WorldWideScience

Sample records for modeling infrared optical

  1. Measurement of infrared refractive indices of organic and organophosphorous compounds for optical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Tonkyn, Russell G.; Danby, Tyler O.; Birnbaum, Jerome C.; Taubman, Matthew S.; Bernacki, Bruce E.; Johnson, Timothy J.; Myers, Tanya L.

    2017-05-03

    The complex optical refractive index contains the optical constants, n($\\tilde{u}$)and k($\\tilde{u}$), which correspond to the dispersion and absorption of light within a medium, respectively. By obtaining the optical constants one can in principle model most optical phenomena in media and at interfaces including reflection, refraction and dispersion. We have developed improved protocols based on the use of multiple path lengths to determine the optical constants for dozens of liquids, including organic and organophosphorous compounds. Detailed description of the protocols to determine the infrared indices will be presented, along with preliminary results using the constants with their applications to optical modeling.

  2. 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.

  3. GRB Optical and Infrared Afterglows

    Science.gov (United States)

    Vreeswijk, P. M.

    2001-05-01

    Gamma-ray burst (GRB) optical and infra-red afterglow observations are reviewed. I will also discuss the indications that long-duration GRBs seem to favour the `collapsar' model. Among these are the debated connection between GRBs and supernovae, and the location of GRB afterglows with respect to their host galaxies. PMV is supported by the NWO Spinoza grant.

  4. 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

    Introduction: Recent and on-going remote and in situ observations indicate that sulfates are present in significant abundances at various locations on Mars [1-7]. The Mars Reconnaissance Orbiter (MRO) imaging spectrometer (CRISM) is returning hyperspectral data at higher spatial resolution [8] than the OMEGA instrument on the Mars Express Mission [3]. Data from both OMEGA and CRISM have provided spectral evidence for the presence of gypsum and various hydrated sulfates on the Martian surface [e.g. 3-7] Thus, the optical properties of sulfates, in general, are of interest to quantitative interpretation of this increasing volume of remotely sensed data. This is because optical constants describe how a material interacts with electromagnetic radiation and represent the fundamental values used in radiative transfer calculations describing a variety of physical environments. Such environments include atmospheres where aerosols are present, planetary and satellite regoliths, and circumstellar dust clouds. Here we focus upon gypsum because of its applicability due to its identification on Mars. Also, gypsum is a mineral that is readily available in samples sizes that are suitable for study using a variety of spectral measurements. In the infrared (>5 μm) several studies reporting the optical constants of gypsum can be used in evaluating the approach used here. Most importantly, there is a general lack of data regarding the optical constants for gypsum at visible and mid-infrared wavelengths (0.4-5 μm) that are being observed by OMEGA and CRISM. Background: In the infrared, there have been several studies focused at determining the optical constants of gypsum using classical dispersion models [9-11]. These have used a variety of samples including; crystals, compressed pellets of pure materials, and grains suspended in a KBr matrix. Spectral measurements of gypsum, and other sulfates, have existed for about 100 years at visible and mid-infrared wavelengths (0.4-5 μm) [e

  5. 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.

  6. Modeling an Optical and Infrared Search for Extraterrestrial Intelligence Survey with Exoplanet Direct Imaging

    Science.gov (United States)

    Vides, Christina; Macintosh, Bruce; Ruffio, Jean-Baptiste; Nielsen, Eric; Povich, Matthew Samuel

    2018-01-01

    Gemini Planet Imager (GPI) is a direct high contrast imaging instrument coupled to the Gemini South Telescope. Its purpose is to image extrasolar planets around young (~Intelligence), we modeled GPI’s capabilities to detect an extraterrestrial continuous wave (CW) laser broadcasted within the H-band have been modeled. By using sensitivity evaluated for actual GPI observations of young target stars, we produced models of the CW laser power as a function of distance from the star that could be detected if GPI were to observe nearby (~ 3-5 pc) planet-hosting G-type stars. We took a variety of transmitters into consideration in producing these modeled values. GPI is known to be sensitive to both pulsed and CW coherent electromagnetic radiation. The results were compared to similar studies and it was found that these values are competitive to other optical and infrared observations.

  7. Flexible optical-infrared metafilter

    Science.gov (United States)

    Brückner, Jean-Baptiste; Brissonneau, Vincent; Le Rouzo, Judikaël.; Ferchichi, Abdelkerim; Gourgon, Cécile; Dubarry, Christophe; Berginc, Gérard; Escoubas, Ludovic

    2014-02-01

    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, we have conceived a flexible filter showing very broad antireflective (AR) properties from the visible to short wavelength infrared region (SWIR: 0.7-1.5 μm) and simultaneously a mirror-like behavior in the mid-infrared wavelength region (MWIR: 3-5 μm) and long-infrared wavelength region (LWIR: 8 to 15 μm). Nanoimprint technology has permitted us to replicate 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 SWIR 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.

  8. 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

  9. 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

  10. Infrared Optical Response of Metallic Graphene Nanoribbons

    Directory of Open Access Journals (Sweden)

    Zigang Duan

    2010-01-01

    Full Text Available We investigate theoretically the infrared optical response characteristics of metallic armchair/zigzag-edge graphene nanoribbons (A/ZGNRs to an external longitudinally polarized electromagnetic field at low temperatures. Within the framework of linear response theory at the perturbation regime, we examine the optical infrared absorption threshold energy, absorption power, dielectric function, and electron energy loss spectra near the neutrality points of the systems. It is demonstrated that, by some numerical examples, the photon-assisted direct interband absorptions for AGNR exist with different selection rules from those for ZGNR and single-walled carbon nanotube at infrared regime. This infrared optical property dependence of GNRs on field frequency may be used to design graphene-based nanoscale optoelectronic devices for the detection of infrared electromagnetic irradiations.

  11. Linear and non-linear infrared response of one-dimensional vibrational Holstein polarons in the anti-adiabatic limit: Optical and acoustical phonon models

    Science.gov (United States)

    Falvo, Cyril

    2018-02-01

    The theory of linear and non-linear infrared response of vibrational Holstein polarons in one-dimensional lattices is presented in order to identify the spectral signatures of self-trapping phenomena. Using a canonical transformation, the optical response is computed from the small polaron point of view which is valid in the anti-adiabatic limit. Two types of phonon baths are considered: optical phonons and acoustical phonons, and simple expressions are derived for the infrared response. It is shown that for the case of optical phonons, the linear response can directly probe the polaron density of states. The model is used to interpret the experimental spectrum of crystalline acetanilide in the C=O range. For the case of acoustical phonons, it is shown that two bound states can be observed in the two-dimensional infrared spectrum at low temperature. At high temperature, analysis of the time-dependence of the two-dimensional infrared spectrum indicates that bath mediated correlations slow down spectral diffusion. The model is used to interpret the experimental linear-spectroscopy of model α-helix and β-sheet polypeptides. This work shows that the Davydov Hamiltonian cannot explain the observations in the NH stretching range.

  12. Towards the mid-infrared optical biopsy

    DEFF Research Database (Denmark)

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

    2016-01-01

    of external cancers, mid-infrared detection of cancer-margins during external surgery for precise removal of diseased tissue, in one go during the surgery, and mid-infrared endoscopy for early diagnosis of internal cancers and their precision removal. The mid-infrared spectral region has previously lacked......, agriculture and in manufacturing and chemical processing. This work is in part supported by the European Commission: Framework Seven (FP7) Large-Scale Integrated Project MINERVA: MId-to-NEaR-infrared spectroscopy for improVed medical diAgnostics (317803; www.minerva-project.eu).......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...

  13. Optical and Infrared Lightcurve Modeling of the Gamma-ray Millisecond Pulsar 2FGL J2339.6-0532

    Directory of Open Access Journals (Sweden)

    Tzu-Ching Yen

    2013-09-01

    Full Text Available We report the detection of a quasi-sinusoidally modulated optical flux with a period of 4.6343 hour in the optical and infrared band of the Fermi source 2FGL J2339.7-0531. Comparing the multi-wavelength observations, we suggest that 2FGL J2339.7- 0531 is a γ-ray emitting millisecond pulsar (MSP in a binary system with an optically visible late-type companion accreted by the pulsar, where the MSP is responsible for the γ-ray emission while the optical and infrared emission originate from the heated side of the companion. Based on the optical properties, the companion star is believed to be heated by the pulsar and reaches peak magnitude when the heated side faces the observer. We conclude that 2FGL J2339.7-0531 is a member of a subclass of γ-ray emitting pulsars -the ‘black widows’- recently revealed to be evaporating their companions in the late-stage of recycling as a prominent group of these newly revealed Fermi sources.

  14. 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)

  15. Research on the aero-thermal effects by 3D analysis model of the optical window of the infrared imaging guidance

    Science.gov (United States)

    Xu, Bo; Li, Lin; Zhu, Ying

    2014-11-01

    Researches on hypersonic vehicles have been a hotspot in the field of aerospace because of the pursuits for higher speed by human being. Infrared imaging guidance is playing a very important role in modern warfare. When an Infrared Ray(IR) imaging guided missile is flying in the air at high speed, its optical dome suffers from serious aero-optic effects because of air flow. The turbulence around the dome and the thermal effects of the optical window would cause disturbance to the wavefront from the target. Therefore, detected images will be biased, dithered and blurred, and the capabilities of the seeker for detecting, tracking and recognizing are weakened. In this paper, methods for thermal and structural analysis with Heat Transfer and Elastic Mechanics are introduced. By studying the aero-thermal effects and aero-thermal radiation effects of the optical window, a 3D analysis model of the optical window is established by using finite element method. The direct coupling analysis is employed as a solving strategy. The variation regularity of the temperature field is obtained. For light with different incident angles, the influence on the ray propagation caused by window deformation is analyzed with theoretical calculation and optical/thermal/structural integrated analysis method respectively.

  16. Modeling and simulation of adaptive multimodal optical sensors for target tracking in the visible to near infrared

    Science.gov (United States)

    Presnar, Michael D.

    This work investigates an integrated aerial remote sensor design approach to address moving target detection and tracking problems within highly cluttered, dynamic ground-based scenes. Sophisticated simulation methodologies and scene phenomenology validations have resulted in advancements in artificial multimodal truth video synthesis. Complex modeling of novel micro-opto-electro-mechanical systems (MOEMS) devices, optical systems, and detector arrays has resulted in a proof of concept for a state-of-the-art imaging spectropolarimeter sensor model that does not suffer from typical multimodal image registration problems. Test methodology developed for this work provides the ability to quantify performance of a target tracking application with varying ground scenery, flight characteristics, or sensor specifications. The culmination of this research is an end-to-end simulated demonstration of multimodal aerial remote sensing and target tracking. Deeply hidden target recognition is shown to be enhanced through the fusing of panchromatic, hyperspectral, and polarimetric image modalities. The Digital Imaging and Remote Sensing Image Generation model was leveraged to synthesize truth spectropolarimetric sensor-reaching radiance image cubes comprised of coregistered Stokes vector bands in the visible to near-infrared. An intricate synthetic urban scene containing numerous moving vehicular targets was imaged from a virtual sensor aboard an aerial platform encircling a stare point. An adaptive sensor model was designed with a superpixel array of MOEMS devices fabricated atop a division of focal plane detector. Degree of linear polarization (DoLP) imagery is acquired by combining three adjacent micropolarizer outputs within each 2x2 superpixel whose respective transmissions vary with wavelength, relative angle of polarization, and wire-grid spacing. A novel micromirror within each superpixel adaptively relays light between a panchromatic imaging channel and a hyperspectral

  17. A Model for the Infrared Radiance of Optically Thin, Particulate Exhaust Plumes Generated by Pyrotechnic Flares Burning in a Vacuum

    National Research Council Canada - National Science Library

    Cohen, Douglas

    2000-01-01

    .... The model is used to predict how a magnesium-Teflon exhaust plume would look when viewed as an approximate point source by a distant infrared sensor and also to analyze the data acquired from three separate magnesium-Teflon flares burned in a large vacuum chamber.

  18. Infrared shield facilitates optical pyrometer measurements

    Science.gov (United States)

    Eichenbrenner, F. F.; Illg, W.

    1965-01-01

    Water-cooled shield facilitates optical pyrometer high temperature measurements of small sheet metal specimens subjected to tensile stress in fatigue tests. The shield excludes direct or reflected radiation from one face of the specimen and permits viewing of the infrared radiation only.

  19. 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...

  20. Chalcogenide Glass Optical Waveguides for Infrared Biosensing

    Science.gov (United States)

    Anne, Marie-Laure; Keirsse, Julie; Nazabal, Virginie; Hyodo, Koji; Inoue, Satoru; Boussard-Pledel, Catherine; Lhermite, Hervé; Charrier, Joël; Yanakata, Kiyoyuki; Loreal, Olivier; Le Person, Jenny; Colas, Florent; Compère, Chantal; Bureau, Bruno

    2009-01-01

    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 (bio)sensors. PMID:22423209

  1. 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.

  2. Galaxy Zoo: Infrared and Optical Morphology

    Science.gov (United States)

    Carla Shanahan, Jesse; Lintott, Chris; Zoo, Galaxy

    2018-01-01

    We present the detailed, visual morphologies of approximately 60,000 galaxies observed by the UKIRT Infrared Deep Sky Survey and then classified by participants in the Galaxy Zoo project. Our sample is composed entirely of nearby objects with redshifts of z ≤ 0.3, which enables us to robustly analyze their morphological characteristics including smoothness, bulge properties, spiral structure, and evidence of bars or rings. The determination of these features is made via a consensus-based analysis of the Galaxy Zoo project data in which inconsistent and outlying classifications are statistically down-weighted. We then compare these classifications of infrared morphology to the objects’ optical classifications in the Galaxy Zoo 2 release (Willett et al. 2013). It is already known that morphology is an effective tool for uncovering a galaxy’s dynamical past, and previous studies have shown significant correlations with physical characteristics such as stellar mass distribution and star formation history. We show that majority of the sample has agreement or expected differences between the optical and infrared classifications, but also present a preliminary analysis of a subsample of objects with striking discrepancies.

  3. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. II. UV, Optical, and Near-infrared Light Curves and Comparison to Kilonova Models

    Science.gov (United States)

    Cowperthwaite, P. S.; Berger, E.; Villar, V. A.; Metzger, B. D.; Nicholl, M.; Chornock, R.; Blanchard, P. K.; Fong, W.; Margutti, R.; Soares-Santos, M.; Alexander, K. D.; Allam, S.; Annis, J.; Brout, D.; Brown, D. A.; Butler, R. E.; Chen, H.-Y.; Diehl, H. T.; Doctor, Z.; Drout, M. R.; Eftekhari, T.; Farr, B.; Finley, D. A.; Foley, R. J.; Frieman, J. A.; Fryer, C. L.; García-Bellido, J.; Gill, M. S. S.; Guillochon, J.; Herner, K.; Holz, D. E.; Kasen, D.; Kessler, R.; Marriner, J.; Matheson, T.; Neilsen, E. H., Jr.; Quataert, E.; Palmese, A.; Rest, A.; Sako, M.; Scolnic, D. M.; Smith, N.; Tucker, D. L.; Williams, P. K. G.; Balbinot, E.; Carlin, J. L.; Cook, E. R.; Durret, F.; Li, T. S.; Lopes, P. A. A.; Lourenço, A. C. C.; Marshall, J. L.; Medina, G. E.; Muir, J.; Muñoz, R. R.; Sauseda, M.; Schlegel, D. J.; Secco, L. F.; Vivas, A. K.; Wester, W.; Zenteno, A.; Zhang, Y.; Abbott, T. M. C.; Banerji, M.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Castander, F. J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; DePoy, D. L.; Desai, S.; Dietrich, J. P.; Drlica-Wagner, A.; Eifler, T. F.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Jeltema, T.; Johnson, M. W. G.; Johnson, M. D.; Kent, S.; Krause, E.; Kron, R.; Kuehn, K.; Nuropatkin, N.; Lahav, O.; Lima, M.; Lin, H.; Maia, M. A. G.; March, M.; Martini, P.; McMahon, R. G.; Menanteau, F.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Neilsen, E.; Nichol, R. C.; Ogando, R. L. C.; Plazas, A. A.; Roe, N.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Thomas, R. C.; Troxel, M. A.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Weller, J.; Yanny, B.; Zuntz, J.

    2017-10-01

    We present UV, optical, and near-infrared (NIR) photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo, the binary neutron star merger GW170817. Our data set extends from the discovery of the optical counterpart at 0.47-18.5 days post-merger, and includes observations with the Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), and the Hubble Space Telescope (HST). The spectral energy distribution (SED) inferred from this photometry at 0.6 days is well described by a blackbody model with T≈ 8300 K, a radius of R≈ 4.5× {10}14 cm (corresponding to an expansion velocity of v≈ 0.3c), and a bolometric luminosity of {L}{bol}≈ 5× {10}41 erg s-1. At 1.5 days we find a multi-component SED across the optical and NIR, and subsequently we observe rapid fading in the UV and blue optical bands and significant reddening of the optical/NIR colors. Modeling the entire data set, we find that models with heating from radioactive decay of 56Ni, or those with only a single component of opacity from r-process elements, fail to capture the rapid optical decline and red optical/NIR colors. Instead, models with two components consistent with lanthanide-poor and lanthanide-rich ejecta provide a good fit to the data; the resulting “blue” component has {M}{ej}{blue}≈ 0.01 {M}⊙ and {v}{ej}{blue}≈ 0.3 {{c}}, and the “red” component has {M}{ej}{red}≈ 0.04 {M}⊙ and {v}{ej}{red}≈ 0.1 {{c}}. These ejecta masses are broadly consistent with the estimated r-process production rate required to explain the Milky Way r-process abundances, providing the first evidence that binary neutron star (BNS) mergers can be a dominant site of r-process enrichment.

  4. Modelling telluric line spectra in the optical and infrared with an application to VLT/X-Shooter spectra

    Science.gov (United States)

    Rudolf, N.; Günther, H. M.; Schneider, P. C.; Schmitt, J. H. M. M.

