works of the authors, two different methods for fabricating SNO probes by using the adiabatic tapering of an optical fibre are considered: the laser-heated mechanical drawing and chemical etching. A nondestructive optical method for controlling the nanometre aperture of SNO probes is proposed, substantiated, and tested experimentally. The method is based on the reconstruction of a near-field source with the help of a theoretical algorithm of the inverse problem from the experimental far-filed intensity distribution. Some prospects for a further refinement of the construction and technology of SNO probes are discussed. (optical microscopy)

  17. Host sensitized near-infrared emission in Nd3+ doped different alkaline-sodium-phosphate phosphors

    Science.gov (United States)

    Balakrishna, A.; Swart, H. C.; Kroon, R. E.; Ntwaeaborwa, O. M.

    2018-04-01

    Near-infrared (NIR) emitting phosphors of different alkaline based sodium-phosphate (MNa[PO4], where M = Mg, Ca, Sr and Ba were prepared by a conventional solution combustion method with fixed doping concentration of Nd3+ (1.0 mol%). The phosphors were characterized by powder X-ray diffraction, field emission scanning electron microscope, Fourier transform infrared spectroscopy, UV-vis spectroscopy and fluorescent spectrophotometry. The optical properties including reflectance, excitation and emission were investigated. The excitation spectra of the phosphors were characterized by a broadband extending from 450 to 900 nm. Upon excitation with a wavelength of 580 nm, the phosphor emits intensely infrared region at 872 nm, 1060 nm and 1325 nm which correspond to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions of Nd3+ ions and were found to vary for the different hosts. The strongest emission wavelength reaches 1060 nm. The most intense emission of Nd3+ was observed from Ca2+ incorporated host. The down conversion emissions of the material fall in the NIR region suggesting that the prepared phosphors have potential application in the development of photonic devices emitting in the NIR.

  18. Tunable infrared reflectance by phonon modulation

    Science.gov (United States)

    Ihlefeld, Jon F.; Sinclair, Michael B.; Beechem, III, Thomas E.

    2018-03-06

    The present invention pertains to the use of mobile coherent interfaces in a ferroelectric material to interact with optical phonons and, ultimately, to affect the material's optical properties. In altering the optical phonon properties, the optical properties of the ferroelectric material in the spectral range near-to the phonon mode frequency can dramatically change. This can result in a facile means to change to the optical response of the ferroelectric material in the infrared.

  19. The continued optical to mid-infrared evolution of V838 Monocerotis

    Energy Technology Data Exchange (ETDEWEB)

    Loebman, S. R. [Department of Astronomy, University of Michigan, 830 Dennison, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Wisniewski, J. P. [Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States); Schmidt, S. J. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Kowalski, A. F. [NASA Postdoctoral Program Fellow, NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Barry, R. K. [NASA Goddard Space Flight Center, Laboratory for Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Bjorkman, K. S. [Ritter Observatory, MS #113, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606-3390 (United States); Hammel, H. B. [AURA, 1212 New York Avenue NW, Suite 450, Washington, DC 20005 (United States); Hawley, S. L.; Szkody, P. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Hebb, L. [Department of Physics, Hobart and William Smith Colleges, 300 Pulteney Street, Geneva, NY 14456 (United States); Kasliwal, M. M. [The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Lynch, D. K.; Russell, R. W. [The Aerospace Corporation, M2-266, P.O. Box 92957, Los Angeles, CA 90009-29257 (United States); Sitko, M. L., E-mail: sloebman@umich.edu [Department of Physics, University of Cincinnati, Cincinnati OH 45221 (United States)

    2015-01-01

    The eruptive variable V838 Monocerotis (V838 Mon) gained notoriety in 2002 when it brightened nine magnitudes in a series of three outbursts and then rapidly evolved into an extremely cool supergiant. We present optical, near-infrared (near-IR), and mid-IR spectroscopic and photometric observations of V838 Mon obtained between 2008 and 2012 at the Apache Point Observatory 3.5 m, NASA IRTF 3 m, and Gemini South 8 m telescopes. We contemporaneously analyze the optical and IR spectroscopic properties of V838 Mon to arrive at a revised spectral type L3 supergiant and effective temperature T{sub eff}∼2000–2200 K. Because there are no existing optical observational data for L supergiants, we speculate that V838 Mon may represent the prototype for L supergiants in this wavelength regime. We find a low level of Hα emission present in the system, consistent with interaction between V838 Mon and its B3V binary; however, we cannot rule out a stellar collision as the genesis event, which could result in the observed Hα activity. Based upon a two-component blackbody fit to all wavelengths of our data, we conclude that, as of 2009, a shell of ejecta surrounded V838 Mon at a radius of R=263±10 AU with a temperature of T=285±2 K. This result is consistent with IR interferometric observations from the same era and predictions from the Lynch et al. model of the expanding system, which provides a simple framework for understanding this complicated system.

  20. The continued optical to mid-infrared evolution of V838 Monocerotis

    International Nuclear Information System (INIS)

    Loebman, S. R.; Wisniewski, J. P.; Schmidt, S. J.; Kowalski, A. F.; Barry, R. K.; Bjorkman, K. S.; Hammel, H. B.; Hawley, S. L.; Szkody, P.; Hebb, L.; Kasliwal, M. M.; Lynch, D. K.; Russell, R. W.; Sitko, M. L.

    2015-01-01

    The eruptive variable V838 Monocerotis (V838 Mon) gained notoriety in 2002 when it brightened nine magnitudes in a series of three outbursts and then rapidly evolved into an extremely cool supergiant. We present optical, near-infrared (near-IR), and mid-IR spectroscopic and photometric observations of V838 Mon obtained between 2008 and 2012 at the Apache Point Observatory 3.5 m, NASA IRTF 3 m, and Gemini South 8 m telescopes. We contemporaneously analyze the optical and IR spectroscopic properties of V838 Mon to arrive at a revised spectral type L3 supergiant and effective temperature T eff ∼2000–2200 K. Because there are no existing optical observational data for L supergiants, we speculate that V838 Mon may represent the prototype for L supergiants in this wavelength regime. We find a low level of Hα emission present in the system, consistent with interaction between V838 Mon and its B3V binary; however, we cannot rule out a stellar collision as the genesis event, which could result in the observed Hα activity. Based upon a two-component blackbody fit to all wavelengths of our data, we conclude that, as of 2009, a shell of ejecta surrounded V838 Mon at a radius of R=263±10 AU with a temperature of T=285±2 K. This result is consistent with IR interferometric observations from the same era and predictions from the Lynch et al. model of the expanding system, which provides a simple framework for understanding this complicated system.

  1. NEAR-INFRARED PHOTOMETRIC PROPERTIES OF 130,000 QUASARS: AN SDSS-UKIDSS-MATCHED CATALOG

    International Nuclear Information System (INIS)

    Peth, Michael A.; Ross, Nicholas P.; Schneider, Donald P.

    2011-01-01

    We present a catalog of over 130,000 quasar candidates with near-infrared (NIR) photometric properties, with an areal coverage of approximately 1200 deg 2 . This is achieved by matching the Sloan Digital Sky Survey (SDSS) in the optical ugriz bands to the UKIRT Infrared Digital Sky Survey (UKIDSS) Large Area Survey (LAS) in the NIR YJHK bands. We match the ∼1 million SDSS DR6 Photometric Quasar catalog to Data Release 3 of the UKIDSS LAS (ULAS) and produce a catalog with 130,827 objects with detections in one or more NIR bands, of which 74,351 objects have optical and K-band detections and 42,133 objects have the full nine-band photometry. The majority (∼85%) of the SDSS objects were not matched simply because these were not covered by the ULAS. The positional standard deviation of the SDSS Quasar to ULAS matches is δ R.A. = 0.''1370 and δ decl. = 0.''1314. We find an absolute systematic astrometric offset between the SDSS Quasar catalog and the UKIDSS LAS, of |R.A. offset | = 0.''025 and |decl. offset | = 0.''040; we suggest the nature of this offset to be due to the matching of catalog, rather than image, level data. Our matched catalog has a surface density of ∼53 deg -2 for K ≤ 18.27 objects; tests using our matched catalog, along with data from the UKIDSS Deep Extragalactic Survey, imply that our limiting magnitude is i ∼ 20.6. Color-redshift diagrams, for the optical and NIR, show a close agreement between our matched catalog and recent quasar color models at redshift z ∼ 4.6, and very high, z > 5.7, redshift previously discovered quasars.

  2. Applications of infrared technology; Proceedings of the Meeting, London, England, June 9, 10, 1988

    International Nuclear Information System (INIS)

    Williams, T.L.

    1988-01-01

    Recent developments in thermal imaging and other infrared systems relating to military, industrial, medical, and scientific applications are reviewed. Papers are presented on a new thermal imager using a linear pyroelectric detector array; multichannel near infrared spectroradiometer; technological constraints on the use of thermal imagery for remote sensing; and infrared optical system of the improved stratospheric and mesospheric sounder. Other topics discussed include infrared thermography development for composite material evaluation; infrared process linescanner, and optical infrared starting radiometer

  3. Decision making based on optical excitation transfer via near-field interactions between quantum dots

    International Nuclear Information System (INIS)

    Naruse, Makoto; Nomura, Wataru; Ohtsu, Motoichi; Aono, Masashi; Sonnefraud, Yannick; Drezet, Aurélien; Huant, Serge; Kim, Song-Ju

    2014-01-01

    Optical near-field interactions between nanostructured matters, such as quantum dots, result in unidirectional optical excitation transfer when energy dissipation is induced. This results in versatile spatiotemporal dynamics of the optical excitation, which can be controlled by engineering the dissipation processes and exploited to realize intelligent capabilities such as solution searching and decision making. Here, we experimentally demonstrate the ability to solve a decision making problem on the basis of optical excitation transfer via near-field interactions by using colloidal quantum dots of different sizes, formed on a geometry-controlled substrate. We characterize the energy transfer behavior due to multiple control light patterns and experimentally demonstrate the ability to solve the multi-armed bandit problem. Our work makes a decisive step towards the practical design of nanophotonic systems capable of efficient decision making, one of the most important intellectual attributes of the human brain.