    2016-01-01

    Context. Earth's atmosphere imprints a large number of telluric absorption and emission lines on astronomical spectra, especially in the near infrared, that need to be removed before analysing the affected wavelength regions. Aims: These lines are typically removed by comparison to A- or B-type stars used as telluric standards that themselves have strong hydrogen lines, which complicates the removal of telluric lines. We have developed a method to circumvent that problem. Methods: For our IDL software package tellrem we used a recent approach to model telluric absorption features with the line-by-line radiative transfer model (LBLRTM). The broad wavelength coverage of the X-Shooter at VLT allows us to expand their technique by determining the abundances of the most important telluric molecules H2O, O2, CO2, and CH4 from sufficiently isolated line groups. For individual observations we construct a telluric absorption model for most of the spectral range that is used to remove the telluric absorption from the object spectrum. Results: We remove telluric absorption from both continuum regions and emission lines without systematic residuals for most of the processable spectral range; however, our method increases the statistical errors. The errors of the corrected spectrum typically increase by 10% for S/N ~ 10 and by a factor of two for high-quality data (S/N ~ 100), I.e. the method is accurate on the percent level. Conclusions: Modelling telluric absorption can be an alternative to the observation of standard stars for removing telluric contamination. Based on observations collected at the European Southern Observatory, Paranal, Chile, 085.C-0764(A) and 60.A-9022(C).The tellrem package is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/585/A113

  5. Optical and infrared detection using microcantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Oden, P.I.; Datskos, P.G.; Warmack, R.J. [Oak Ridge National Lab., TN (United States)]|[Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics; Wachter, E.A.; Thundat, T. [Oak Ridge National Lab., TN (United States)

    1996-05-01

    The feasibility of micromechanical optical and infrared (IR) detection using microcantilevers is demonstrated. Microcantilevers provide a simple means for developing single- and multi-element sensors for visible and infrared radiation that are smaller, more sensitive and lower in cost than quantum or thermal detectors. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress originating from the bimetallic effect. Bending is proportional to the amount of heat absorbed and can be detected using optical or electrical methods such as resistance changes in piezoresistive cantilevers. The microcantilever sensors exhibit two distinct thermal responses: a fast one ({theta}{sub 1}{sup thermal} < ms) and a slower one ({tau}{sub 2}{sup thermal} {approximately} 10 ms). A noise equivalent temperature difference, NEDT = 90 mK was measured. When uncoated microcantilevers were irradiated by a low-power diode laser ({lambda} = 786 nm) the noise equivalent power, NEP, was found to be 3.5nW/{radical}Hz which corresponds to a specific detectivity, D*, of 3.6 {times} 10{sup 7} cm {center_dot} {radical}Hz/W at a modulation frequency of 20 Hz.

  6. Invited Article: An integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument

    Science.gov (United States)

    Kühne, P.; Herzinger, C. M.; Schubert, M.; Woollam, J. A.; Hofmann, T.

    2014-07-01

    We report on the development of the first integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument, covering an ultra wide spectral range from 3 cm-1 to 7000 cm-1 (0.1-210 THz or 0.4-870 meV). The instrument comprises four sub-systems, where the magneto-cryostat-transfer sub-system enables the usage of the magneto-cryostat sub-system with the mid-infrared ellipsometer sub-system, and the far-infrared/terahertz ellipsometer sub-system. Both ellipsometer sub-systems can be used as variable angle-of-incidence spectroscopic ellipsometers in reflection or transmission mode, and are equipped with multiple light sources and detectors. The ellipsometer sub-systems are operated in polarizer-sample-rotating-analyzer configuration granting access to the upper left 3 × 3 block of the normalized 4 × 4 Mueller matrix. The closed cycle magneto-cryostat sub-system provides sample temperatures between room temperature and 1.4 K and magnetic fields up to 8 T, enabling the detection of transverse and longitudinal magnetic field-induced birefringence. We discuss theoretical background and practical realization of the integrated mid-infrared, far-infrared, and terahertz optical Hall effect instrument, as well as acquisition of optical Hall effect data and the corresponding model analysis procedures. Exemplarily, epitaxial graphene grown on 6H-SiC, a tellurium doped bulk GaAs sample and an AlGaN/GaN high electron mobility transistor structure are investigated. The selected experimental datasets display the full spectral, magnetic field and temperature range of the instrument and demonstrate data analysis strategies. Effects from free charge carriers in two dimensional confinement and in a volume material, as well as quantum mechanical effects (inter-Landau-level transitions) are observed and discussed exemplarily.

  7. 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...

  8. Cryo-Infrared Optical Characterization at NASA GSFC

    Science.gov (United States)

    Boucarut, Ray; Quijada, Manuel A.; Henry, Ross M.

    2004-01-01

    The development of large space infrared optical systems, such as the Next Generation Space Telescope (NGST), has increased requirements for measurement accuracy in the optical properties of materials. Many materials used as optical components in infrared optical systems, have strong temperature dependence in their optical properties. Unfortunately, data on the temperature dependence of most of these materials is sparse. In this paper, we provide a description of the capabilities existing in the Optics Branch at the Goddard Space Flight Center that enable the characterization of the refractive index and absorption coefficient changes and other optical properties in infrared materials at cryogenic temperatures. Details of the experimental apparatus, which include continuous flow liquid helium optical cryostat, and a Fourier Transform Infrared (FTIR) spectrometer are discussed.

  9. Micromachined silicon grisms for infrared optics.

    Science.gov (United States)

    Mar, Douglas J; Marsh, Jasmina P; Deen, Casey P; Ling, Hao; Choo, Hosung; Jaffe, Daniel T

    2009-02-20

    We demonstrate the successful fabrication of large format (approximately 50 mm × 50 mm) gratings in monolithic silicon for use as high-efficiency grisms at infrared wavelengths. The substrates for the grisms were thick (8-16 mm) disks of precisely oriented single-crystal silicon (refractive index, n ~ 3.42). We used microlithography and chemical wet etching techniques to produce the diffraction gratings on one side of these substrates. These techniques permitted the manufacture of coarse grooves (as few as 7 grooves/mm) with precise control of the blaze angle and groove profile and resulted in excellent groove surface quality. Profilometric measurements of the groove structure of the gratings confirm that the physical dimensions of the final devices closely match their design values. Optical performance of these devices exceeds the specifications required for diffraction-limited performance (RMS wave surface error silicon transmits well, the blaze control and high index permit high-resolution, high-order dispersion in a compact space. The first application of these grisms is to provide FORCAST, a mid-infrared camera on NASA's airborne observatory, with a moderate resolution (R=100-1000) spectroscopic capability.

  10. Measurement of the infrared optical constants for spectral modeling: n and k values for (NH4)2SO4 via single-angle reflectance and ellipsometric methods

    Science.gov (United States)

    Blake, Thomas A.; Brauer, Carolyn S.; Kelly-Gorham, Molly Rose; Burton, Sarah D.; Bliss, Mary; Myers, Tanya L.; Johnson, Timothy J.; Tiwald, Thomas E.

    2017-05-01

    The complex index of refraction, ñ = n + ik, has two components, n(ν) and k(ν), both a function of frequency, ν. The constant n is the real component, and k is the complex component, proportional to the absorption. In combination with other parameters, n and k can be used to model infrared spectra. However, obtaining reliable n/k values for solid materials is often difficult. In the past, the best results for n and k have been obtained from bulk, polished homogeneous materials free of defects; i.e. materials where the Fresnel equations are valid and there is no appreciable light scattering. Since it is often not possible to obtain such pure macroscopic samples, the alternative is to press the powder form of the material into a uniform disk. Recently, we have pressed such pellets from ammonium sulfate powder, and have measured the pellets' n and k values via two independent methods: 1) ellipsometry, which measures the changes in amplitude and phase of light reflected from the material of interest as a function of wavelength and angle of incidence, and 2) single-angle reflectance using a specular reflectance device within a Fourier transform infrared spectrometer. This technique measures the change in amplitude of light reflected from the material of interest as a function of wavelength over a wide spectral domain. The optical constants are determined from the single-angle measurements using the Kramers-Kronig relationship, whereas an oscillator model is used to analyze the ellipsometric measurements. The n(ν) and k(ν) values determined by the two methods were compared to previous values determined from single crystal samples from which transmittance and reflectance measurements were made and converted to n(ν) and k(ν) using a simple dispersion model. [Toon et al., Journal of Geophysical Research, 81, 5733-5748, (1976)]. Comparison with the literature values shows good agreement, indicating that these are promising techniques to measure the optical constants

  11. Infrared/submillimeter optical properties data base

    Science.gov (United States)

    Alley, Phillip W.

    1989-01-01

    The general goal was to build a data base containing optical properties, such as reflectance, transmittance, refractive index, in the far infrared to submillimeter wavelength region. This data base would be limited to selected crystalline materials and temperature between 300 and 2 K. The selected materials were: lithium, lead, and strontium; the bromides of potassium and thallium; the carbides of silicone and tungsten; and the materials of KRS5, KRS6, diamond, and sapphire. Last summer, barium fluoride was selected as prototype material for building the data base. This summer the literature search, preparation of the data for barium fluoride was completed. In addition the literature search for data related to the compounds mentioned was completed. The current status is that barium fluoride is in a form suitable for a NASA internal publication. The papers containing the data on the other materials were xeroxed and they are ready to be reduced. On the reverse side, the top figure is a sample combination of data for the index of refraction at 300 K. The lower figure shows the transmittance vs wavelength at 300 and 80 K. These figures are a sample of many which were developed. Since barium fluoride was studied more than most of the materials listed above, it is clear that additional measurements should be made to fill in the gaps present on both temperature and wavelength data.

  12. Optical properties of mineral dust aerosol in the thermal infrared

    Science.gov (United States)

    Köhler, Claas H.

    2017-02-01

    The optical properties of mineral dust and biomass burning aerosol in the thermal infrared (TIR) are examined by means of Fourier Transform Infrared Spectrometer (FTIR) measurements and radiative transfer (RT) simulations. The measurements were conducted within the scope of the Saharan Mineral Dust Experiment 2 (SAMUM-2) at Praia (Cape Verde) in January and February 2008. The aerosol radiative effect in the TIR atmospheric window region 800-1200 cm-1 (8-12 µm) is discussed in two case studies. The first case study employs a combination of IASI measurements and RT simulations to investigate a lofted optically thin biomass burning layer with emphasis on its potential influence on sea surface temperature (SST) retrieval. The second case study uses ground based measurements to establish the importance of particle shape and refractive index for benchmark RT simulations of dust optical properties in the TIR domain. Our research confirms earlier studies suggesting that spheroidal model particles lead to a significantly improved agreement between RT simulations and measurements compared to spheres. However, room for improvement remains, as the uncertainty originating from the refractive index data for many aerosol constituents prohibits more conclusive results.

  13. Measurement of the infrared optical constants for spectral modeling: n and k values for (NH4)2SO4 via single-angle reflectance and ellipsometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Blake, Thomas A.; Brauer, Carolyn S.; Kelly-Gorham, Molly Rose K.; Burton, Sarah D.; Bliss, Mary; Myers, Tanya L.; Johnson, Timothy J.; Tiwald, Thomas E.

    2017-05-05

    The optical constants n and k can be used to model infrared spectra, including refraction, absorption, reflectance, and emissivity, but obtaining reliable values for solid materials (pure or otherwise) presents a challenge: In the past, the best results for n and k have been obtained from bulk, homogeneous materials, free of defects. That is, materials where the Fresnel equations are operant since there is no light scattering. Since it is often not possible to obtain a pure macroscopic (crystalline) material, it may be possible to press the material into a (uniform, void-free) disk. We have recently been able to do this with ammonium sulfate powder and then measured the n & k values via two independent methods: 1) Ellipsometry - which measures the changes in amplitude and phase of light reflected from the material of interest as a function of wavelength and angle of incidence, and 2) Single angle specular reflectance with an FT spectrometer using a specular reflectance device within an FT instrument which measures the change in amplitude of light reflected from the material of interest as a function of wavelength and angle of incidence over a wide wavelength range. The quality of the derived n & k values was tested by generating the reflectance spectra of the pellet and comparing to the calculated to measured reflectance spectra of the pure material which has been previously published. The comparison to literature values showed good accuracy and good agreement, indicating promise to measure other materials by such methods.

  14. OPTICAL PHENOMENA IN FIBER WAVEGUIDES: Determination of the optical characteristics of infrared fiber-optic waveguides

    Science.gov (United States)

    Vasil'ev, A. V.; Plotnichenko, V. G.

    1987-04-01

    A description is given of the features distinguishing determination of the optical characteristics of fiber-optic waveguides in the middle infrared region. The spectral dependences are given of the overall optical losses for single-crystal two-layer fiber-optic waveguides utilizing cesium bromide and single-layer waveguides made of a chalcogenide glass of the Ge-As-Se system in an F-42 fluoroplastic polymer cladding. In the case of the latter waveguides, a study was made of the angular dependences of the radiation power distribution inside the waveguide when CO laser radiation was coupled in at different angles.

  15. Far-Infrared Interferometric Telescope Experiment (FITE): II. Sensor Optics

    Science.gov (United States)

    Kohyama, Tsunehito; Shibai, Hiroshi; Kawada, Mitsunobu; Watabe, Toyoki; Matsuo, Taro; Mochizuki, Shun; Matsumoto, Yuka; Morishita, Hirono; Doi, Yasuo

    We developed the sensor optics of the Far Infrared Interferometric Telescope (FITE). The spatial resolution of FITE is expected to be 2.5 arcseconds. In order to reconstruct images, precise measurements of the visibility of the interference are necessary. For this purpose, we designed the focal plane of FITE. The focal plane is the entrance focus of the sensor optics. Its camera optics has the F/106 beam for each beam of the interferometer. The PSF is dominated by diffraction, and its size corresponds approximately to the array size so that the fringe pattern can be measured by the array in the sheet. The sensor optics consists of two infrared detectors and the optical CCD. Each detector is installed on the final focal plane of the sensor optics. The far-infrared detector has the format of 15 pixels with 1.5 mm pitch. The mid-infrared detector and the optical CCD are developed as the sensor for the interferometer alignment. The sensor optics and the detectors are installed on the cryostat. Because of their sufficient specifications, we believe to achieve the 2.5 arcsecond spatial resolution.

  16. Quality Monitoring of Infrared Optics Using Ultrasound Signals

    Science.gov (United States)

    Neumeier, Benedikt; Schmitt-Landsiedel, Doris

    During laser processing with beam powers in the multi-kilowatt range a fraction of the emission is absorbed in optical elements, leading to thermal loading on the optics. This temperature rise of the optics results in thermal lensing, impairing the power density at the processing location. In a number of niche applications, the CO2 laser still is preferred over solid-state lasers due to its unrivaled features in processing materials like fused silica, glasses, wood, ceramics or plastics. Applying existing techniques to monitor the temperature of CO2 laser optics using pyrometers prove to be unreliable due to the transmissivity in the infrared of the optical materials used. The object of this study is experimental identification of temperature increase of ZnSe optics during use for processing in a laser cutting machine, and development of a method utilizing ultrasound to measure the temperature of the infrared optics. The method enables the testing of the absorption properties of infrared optics as well as solid-state laser optics.

  17. 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

  18. Temperature dependence of the infrared optical constants of germanium films

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dandan, E-mail: ldd6162@163.com; Liu, Huasong; Jiang, Chenghui; Leng, Jian; Zhang, Yanmin; Zhao, Zhihong; Zhuang, Kewen; Jiang, Yugang; Ji, Yiqin

    2015-10-01

    High-temperature transmittance spectrum of germanium films was obtained by a Fourier Transform infrared spectroscopy with a high-temperature accessory. The optical constants were determined by transmittance spectrum fitting with a Gaussian oscillator as the dispersion model. The analysis results showed that both the refractive index and extinction coefficient increased with the increasing temperature. The square of the refractive index increased linearly with the increasing temperature. The higher the temperature was, the faster the absorption coefficient increased. The germanium films were deposited on chemical vapor deposition ZnS substrates by ion-beam-assisted deposition. The region of temperature was between room temperature and 773 K, and the analysis spectrum was between 2000 nm and 5000 nm. - Highlights: • Temperature dependence of transmittance spectrum of Germanium films • Temperature properties of refractive index of Germanium films • Temperature properties of absorption coefficient of Germanium films.

  19. 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.

  20. Far-Infrared Interferometeric Telescope Experiment (FITE): sensor optics

    Science.gov (United States)

    Kohyama, Tsunehito; Shibai, Hiroshi; Kawada, Mitsunobu; Watabe, Toyoki; Matsuo, Taro; Ohkubo, Atsushi; Katoh, Eri; Kanoh, Tetsuo; Suzuki, Miki; Mochizuki, Shun; Matsumoto, Yuka; Morishita, Hirono; Yamamoto, Koudai; Kanoh, Ryoko; Nakashima, Asami; Tanabe, Mitsuhiro; Doi, Yasuo; Narita, Masanao

    2008-07-01

    We have developed a sensor optical system for the Far Infrared Interferometric Telescope (FITE). The spatial resolution of FITE is expected to be 2.5 arcseconds. In order to derive the spatial extent of target objects, the visibility of interference fringes has to be measured precisely. For this purpose, we constructed the focal plane assembly of the FITE interferometer with the sensor optics. The focal plane is the entrance focus of the sensor optics. A far-infrared (FIR) array detector is installed on the final focal plane of the sensor optics. Its camera optics has F/106 beam for each beam of the interferometer. The PSF is dominated by diffraction, and its size corresponds approximately to the array size so that the fringe pattern can be measured by the array in real time. This system employs of two IR detectors and an optical CCD. The FIR detector has a format of 1.5mm ×15 pixels. In addition to the FIR array detector, we have a mid-IR detector and an optical CCD. They are also installed on the final focal plane of the sensor optics. These two detectors are used for the precise alignment of the interferometer optics.

  1. 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.