  4. Decision making based on optical excitation transfer via near-field interactions between quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Makoto, E-mail: naruse@nict.go.jp [Photonic Network Research Institute, National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795 (Japan); Nomura, Wataru; Ohtsu, Motoichi [Department of Electrical Engineering and Information Systems, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Aono, Masashi [Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguru-ku, Tokyo 152-8550 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi-shi, Saitama 332-0012 (Japan); Sonnefraud, Yannick; Drezet, Aurélien; Huant, Serge [Université Grenoble Alpes, Inst. NEEL, F-38000 Grenoble (France); CNRS, Inst. NEEL, F-38042 Grenoble (France); Kim, Song-Ju [WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-10-21

    Optical near-field interactions between nanostructured matters, such as quantum dots, result in unidirectional optical excitation transfer when energy dissipation is induced. This results in versatile spatiotemporal dynamics of the optical excitation, which can be controlled by engineering the dissipation processes and exploited to realize intelligent capabilities such as solution searching and decision making. Here, we experimentally demonstrate the ability to solve a decision making problem on the basis of optical excitation transfer via near-field interactions by using colloidal quantum dots of different sizes, formed on a geometry-controlled substrate. We characterize the energy transfer behavior due to multiple control light patterns and experimentally demonstrate the ability to solve the multi-armed bandit problem. Our work makes a decisive step towards the practical design of nanophotonic systems capable of efficient decision making, one of the most important intellectual attributes of the human brain.

  5. Near-infrared polarization and color of Comet Halley: What can we learn about the grains

    International Nuclear Information System (INIS)

    Brooke, T.Y.; Knacke, R.F.

    1988-01-01

    The near infrared polarization and JHK colors of light scattered by dust grains in comet Halley were measured over a wide range in phase angle and heliocentric distance. Colors were redder than solar with no statistically significant variation with phase angle, heliocentric distance, or pre- and post-perihelion. This suggests that the grain population did not change drastically over time and that the data may be combined and modeled. However, short term variations in visible polarization and dust albedo were seen in Halley. Also, near infrared colors became systematically bluer after the observations were completed. The near infrared colors of Halley fall in the range of those of other comets. The near infrared polarization is similar to the visible polarization of Halley and other comets in showing a negative branch at small phase angles and an approximately linear rise toward positive values at larger phase angles. Mie theory calculations and a size distribution based on spacecraft data were used to model the near infrared polarization and color of comet Halley. Numerous lines of evidence point to the presence of dark, absorbing, probably carbonaceous materials in comets

  6. Near-infrared (NIR) optogenetics using up-conversion system

    Science.gov (United States)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Yawo, Hiromu

    2015-03-01

    Non-invasive remote control technologies designed to manipulate neural functions for a comprehensive and quantitative understanding of the neuronal network in the brain as well as for the therapy of neurological disorders have long been awaited. Recently, it has become possible to optically manipulate the neuronal activity using biological photo-reactive molecules such as channelrhodopsin-2 (ChR2). However, ChR2 and its relatives are mostly reactive to visible light which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light penetrates deep into the tissues because biological systems are almost transparent to light within this so-called `imaging window'. Here we used lanthanide nanoparticles (LNPs), which are composed of rare-earth elements, as luminous bodies to activate channelrhodopsins (ChRs) since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Neuron-glioma-hybrid ND-7/23 cells were cultured with LNP(NaYF4:Sc/Yb/Er) particles (peak emission, 543 nm) and transfected to express C1V1 (peak absorbance, 539 nm), a chimera of ChR1 and VChR1. The photocurrents were generated in response to NIR laser light (976 nm) to a level comparable to that evoked by a filtered Hg lamp (530-550 nm). NIR light pulses also evoked action potentials in the cultured neurons that expressed C1V1. It is suggested that the green luminescent light emitted from LNPs effectively activated C1V1 to generate the photocurrent. With the optimization of LNPs, acceptor photo-reactive biomolecules and optics, this system could be applied to non-invasively actuate neurons deep in the brain.

  7. Stanford MFEL and Near Infrared Science Center

    Science.gov (United States)

    2011-01-28

    are incorporated into glass catadioptric lenses that are mounted and sealed at each end of the stainless steel microscope. In addition to the self...highly effective in preventing biofilm formation , as well as in killing biofilms that are already present. b) Peer-Reviewed publications (in reversed...Multiphoton Microscopy in the Biomedical Sciences VII, SPIE, vol. 6442 (2007). 3. On Image formation in Near-field Infrared Microscopy, D. M

  8. Observation of near and intermediate infrared galactic radiation by the rocket K-10-14

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Matsumoto, Toshio; Mizuno, Tomohisa; Murakami, Hiroshi; Noguchi, Kunio

    1981-01-01

    The spatial and the energy spectra of near and intermediate infrared radiation were observed by using a detector system loaded on a rocket. The detector system is a He-cooled infrared telescope, and consists of an optical system, a cryostat, an electronic system, and a star sensor. The system was loaded on the rocket K-10-14, and the observation was made for about 400 second on August 27, 1980. For the radiation with wavelength of 2.4 mu m and 4.6 mu m, the intensity of galactic light around 338, 9, 15 and 12 degree of galactic longitude was observed. For the wavelength of 7.6, 10.1 and 14.7 mu m, the data around 340 and 10 degree of galactic longitude were obtained. The latitudinal distribution of radiation of 2.4 and 4.6 mu m was measured. After the correction for interstellar absorption, it can be said that the galactic radiation of wavelength between 2.4 mu m and 7.6 mu m was mainly composed of the radiation from light balls of late type stars. (Kato, T.)