  2. Chinese vinegar classification via volatiles using long-optical-path infrared spectroscopy and chemometrics.

    Science.gov (United States)

    Dong, D; Zheng, W; Jiao, L; Lang, Y; Zhao, X

    2016-03-01

    Different brands of Chinese vinegar are similar in appearance, color and aroma, making their discrimination difficult. The compositions and concentrations of the volatiles released from different vinegars vary by raw material and brewing process and thus offer a means to discriminate vinegars. In this study, we enhanced the detection sensitivity of the infrared spectrometer by extending its optical path. We measured the infrared spectra of the volatiles from 5 brands of Chinese vinegar and observed the spectral characteristics corresponding to alcohols, esters, acids, furfural, etc. Different brands of Chinese vinegar had obviously different infrared spectra and could be classified through chemometrics analysis. Furthermore, we established classification models and demonstrated their effectiveness for classifying different brands of vinegar. This study demonstrates that long-optical-path infrared spectroscopy has the ability to discriminate Chinese vinegars with the advantages that it is fast and non-destructive and eliminates the need for sampling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. 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

  4. 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.

  5. MERTIS: geometrical calibration of thermal infrared optical system by applying diffractive optical elements

    Science.gov (United States)

    Bauer, M.; Baumbach, D.; Buder, M.; Börner, A.; Grießbach, D.; Peter, G.; Santier, E.; Säuberlich, T.; Schischmanow, A.; Schrader, S.; Walter, I.

    2015-09-01

    Geometrical sensor calibration is essential for space applications based on high accuracy optical measurements, in this case for the thermal infrared push-broom imaging spectrometer MERTIS. The goal is the determination of the interior sensor orientation. A conventional method is to measure the line of sight for a subset of pixels by single pixel illumination with collimated light. To adjust angles, which define the line of sight of a pixel, a manipulator construction is used. A new method for geometrical sensor calibration is using Diffractive Optical Elements (DOE) in connection with laser beam equipment. Diffractive optical elements (DOE) are optical microstructures, which are used to split an incoming laser beam with a dedicated wavelength into a number of beams with well-known propagation directions. As the virtual sources of the diffracted beams are points at infinity, the resulting image is invariant against translation. This particular characteristic allows a complete geometrical sensor calibration with only one taken image avoiding complex adjustment procedures, resulting in a significant reduction of calibration effort. We present a new method for geometrical calibration of a thermal infrared optical system, including an thermal infrared test optics and the MERTIS spectrometer bolometer detector. The fundamentals of this new approach for geometrical infrared optical systems calibration by applying diffractive optical elements and the test equipment are shown.

  6. 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...

  7. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. II. UV, Optical, and Near-infrared Light Curves and Comparison to Kilonova Models

    Energy Technology Data Exchange (ETDEWEB)

    Cowperthwaite, P. S.; Berger, E.; Villar, V. A.; Metzger, B. D.; Nicholl, M.; Chornock, R.; Blanchard, P. K.; Fong, W.; Margutti, R.; Soares-Santos, M.; Alexander, K. D.; Allam, S.; Annis, J.; Brout, D.; Brown, D. A.; Butler, R. E.; Chen, H. -Y.; Diehl, H. T.; Doctor, Z.; Drout, M. R.; Eftekhari, T.; Farr, B.; Finley, D. A.; Foley, R. J.; Frieman, J. A.; Fryer, C. L.; García-Bellido, J.; Gill, M. S. S.; Guillochon, J.; Herner, K.; Holz, D. E.; Kasen, D.; Kessler, R.; Marriner, J.; Matheson, T.; Neilsen, E. H.; Quataert, E.; Palmese, A.; Rest, A.; Sako, M.; Scolnic, D. M.; Smith, N.; Tucker, D. L.; Williams, P. K. G.; Balbinot, E.; Carlin, J. L.; Cook, E. R.; Durret, F.; Li, T. S.; Lopes, P. A. A.; Lourenço, A. C. C.; Marshall, J. L.; Medina, G. E.; Muir, J.; Muñoz, R. R.; Sauseda, M.; Schlegel, D. J.; Secco, L. F.; Vivas, A. K.; Wester, W.; Zenteno, A.; Zhang, Y.; Abbott, T. M. C.; Banerji, M.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Castander, F. J.; Crocce, M.; Cunha, C. E.; D’Andrea, C. B.; Costa, L. N. da; Davis, C.; DePoy, D. L.; Desai, S.; Dietrich, J. P.; Drlica-Wagner, A.; Eifler, T. F.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Jeltema, T.; Johnson, M. W. G.; Johnson, M. D.; Kent, S.; Krause, E.; Kron, R.; Kuehn, K.; Nuropatkin, N.; Lahav, O.; Lima, M.; Lin, H.; Maia, M. A. G.; March, M.; Martini, P.; McMahon, R. G.; Menanteau, F.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Neilsen, E.; Nichol, R. C.; Ogando, R. L. C.; Plazas, A. A.; Roe, N.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Thomas, R. C.; Troxel, M. A.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Weller, J.; Yanny, B.; Zuntz, J.

    2017-10-16

    We present UV, optical, and NIR photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced LIGO/Virgo, the binary neutron star merger GW170817. Our data set extends from the discovery of the optical counterpart at $0.47$ days to $18.5$ days post-merger, and includes observations with the Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), and the {\\it Hubble Space Telescope} ({\\it HST}). The spectral energy distribution (SED) inferred from this photometry at $0.6$ days is well described by a blackbody model with $T\\approx 8300$ K, a radius of $R\\approx 4.5\\times 10^{14}$ cm (corresponding to an expansion velocity of $v\\approx 0.3c$), and a bolometric luminosity of $L_{\\rm bol}\\approx 5\\times10^{41}$ erg s$^{-1}$. At $1.5$ days we find a multi-component SED across the optical and NIR, and subsequently we observe rapid fading in the UV and blue optical bands and significant reddening of the optical/NIR colors. Modeling the entire data set we find that models with heating from radioactive decay of $^{56}$Ni, or those with only a single component of opacity from $r$-process elements, fail to capture the rapid optical decline and red optical/NIR colors. Instead, models with two components consistent with lanthanide-poor and lanthanide-rich ejecta provide a good fit to the data, the resulting "blue" component has $M_\\mathrm{ej}^\\mathrm{blue}\\approx 0.01$ M$_\\odot$ and $v_\\mathrm{ej}^\\mathrm{blue}\\approx 0.3$c, and the "red" component has $M_\\mathrm{ej}^\\mathrm{red}\\approx 0.04$ M$_\\odot$ and $v_\\mathrm{ej}^\\mathrm{red}\\approx 0.1$c. These ejecta masses are broadly consistent with the estimated $r$-process production rate required to explain the Milky Way $r$-process abundances, providing the first evidence that BNS mergers can be a dominant site of $r$-process enrichment.

  8. 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

  9. 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

  10. Organic infrared and near-infrared light-emitting materials and devices for optical communication applications

    Science.gov (United States)

    Suzuki, Hiroyuki

    2004-06-01

    The luminescent properties of organic infrared (IR) and near-infrared (NIR) light-emitting materials were investigated for optical communication applications. These materials consisted of two organic ionic dyes, (2-[6-(4-dimethylaminophenyl)-2,4-neopentylene-1,3,5-hexatrienyl]-3-methyl-benzothiazonium perchlorate) (LDS821) and [C41H33Cl2N2]+×BF4- (IR1051), and an organic rare-earth complex, erbium (III) tris(8-hydroxyquinoline) (ErQ). The three materials are both photoluminescent and electroluminescent in the 0.8-, 1.1- and 1.5-μm wavelength regions, respectively, and so can be used as optically active species in devices operated by either optical or current excitation. Three device forms were fabricated with these light-emitting materials as optically active species, namely vacuum-deposited or spin-coated polymer thin-films, monodispersed polymer microparticles and embedded polymeric optical waveguides. Their luminescent processes are discussed and possible optical communication applications are proposed.

  11. Optical properties of infrared FELs from the FELI Facility II

    Energy Technology Data Exchange (ETDEWEB)

    Saeki, K.; Okuma, S.; Oshita, E. [Free Electron Laser Institute, Osaka (Japan)] [and others

    1995-12-31

    The FELI Facility II has succeeded in infrared FEL oscillation at 1.91 {mu} m using a 68-MeV, 40-A electron beam from the FELI S-band linac in February 27, 1995. The FELI Facility II is composed of a 3-m vertical type undulator ({lambda}u=3.8cm, N=78, Km a x=1.4, gap length {ge}20mm) and a 6.72-m optical cavity. It can cover the wavelength range of 1-5{mu}m. The FELs can be delivered from the optical cavity to the diagnostics room through a 40-m evacuated optical pipeline. Wavelength and cavity length dependences of optical properties such as peak power, average power, spectrum width, FEL macropulse, FEL transverse profile are reported.

  12. High-Contrast Observations in Optical and Infrared Astronomy

    OpenAIRE

    Oppenheimer, Ben R.; Hinkley, Sasha

    2009-01-01

    High-contrast observations in optical and infrared astronomy are defined as any observation requiring a technique to reveal a celestial object of interest that is in such close angular proximity to another source brighter by a factor of at least 10^5 that optical effects hinder or prevent the collection of photons directly from the target of observation. This is a relatively new type of observation that enables research on previously obscured parts of the Universe. In particular, it is most a...

  13. A Lunar Optical-Ultraviolet-Infrared Synthesis Array (LOUISA)

    Science.gov (United States)

    Burns, Jack O. (Editor); Johnson, Stewart W. (Editor); Duric, Nebojsa (Editor)

    1992-01-01

    This document contains papers presented at a workshop held to consider 'optical ultraviolet infrared' interferometric observations from the moon. Part 1 is an introduction. Part 2 is a description of current and planned ground-based interferometers. Part 3 is a description of potential space-based interferometers. Part 4 addresses the potential for interferometry on the moon. Part 5 is the report of the workshop's working groups. Concluding remarks, summary, and conclusions are presented in Part 6.

  14. Optical bistability and optical response of an infrared quantum dot hybridized to VO2 nanoparticle

    Science.gov (United States)

    Zamani, Naser; Hatef, Ali; Nadgaran, Hamid; Keshavarz, Alireza

    2017-08-01

    In this work, we theoretically investigate optical bistability and optical response of a hybrid system consisting of semiconductor quantum dot (SQD) coupled with a vanadium dioxide nanoparticle (VO2NP) in the infrared (IR) regime. The VO2 material exists in semiconductor and metallic phases below and above the critical temperature, respectively where the particle optical properties dramatically change during this phase transition. In our calculations a filling fraction factor controls the VO2NP phase transition when the hybrid system interacts with a laser field. We demonstrate that the switch-up threshold for optical bistability is strongly controlled by filling fraction without changing the structure of the hybrid system. Also, it is shown that, the threshold of optical bistability increases when the VO2NP phases changes from semiconductor to metallic phase. The presented results have the potential to be applied in designing optical switching and optical storage.

  15. Effects of passive isolation on several optically pumped far-infrared laser lines

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, D.K.; Tesauro, G.J.; Johnson, L.C.; Semet, A.

    1981-05-01

    The effects of a recently introduced passive-isolation scheme for optically pumped far-infrared lasers have been investigated on several well-known far-infrared laser lines. In addition to increasing the laser output stability, the isolation scheme alters the pump-to-far-infrared power-conversion efficiency and the polarization state of the far-infrared output.

  16. Nearest-neighbour-interaction model in the coupled-optical-phonon-mode theory of the infrared dispersion in monoclinic crystals: Application to Tutton salt single crystal.

    Science.gov (United States)

    Ivanovski, V; Ivanovski, G

    2010-05-01

    The coupled-optical-phonon-mode theory of Barker and Hopfield of two mode interaction in isotropic crystals has been extended to monoclinic crystals. The analytical expressions for the calculation of the dielectric tensor elements in the ac crystal plane have been derived. It has been shown that the interaction dielectric model is a generalized expression of the dielectric tensor for monoclinic case when no interaction between modes is present. Also, the results of Barker and Hopfield are obtained from this more general theory, when an isotropic case is considered. In order to be able to investigate real crystals, meaning extending the interactions to a large number of pairs of modes, but at the same time to make the fitting procedure possible, a model dielectric function taking into account the interaction between modes with closest frequencies has been derived. The validity of the model obtained has been tested on a Tutton salt single crystal of K(2)Co(SO(4))(2).6H(2)O. The recorded spectra from the ac crystal plane were fitted in order to obtain best fit parameters. The comparison between the experimentally recorded spectra and the model reflectance function give good results and verify this model to be applicable. Copyright 2010 Elsevier B.V. All rights reserved.

  17. Engineering materials for mid-infrared optical sensor applications

    Directory of Open Access Journals (Sweden)

    Richardson K. A

    2013-11-01

    Full Text Available Planar optical structures based on functionalized chalcogenide glasses provide a superb device platform for chemical and biological sensing applications. Chalcogenide glasses have demonstrated promise as materials for infrared sensing as they exhibit transparency over a large range of infrared wavelengths and tunable optical properties through doping and/or compositional tailoring. Waveguides, resonators and other components processed on-chip (silicon, Si can be realized such that the strong enhancement in the electromagnetic field confined within a high index contrast resonator, leads to highly sensitive photon-matter interactions in a small footprint. In this paper we discuss the development of highly sensitive chalcogenide glass based microdisk resonator sensors that measure resonant peak shifts caused by refractive index change upon exposure to a chemical analyte. The specificity of the microdisk resonator sensors is enhanced by applying specialized polymer films and nanofoams that respond in a predictable fashion when exposed to a chemical analyte of interest. Discussed are key material science challenges needed to enable highly sensitive and specific sensors based on such complex multi-material assemblies and the fabrication issues that ultimately define resulting optical performance.

  18. Miniaturized multi channel infrared optical gas sensor system

    Science.gov (United States)

    Wöllenstein, Jürgen; Eberhardt, Andre; Rademacher, Sven; Schmitt, Katrin

    2011-06-01

    Infrared spectroscopy uses the characteristic absorption of the molecules in the mid infrared and allows the determination of the gases and their concentration. Especially by the absorption at longer wavelengths between 8 μm and 12 μm, the so called "fingerprint" region, the molecules can be measured with highest selectivity. We present an infrared optical filter photometer for the analytical determination of trace gases in the air. The challenge in developing the filter photometer was the construction of a multi-channel system using a novel filter wheel concept - which acts as a chopper too- in order to measure simultaneously four gases: carbon monoxide, carbon dioxide, methane and ammonia. The system consists of a broadband infrared emitter, a long path cell with 1.7m optical path length, a filter wheel and analogue and digital signal processing. Multi channel filter photometers normally need one filter and one detector per target gas. There are small detection units with one, two or more detectors with integrated filters available on the market. One filter is normally used as reference at a wavelength without any cross-sensitivities to possible interfering gases (e.g. at 3.95 μm is an "atmospheric window" - a small spectral band without absorbing gases in the atmosphere). The advantage of a filter-wheel set-up is that a single IR-detector can be used, which reduces the signal drift enormously. Pyroelectric and thermopile detectors are often integrated in these kinds of spectrometers. For both detector types a modulation of the light is required and can be done - without an additional chopper - with the filter wheel.

  19. 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

    ... (mesosphere and thermosphere) in terms of the structure of the underlying medium. Advances in non-LTE radiative transfer and atmospheric waves and localized excitations are detailed, as well as analysis and modeling of the databases resulting from two groundbreaking space infrared experiments, DoD MSX/SPIRIT III and NASA TIMED/SABER.

  20. Study of optical techniques for the Ames unitary wind tunnel. Part 5: Infrared imagery

    Science.gov (United States)

    Lee, George

    1992-01-01

    A survey of infrared thermography for aerodynamics was made. Particular attention was paid to boundary layer transition detection. IR thermography flow visualization of 2-D and 3-D separation was surveyed. Heat transfer measurements and surface temperature measurements were also covered. Comparisons of several commercial IR cameras were made. The use of a recently purchased IR camera in the Ames Unitary Plan Wind Tunnels was studied. Optical access for these facilities and the methods to scan typical models was investigated.

  1. Nanoscale Optical Imaging and Spectroscopy from Visible to Mid-Infrared

    Science.gov (United States)

    2015-11-13

    Nanoscale Optical Imaging and Spectroscopy from Visible to Mid-infrared The PIs completed the acquisition of a nanoscale optical imaging and...of Papers published in non peer-reviewed journals: Final Report: Nanoscale Optical Imaging and Spectroscopy from Visible to Mid-infrared Report Title... spectroscopy system with extremely broad spectral capability spanning the ultraviolet to the near-infrared. The equipment provides new capabilities of

  2. Measurement of Machining Temperature Using Infrared Radiation Pyrometer With Optical Fiber: Characteristics of Pyrometer

    OpenAIRE

    上田, 隆司; 金田, 泰幸; 佐藤, 昌彦; 杉田, 忠彰

    1992-01-01

    The fundamental characteristics of a new type of infrared radiation pyrometer using an optical fiber are investigated theoretically and experimentally. The structure of this pyrometer is that the optical fiber accepts the infrared flux radiated from the object and transmits it to an infrared detector InSb cell. This I. R. P. is suitable for measuring the temperature of a very small object whose temperature changes rapidly. The flexibility of the optical fiber also makes it possible to measure...

  3. An infrared and optical analysis of a sample of XBONGs and optically elusive AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K. L.; Mushotzky, R. F. [Department of Astronomy, University of Maryland, College Park, MD (United States); Koss, M., E-mail: klsmith@astro.umd.edu, E-mail: richard@astro.umd.edu, E-mail: mike.koss@phys.ethz.ch [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland)

    2014-10-20

    We present near-infrared (NIR) spectra of four optically elusive active galactic nuclei (AGNs) and four X-ray bright, optically normal galaxies (XBONGs) from the Swift-BAT survey. With archival observations from the Sloan Digital Sky Survey, the Two Micron All Sky Survey, Spitzer, and the Wide-field Infrared Survey Explorer (WISE), we test a number of AGN indicators in the NIR and mid-infrared; namely, NIR emission line diagnostic ratios, the presence of coronal high-ionization lines, and infrared photometry. Of our eight hard X-ray selected AGNs, we find that optical normalcy has a variety of causes from object to object, and no one explanation applies. Our objects have normal Eddington ratios and so are unlikely to host radiatively inefficient accretion flows. It is unlikely that star formation in the host or starlight dilution is contributing to their failure of optical diagnostics, except perhaps in two cases. The NIR continua are well fit by two blackbodies: one at the stellar temperature, and a hot dust component near the dust sublimation temperature. The XBONGs are more likely to have significant hot dust components, while these components are small relative to starlight in the optically elusive AGN. Some of our sample have NIR line ratios typical of AGNs, but NIR diagnostics are unsuccessful in distinguishing H II regions from AGNs in general. In one object, we discover a hidden broad-line region in the NIR. These results have strong relevance to the origin of optically normal AGNs in deep X-ray surveys.

  4. Infrared

    Science.gov (United States)

    Vollmer, M.

    2013-11-01

    underlying physics. There are now at least six different disciplines that deal with infrared radiation in one form or another, and in one or several different spectral portions of the whole IR range. These are spectroscopy, astronomy, thermal imaging, detector and source development and metrology, as well the field of optical data transmission. Scientists working in these fields range from chemists and astronomers through to physicists and even photographers. This issue presents examples from some of these fields. All the papers—though some of them deal with fundamental or applied research—include interesting elements that make them directly applicable to university-level teaching at the graduate or postgraduate level. Source (e.g. quantum cascade lasers) and detector development (e.g. multispectral sensors), as well as metrology issues and optical data transmission, are omitted since they belong to fundamental research journals. Using a more-or-less arbitrary order according to wavelength range, the issue starts with a paper on the physics of near-infrared photography using consumer product cameras in the spectral range from 800 nm to 1.1 µm [1]. It is followed by a series of three papers dealing with IR imaging in spectral ranges from 3 to 14 µm [2-4]. One of them deals with laboratory courses that may help to characterize the IR camera response [2], the second discusses potential applications for nondestructive testing techniques [3] and the third gives an example of how IR thermal imaging may be used to understand cloud cover of the Earth [4], which is the prerequisite for successful climate modelling. The next two papers cover the vast field of IR spectroscopy [5, 6]. The first of these deals with Fourier transform infrared spectroscopy in the spectral range from 2.5 to 25 µm, studying e.g. ro-vibrational excitations in gases or optical phonon interactions within solids [5]. The second deals mostly with the spectroscopy of liquids such as biofuels and special

  5. Fibre-optic laser-assisted infrared tumour diagnostics (FLAIR)

    International Nuclear Information System (INIS)

    Bindig, U; Mueller, G

    2005-01-01

    Laser based fibre-optic surgery procedures are commonly used in minimal invasive surgery. Despite the development of precise and efficient laser systems there are also innovative attempts in the field of bio-medical diagnostics. As a direct result of the tissue's optical properties most applications are focused on the visible wavelength range of the spectrum. The extension of the spectrum up to the mid-infrared (IR) region will offer a broad range of possibilities for novel strategies with a view to non-invasive diagnostics in medicine. We describe a method to detect differences between diseased and normal tissues, which involve Fourier transform IR microspectroscopy and fibre-optics methods. Regions of interest on 10 μm thin tissue sections were mapped using an IR microscope in transmission mode. After IR-mapping, the samples were analysed using standard pathological techniques. Quadratic discriminant and correlation analyses were applied to the IR maps obtained allowing differentiation between cancerous and normal tissue. The use of optical fibres, transparent in the mid-IR, allowed measurements to be made in the attenuated total reflectance (ATR)-mode at a remote location. The IR sensor is in contact with the sample that shows characteristic absorption lines. The total transmission of the fibre and the sample will decrease at these lines. This method can be used to determine the absorption of a sample in a non-destructive manner. In this paper we report on our efforts to develop an IR fibre-optic sensor for tissue identification as well as to differentiate between malignant and healthy tissue in vivo. We also describe the technical design of the laboratory set-up and the results of developments made. Silver halide fibres and a special sensor tip were used for the ATR measurements on tissue specimens. The results indicate that fibre-optic IR spectrometry will be a useful tool for bio-diagnostics

  6. Fibre-optic laser-assisted infrared tumour diagnostics (FLAIR)

    Science.gov (United States)

    Bindig, U.; Müller, G.

    2005-08-01

    Laser based fibre-optic surgery procedures are commonly used in minimal invasive surgery. Despite the development of precise and efficient laser systems there are also innovative attempts in the field of bio-medical diagnostics. As a direct result of the tissue's optical properties most applications are focused on the visible wavelength range of the spectrum. The extension of the spectrum up to the mid-infrared (IR) region will offer a broad range of possibilities for novel strategies with a view to non-invasive diagnostics in medicine. We describe a method to detect differences between diseased and normal tissues, which involve Fourier transform IR microspectroscopy and fibre-optics methods. Regions of interest on 10 µm thin tissue sections were mapped using an IR microscope in transmission mode. After IR-mapping, the samples were analysed using standard pathological techniques. Quadratic discriminant and correlation analyses were applied to the IR maps obtained allowing differentiation between cancerous and normal tissue. The use of optical fibres, transparent in the mid-IR, allowed measurements to be made in the attenuated total reflectance (ATR)-mode at a remote location. The IR sensor is in contact with the sample that shows characteristic absorption lines. The total transmission of the fibre and the sample will decrease at these lines. This method can be used to determine the absorption of a sample in a non-destructive manner. In this paper we report on our efforts to develop an IR fibre-optic sensor for tissue identification as well as to differentiate between malignant and healthy tissue in vivo. We also describe the technical design of the laboratory set-up and the results of developments made. Silver halide fibres and a special sensor tip were used for the ATR measurements on tissue specimens. The results indicate that fibre-optic IR spectrometry will be a useful tool for bio-diagnostics.

  7. Long-term optical-infrared color variability of blazars

    International Nuclear Information System (INIS)

    Zhang, Bing-Kai; Zhou, Xiao-Shan; Zhao, Xiao-Yun; Dai, Ben-Zhong

    2015-01-01

    The long-term optical and infrared color variability of blazars has been investigated with monitoring data from the Small and Moderate Aperture Research Telescope System (SMARTS). The sample in this study consists of 49 flat spectrum radio quasars (FSRQs) and 22 BL Lacertae objects (BL Lacs). The fractional variability amplitudes of each source have been calculated in both optical R band and infrared J band. Overall, the variability amplitudes of FSRQs are larger than those of BL Lacs. The results also suggest that the variability amplitude of most FSRQs is larger at a lower energy band (J band) than at a higher one (R band), but the variability amplitude of BL Lacs is larger at the higher energy band. Both types of blazars display color variation along with variability in brightness. However, they show different variation behaviors in general. In the whole data set, 35 FSRQs exhibit redder-when-brighter trends, and 11 FSRQs exhibit opposite trends; 11 BL Lacs follow bluer-when-brighter trends, and seven BL Lacs follow opposite trends. A detailed examination indicates that there are 10 blazars showing redder-when-brighter trends in their low state, and bluer-when-brighter or stable-when-brighter trends in their high state. Some more complicated color behaviors have also been detected in several blazars. The non-thermal jet emission and the thermal emission from the accretion disk are employed to explain the observed color behaviors. (paper)

  8. Optical/Infrared Polarised Emission in X-ray Binaries

    Directory of Open Access Journals (Sweden)

    David M. Russell

    2018-01-01

    Full Text Available Recently, evidence for synchrotron emission in both black-hole (BH and neutron star X-ray binaries has been mounting, from optical/infrared spectral, polarimetric, and fast timing signatures. The synchrotron emission of jets can be highly linearly polarised, depending on the configuration of the magnetic field (B-field. Optical and infrared (OIR polarimetric observations of X-ray binaries are presented in this brief review. The OIR polarimetric signature of relativistic jets is detected at levels of ∼1–10%, similarly to for active galactic nuclei (AGN cores. This reveals that the magnetic geometry in the compact jets may be similar for supermassive and stellar-mass BHs. The B-fields near the jet base in most of these systems appear to be turbulent, variable and on average, aligned with the jet axis, although there are some exceptions. These measurements probe the physical conditions in the accretion (outflow and demonstrate a new way of connecting inflow and outflow, using both rapid timing and polarisation. Variations in polarisation could be due to rapid changes of the ordering of the B-field in the emitting region, or in one case, flares from individual ejections or collisions between ejecta. It is predicted that in some cases, variable levels of X-ray polarisation from synchrotron emission originating in jets will be detected from accreting galactic BHs with upcoming spaceborne X-ray polarimeters.

  9. Modeling Optical Lithography Physics

    Science.gov (United States)

    Neureuther, Andrew R.; Rubinstein, Juliet; Chin, Eric; Wang, Lynn; Miller, Marshal; Clifford, Chris; Yamazoe, Kenji

    2010-06-01

    Key physical phenomena associated with resists, illumination, lenses and masks are used to show the progress in models and algorithms for modeling optical projection printing as well as current simulation challenges in managing process complexity for manufacturing. The amazing current capability and challenges for projection printing are discussed using the 22 nm device generation. A fundamental foundation for modeling resist exposure, partial coherent imaging and defect printability is given. The technology innovations of resolution enhancement and chemically amplified resist systems and their modeling challenges are overviewed. Automated chip-level applications in pattern pre-compensation and design-anticipation of residual process variations require new simulation approaches.

  10. 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.

  11. Accurate optical parameter extraction procedure for broadband near-infrared spectroscopy of brain matter.

    Science.gov (United States)

    Sultan, Ebraheem; Najafizadeh, Laleh; Gandjbakhche, Amir H; Pourrezaei, Kambiz; Daryoush, Afshin

    2013-01-01

    Modeling behavior of broadband (30 to 1000 MHz) frequency modulated near-infrared (NIR) photons through a phantom is the basis for accurate extraction of optical absorption and scattering parameters of biological turbid media. Photon dynamics in a phantom are predicted using both analytical and numerical simulation and are related to the measured insertion loss (IL) and insertion phase (IP) for a given geometry based on phantom optical parameters. Accuracy of the extracted optical parameters using finite element method (FEM) simulation is compared to baseline analytical calculations from the diffusion equation (DE) for homogenous brain phantoms. NIR spectroscopy is performed using custom-designed, broadband, free-space optical transmitter (Tx) and receiver (Rx) modules that are developed for photon migration at wavelengths of 680, 780, and 820 nm. Differential detection between two optical Rx locations separated by 0.3 cm is employed to eliminate systemic artifacts associated with interfaces of the optical Tx and Rx with the phantoms. Optical parameter extraction is achieved for four solid phantom samples using the least-square-error method in MATLAB (for DE) and COMSOL (for FEM) simulation by fitting data to measured results over broadband and narrowband frequency modulation. Confidence in numerical modeling of the photonic behavior using FEM has been established here by comparing the transmission mode's experimental results with the predictions made by DE and FEM for known commercial solid brain phantoms.

  12. Optical, infrared and radio astronomy from techniques to observation

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

    This textbook presents the established sciences of optical, infrared, and radio astronomy as distinct research areas, focusing on the science targets and the constraints that they place on instrumentation in the different domains. It aims to bridge the gap between specialized books and practical texts, presenting the state of the art in different techniques. For each type of astronomy, the discussion proceeds from the orders of magnitude for observable quantities that drive the building of instrumentation and the development of advanced techniques. The specific telescopes and detectors are then presented, together with the techniques used to measure fluxes and spectra. Finally, the instruments and their limits are discussed to assist readers in choice of setup, planning and execution of observations, and data reduction. The volume also includes worked examples and problem sets to improve student understanding; tables and figures in chapters summarize the state of the art of instrumentation and techniques.

  13. Moulded infrared optics making night vision for cars within reach

    Science.gov (United States)

    Bourget, Antoine; Guimond, Yann; Franks, John; Van Den Bergh, Marleen

    2005-02-01

    Sustainable mobility is a major public concern, making increased safety one of the major challenges for the car of the future. About half of all serious traffic accidents occur at night, while only a minority of journeys is at night. Reduced visibility is one of the main reasons for these striking statistics and this explains the interest of the automobile industry in Enhanced Night Vision Systems. As an answer to the need for high volume, low cost optics for these applications, Umicore has developed GASIR. This material is transparent in the NEAR and FAR infrared, and is mouldable into high quality finished spherical, aspherical and diffractive lenses. Umicore's GASIR moulded lenses are an ideal solution for thermal imaging for cars (Night Vision) and for sensing systems like pedestrian detection, collision avoidance, occupation detection, intelligent airbag systems etc.

  14. Quasi-optical analysis of a far-infrared spatio-spectral space interferometer concept

    Science.gov (United States)

    Bracken, C.; O'Sullivan, C.; Murphy, J. A.; Donohoe, A.; Savini, G.; Lightfoot, J.; Juanola-Parramon, R.; Fisica Consortium

    2016-07-01

    FISICA (Far-Infrared Space Interferometer Critical Assessment) was a three year study of a far-infrared spatio-spectral double-Fourier interferometer concept. One of the aims of the FISICA study was to set-out a baseline optical design for such a system, and to use a model of the system to simulate realistic telescope beams for use with an end-to-end instrument simulator. This paper describes a two-telescope (and hub) baseline optical design that fulfils the requirements of the FISICA science case, while minimising the optical mass of the system. A number of different modelling techniques were required for the analysis: fast approximate simulation tools such as ray tracing and Gaussian beam methods were employed for initial analysis, with GRASP physical optics used for higher accuracy in the final analysis. Results are shown for the predicted far-field patterns of the telescope primary mirrors under illumination by smooth walled rectangular feed horns. Far-field patterns for both on-axis and off-axis detectors are presented and discussed.

  15. 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.

  16. Amplitude modulation in infrared metamaterial absorbers based on electro-optically tunable conducting oxides

    Science.gov (United States)

    Zografopoulos, D. C.; Sinatkas, G.; Lotfi, E.; Shahada, L. A.; Swillam, M. A.; Kriezis, E. E.; Beccherelli, R.

    2018-02-01

    A class of electro-optically tunable metamaterial absorbers is designed and theoretically investigated in the infrared regime towards realizing free-space amplitude modulators. The spacer between a subwavelength metallic stripe grating and a back metal reflector is occupied by a bilayer of indium tin oxide (ITO) and hafnium oxide (HfO_2). The application of a bias voltage across the bilayer induces free-carrier accumulation at the HfO_2/ITO interface that locally modulates the ITO permittivity and drastically modifies the optical response of the absorber owing to the induced epsilon-near-zero (ENZ) effect. The carrier distribution and dynamics are solved via the drift-diffusion model, which is coupled with optical wave propagation studies in a common finite-element method platform. Optimized structures are derived that enable the amplitude modulation of the reflected wave with moderate insertion losses, theoretically infinite extinction ratio, sub-picosecond switching times and low operating voltages.

  17. The Combined Ultraviolet, Optical, and Near-infrared Light Curves of the Kilonova Associated with the Binary Neutron Star Merger GW170817: Unified Data Set, Analytic Models, and Physical Implications

    Science.gov (United States)

    Villar, V. A.; Guillochon, J.; Berger, E.; Metzger, B. D.; Cowperthwaite, P. S.; Nicholl, M.; Alexander, K. D.; Blanchard, P. K.; Chornock, R.; Eftekhari, T.; Fong, W.; Margutti, R.; Williams, P. K. G.

    2017-12-01

    We present the first effort to aggregate, homogenize, and uniformly model the combined ultraviolet, optical, and near-infrared data set for the electromagnetic counterpart of the binary neutron star merger GW170817. By assembling all of the available data from 18 different papers and 46 different instruments, we are able to identify and mitigate systematic offsets between individual data sets and to identify clear outlying measurements, with the resulting pruned and adjusted data set offering an opportunity to expand the study of the kilonova. The unified data set includes 647 individual flux measurements, spanning 0.45-29.4 days post-merger, and thus has greater constraining power for physical models than any single data set. We test a number of semi-analytical models and find that the data are well modeled with a three-component kilonova model: a “blue” lanthanide-poor component (κ =0.5 cm2 g-1) with {M}{ej}≈ 0.020 {M}⊙ and {v}{ej}≈ 0.27c; an intermediate opacity “purple” component (κ =3 cm2 g-1) with {M}{ej}≈ 0.047 {M}⊙ and {v}{ej}≈ 0.15c; and a “red” lanthanide-rich component (κ =10 cm2 g-1) with {M}{ej}≈ 0.011 {M}⊙ and {v}{ej}≈ 0.14c. We further explore the possibility of ejecta asymmetry and its impact on the estimated parameters. From the inferred parameters we draw conclusions about the physical mechanisms responsible for the various ejecta components, the properties of the neutron stars, and, combined with an up-to-date merger rate, the implications for r-process enrichment via this channel. To facilitate future studies of this keystone event we make the unified data set and our modeling code public.

  18. Models of optical quantum computing

    Directory of Open Access Journals (Sweden)

    Krovi Hari

    2017-03-01

    Full Text Available I review some work on models of quantum computing, optical implementations of these models, as well as the associated computational power. In particular, we discuss the circuit model and cluster state implementations using quantum optics with various encodings such as dual rail encoding, Gottesman-Kitaev-Preskill encoding, and coherent state encoding. Then we discuss intermediate models of optical computing such as boson sampling and its variants. Finally, we review some recent work in optical implementations of adiabatic quantum computing and analog optical computing. We also provide a brief description of the relevant aspects from complexity theory needed to understand the results surveyed.

  19. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  20. 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...

  1. 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...

  2. 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.

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

    Science.gov (United States)

    Brückner, Jean-Baptiste; Brissonneau, Vincent; Le Rouzo, Judikaël; Ferchichi, Abdelkerim; Gourgon, Cécile; Dubarry, Christophe; Berginc, Gérard; Escoubas, Ludovic

    2014-02-01

    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.

  4. [Optical Design of Miniature Infrared Gratings Spectrometer Based on Planar Waveguide].