  9. Dilute nitride based double-barrier quantum-well infrared photodetector operating in the near infrared

    International Nuclear Information System (INIS)

    Luna, E.; Hopkinson, M.; Ulloa, J. M.; Guzman, A.; Munoz, E.

    2003-01-01

    Near-infrared detection is reported for a double-barrier quantum-well infrared photodetector based on a 30-A GaAs 1-y N y (y≅0.01) quantum well. The growth procedure using plasma-assisted molecular-beam epitaxy is described. The as-grown sample exhibits a detection wavelength of 1.64 μm at 25 K. The detection peak strengthens and redshifts to 1.67 μm following rapid thermal annealing at 850 deg. C for 30 s. The detection peak position is consistent with the calculated band structure based on the band-anticrossing model for nitrogen incorporation into GaAs

  10. Electromagnetically induced transparency in metamaterials at near-infrared frequency

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Xiao, Sanshui; Jeppesen, Claus

    2010-01-01

    We employ a planar metamaterial structure composed of a splitring-resonator (SRR) and paired nano-rods to experimentally realize a spectral response at near-infrared frequencies resembling that of electromagnetically induced transparency. A narrow transparency window associated with low loss...

  11. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas

    2015-01-01

    OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care unit...

  12. [Application of near-infrared spectroscopy in golf turfgrass management].

    Science.gov (United States)

    Li, Shu-Ying; Han, Jian-Guo

    2008-07-01

    The management of golf course is different from other turfs. Its particularity lies in its higher and more precise requirement during maintenance compare with other turfs. In case something happened to turf of golf course, more effective and higher speed detecting and resolution are required. Only the data about turf growth and environment were mastered precisely in time, the friendly environmental and scientific management goal could be completed effectively and economically. The near infrared spectroscopy is a new kind of effective, convenient and non-destructive analytical method in the turfgrass management of golf course in recent years. Many factors of turf-soil system in golf course could be determined by near infrared spectroscopy at the same time. In this paper, the existing literature that use of near infrared spectroscopy to study turfgrass and soil nutrient content, soil hygroscopic moisture, feasible fertilizer application time and rate, to fix the time and volume of irrigation, turfgrass visual quality evaluation, turfgrass disease prediction and prevention were reviewed. Most researchers considered the nutrition condition of turf impacted the visual and playing quality of golf course directly and then indirectly influenced most of assistant cultivation such as fertilization, mowing and irrigation and so on. The using of NIRS can detect the nutrient content of turfgrass effectively and estimate the nutrient is excessive or deficient quickly. And then the feasible time and rate of fertilizers can be decided. Comparing with the common judgment ways based on the season fertilization and visual estimation, the using of NIRS can reduce the application of fertilizers on the base of keeping the same turf quality simultaneously. NIRS can analysis many items of soil such as moisture, elements concentration, textures on the spot by the thousands. This method can get lots of cover-all data non-destructively. What's more, NIRS can analysis soil betimes quickly

  13. The near-infrared waveguide properties of an LGS crystal formed by swift Kr{sup 8+} ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yu-Fan; Liu, Peng; Liu, Tao; Zhang, Lian [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China); Sun, Jian-Rong; Wang, Zhi-Guang [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Xue-Lin, E-mail: xuelinwang@sdu.edu.cn [School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan 250100 (China)

    2013-11-15

    In this work, we report on the optical properties in the near-infrared region of a LGS crystal planar waveguide formed by swift heavy ion irradiation. The planar optical waveguide in a LGS crystal was fabricated by 330 MeV Kr{sup 8+}-ion implantation at a fluence of 1 × 10{sup 12} cm{sup −2}. The initial beam had an energy of 2.1 GeV and was slowed down by passing it through a 259 μm thick Al foil. The guided mode was measured using a prism coupler at a wavelength of 1539 nm. The near-field intensity distribution of the mode was recorded by a CCD camera using the end-face coupling method. The FD-BPM was used to simulate the guided mode profile. The lattice damage induced by SHI irradiation in the LGS crystal was studied using micro-Raman spectroscopy. The Raman spectra are consistent with the stopping power distributions of the Kr{sup 8+} ions simulated by SRIM and with the micro-photograph of the waveguide taken by a microscope using polarized light.

  14. Near-Infrared Confocal Laser Reflectance Cytoarchitectural Imaging of the Substantia Nigra and Cerebellum in the Fresh Human Cadaver.