    Science.gov (United States)

    Li, Yang-yu; Fang, Yong-hua; Li, Da-cheng; Liu, Yang

    2015-03-01

    In order to miniaturize an infrared spectrometer, we analyze the current optical design of miniature spectrometers and propose a method for designing a miniature infrared gratings spectrometer based on planar waveguide. Common miniature spectrometer uses miniature optical elements to reduce the size of system, which also shrinks the effective aperture. So the performance of spectrometer has dropped. Miniaturization principle of planar waveguide spectrometer is different from the principle of common miniature spectrometer. In planar waveguide spectrometer, the propagation of light is limited in a thin planar waveguide, which looks like the whole optical system is squashed flat. In the direction parallel to the planar waveguide, the light through the slit is collimated, dispersed and focused. And a spectral image is formed in the detector plane. This propagation of light is similar to the light in common miniature spectrometer. In the direction perpendicular to the planar waveguide, light is multiple reflected by the upper and lower surfaces of the planar waveguide and propagates in the waveguide. So the size of corresponding optical element could be very small in the vertical direction, which can reduce the size of the optical system. And the performance of the spectrometer is still good. The design method of the planar waveguide spectrometer can be separated into two parts, Czerny-Turner structure design and planar waveguide structure design. First, by using aberration theory an aberration-corrected (spherical aberration, coma, focal curve) Czerny-Turner structure is obtained. The operation wavelength range and spectral resolution are also fixed. Then, by using geometrical optics theory a planar waveguide structure is designed for reducing the system size and correcting the astigmatism. The planar waveguide structure includes a planar waveguide and two cylindrical lenses. Finally, they are modeled together in optical design software and are optimized as a whole. An

  5. Design of infrared multilayer diffractive optical elements with low temperature sensibility

    Science.gov (United States)

    Yang, Hongfang; Xue, Changxi

    2018-01-01

    An optimal method was presented to prevent the decrease of diffraction efficiency when the infrared diffractive optical elements working in a wide temperature range. The method can lower the cost of thermal infrared diffractive lenses by decreasing the microstructure height and volume of multilayer diffractive optical elements (MLDOEs). The diffraction efficiency of the results was compared to the previous methods with wavelengths between long wave infrared and middle wave infrared. Those comparisons show the better temperature stability of MLDOEs when the elements working in a wide temperature range.

  6. Immunosensing with Near-Infrared Plasmonic Optical Fiber Gratings.

    Science.gov (United States)

    Caucheteur, Christophe; Ribaut, Clotilde; Malachovska, Viera; Wattiez, Ruddy

    2017-01-01

    Surface Plasmon resonance (SPR) optical fiber biosensors constitute a miniaturized counterpart to the bulky prism configuration and offer remote operation in very small volumes of analyte. They are a cost-effective and relatively straightforward technique to yield in situ (or even possibly in vivo) molecular detection. They are usually obtained from a gold-coated fiber segment for which the core-guided light is brought into contact with the surrounding medium, either by etching (or side-polishing) or by using grating coupling. Recently, SPR generation was achieved in gold-coated tilted fiber Bragg gratings (TFBGs). These sensors probe the surrounding medium with near-infrared narrowband resonances, which enhances both the penetration depth of the evanescent field in the external medium and the wavelength resolution of the interrogation. They constitute the unique configuration able to probe all the fiber cladding modes individually, with high Q-factors. We use these unique spectral features in our work to sense proteins and extra-cellular membrane receptors that are both overexpressed in cancerous tissues. Impressive limit of detection (LOD) and sensitivity are reported, which paves the way for the further use of such immunosensors for cancer diagnosis.

  7. Infrared fiber optic probes for evaluation of musculoskeletal tissue pathology

    Science.gov (United States)

    Padalkar, Mugdha; McGoverin, Cushla; Onigbanjo, Quam; Spencer, Richard; Barbash, Scott; Kropf, Eric; Pleshko, Nancy

    2014-03-01

    Musculoskeletal pathology of the knee commonly occurs with aging and as a result of injury. The incidence of anterior cruciate ligament (ACL) injuries continues to increase annually, and may precede the eventual onset of osteoarthritis (OA), a debilitating and prevalent disease characterized by cartilage degeneration. Early detection of OA remains elusive, with current imaging methods lacking adequate sensitivity to detect early pathologic cartilage changes. We used mid- and near- infrared (IR) spectroscopy through arthroscopic-based fiber-optic devices to assess cartilage damage and differentiate tendon from ligament. Mid-IR spectroscopy is characterized by distinct bands and low penetration depth (< 10 μm) and near-IR spectroscopy is characterized by complex overlapping bands and greater penetration depths (< 1 cm). We have found that combined mid- and near-IR analysis greatly extends the information available through either in the analysis of soft tissues, including cartilage, ligaments and tendons. We discuss here basic science studies and the potential for translation to clinical research with novel arthroscopic probes.

  8. 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.

  9. Airborne Thematic Thermal InfraRed and Electro-Optical Imaging System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is an advanced Airborne Thematic Thermal InfraRed and Electro-Optical Imaging System (ATTIREOIS). ATTIREOIS sensor payload consists of two sets of...

  10. A Near-Infrared Optical Tomography System Based on Photomultiplier Tube

    Directory of Open Access Journals (Sweden)

    Huacheng Feng

    2007-01-01

    Full Text Available Diffuse optical tomography (DOT is a rapidly growing discipline in recent years. It plays an important role in many fields, such as detecting breast cancer and monitoring the cerebra oxygenation. In this paper, a relatively simple, inexpensive, and conveniently used DOT system is presented in detail, in which only one photomultiplier tube is employed as the detector and an optical multiplexer is used to alter the detector channels. The 32-channel imager is consisted of 16-launch fibers and 16-detector fibers bundles, which works in the near-infrared (NIR spectral range under continuous-wave (CW model. The entire imaging system can work highly automatically and harmoniously. Experiments based on the proposed imaging system were performed, and the desired results can be obtained. The experimental results suggested that the proposed imaging instrumentation is effective.

  11. Numerical Study on Infrared Optical Property of Diffuse Coal Particles in Mine Fully Mechanized Working Combined with CFD Method

    Directory of Open Access Journals (Sweden)

    Wen-Zheng Wang

    2015-01-01

    Full Text Available Coal dust seriously threatens the safety and occupational health of coal mines. Numerical simulation research on the infrared radiation characteristics of diffused coal dust is carried out in fully mechanized working faces based on the optical monitoring problem of dust particles in mine atmospheric environments. The CFD method is applied to obtain the law of dust transport and distribution. Combined with Mie scattering model, the infrared radiation change characteristics and spectral selection of diffused coal dust particles are simulated and analyzed along the working face. The comparison results show the following: the attenuation and scattering characteristics of mine dust particles system are first enhanced, and then they weaken as the distance from dust source increases. The infrared attenuation of mine dust at the center of the vertical cross-section is generally greater than that at the roof and floor in the same location. The dispersion of mine dust directly determines the attenuation contribution of respirable dust to total dust. Moreover, the infrared absorption effect of functional groups in coal causes the infrared attenuation effect of coal dust to have obvious optical selectivity along the roadway, the existing optical “window.”

  12. [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.

  13. 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.

  14. EXORCISM: EXOR optiCal Infrared Systematic Monitoring

    Science.gov (United States)

    Antoniucci, Simone; Arkharov, Arkady A.; Di Paola, Andrea; Giannini, Teresa; Kishimoto, Makoto; Kloppenborg, Brian; Larionov, Valeri M.; Li Causi, Gianluca; Lorenzetti, Dario; Vitali, Fabrizio

    2013-07-01

    EXors are pre-main sequence eruptive stars showing intermittent outbursts (Dmag about 3-4) of short duration (months) superposed on longer (years) quiescence periods. While a general consensus exists about the origin of the outbursts (i.e. accretion events from the circumstellar disk), many important details (e.g. the trigger mechanism, the disk heating/cooling and its final fragmentation) are not clarified yet. To perform a comprehensive study of EXors, we have recently activated a regular optical/NIR photometric and spectroscopic monitoring program (EXORCISM - EXORs optiCal-Infrared Systematic Monitoring), which will carry on in a more systematic way an observational program that we started a few years ago. During this period we have already obtained interesting results that will be discussed here: (i) EXors become bluer (redder) when brightening (fading), but extinction cannot be uniquely responsible for that; (ii) (quasi-)simultaneous light-curves taken in different bands show a systematic lag with the wavelength; (iii) SEDs at outburst and quiescence differ by a single temperature black-body interpreted as the sudden heating of the inner disk wall by hot spots on the stellar surface; (iv) EXor near-IR spectra look like those of accreting T Tauri stars more than those of FUOr objects; (v) notably, near IR permitted line emission weakens when the continuum fades, but the continuum fluctuations appear faster than those of the lines. These results will help to clarify the scopes of our EXORCISM project and, more importantly, to framework new results on the mid-IR properties of EXors (mainly derived from WISE data), which are so far quite unexplored.

  15. 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.

  16. Low-loss graphene-based optical phase modulator operating at mid-infrared wavelength

    Science.gov (United States)

    Yamaguchi, Yuki; Takagi, Shinichi; Takenaka, Mitsuru

    2018-04-01

    We numerically analyzed a graphene optical phase modulator with a Si or Ge waveguide operating at a mid-infrared wavelength. We found that the change in operating wavelength from a near-infrared wavelength to a mid-infrared wavelength enables phase modulation with a significantly small optical loss at a realistic bias voltage. We analyzed the wavelength dependence of the modulation characteristics in the wavelength range from 1.55 to 10 µm, which revealed that the minimum insertion of 4 dB with 1 dB optical loss change during phase modulation can be achieved at a wavelength of 4 µm. The phase modulation efficiency was expected to be 0.045 V·cm. Thus, we can obtain a practical graphene optical phase modulator at a wavelength of 4 µm, which will be useful for optical communication and sensing.

  17. Efficient control of ultrafast optical nonlinearity of reduced graphene oxide by infrared reduction

    Energy Technology Data Exchange (ETDEWEB)

    Bhattachraya, S.; Maiti, R.; Das, A. C.; Saha, S.; Mondal, S.; Ray, S. K.; Bhaktha, S. N. B.; Datta, P. K., E-mail: pkdatta.iitkgp@gmail.com [Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2016-07-07

    Simultaneous occurrence of saturable absorption nonlinearity and two-photon absorption nonlinearity in the same medium is well sought for the devices like optical limiter and laser mode-locker. Pristine graphene sheet consisting entirely of sp{sup 2}-hybridized carbon atoms has already been identified having large optical nonlinearity. However, graphene oxide (GO), a precursor of graphene having both sp{sup 2} and sp{sup 3}-hybridized carbon atom, is increasingly attracting cross-discipline researchers for its controllable properties by reduction of oxygen containing groups. In this work, GO has been prepared by modified Hummers method, and it has been further reduced by infrared (IR) radiation. Characterization of reduced graphene oxide (RGO) by means of Raman spectroscopy, X-ray photoelectron spectroscopy, and UV-Visible absorption measurements confirms an efficient reduction with infrared radiation. Here, we report precise control of non-linear optical properties of RGO in femtosecond regime with increased degrees of IR reduction measured by open aperture z-scan technique. Depending on the intensity, both saturable absorption and two-photon absorption effects are found to contribute to the non-linearity of all the samples. Saturation dominates at low intensity (∼127 GW/cm{sup 2}) while two-photon absorption becomes prominent at higher intensities (from 217 GW/cm{sup 2} to 302 GW/cm{sup 2}). The values of two-photon absorption co-efficient (∼0.0022–0.0037 cm/GW for GO, and ∼0.0128–0.0143 cm/GW for RGO) and the saturation intensity (∼57 GW/cm{sup 2} for GO, and ∼194 GW/cm{sup 2} for RGO) increase with increasing reduction, indicating GO and RGO as novel tunable photonic devices. We have also explained the reason of tunable nonlinear optical properties by using amorphous carbon model.

  18. 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

  19. MOONS: the Multi-Object Optical and Near-infrared Spectrograph for the VLT

    NARCIS (Netherlands)

    Cirasuolo, M.; Afonso, J.; Carollo, M.; Flores, H.; Maiolino, R.; Oliva, E.; Paltani, S.; Vanzi, Leonardo; Evans, Christopher; Abreu, M.; Atkinson, David; Babusiaux, C.; Beard, Steven; Bauer, F.; Bellazzini, M.; Bender, Ralf; Best, P.; Bezawada, N.; Bonifacio, P.; Bragaglia, A.; Bryson, I.; Busher, D.; Cabral, A.; Caputi, K.; Centrone, M.; Chemla, F.; Cimatti, A.; Cioni, M.-R.; Clementini, G.; Coelho, J.; Crnojevic, D.; Daddi, E.; Dunlop, J.; Eales, S.; Feltzing, S.; Ferguson, A.; Fisher, M.; Fontana, A.; Fynbo, J.; Garilli, B.; Gilmore, G.; Glauser, A.; Guinouard, I.; Hammer, F.; Hastings, P.; Hess, A.; Ivison, R.; Jagourel, P.; Jarvis, M.; Kaper, L.; Kauffman, G.; Kitching, A. T.; Lawrence, A.; Lee, D.; Lemasle, B.; Licausi, G.; Lilly, S.; Lorenzetti, D.; Lunney, D.; Maiolino, R.; Mannucci, F.; McLure, R.; Minniti, D.; Montgomery, D.; Muschielok, B.; Nandra, K.; Navarro, R.; Norberg, P.; Oliver, S.; Origlia, L.; Padilla, N.; Peacock, J.; Pedichini, F.; Peng, J.; Pentericci, L.; Pragt, J.; Puech, M.; Randich, S.; Rees, P.; Renzini, A.; Ryde, N.; Rodrigues, M.; Roseboom, I.; Royer, F.; Saglia, R.; Sanchez, A.; Schiavon, R.; Schnetler, H.; Sobral, D.; Speziali, R.; Sun, D.; Stuik, R.; Taylor, A.; Taylor, W.; Todd, S.; Tolstoy, E.; Torres, M.; Tosi, M.; Vanzella, E.; Venema, L.; Vitali, F.; Wegner, M.; Wells, M.; Wild, V.; Wright, G.; Zamorani, G.; Zoccali, M.

    2014-01-01

    MOONS is a new Multi-Object Optical and Near-infrared Spectrograph selected by ESO as a third generation instrument for the Very Large Telescope (VLT). The grasp of the large collecting area offered by the VLT (8.2m diameter), combined with the large multiplex and wavelength coverage (optical to

  20. STELLAR POPULATIONS IN MEDIUM REDSHIFT CLUSTERS .2. OPTICAL-INFRARED PHOTOMETRY AND SPECTRA

    NARCIS (Netherlands)

    PICKLES, AJ; VANDERKRUIT, PC

    1991-01-01

    We present optical and infrared photometry (BV RI, J H K) and spectra of galaxies in 6 medium redshift clusters covering the redshift range 0.19 less-than-or-equal-to z less-than-or-equal-to 0.4. The array photometry is used to note the radial distribution of the cluster galaxies with optical and

  1. 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.

  2. 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.

  3. 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.

  4. Precise Prediction of Optical Performance for Near Infrared Instrument Using Adaptive Fitting Line

    OpenAIRE

    Kyeongyeon Ko; Jeong-Yeol Han; Jakyoung Nah; Heeyoung Oh; In-Soo Yuk; Chan Park; Moo-Young Chun; Jae Sok Oh; Kang-Min Kim; Hanshin Lee; Ueejeong Jeong; Daniel T. Jaffe

    2013-01-01

    Infrared optical systems are operated at low temperature and vacuum (LT-V) condition, whereas the assembly and alignment are performed at room temperature and non-vacuum (RT-NV) condition. The differences in temperature and pressure between assembly/alignment environments and operation environment change the physical characteristics of optical and opto-mechanical parts (e.g., thickness, height, length, curvature, and refractive index), and the resultant optical performance changes...

  5. Ultraviolet, optical, and infrared observations of the intermediate polar TV Columbae

    Science.gov (United States)

    Mateo, M.; Szkody, P.; Hutchings, J.

    1985-01-01

    Forty-three IUE spectra of the X-ray discovered, triply periodic cataclysmic variable, TV Col are examined. The results show that the UV flux varies with the four-day period discovered by Motch in 1981. By fitting continuum models to the UV and optical fluxes, it is inferred that this modulation corresponds to the periodic heating of a normally 9000 K source within the binary system due to reprocessing of beamed X-ray and (possibly) EUV radiation from the vicinity of the degenerate star. The observed flux from this heated source is consistent with its origin at either the disk hot spot or the secondary star. Phasing arguments, however, favor the identification of the latter as the primary reprocessing site in the system. The infrared observations are not consistent with the model proposed by Watts et al. in 1982 and imply that the four-day period does not correspond to the orbital period of the binary.

  6. Development of a 2-Channel Embedded Infrared Fiber-Optic Temperature Sensor Using Silver Halide Optical Fibers

    Directory of Open Access Journals (Sweden)

    Bongsoo Lee

    2011-10-01

    Full Text Available A 2-channel embedded infrared fiber-optic temperature sensor was fabricated using two identical silver halide optical fibers for accurate thermometry without complicated calibration processes. In this study, we measured the output voltages of signal and reference probes according to temperature variation over a temperature range from 25 to 225 °C. To decide the temperature of the water, the difference between the amounts of infrared radiation emitted from the two temperature sensing probes was measured. The response time and the reproducibility of the fiber-optic temperature sensor were also obtained. Thermometry with the proposed sensor is immune to changes if parameters such as offset voltage, ambient temperature, and emissivity of any warm object. In particular, the temperature sensing probe with silver halide optical fibers can withstand a high temperature/pressure and water-chemistry environment. It is expected that the proposed sensor can be further developed to accurately monitor temperature in harsh environments.

  7. Infrared landmine detection and thermal model analysis

    NARCIS (Netherlands)

    Schwering, P.B.W.; Kokonozi, A.; Carter, L.J.; Lensen, H.A.; Franken, E.M.

    2001-01-01

    Infrared imagers are capable of the detection of surface laid mines. Several sensor fused land mine detection systems make use of metal detectors, ground penetrating radar and infrared imagers. Infrared detection systems are sensitive to apparent temperature contrasts and their detection

  8. Retrieval of Saharan desert dust optical depth from thermal infrared measurements by IASI

    Science.gov (United States)

    Vandenbussche, S.; Kochenova, S.; Vandaele, A.-C.; Kumps, N.; De Mazière, M.

    2012-04-01

    Aerosols are a major actor in the climate system. They are responsible for climate forcing by both direct (by emission, absorption and scattering) and indirect effects (for example, by altering cloud microphysics). A better knowledge of aerosol optical properties, of the atmospheric aerosol load and of aerosol sources and sinks may therefore significantly improve the modeling of climate changes. Aerosol optical depth and other properties are retrieved on an operational basis from daytime measurements in the visible and near infrared spectral range by a number of instruments, like the satellite instruments MODIS, CALIOP, POLDER, MISR and ground-based sunphotometers. Aerosol retrievals from day and night measurements at thermal infrared (TIR) wavelengths (for example, from SEVIRI, AIRS and IASI satellite instruments) are less common, but they receive growing interest in more recent years. Among those TIR measuring instruments, IASI on METOP has one major advantage for aerosol retrievals: its large continuous spectral coverage, allowing to better capture the broadband signature of aerosols. Furthermore, IASI has a high spectral resolution (0.5cm-1 after apodization) which allows retrieving a large number of trace gases at the same time, it will nominally be in orbit for 15 years and offers a quasi global Earth coverage twice a day. Here we will show recently obtained results of desert aerosol properties (concentration, altitude, optical depth) retrieved from IASI TIR measurements, using the ASIMUT software (BIRA-IASB, Belgium) linked to (V)LIDORT (R. Spurr, RTsolutions Inc, US) and to SPHER (M. Mishchenko, NASA GISS, USA). In particular, we will address the case of Saharan desert dust storms, which are a major source of desert dust particles in the atmosphere. Those storms frequently transport sand to Europe, Western Asia or even South America. We will show some test-case comparisons between our retrievals and measurements from other instruments like those listed

  9. 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.

  10. Near-infrared optical imaging of human brain based on the semi-3D reconstruction algorithm

    Science.gov (United States)

    Liu, Ming; Meng, Wei; Qin, Zhuanping; Zhou, Xiaoqing; Zhao, Huijuan; Gao, Feng

    2013-03-01

    In the non-invasive brain imaging with near-infrared light, precise head model is of great significance to the forward model and the image reconstruction. To deal with the individual difference of human head tissues and the problem of the irregular curvature, in this paper, we extracted head structure with Mimics software from the MRI image of a volunteer. This scheme makes it possible to assign the optical parameters to every layer of the head tissues reasonably and solve the diffusion equation with the finite-element analysis. During the solution of the inverse problem, a semi-3D reconstruction algorithm is adopted to trade off the computation cost and accuracy between the full 3-D and the 2-D reconstructions. In this scheme, the changes in the optical properties of the inclusions are assumed either axially invariable or confined to the imaging plane, while the 3-D nature of the photon migration is still retained. This therefore leads to a 2-D inverse issue with the matched 3-D forward model. Simulation results show that comparing to the 3-D reconstruction algorithm, the Semi-3D reconstruction algorithm cut 27% the calculation time consumption.

  11. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Oliver; Stark, Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it.

  12. Far infrared submillimeter spectroscopy with an optically pumped laser

    International Nuclear Information System (INIS)

    Bean, B.L.; Perkowitz, S.

    1979-01-01

    The pumped laser theory of operation is discussed along with the availability of submillimeter lines and media. Spectroscopic systems are described including a pump laser, far infrared laser, and system electronics for laser stabilization and FIR detection. Emphasis is placed on system performance and spectroscopic applications

  13. Spectrophotometry in the far infrared. Optical and Hertzian processes

    International Nuclear Information System (INIS)

    Coste, Andre

    1968-01-01

    After a general study of problems related to instrumental spectroscopy in the far infrared, this research thesis examines the theory and technique of construction of slit spectrometers. The author then studied the possibilities to increase brightness and resolution using Fabry-Perot interferometers, and the Fourier transform interferential spectrometry, and finally addressed methods used with micro-waves

  14. Non-Linear Optical Studies of IR Materials with Infrared Femtosecond Laser

    Science.gov (United States)

    2016-12-15

    AFRL-RD-PS- AFRL-RD-PS- TR-2016-0055 TR-2016-0055 NON-LINEAR OPTICAL STUDIES OF IR MATERIALS WITH INFRARED FEMTOSECOND LASER Enam...TITLE AND SUBTITLE Non-Linear Optical Studies of IR Materials with Infrared Femtosecond Laser 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9451-14-1...femtosecond mid- IR (MIR) pulses from 2 - 4 micron wavelength at a 1 kHz repetition rate were used to explore nonlinear effects into various MIR materials

  15. Investigation of optical/infrared sensor techniques for application satellites

    Science.gov (United States)

    Kaufman, I.

    1972-01-01

    A method of scanning an optical sensor array by acoustic surface waves is discussed. Data cover detailed computer based analysis of the operation of a multielement acoustic surface-wave-scanned optical sensor, the development of design and operation techniques that were used to show the feasibility of an integrated array to design several such arrays, and experimental verification of a number of the calculations with discrete sensor devices.

  16. Recommended conceptual optical system design for China's Large Optical-infrared Telescope (LOT).

    Science.gov (United States)

    Ma, Donglin

    2018-01-08

    Recently, China is planning to construct a new large optical-infrared telescope (LOT), in which the aperture of the primary mirror is as large as 12m. China's LOT is a general-purpose telescope, which is aimed to work with multiple scientific instruments such as spectrographs. Based on the requirements of LOT telescope, we have compared the performance of Ritchey-Chrétien (RC) design and Aplanatic-Gregorian (AG) design from the perspective of scientific performance and construction cost. By taking the primary focal ratio, Nasmyth focal ratio, and telescope's site condition into consideration, we finally recommend a RC f/1.6 design configuration for LOT's Nasmyth telescope system. Unlike the general identical configuration, we choose a non-identical configuration for the telescope system which has a shorter Cassegrain focal ratio compared to the designed Nasmyth focal ratio. The non-identical design can allow for a shorter back focal distance and therefore a shorter telescope fork to guarantee the gravitational stability of the whole telescope structure, as well as relatively lower construction cost. Detailed analysis for the feasibility of our recommended design is provided in this paper.

  17. Acoustic Models of Optical Mirrors

    Science.gov (United States)

    Mayer, V. V.; Varaksina, E. I.

    2014-01-01

    Students form a more exact idea of the action of optical mirrors if they can observe the wave field being formed during reflection. For this purpose it is possible to organize model experiments with flexural waves propagating in thin elastic plates. The direct and round edges of the plates are used as models of plane, convex and concave mirrors.…

  18. 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)

  19. An early-time infrared and optical study of the type Ia supernovae SN 1994D and 1991T

    NARCIS (Netherlands)

    Meikle, WPS; Cumming, RJ; Geballe, TR; Lewis, [No Value; Walton, NA; Balcells, M; Cimatti, A; Croom, SM; Dhillon, VS; Economou, F; Jenkins, CR; Knapen, JH; Lucey, [No Value; Meadows, VS; Morris, PW; PerezFournon, [No Value; Shanks, T; Smith, LJ; Tanvir, NR; Veilleux, S; Vilchez, J; Wall, JV

    1996-01-01

    We present early-time infrared (IR) and optical spectroscopy, and optical photometry, of the Type Ia supernova 1994D. These observations provide the most complete optical-IR spectral coverage ever achieved for a Type Ia at this phase. Optical and IR spectra were obtained as early as 9 d before

  20. Seeing in a Different Light--Using an Infrared Camera to Teach Heat Transfer and Optical Phenomena

    Science.gov (United States)

    Wong, Choun Pei; Subramaniam, R.

    2018-01-01

    The infrared camera is a useful tool in physics education to 'see' in the infrared. In this paper, we describe four simple experiments that focus on phenomena related to heat transfer and optics that are encountered at undergraduate physics level using an infrared camera, and discuss the strengths and limitations of this tool for such purposes.

  1. Seeing in a different light—using an infrared camera to teach heat transfer and optical phenomena

    Science.gov (United States)

    Pei Wong, Choun; Subramaniam, R.

    2018-05-01

    The infrared camera is a useful tool in physics education to ‘see’ in the infrared. In this paper, we describe four simple experiments that focus on phenomena related to heat transfer and optics that are encountered at undergraduate physics level using an infrared camera, and discuss the strengths and limitations of this tool for such purposes.

  2. Precise Prediction of Optical Performance for Near Infrared Instrument Using Adaptive Fitting Line

    Directory of Open Access Journals (Sweden)

    Kyeongyeon Ko

    2013-12-01

    Full Text Available Infrared optical systems are operated at low temperature and vacuum (LT-V condition, whereas the assembly and alignment are performed at room temperature and non-vacuum (RT-NV condition. The differences in temperature and pressure between assembly/alignment environments and operation environment change the physical characteristics of optical and opto-mechanical parts (e.g., thickness, height, length, curvature, and refractive index, and the resultant optical performance changes accordingly. In this study, using input relay optics (IO, among the components of the Immersion GRating INfrared Spectrograph (IGRINS which is an infrared spectrograph, a simulation based on the physical information of this optical system and an actual experiment were performed; and optical performances in the RT-NV, RT-V, and LT-V environments were predicted with an accuracy of 0.014±0.007 λ rms WFE, by developing an adaptive fitting line. The developed adaptive fitting line can quantitatively control assembly and alignment processes below λ/70 rms WFE. Therefore, it is expected that the subsequent processes of assembly, alignment, and performance analysis could not be repeated.

  3. Precise Prediction of Optical Performance for Near Infrared Instrument Using Adaptive Fitting Line

    Science.gov (United States)

    Ko, Kyeongyeon; Han, Jeong-Yeol; Nah, Jakyoung; Oh, Heeyoung; Yuk, In-Soo; Park, Chan; Chun, Moo-Young; Oh, Jae Sok; Kim, Kang-Min; Lee, Hanshin; Jeong, Ueejeong; Jaffe, Daniel T.

    2013-12-01

    Infrared optical systems are operated at low temperature and vacuum (LT-V) condition, whereas the assembly and alignment are performed at room temperature and non-vacuum (RT-NV) condition. The differences in temperature and pressure between assembly/alignment environments and operation environment change the physical characteristics of optical and opto-mechanical parts (e.g., thickness, height, length, curvature, and refractive index), and the resultant optical performance changes accordingly. In this study, using input relay optics (IO), among the components of the Immersion GRating INfrared Spectrograph (IGRINS) which is an infrared spectrograph, a simulation based on the physical information of this optical system and an actual experiment were performed; and optical performances in the RT-NV, RT-V, and LT-V environments were predicted with an accuracy of 0.014±0.007 λ rms WFE, by developing an adaptive fitting line. The developed adaptive fitting line can quantitatively control assembly and alignment processes below λ/70 rms WFE. Therefore, it is expected that the subsequent processes of assembly, alignment, and performance analysis could not be repeated.

  4. 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.

  5. Second NATO Workshop on Passive Infrared Optical Materials and Coatings

    Science.gov (United States)

    1987-12-01

    bias voltage, deposition technique ( PACVD ). This new iq the most important parameter which coating is the forerunner of a family of strongly influences...the optical and me- superdurable multilayer coatings which chanical properties of the films. The can be prepared through the use of PACVD . typf of

  6. 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

  7. 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, E.; Vanzi, L.; Abreu, M.; Atad-Ettedgui, E.; Babusiaux, C.; Bauer, F.E.; Best, P.; Bezawada, N.; Bryson, I.R.; Cabral, A.; Caputi, K.; Centrone, M.; Chemla, F.; Cimatti, A.; Cioni, M.R.; Clementini, G.; Coelho, J.; Daddi, E.; Dunlop, J.S.; Feltzing, S.; Ferguson, A.; Flores, H.; Fontana, A.; Fynbo, J.; Garilli, B.; Glauser, A.M.; Guinouard, I.; Hammer, J.-F.; Hastings, P.R.; Hess, H.-J.; Ivison, R.J.; Jagourel, P.; Jarvis, M.; 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.

    2012-01-01

    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

  8. The ultraviolet, optical, and infrared properties of Sloan Digital Sky Survey sources detected by GALEX

    NARCIS (Netherlands)

    Agueros, MA; Ivezic, Z; Covey, KR; Obric, M; Hao, L; Walkowicz, LM; West, AA; Vanden Berk, DE; Lupton, RH; Knapp, GR; Gunn, JE; Richards, GT; Bochanski, J; Brooks, A; Claire, M; Haggard, D; Kaib, N; Kimball, A; Gogarten, SM; Seth, A; Solontoi, M

    We discuss the ultraviolet, optical, and infrared properties of the Sloan Digital Sky Survey (SDSS) sources detected by the Galaxy Evolution Explorer ( GALEX) as part of its All-sky Imaging Survey Early Release Observations. Virtually all (> 99%) the GALEX sources in the overlap region are detected

  9. 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

  10. An improved thin film approximation to accurately determine the optical conductivity of graphene from infrared transmittance

    NARCIS (Netherlands)

    Weber, J. W.; Bol, A. A.; M. C. M. van de Sanden,

    2014-01-01

    This work presents an improved thin film approximation to extract the optical conductivity from infrared transmittance in a simple yet accurate way. This approximation takes into account the incoherent reflections from the backside of the substrate. These reflections are shown to have a significant

  11. MOONS: The Multi-Object Optical and Near-infrared Spectrograph

    NARCIS (Netherlands)

    Cirasuolo, M.; Afonso, J.; Bender, R.; Bonifacio, P.; Evans, C.; Kaper, L.; Oliva, E.; Vanzi, L.

    2011-01-01

    MOONS (Multi-Object Optical and Near-infrared Spectrograph) is a large field (500 square arcminutes), multi-object (500 object + 500 sky fibres) instrument with spectral resolution of 5000 and 20000 proposed for the VLT Nasmyth focus. The science case for MOONS, covering Galactic structure and

  12. The optical design of a far infrared imaging FTS for SPICA

    NARCIS (Netherlands)

    Pastor, Carmen; Zuluaga, Pablo; Jellema, Willem; González Fernández, Luis Miguel; Belenguer, Tomas; Torres Redondo, Josefina; Kooijman, Peter Paul; Najarro, Francisco; Eggens, Martin; Roelfsema, Peter; Nakagawa, Takao

    This paper describes the optical design of the far infrared imaging spectrometer for the JAXA's SPICA mission. The SAFARI instrument, is a cryogenic imaging Fourier transform spectrometer (iFTS), designed to perform backgroundlimited spectroscopic and photometric imaging in the band 34-210 μm. The

  13. Electrical and optical properties of multiple quantum well structures and their applications to infrared detectors

    International Nuclear Information System (INIS)

    Helgesen, P.

    1992-04-01

    In this work the author investigate the subband nature of multiple quantum well structures by photoconductance spectroscopy, optical absorption measurements and tunneling experiments. Both interband and intraband transitions have been studied. The work is aimed at making an infrared detector using wide band gap semiconductors. 14 refs

  14. Standardizing Type Ia supernovae optical brightness using near-infrared rebrightening time

    Science.gov (United States)

    Shariff, H.; Dhawan, S.; Jiao, X.; Leibundgut, B.; Trotta, R.; van Dyk, D. A.

    2016-12-01

    Accurate standardization of Type Ia supernovae (SNIa) is instrumental to the usage of SNIa as distance indicators. We analyse a homogeneous sample of 22 low-z SNIa, observed by the Carnegie Supernova Project in the optical and near-infrared (NIR). We study the time of the second peak in the J band, t2, as an alternative standardization parameter of SNIa peak optical brightness, as measured by the standard SALT2 parameter mB. We use BAHAMAS, a Bayesian hierarchical model for SNIa cosmology, to estimate the residual scatter in the Hubble diagram. We find that in the absence of a colour correction, t2 is a better standardization parameter compared to stretch: t2 has a 1σ posterior interval for the Hubble residual scatter of σΔμ = {0.250, 0.257} mag, compared to σΔμ = {0.280, 0.287} mag when stretch (x1) alone is used. We demonstrate that when employed together with a colour correction, t2 and stretch lead to similar residual scatter. Using colour, stretch and t2 jointly as standardization parameters does not result in any further reduction in scatter, suggesting that t2 carries redundant information with respect to stretch and colour. With a much larger SNIa NIR sample at higher redshift in the future, t2 could be a useful quantity to perform robustness checks of the standardization procedure.

  15. Ultrafast optical switching of infrared plasmon polaritons in high-mobility graphene

    Science.gov (United States)

    Ni, G. X.; Wang, L.; Goldflam, M. D.; Wagner, M.; Fei, Z.; McLeod, A. S.; Liu, M. K.; Keilmann, F.; Özyilmaz, B.; Castro Neto, A. H.; Hone, J.; Fogler, M. M.; Basov, D. N.

    2016-04-01

    The success of metal-based plasmonics for manipulating light at the nanoscale has been empowered by imaginative designs and advanced nano-fabrication. However, the fundamental optical and electronic properties of elemental metals, the prevailing plasmonic media, are difficult to alter using external stimuli. This limitation is particularly restrictive in applications that require modification of the plasmonic response at sub-picosecond timescales. This handicap has prompted the search for alternative plasmonic media, with graphene emerging as one of the most capable candidates for infrared wavelengths. Here we visualize and elucidate the properties of non-equilibrium photo-induced plasmons in a high-mobility graphene monolayer. We activate plasmons with femtosecond optical pulses in a specimen of graphene that otherwise lacks infrared plasmonic response at equilibrium. In combination with static nano-imaging results on plasmon propagation, our infrared pump-probe nano-spectroscopy investigation reveals new aspects of carrier relaxation in heterostructures based on high-purity graphene.