    Science.gov (United States)

    Cheyuo, Cletus; Grand, Walter; Balos, Lucia L

    2017-01-01

    Cytoarchitectural neuroimaging remains critical for diagnosis of many brain diseases. Fluorescent dye-enhanced, near-infrared confocal in situ cellular imaging of the brain has been reported. However, impermeability of the blood-brain barrier to most fluorescent dyes limits clinical utility of this modality. The differential degree of reflectance from brain tissue with unenhanced near-infrared imaging may represent an alternative technique for in situ cytoarchitectural neuroimaging. We assessed the utility of unenhanced near-infrared confocal laser reflectance imaging of the cytoarchitecture of the cerebellum and substantia nigra in 2 fresh human cadaver brains using a confocal near-infrared laser probe. Cellular images based on near-infrared differential reflectance were captured at depths of 20-180 μm from the brain surface. Parts of the cerebellum and substantia nigra imaged using the probe were subsequently excised and stained with hematoxylin and eosin for histologic correlation. Near-infrared reflectance imaging revealed the 3-layered cytoarchitecture of the cerebellum, with Purkinje cells appearing hyperreflectant. In the substantia nigra, neurons appeared hyporeflectant with hyperreflectant neuromelanin cytoplasmic inclusions. Cytoarchitecture of the cerebellum and substantia nigra revealed on near-infrared imaging closely correlated with the histology on hematoxylin-eosin staining. We showed that unenhanced near-infrared reflectance imaging of fresh human cadaver brain can reliably identify and distinguish neurons and detailed cytoarchitecture of the cerebellum and substantia nigra. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Tunable infrared reflectance by phonon modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ihlefeld, Jon F.; Sinclair, Michael B.; Beechem, III, Thomas E.

    2018-03-06

    The present invention pertains to the use of mobile coherent interfaces in a ferroelectric material to interact with optical phonons and, ultimately, to affect the material's optical properties. In altering the optical phonon properties, the optical properties of the ferroelectric material in the spectral range near-to the phonon mode frequency can dramatically change. This can result in a facile means to change to the optical response of the ferroelectric material in the infrared.

  16. Development of Nanostructured Antireflection Coatings for Infrared and Electro-Optical Systems

    Directory of Open Access Journals (Sweden)

    Gopal G. Pethuraja

    2017-07-01

    Full Text Available Electro-optic infrared technologies and systems operating from ultraviolet (UV to long-wave infrared (LWIR spectra are being developed for a variety of defense and commercial systems applications. Loss of a significant portion of the incident signal due to reflection limits the performance of electro-optic infrared (IR sensing systems. A critical technology being developed to overcome this limitation and enhance the performance of sensing systems is advanced antireflection (AR coatings. Magnolia is actively involved in the development and advancement of nanostructured AR coatings for a wide variety of defense and commercial applications. Ultrahigh AR performance has been demonstrated for UV to LWIR spectral bands on various substrates. The AR coatings enhance the optical transmission through optical components and devices by significantly minimizing reflection losses, a substantial improvement over conventional thin-film AR coating technologies. Nanostructured AR coatings have been fabricated using a nanomanufacturable self-assembly process on substrates that are transparent for a given spectrum of interest ranging from UV to LWIR. The nanostructured multilayer structures have been designed, developed and optimized for various optoelectronic applications. The optical properties of optical components and sensor substrates coated with AR structures have been measured and the process parameters fine-tuned to achieve a predicted high level of performance. In this paper, we review our latest work on high quality nanostructure-based AR coatings, including recent efforts on the development of nanostructured AR coatings on IR substrates.

  17. Near-infrared polarimetry of the edge-on galaxy NGC 891

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, J. D.; Clemens, D. P., E-mail: montgojo@bu.edu, E-mail: clemens@bu.edu [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)

    2014-05-01

    The edge-on galaxy NGC 891 was probed using near-infrared (NIR) imaging polarimetry in the H band (1.6 μm) with the Mimir instrument on the 1.8 m Perkins Telescope. Polarization was detected with a signal-to-noise ratio greater than three out to a surface brightness of 18.8 mag arcsec{sup –2}. The unweighted average and dispersion in polarization percentage (P) across the full disk were 0.7% and 0.3%, respectively, and the same quantities for polarization position angle (P.A.) were 12° and 19°, respectively. At least one polarization null point, where P falls nearly to zero, was detected in the northeast disk but not the southwest disk. Several other asymmetries in P between the northern and southern disk were found and may be related to spiral structure. Profiles of P and P.A. along the minor axis of NGC 891 suggest a transition from magnetic (B) field tracing dichroic polarization near the disk mid-plane to scattering dominated polarization off the disk mid-plane. A comparison between NIR P.A. and radio (3.6 cm) synchrotron polarization P.A. values revealed similar B-field orientations in the central-northeast region, which suggests that the hot plasma and cold, star-forming interstellar medium may share a common B-field. Disk-perpendicular polarizations previously seen at optical wavelengths are likely caused by scattered light from the bright galaxy center and are unlikely to be tracing poloidal B-fields in the outer disk.

  18. Near-Infrared Spectroscopic Study of Chlorite Minerals

    Directory of Open Access Journals (Sweden)

    Min Yang

    2018-01-01

    Full Text Available The mineral chemistry of twenty chlorite samples from the United States Geological Survey (USGS spectral library and two other regions, having a wide range of Fe and Mg contents and relatively constant Al and Si contents, was studied via infrared (IR spectroscopy, near-infrared (NIR spectroscopy, and X-ray fluorescence (XRF analysis. Five absorption features of the twenty samples near 4525, 4440, 4361, 4270, and 4182 cm−1 were observed, and two diagnostic features at 4440 and 4280 cm−1 were recognized. Assignments of the two diagnostic features were made for two combination bands (ν+δAlAlO−OH and ν+δSiAlO−OH by regression with IR fundamental absorptions. Furthermore, the determinant factors of the NIR band position were found by comparing the band positions with relative components. The results showed that Fe/(Fe + Mg values are negatively correlated with the two NIR combination bands. The findings provide an interpretation of the NIR band formation and demonstrate a simple way to use NIR spectroscopy to discriminate between chlorites with different components. More importantly, spectroscopic detection of mineral chemical variations in chlorites provides geologists with a tool with which to collect information on hydrothermal alteration zones from hyperspectral-resolution remote sensing data.