  16. Optical Excisor Modeling

    Science.gov (United States)

    1989-09-01

    The model is a set of equations which may be solved manually or by means of a computer to determine the behavior of the system under a specific set of...PMW 144-2, CDR Frentzel) Washington DC 20363-5103 7. Comando de Operaciones Navales 2 Edificio Libertad Comodoro Py 2055 Buenos Aires (1104) Reptiblica

  17. 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

  18. Collision models in quantum optics

    Science.gov (United States)

    Ciccarello, Francesco

    2017-12-01

    Quantum collision models (CMs) provide advantageous case studies for investigating major issues in open quantum systems theory, and especially quantum non-Markovianity. After reviewing their general definition and distinctive features, we illustrate the emergence of a CM in a familiar quantum optics scenario. This task is carried out by highlighting the close connection between the well-known input-output formalism and CMs. Within this quantum optics framework, usual assumptions in the CMs' literature - such as considering a bath of noninteracting yet initially correlated ancillas - have a clear physical origin.

  19. Optical Properties of Astronomical Silicates with Infrared Techniques (OPASI-T)

    Science.gov (United States)

    Rinehart, Stephen

    2010-01-01

    Astronomical dust is observed in a variety of astrophysical environments and plays an important role in radiative processes and chemical evolution in the galaxy. Depending upon the environment, dust can be either carbon-rich or oxygen-rich (silicate grains). Both astronomical observations and ground-based data show that the optical properties of silicates can change dramatically with the crystallinity of the material, and recent laboratory research provides evidence that the optical properties of silicate dust vary as a function of temperature as well. Therefore, correct interpretation of a vast array of astronomical data relies on the understanding of the properties of silicate dust as functions of wavelength, temperature, and crystallinity. The OPASI-T (Optical Properties of Astronomical Silicates with Infrared Techniques) project addresses the need for high quality optical characterization of metal-enriched silicate condensates using a variety of techniques. A combination of both new and established experiments are used to measure the extinction, reflection, and emission properties of amorphous silicates across the infrared (near infrared to millimeter wavelengths), providing a comprehensive data set characterizing the optical parameters of dust samples. We present room temperature measurements and the experimental apparatus to be used to investigate and characterize additional metal-silicate materials.

  20. Spectroscopic infrared scanning near-field optical microscopy (IR-SNOM)

    International Nuclear Information System (INIS)

    Vobornik, D.; Margaritondo, G.; Sanghera, J.S.; Thielen, P.; Aggarwal, I.D.; Ivanov, B.; Tolk, N.H.; Manni, V.; Grimaldi, S.; Lisi, A.; Rieti, S.; Piston, D.W.; Generosi, R.; Luce, M.; Perfetti, P.; Cricenti, A.

    2005-01-01

    Scanning near-field optical microscopy (SNOM or NSOM) is the technique with the highest lateral optical resolution available today, while infrared (IR) spectroscopy has a high chemical specificity. Combining SNOM with a tunable IR source produces a unique tool, IR-SNOM, capable of imaging distributions of chemical species with a 100 nm spatial resolution. We present in this paper boron nitride (BN) thin film images, where IR-SNOM shows the distribution of hexagonal and cubic phases within the sample. Exciting potential applications in biophysics and medical sciences are illustrated with SNOM images of the distribution of different chemical species within cells. We present in this article images with resolutions of the order of λ/60 with SNOM working with infrared light. With our SNOM setup, we routinely get optical resolutions between 50 and 150 nm, regardless of the wavelength of the light used to illuminate the sample

  1. 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.

  2. Optical design of a compact near-infrared multispecies gas sensor

    Science.gov (United States)

    Larson, Joshua; Toor, Fatima

    In this work we present the design of a compact and cost effective near infrared (NIR) gas sensor system that can detect nitrous oxide (NOx) , ammonia (NH3) , and methane (CH4) simultaneously. These three gases were chosen as they are environmental pollutants and their monitoring is especially important in agricultural states like Iowa. As a first step in our design process, we have developed a Matlab model based on Beer-Lambert's law to generate sample sensor data for each of the gases at different concentrations. The data measured from the sensor system will be as a function of time instead of wavelength, so we performed Fourier Transform analysis on the sensor data to convert it to voltage versus time. The simulated sensor data will enable to design software algorithms to separate the absorption signals for each of the three gases. As a second step, we have developed a lab-based sensor system comprising of three components: (i) a NIR lead sulfide (PbS) photodiode, (ii) an LED that emits 1900 nm to 2600 nm, and (iii) an optical cavity where the gases are introduced. We are designing the optical cavity using ray optics COMSOL finite element method simulator using the principles of a compact chaotic cavity that will allow the LED light to have a path length of greater than 100 m within the cavity, enabling high sensitivity gas detection. Our end goal is to have an autonomous drone mounted device that is simple and inexpensive to use. We plan to license this technology to agricultural equipment manufacturers.

  3. 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.

  4. Diagnosis of colorectal cancer by near-infrared optical fiber spectroscopy and random forest

    Science.gov (United States)

    Chen, Hui; Lin, Zan; Wu, Hegang; Wang, Li; Wu, Tong; Tan, Chao

    2015-01-01

    Near-infrared (NIR) spectroscopy has such advantages as being noninvasive, fast, relatively inexpensive, and no risk of ionizing radiation. Differences in the NIR signals can reflect many physiological changes, which are in turn associated with such factors as vascularization, cellularity, oxygen consumption, or remodeling. NIR spectral differences between colorectal cancer and healthy tissues were investigated. A Fourier transform NIR spectroscopy instrument equipped with a fiber-optic probe was used to mimic in situ clinical measurements. A total of 186 spectra were collected and then underwent the preprocessing of standard normalize variate (SNV) for removing unwanted background variances. All the specimen and spots used for spectral collection were confirmed staining and examination by an experienced pathologist so as to ensure the representative of the pathology. Principal component analysis (PCA) was used to uncover the possible clustering. Several methods including random forest (RF), partial least squares-discriminant analysis (PLSDA), K-nearest neighbor and classification and regression tree (CART) were used to extract spectral features and to construct the diagnostic models. By comparison, it reveals that, even if no obvious difference of misclassified ratio (MCR) was observed between these models, RF is preferable since it is quicker, more convenient and insensitive to over-fitting. The results indicate that NIR spectroscopy coupled with RF model can serve as a potential tool for discriminating the colorectal cancer tissues from normal ones.

  5. Self-calibration in optical/infrared interferometry

    Science.gov (United States)

    Millour, Florentin; Dalla Vedova, Gaetan

    2015-08-01

    Optical interferometry produces nowadays images of the observed stars. However, the image quality of the current facilities (VLTI, CHARA) is impaired by the lack of phases measurements. We will describe here a method used to improve the image reconstruction that takes profit of a badly used observable: the wavelength differential phase. This phase shares some properties with the interferometric phase. That method is parent to the self-calibration which was developed in the 80's for radio astronomy to get rid of calibratioon artifacts, and produces a significant improvement on image quality over the current available methods.

  6. LOUISA - A lunar optical-ultraviolet-infrared synthesis array

    Science.gov (United States)

    Burns, Jack O.; Duric, Nebojsa; Taylor, Jeffrey; Johnson, Stewart

    1990-01-01

    The emplacement of an optical wavelength interferometric array on the lunar surface is proposed. It will consist of 42 1.5-m mirrors distributed in two concentric circles with an outer diameter of 10-km. The resolution of LOUISA will be 10 microarcsec at a wavelength of 0.5 microns - a factor of 4100 times better than the HST. With such a resolution, astronomers will be able to image earthlike extrasolar planets, active regions on other stars, and collimated outflows from young stellar objects and the nuclei of active galaxies.

  7. Transrectal Near-Infrared Optical Tomography for Prostate Imaging

    Science.gov (United States)

    2011-03-01

    initial exam with an overdose of pentobarbital sodium. A com- plete necropsy was performed and the prostate and peri-prostatic structures were submitted... Raton , FL: CRC Press, 2003. [32] Schmitz, C. H., et al., “Instrumentation for fast functional optical tomography,” Rev. Sci. Instr. 73(2) (2002): 429...domain techniques,” in T. Vo-Dinh (ed.), Biomedical Photonics Handbook, 22–22–17<AQ: page span correct?>, Boca Raton , FL: CRC Press, 2003. [38] Piao, D

  8. Modeling of the shape of infrared stimulated luminescence signals in feldspars

    DEFF Research Database (Denmark)

    Pagonis, Vasilis; Jain, Mayank; Murray, Andrew S.

    2012-01-01

    This paper presents a new empirical model describing infrared (IR) stimulation phenomena in feldspars. In the model electrons from the ground state of an electron trap are raised by infrared optical stimulation to the excited state, and subsequently recombine with a nearest-neighbor hole via...... a tunneling process, leading to the emission of light. The model explains the experimentally observed existence of two distinct time intervals in the luminescence intensity; a rapid initial decay of the signal followed by a much slower gradual decay of the signal with time.The initial fast decay region...... corresponds to a fast rate of recombination processes taking place along the infrared stimulated luminescence (IRSL) curves. The subsequent decay of the simulated IRSL signal is characterized by a much slower recombination rate, which can be described by a power-law type of equation.Several simulations...

  9. Simulation of the fixed optical path difference of near infrared wind imaging interferometer

    Science.gov (United States)

    Rong, Piao; Zhang, Chunmin; Yan, Tingyu; Liu, Dongdong; Li, Yanfen

    2017-02-01

    As an important part of the earth, atmosphere plays a vital role in filtering the solar radiation, adjusting the temperature and organizing the water circulation and keeping human survival. The passive atmospheric wind measurement is based on the imaging interferometer technology and Doppler effect of electromagnetic wave. By using the wind imaging interferometer to get four interferograms of airglow emission lines, the atmospheric wind velocity, temperature, pressure and emission rate can be derived. Exploring the multi-functional and integrated innovation of detecting wind temperature, wind velocity and trace gas has become a research focus in the field. In the present paper, the impact factors of the fixed optical path difference(OPD) of near infrared wind imaging interferometer(NIWII) are analyzed and the optimum value of the fixed optical path difference is simulated, yielding the optimal results of the fixed optical path difference is 20 cm in near infrared wave band (the O2(a1Δg) airglow emission at 1.27 microns). This study aims at providing theoretical basis and technical support for the detection of stratosphere near infrared wind field and giving guidance for the design and development of near infrared wind imaging interferometer.

  10. Embedded infrared fiber-optic sensor for thermometry in a high temperature/pressure environment

    Science.gov (United States)

    Yoo, Wook Jae; Jang, Kyoung Won; Moon, Jinsoo; Han, Ki-Tek; Jeon, Dayeong; Lee, Bongsoo; Park, Byung Gi

    2012-11-01

    In this study, we developed an embedded infrared fiber-optic temperature sensor for thermometry in high temperature/pressure and water-chemistry environments by using two identical silver-halide optical fibers. The performance of the fabricated temperature sensor was assessed in an autoclave filled with an aqueous coolant solution containing boric acid and lithium hydroxide. We carried out real-time monitoring of the infrared radiation emitted from the signal and reference probes for various temperatures over a temperature range from 95 to 225 °C. In order to decide the temperature of the synthetic coolant solution, we measured the difference between the infrared radiation emitted from the two temperature-sensing probes. Thermometry with the proposed sensor is immune to any changes in the physical conditions and the emissivity of the heat source. From the experimental results, the embedded infrared fiber-optic temperature sensor can withstand, and normally operate in a high temperature/pressure test loop system corresponding to the coolant system used for nuclear power plant simulation. We expect that the proposed sensor can be developed to accurately monitor temperatures in harsh environments.

  11. 3D Temperature Distribution Model Based on Thermal Infrared Image

    Directory of Open Access Journals (Sweden)

    Tong Jia

    2017-01-01

    Full Text Available This paper aims to study the construction of 3D temperature distribution reconstruction system based on binocular vision technology. Initially, a traditional calibration method cannot be directly used, because the thermal infrared camera is only sensitive to temperature. Therefore, the thermal infrared camera is calibrated separately. Belief propagation algorithm is also investigated and its smooth model is improved in terms of stereo matching to optimize mismatching rate. Finally, the 3D temperature distribution model is built based on the matching of 3D point cloud and 2D thermal infrared information. Experimental results show that the method can accurately construct the 3D temperature distribution model and has strong robustness.

  12. Numerical study of optical-cavity misalignment effects for a far-infrared FEL

    CERN Document Server

    Sobajima, M; Yokoyama, M; Oda, F; Kawai, M; Miura, H

    2002-01-01

    A far-infrared FEL will be newly installed in the IR FEL Research Center at the Science University of Tokyo (FEL-SUT) in 2002. In this study, optical cavity misalignment effects for the far-infrared FEL are researched by using the simulation code that has been developed at Kawasaki Heavy Industries, Ltd. Results show not only cavity losses but also the gain reduction by the tilt and the offset of the mirror and the offset of the electron beam. The required alignment accuracy is also obtained in this study.

  13. Optical and Infrared Variability of UX Ori-Type Stars

    Science.gov (United States)

    Rostopchina-Shakhovskaya, A.; Grinin, V.; Shenavrin, V.; Shakhovskoy, D.; Demidova, T.; Belan, S.

    2017-06-01

    Analyzing data of the long-term simultaneous NIR and optical photometry of five UX Ori type stars we estimate intrinsic NIR luminosity of their circumstellar disks in I, J, H bands. The H to J flux ratio for WW Vul, CQ Tau, RR Tau, UX Ori is consistent with 1500 K blackbody radiation, a typical temperature of dust sublimation. For the same stars except RR Tau, J to I flux ratio suggests much hotter source with T>2000 K, probably the inner dust-free disk. In case of RR Tau this value is close to 1500 K, implying sublimating dust as a main contributor in all three bands. The SED for BF Ori differs from the rest of objects, with flux density peaking in J band, probably due to an unresolved cool companion.

  14. Practical optical interferometry imaging at visible and infrared wavelengths

    CERN Document Server

    Buscher, David F

    2015-01-01

    Optical interferometry is a powerful technique to make images on angular scales hundreds of times smaller than is possible with the largest telescopes. This concise guide provides an introduction to the technique for graduate students and researchers who want to make interferometric observations and acts as a reference for technologists building new instruments. Starting from the principles of interference, the author covers the core concepts of interferometry, showing how the effects of the Earth's atmosphere can be overcome using closure phase, and the complete process of making an observation, from planning to image reconstruction. This rigorous approach emphasizes the use of rules-of-thumb for important parameters such as the signal-to-noise ratios, requirements for sampling the Fourier plane and predicting image quality. The handbook is supported by web resources, including the Python source code used to make many of the graphs, as well as an interferometry simulation framework, available at www.cambridg...

  15. Infrared and optical properties of the emission-line galaxies NGC 1386 and NGC 1365

    International Nuclear Information System (INIS)

    Phillips, M.M.; Frogel, J.A.

    1980-01-01

    We have obtained optical spectrophotometry and broad-band infrared data for the nucleus of the emission-line galaxy NGC 1386. These observations are discussed and compared with our own optical spectrophotometry as well as published optical and infrared measurements of the nucleus of the neighboring ''hot spot'' galaxy NGC 1365. Both galaxies show large infared excesses. The very high excitation emission-line spectrum of NGC 1386 is that of a type of 2 Seyfert, making this galaxy the closest known member of this class of objects. We find direct evidence for a significant early-type stellar population in the nucleus of NGC 1365, thus strengthening the previous conclusion that the nuclear emission lines of this galaxy are excited by the radiation of young, hot stars. In addition, we confirm the presence of weak [Ne V] and He II emission, which suggests that a nonthermal source of ionization may also be present. The nucleus of NGC 1365 is emitting a factor of 10 more energy in both the optical emission lines and the infrared than is that of NGC 1386. Finally, we point out the uncertainty in identification of NGC 1365 as an X-ray source in view of its proximity of a Seyfert 2, galaxy, several of which have now been shown to be strong X-ray emitters

  16. The neutron optical model potential

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1989-01-01

    The present status of optical model calculations of neutron scattering and interactions is reviewed, with special emphasis on more recent developments and the more promising lines of research. The use of dispersion relations to provide an extra constraint on the potential is discussed, together with their application to studies of the Fermi surface anomaly. The application of potential inversion techniques to determine the form of the potential is also considered. (author). 39 refs, figs

  17. Pinpointing the near-infrared location of Sgr A* by correcting optical distortion in the NACO imager

    Science.gov (United States)

    Plewa, P. M.; Gillessen, S.; Eisenhauer, F.; Ott, T.; Pfuhl, O.; George, E.; Dexter, J.; Habibi, M.; Genzel, R.; Reid, M. J.; Menten, K. M.

    2015-11-01

    Near-infrared observations of stellar orbits at the Galactic Center provide conclusive evidence for a massive black hole associated with the compact radio source Sgr A*. The astrometric reference frame for these observations is tied to a set of red giant stars, which are also detectable at radio wavelengths through SiO maser emission in their envelopes. We have improved the precision and long-term stability of this reference frame, in which Sgr A* is localized to within a factor 5 better than previously: ˜0.17 mas in position (in 2009) and ˜0.07 mas yr-1 in velocity. This improvement is the result of modelling and correcting optical distortion in the VLT/NACO imager to a submas level and including new infrared and radio measurements, which now both span more than a decade in time. A further improvement will follow future observations and facilitate the detection of relativistic orbital effects.

  18. Comparison of methods for transfer of calibration models in near-infared spectroscopy: a case study based on correcting path length differences using fiber-optic transmittance probes in in-line near-infrared spectroscopy.

    Science.gov (United States)

    Sahni, Narinder Singh; Isaksson, Tomas; Naes, Tormod

    2005-04-01

    This article addresses problems related to transfer of calibration models due to variations in distance between the transmittance fiber-optic probes. The data have been generated using a mixture design and measured at five different probe distances. A number of techniques reported in the literature have been compared. These include multiplicative scatter correction (MSC), path length correction (PLC), finite impulse response (FIR), orthogonal signal correction (OSC), piecewise direct standardization (PDS), and robust calibration. The quality of the predictions was expressed in terms of root mean square error of prediction (RMSEP). Robust calibration gave good calibration transfer results, while the other methods did not give acceptable results.