  19. The Formation of Massive Stars: from Herschel to Near-Infrared

    Directory of Open Access Journals (Sweden)

    Paolo Persi

    2014-12-01

    Full Text Available We have studied a number of selected high mass star forming regions, including high resolution near-infrared broad- and narrow-band imaging, Herschel (70, 160, 250, 350 and 500 μm and Spitzer (3.6, 4.5, 5.8 and 8.0 m images. The preliminary results of one of this region, IRAS 19388+2357(MOL110 are discussed. In this region a dense core has been detected in the far-infrared, and a young stellar cluster has been found around this core. Combining near-IR data with Spitzer and Herschel photometry we have derived the spectral energy distribution of Mol110. Finally comparing our H2 and Kc narrow-band images, we have found an H2 jet in this region.

  20. A design of an on-orbit radiometric calibration device for high dynamic range infrared remote sensors

    Science.gov (United States)

    Sheng, Yicheng; Jin, Weiqi; Dun, Xiong; Zhou, Feng; Xiao, Si

    2017-10-01

    With the demand of quantitative remote sensing technology growing, high reliability as well as high accuracy radiometric calibration technology, especially the on-orbit radiometric calibration device has become an essential orientation in term of quantitative remote sensing technology. In recent years, global launches of remote sensing satellites are equipped with innovative on-orbit radiometric calibration devices. In order to meet the requirements of covering a very wide dynamic range and no-shielding radiometric calibration system, we designed a projection-type radiometric calibration device for high dynamic range sensors based on the Schmidt telescope system. In this internal radiometric calibration device, we select the EF-8530 light source as the calibration blackbody. EF-8530 is a high emittance Nichrome (Ni-Cr) reference source. It can operate in steady or pulsed state mode at a peak temperature of 973K. The irradiance from the source was projected to the IRFPA. The irradiance needs to ensure that the IRFPA can obtain different amplitude of the uniform irradiance through the narrow IR passbands and cover the very wide dynamic range. Combining the internal on-orbit radiometric calibration device with the specially designed adaptive radiometric calibration algorithms, an on-orbit dynamic non-uniformity correction can be accomplished without blocking the optical beam from outside the telescope. The design optimizes optics, source design, and power supply electronics for irradiance accuracy and uniformity. The internal on-orbit radiometric calibration device not only satisfies a series of indexes such as stability, accuracy, large dynamic range and uniformity of irradiance, but also has the advantages of short heating and cooling time, small volume, lightweight, low power consumption and many other features. It can realize the fast and efficient relative radiometric calibration without shielding the field of view. The device can applied to the design and

  1. Infrared and optical light curves of EX Hydrae and VW Hydri

    International Nuclear Information System (INIS)

    Sherrington, M.R.; Lawson, P.A.; King, A.R.; Jameson, R.F.

    1980-01-01

    Optical and infrared light curves of EX Hya (V and K) and VW Hyi (J and K) are presented. The infrared colours imply very large discs for these systems. It is also found for EX Hya that the structure of the light curves is non-repeatable. (author)

  2. Near-infrared spectroscopy can reveal increases in brain activity related to animal-assisted therapy.

    Science.gov (United States)

    Morita, Yuka; Ebara, Fumio; Morita, Yoshimitsu; Horikawa, Etsuo

    2017-08-01

    [Purpose] Previous studies have indicated that animal-assisted therapy can promote recovery of psychological, social, and physiological function in mental disorders. This study was designed as a pilot evaluation of the use of near-infrared spectroscopy to objectively identify changes in brain activity that could mediate the effect of animal-assisted therapy. [Subjects and Methods] The participants were 20 healthy students (10 males and 10 females; age 19-21 years) of the Faculty of Agriculture, Saga University. Participants were shown a picture of a Tokara goat or shack (control) while prefrontal cortical oxygenated haemoglobin levels (representing neural activity) were measured by near-infrared spectroscopy. [Results] The prefrontal cortical near-infrared spectroscopy signal was significantly higher during viewing of the animal picture than during a rest condition or during viewing of the control picture. [Conclusion] Our results suggest that near-infrared spectroscopy can be used to objectively identify brain activity changes during human mentation regarding animals; furthermore, these preliminary results suggest the efficacy of animal-assisted therapy could be related to increased activation of the prefrontal cortex.

  3. Optical system design with common aperture for mid-infrared and laser composite guidance

    Science.gov (United States)

    Zhang, Xuanzhi; Yang, Zijian; Sun, Ting; Yang, Huamei; Han, Kunye; Hu, Bo

    2017-02-01

    When the field of operation of precision strike missiles is more and more complicated, autonomous seekers will soon encounter serious difficulties, especially with regard to low signature targets and complex scenarios. So the dual-mode sensors combining an imaging sensor with a semi-active laser seeker are conceived to overcome these specific problems. Here the sensors composed a dual field of view mid-infrared thermal imaging camera and a laser range finder have the common optical aperture which produced the minization of seeker construction. The common aperture optical systems for mid-infrared and laser dual-mode guildance have been developed, which could meet the passive middle infrared high-resolution imaging and the active laser high-precision indication and ranging. The optical system had good image quality, and fulfilled the performance requirement of seeker system. The design and expected performance of such a dual-mode optical system will be discussed.

  4. Direct Determination of the Absorption of Graphene Mono- and Multi-layers in the Visible and Near-Infrared

    Science.gov (United States)

    Wu, Yang; Mak, Kin Fai; Lui, Chun Hung; Maultzsch, Janina; Heinz, Tony

    2008-03-01

    Single-crystal mono- and multi-layer graphene samples were prepared by mechanical exfoliation on quartz substrates. The absorption spectra of samples of 1 -- 8 monolayer thickness were measured in the optical and near-infrared range. The absorption coefficient was found to be largely independent of photon energy and linear in the number of graphene layers. Such absorption measurements can thus be used to determine the thickness of mesoscopic graphite to monolayer accuracy, as already demonstrated in the context of Rayleigh scattering [Casiraghi et al. Nano Letters 2007]. By analysis of the optical transmission problem for a thin film at the air-quartz interface, we deduced an absorption of 2.3% per layer. The magnitude of the monolayer absorption agrees with the value of πα, where α is the fine-structure constant, and corresponds the result obtained from a tight-binding model of the graphene electronic structure [Gusynin et al. PRL 2006]. The predicted (and measured) optical absorption, we note, is equivalent to a constant optical conductance ofπe^22h=6.09x10-5φ-1.

  5. Functional Near Infrared Spectroscopy: Enabling Routine Functional Brain Imaging.

    Science.gov (United States)

    Yücel, Meryem A; Selb, Juliette J; Huppert, Theodore J; Franceschini, Maria Angela; Boas, David A

    2017-12-01

    Functional Near-Infrared Spectroscopy (fNIRS) maps human brain function by measuring and imaging local changes in hemoglobin concentrations in the brain that arise from the modulation of cerebral blood flow and oxygen metabolism by neural activity. Since its advent over 20 years ago, researchers have exploited and continuously advanced the ability of near infrared light to penetrate through the scalp and skull in order to non-invasively monitor changes in cerebral hemoglobin concentrations that reflect brain activity. We review recent advances in signal processing and hardware that significantly improve the capabilities of fNIRS by reducing the impact of confounding signals to improve statistical robustness of the brain signals and by enhancing the density, spatial coverage, and wearability of measuring devices respectively. We then summarize the application areas that are experiencing rapid growth as fNIRS begins to enable routine functional brain imaging.

  6. Embedded clusters in NGC1808 central starburst - Near-infrared imaging and spectroscopy

    OpenAIRE

    Galliano, E.; Alloin, D.

    2008-01-01

    In the course of a mid-infrared imaging campaign of close-by active galaxies, we discovered the mid-infrared counterparts of bright compact radio sources in the central star-forming region of NGC1808. We aim at confirming that these sources are deeply embedded, young star clusters and at deriving some of their intrinsic properties. To complement the mid-infrared data, we have collected a set of near-infrared data with ISAAC at the VLT: J, Ks, and L' images, as well as low-resolution, long-sli...

  7. A new method to measure local oxygen consumption in human skeletal muscle during dynamic exercise using near-infrared spectroscopy

    International Nuclear Information System (INIS)

    Binzoni, Tiziano; Cooper, Chris E; Wittekind, Anna L; Beneke, Ralph; Elwell, Clare E; Leung, Terence S; Van De Ville, Dimitri

    2010-01-01

    Near infrared spectroscopy (NIRS) can readily report on changes in blood volume and oxygenation. However, it has proved more problematic to measure real-time changes in blood flow and oxygen consumption. Here we report the development of a novel method using NIRS to measure local oxygen consumption in human muscle. The method utilizes the blood volume changes induced by the muscle pump during rhythmically contracting exercising skeletal muscle. We found that the saturation of the blood during the contraction phase was lower than that during the relaxation phase. The calculated oxygen drop was then divided by the contraction time to generate a value for the muscle oxygen consumption in the optical region of interest. As a test we measured the muscle oxygen consumption in the human vastus lateralis during exercise on a cycle ergometer by 11 trained male athletes (32 ± 11 years old) at 40% and 110% peak aerobic power. We saw an increase from 13.78 µmol 100 g −1 min −1 to 19.72 µmol 100 g −1 min −1 with the increase in power. The measurements are theoretically exempt from usual NIRS confounders such as myoglobin and adipose tissue and could provide a useful tool for studying human physiology

  8. Research on visible and near infrared spectral-polarimetric properties of soil polluted by crude oil

    Science.gov (United States)

    Shen, Hui-yan; Zhou, Pu-cheng; Pan, Bang-long

    2017-10-01

    Hydrocarbon contaminated soil can impose detrimental effects on forest health and quality of agricultural products. To manage such consequences, oil leak indicators should be detected quickly by monitoring systems. Remote sensing is one of the most suitable techniques for monitoring systems, especially for areas which are uninhabitable and difficulty to access. The most available physical quantities in optical remote sensing domain are the intensity and spectral information obtained by visible or infrared sensors. However, besides the intensity and wavelength, polarization is another primary physical quantity associated with an optical field. During the course of reflecting light-wave, the surface of soil polluted by crude oil will cause polarimetric properties which are related to the nature of itself. Thus, detection of the spectralpolarimetric properties for soil polluted by crude oil has become a new remote sensing monitoring method. In this paper, the multi-angle spectral-polarimetric instrument was used to obtain multi-angle visible and near infrared spectralpolarimetric characteristic data of soil polluted by crude oil. And then, the change rule between polarimetric properties with different affecting factors, such as viewing zenith angle, incidence zenith angle of the light source, relative azimuth angle, waveband of the detector as well as different grain size of soil were discussed, so as to provide a scientific basis for the research on polarization remote sensing for soil polluted by crude oil.

  9. Optical characterization of semiconductors infrared, Raman, and photoluminescence spectroscopy

    CERN Document Server

    Perkowitz, Sidney

    1993-01-01

    This is the first book to explain, illustrate, and compare the most widely used methods in optics: photoluminescence, infrared spectroscopy, and Raman scattering. Written with non-experts in mind, the book develops the background needed to understand the why and how of each technique, but does not require special knowledge of semiconductors or optics. Each method is illustrated with numerous case studies. Practical information drawn from the authors experience is given to help establish optical facilities, including commercial sources for equipment, and experimental details. For industrial sci

  10. Infrared spectromicroscopy and magneto-optical imaging stations at SPring-8

    CERN Document Server

    Kimura, S; Sada, T; Okuno, M; Matsunami, M; Shinoda, K; Kimura, H; Moriwaki, T; Yamagata, M; Kondo, Y; Yoshimatsu, Y; Takahashi, T; Fukui, K; Kawamoto, T; Ishikawa, T

    2001-01-01

    At the BL43IR of SPring-8, infrared microanalysis on various kinds of solid specimens under multiple environments with a spatial resolution smaller than 10 mu m in diameter is planned in the infrared region. In order to perform such analysis, two different stations, a multipurpose spectromicroscopy apparatus and a magneto-optical imaging one have been constructed. Measurements on the spatial two-dimensional cross-section of the infrared beam at the spectromicroscopy station have proven that the stations have a good prospective feature in the performance.

  11. COBE DIRBE near-infrared polarimetry of the zodiacal light: Initial results

    Science.gov (United States)

    Berriman, G. B.; Boggess, N. W.; Hauser, M. G.; Kelsall, T.; Lisse, C. M.; Moseley, S. H.; Reach, W. T.; Silverberg, R. F.

    1994-01-01

    This Letter describes near-infrared polarimetry of the zodiacal light at 2.2 micrometers, measured with the Diffuse Infrared Background Experiment (DIRBE) aboard the Cosmic Background Explorer (COBE) spacecraft. The polarization is due to scattering of sunlight. The polarization vector is perpendicular to the scattering plane, and its observed amplitude on the ecliptic equator at an elongation of 90 deg and ecliptic longitude of 10 deg declines from 12.0 +/- 0.4% at 1.25 micrometers to 8.0 +/- 0.6% at 3.5 micrometers (cf. 16% in the visible); the principal source of uncertainty is photometric noise due to stars. The observed near-infrared colors at this location are redder than Solar, but at 3.5 micrometers this is due at least in part to the thermal emission contribution from the interplanetary dust. Mie theory calculations show that both polarizations and colors are important in constraining models of interplanetary dust.

  12. High Resolution Near Infrared Spectrometer to Study the Zodiacal Light Spectrum

    Science.gov (United States)

    Kutyrev, Alexander; Arendt, R.; Dwek, E.; Moseley, S. H.; Silverberg, R.; Rapchun, D.

    2007-12-01

    We are developing a near infrared spectrometer for measuring solar absorption lines in the zodiacal light in the near infrared region. R. Reynolds at el. (2004, ApJ 612, 1206) demonstrated that observing single Fraunhofer line can be a powerful tool for extracting zodiacal light parameters based on their measurements of the profile of the Mg I line at 5184 A. We are extending this technique to the near infrared with the primary goal of measuring the absolute intensity of the zodiacal light. This measurement will provide the crucial information needed to accurately subtract zodiacal emission from the DIRBE measurements to get a much higher quality measurement of the extragalactic IR background. The instrument design is based on a dual Fabry-Perot interferometer with a narrow band filter. Its double etalon design allows to achieve high spectral contrast to reject the bright out of band telluric OH emission. High spectral contrast is absolutely necessary to achieve detection limits needed to accurately measure the intensity of the absorption line. We present the design, estimated performance of the instrument with the expected results of the observing program. The project is supported by NASA ROSES-APRA grant.

  13. Polarization resolved imaging with a reflection near-field optical microscope

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Xiao, Mufei; Hvam, Jørn Märcher

    1999-01-01

    Using a rigorous microscopic point-dipole description of probe-sample interactions, we study imaging with a reflection scanning near-field optical microscope. Optical content, topographical artifacts, sensitivity window-i.e., the scale on which near-field optical images represent mainly optical...... configuration is preferable to the cross-linear one, since it ensures more isotropic (in the surface plane) near-field imaging of surface features. The numerical results are supported with experimental near-field images obtained by using a reflection micros