  19. Design of large zoom for visible and infrared optical system in hemisphere space

    Science.gov (United States)

    Xing, Yang-guang; Li, Lin; Zhang, Juan

    2018-01-01

    In the field of space optical, the application of advanced optical instruments for related target detection and identification has become an advanced technology in modern optics. In order to complete the task of search in wide field of view and detailed investigation in small field of view, it is inevitable to use the structure of the zoom system to achieve a better observation for important targets. The innovation of this paper lies in using the zoom optical system in space detection, which achieve firstly military needs of searched target in the large field of view and recognized target in the small field of view. At the same time, this paper also completes firstly the design of variable focus optical detection system in the range of hemisphere space, the zoom optical system is working in the range of visible and infrared wavelengths, the perspective angle reaches 360 ° and the zoom ratio of the visible system is up to 15. The visible system has a zoom range of 60-900 mm, a detection band of 0.48-0.70μm, and a F-number of 2.0 to 5.0. The infrared system has a zoom range of 150 900mm, a detection band of 8-12μm, and a F-number of 1.2 to 3.0. The MTF of the visible zoom system is above 0.4 at spatial frequency of 45 lp / mm, and the infrared zoom system is above 0.4 at spatial frequency of 11 lp / mm. The design results show that the system has a good image quality.

  20. Electrically controlled infrared optical transmission and reflection through metallic grating using NEMS technology

    Science.gov (United States)

    Yamaguchi, Kenzo; Fujii, Masamitsu

    2015-12-01

    The enhanced optical properties of metallic subwavelength gratings with very narrow slits have recently been extensively studied in the field of plasmonics. The optical transmission and reflection of such nanostructures, which act as nano-electro-mechanical systems (NEMS) actuators, can be electrically controlled by varying their geometrical parameters, giving them great flexibility for numerous applications in photonics, opto-electronics, and sensing. The previous challenges in controlling the optical properties were overcome by forming a metallic subwavelength grating with an NEMS actuator in mid-air, allowing the grating to be physically moved with the bias voltage. The device can shift the plasmon resonance wavelength with an electrical signal. The resonance wavelength for Wood's anomaly at the infrared region is predicted through simulations to shift by approximately 150 nm. We discuss the effect of polarization on the optical properties and grating mechanism. The reported effect may be used to achieve active spectral tuning and switching in a wide range of applications.

  1. The Design and Capabilities of the EXIST Optical and Infra-Red Telescope (IRT)

    Science.gov (United States)

    Kutyrev, A S.; Moseley, S. H.; Golisano, C.; Gong, Q.; Allen, B. T.; Gehrels, N.; Grindlay, J. E.; Hong, J. S.; Woodgate, B. E.

    2010-01-01

    The Infra-Red Telescope is a critical element of the EXIST (Energetic X-Ray Imaging Survey Telescope) observatory. The primary goal of the IRT is to obtain photometric and spectroscopic measurements of high redshift (> or =6) gamma ray reaching to the epoque of reionization. The photometric and spectral capabilities of the IRT will allow to use GRB afterglow as probes of the composition and ionization state of the intergalactic medium of the young universe. A prompt follow up (within three minutes) of the transient discovered by the EXIST makes IRT a unique tool for detection and study of these events in the infrared and optical wavelength, which is particularly valuable at wavelengths unavailable to the ground based observatories. We present the results of the mission study development on the IRT as part of the EXIST observatory. Keywords: infrared spectroscopy, space telescope, gamma ray bursts, early universe

  2. Mathematical and computer modeling of electro-optic systems using a generic modeling approach

    OpenAIRE

    Smith, M.I.; Murray-Smith, D.J.; Hickman, D.

    2007-01-01

    The conventional approach to modelling electro-optic sensor systems is to develop separate models for individual systems or classes of system, depending on the detector technology employed in the sensor and the application. However, this ignores commonality in design and in components of these systems. A generic approach is presented for modelling a variety of sensor systems operating in the infrared waveband that also allows systems to be modelled with different levels of detail and at diffe...

  3. Fourier transform infrared (FTIR) fiber optic monitoring of composites during cure in an autoclave

    Science.gov (United States)

    Druy, Mark A.; Elandjian, Lucy; Stevenson, William A.; Driver, Richard D.; Leskowitz, Garett M.

    1990-01-01

    Real-time in situ monitoring of the chemical states of epoxy resins was investigated during cure in an autoclave using infrared evanescent spectroscopy. Fiber evanescent sensors were developed which may be sandwiched between the plies of the prepreg sample. A short length of sapphire fiber was used as the sensor cell portion of the fiber probe. Heavy metal fluoride glass optical fiber cables were designed for connecting the FTIR spectrometer to the sensor fiber within the autoclave. The sapphire fibers have outstanding mechanical thermal properties which should permit their use as an embedded link in all thermoset composites. The system is capable of operation at a temperature of 250 C for periods up to 8 hours without major changes to the fiber transmission. A discussion of the selection of suitable sensor fibers, the construction of a fiber-optic interface, and the interpretation of in situ infrared spectra of the curing process is presented.

  4. Initial Technology Assessment for the Large UV-Optical-Infrared (LUVOIR) Mission Concept Study

    Science.gov (United States)

    Bolcar, Matthew R.; Feinberg, Lee D.; France, Kevin; Rauscher, Bernard J.; Redding, David; Schiminovich, David

    2016-01-01

    The NASA Astrophysics Divisions 30-Year Roadmap prioritized a future large-aperture space telescope operating in the ultra-violet-optical-infrared wavelength regime. The Association of Universities for Research in Astronomy envisioned a similar observatory, the High Definition Space Telescope. And a multi-institution group also studied the Advanced Technology Large Aperture Space Telescope. In all three cases, a broad science case is outlined, combining general astrophysics with the search for bio-signatures via direct-imaging and spectroscopic characterization of habitable exo-planets. We present an initial technology assessment that enables such an observatory that is currently being studied for the 2020 Decadal Survey by the Large UV-Optical Infrared (LUVOIR) surveyor Science and Technology Definition Team. We present here the technology prioritization for the 2016 technology cycle and define the required technology capabilities and current state-of-the-art performance. Current, planned, and recommended technology development efforts are also reported.

  5. Initial Technology Assessment for the Large-Aperture UV-Optical-Infrared (LUVOIR) Mission Concept Study

    Science.gov (United States)

    Bolcar, Matthew R.; Feinberg, Lee; France, Kevin; Rauscher, Bernard J.; Redding, David; Schiminovich, David

    2016-01-01

    The NASA Astrophysics Division's 30-Year Roadmap prioritized a future large-aperture space telescope operating in the ultra-violet/optical/infrared wavelength regime. The Association of Universities for Research in Astronomy envisioned a similar observatory, the High Definition Space Telescope. And a multi-institution group also studied the Advanced Technology Large Aperture Space Telescope. In all three cases, a broad science case is outlined, combining general astrophysics with the search for biosignatures via direct-imaging and spectroscopic characterization of habitable exoplanets. We present an initial technology assessment that enables such an observatory that is currently being studied for the 2020 Decadal Survey by the Large UV/Optical/Infrared (LUVOIR) surveyor Science and Technology Definition Team. We present here the technology prioritization for the 2016 technology cycle and define the required technology capabilities and current state-of-the-art performance. Current, planned, and recommended technology development efforts are also reported.

  6. 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.

  7. Molecular imaging with optics: primer and case for near-infrared fluorescence techniques in personalized medicine

    Science.gov (United States)

    Sevick-Muraca, Eva M.; Rasmussen, John C.

    2010-01-01

    We compare and contrast the development of optical molecular imaging techniques with nuclear medicine with a didactic emphasis for initiating readers into the field of molecular imaging. The nuclear imaging techniques of gamma scintigraphy, single-photon emission computed tomography, and positron emission tomography are first briefly reviewed. The molecular optical imaging techniques of bioluminescence and fluorescence using gene reporter/probes and gene reporters are described prior to introducing the governing factors of autofluorescence and excitation light leakage. The use of dual-labeled, near-infrared excitable and radio-labeled agents are described with comparative measurements between planar fluorescence and nuclear molecular imaging. The concept of time-independent and -dependent measurements is described with emphasis on integrating time-dependent measurements made in the frequency domain for 3-D tomography. Finally, we comment on the challenges and progress for translating near-infrared (NIR) molecular imaging agents for personalized medicine. PMID:19021311

  8. Highly efficient oscillator for an optically pumped 192-μm far-infrared laser

    Science.gov (United States)

    Liu, Chuang; Qu, Yanchen; Zhao, Weijiang; Zhang, Ruiliang

    2016-02-01

    We demonstrate an efficient CH3F oscillator based on an anti-reflection coated Ge dichroic beam splitter. When pumped by the 10R32 line of a CO2 laser (10.17 μm), 0.81-mJ far-infrared laser is obtained with the wavelength of 192 μm. The energy conversion efficiency of 0.16 % is the highest for an optically pumped 192-μm laser system to our knowledge. The beam quality factor of Mx2 and My2 is 1.53 and 1.57, respectively. Further, this oscillator can be extended to optically pumped far-infrared lasers with various wavelengths.

  9. Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy

    International Nuclear Information System (INIS)

    Sarmiento, Raymund; Cemine, Vernon Julius; Tagaca, Imee Rose; Salvador, Arnel; Mar Blanca, Carlo; Saloma, Caesar

    2007-01-01

    We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change.We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emittingp-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity

  10. Infrared spectrophotometry and radiative transfer in optically thick circumstellar dust envelopes

    International Nuclear Information System (INIS)

    Merrill, K.M.

    1976-01-01

    The Two-Micron Sky Survey of Neugebauer and Leighton and, more recently, the AFCRL Infrared Sky Survey of Walker and Price have detected numerous compact, isolated, bright infrared sources which are not identified with previously cataloged stars. Observations of many such objects suggest that extensive circumstellar dust envelopes modify the flux from a central source. The present investigations employ broad bandpass photometry at lambda lambda 1.65 μm to 12.5 μm and narrow bandpass spectrophotometry (Δ lambda/lambda approximately 0.015) at lambda lambda 2-4 μm and lambda lambda 8-13 μm to determine the properties of a large sample of such infrared sources. Infrared spectrophotometry can clearly differentiate between normal stars of spectral types M(''oxygen-rich'') and C (''carbon-rich'') on the basis of characteristic absorption bands arising in cool stellar atmospheres. Most of the 2 μ Sky Survey and many of the AFCRL Sky Survey sources appear to be stars of spectral types M and C which are differentiated from normal cool comparison stars only by the presence of extensive circumstellar dust envelopes. Due to the large optical depth of the envelopes, the flux from the star and from the dust cannot be simply separated. Hence solutions of radiative transfer through spherically symmetric envelopes of arbitrary optical depth were generated by a generalized computer code which employed opacities of real dust

  11. Near-infrared absorption fiber-optic sensors for ultra-sensitive CO2 detection

    Science.gov (United States)

    Chong, Xinyuan; Kim, Ki-Joong; Ohodnicki, Paul R.; Chang, Chih-Hung; Wang, Alan X.

    2015-05-01

    We present a fiber-optic sensor working at near-infrared (NIR) wavelength (~1.57μm) for CO2 detection. In order to increase the NIR absorption, we utilize functional sensor materials metalorganic framework (MOF) on the surface of the core of a multimode-fiber with the cladding layer etched away. The selected functional materials demonstrated excellent adsorption capacity of CO2 and significantly increased the detection sensitivity down to 500 ppm with only 8-centimeter absorption length.

  12. Near-infrared Au nanorods in photodynamic therapy, hyperthermia agents, and near-infrared optical imaging

    Science.gov (United States)

    Kuo, Wen-Shuo; Chang, Chich-Neng; Chang, Yi-Ting; Yang, Meng-Heng; Chien, Yi-Hsin; Chen, Shean-Jen; Yeh, Chen-Sheng

    2011-03-01

    The development of multifunctional nanomaterials is currently a topic of interest in the field of nanotechnology. Integrated systems that incorporate therapeutics, molecular targeting, and diagnostic imaging capabilities are considered to be the next generation of multifunctional nanomedicine. In this work, we present the first example of using Au nanorods simultaneously serving not only as photodynamic and photothermal agents to destroy A549 malignant cells but also as optical contrast agents simultaneously to monitor cellular image. Au nanorods were successfully conjugated with hydrophilic photosensitizer, indocyanine green (ICG), to achieve photodynamic therapy (PDT) and hyperthermia. With the combination of PDT and hyperthermia proved to be efficiently killing cancer cells as compared to PDT or hyperthermia treatment alone and enhanced the effectiveness of photodestruction. Moreover, Au nanorods conjugated with ICG displayed high chemical stability and simultaneously acted as a promising cellular image probe. As a result, the preparation of Au nanorods conjugated with photosensitizers as well as their use in biomedical applications is valuable developments in multifunctional nanomaterials.

  13. Bio-analytical applications of mid-infrared spectroscopy using silver halide fiber-optic probes

    International Nuclear Information System (INIS)

    Heise, H.M.; Kuepper, L.; Butvina, L.N.

    2002-01-01

    Infrared-spectroscopy has proved to be a powerful method for the study of various biomedical samples, in particular for in-vitro analysis in the clinical laboratory and for non-invasive diagnostics. In general, the analysis of biofluids such as whole blood, urine, microdialysates and bioreactor broth media takes advantage of the fact that a multitude of analytes can be quantified simultaneously and rapidly without the need for reagents. Progress in the quality of infrared silver halide fibers enabled us to construct several flexible fiber-optic probes of different geometries, which are particularly suitable for the measurement of small biosamples. Recent trends show that dry film measurements by mid-infrared spectroscopy could revolutionize analytical tools in the clinical chemistry laboratory, and an example is given. Infrared diagnostic tools show a promising potential for patients, and minimal-invasive blood glucose assays or skin tissue pathology in particular cannot be left out using mid-infrared fiber-based probes. Other applications include the measurement of skin samples including penetration studies of vitamins and constituents of cosmetic cream formulations. A further field is the micro-domain analysis of biopsy samples from bog mummified corpses, and recent results on the chemistry of dermis and hair samples are reported. Another field of application, for which results are reported, is food analysis and bio-reactor monitoring

  14. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Cloud Optical Thickness (COT) Environmental Data Record (EDR) from IDPS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of Cloud Optical Thickness (COT) from the Visible Infrared Imaging Radiometer Suite...

  15. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Nighttime Cloud Optical Microphysical Properties (NCOMP) Environmental Data Record (EDR) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains a high quality Environmental Data Record (EDR) of nighttime cloud optical and microphysical properties (NCOMP) from the Visible Infrared...

  16. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Daytime Cloud Optical and Microphysical Properties (DCOMP) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains a high quality Environmental Data Record (EDR) of daytime cloud optical and microphysical properties (DCOMP) from the Visible Infrared Imaging...

  17. Combination of optical coherence tomography and near infrared spectroscopy enhances determination of articular cartilage composition and structure

    NARCIS (Netherlands)

    Sarin, Jaakko K; Rieppo, Lassi; Brommer, Harold; Afara, Isaac O.; Saarakkala, Simo; Töyräs, Juha

    2017-01-01

    Conventional arthroscopic evaluation of articular cartilage is subjective and poorly reproducible. Therefore, implementation of quantitative diagnostic techniques, such as near infrared spectroscopy (NIRS) and optical coherence tomography (OCT), is essential. Locations (n = 44) with various

  18. Machining approach of freeform optics on infrared materials via ultra-precision turning.

    Science.gov (United States)

    Li, Zexiao; Fang, Fengzhou; Chen, Jinjin; Zhang, Xiaodong

    2017-02-06

    Optical freeform surfaces are of great advantage in excellent optical performance and integrated alignment features. It has wide applications in illumination, imaging and non-imaging, etc. Machining freeform surfaces on infrared (IR) materials with ultra-precision finish is difficult due to its brittle nature. Fast tool servo (FTS) assisted diamond turning is a powerful technique for the realization of freeform optics on brittle materials due to its features of high spindle speed and high cutting speed. However it has difficulties with large slope angles and large rise-and-falls in the sagittal direction. In order to overcome this defect, the balance of the machining quality on the freeform surface and the brittle nature in IR materials should be realized. This paper presents the design of a near-rotational freeform surface (NRFS) with a low non-rotational degree (NRD) to constraint the variation of traditional freeform optics to solve this issue. In NRFS, the separation of the surface results in a rotational part and a residual part denoted as a non-rotational surface (NRS). Machining NRFS on germanium is operated by FTS diamond turning. Characteristics of the surface indicate that the optical finish of the freeform surface has been achieved. The modulation transfer function (MTF) of the freeform optics shows a good agreement to the design expectation. Images of the final optical system confirm that the fabricating strategy is of high efficiency and high quality. Challenges and prospects are discussed to provide guidance of future work.

  19. Low Size, Weight and Power Concept for Mid-Wave Infrared Optical Communication Transceivers Based on Quantum Cascade Lasers

    Science.gov (United States)

    Luzhanskiy, Edward; Choa, Fow-Sen; Merritt, Scott; Yu, Anthony; Krainak, Michael

    2015-01-01

    The low complexity, low size, weight and power Mid-Wavelength Infra-Red optical communications transceiver concept presented, realized and tested in the laboratory environment. Resilience to atmospheric impairments analyzed with simulated turbulence. Performance compared to typical telecom based Short Wavelength Infra-Red transceiver.

  20. Broadly, independent-tunable, dual-wavelength mid-infrared ultrafast optical parametric oscillator.

    Science.gov (United States)

    Jin, Yuwei; Cristescu, S M; Harren, Frans J M; Mandon, Julien

    2015-08-10

    We demonstrate a two-crystal mid-infrared dual-wavelength optical parametric oscillator, synchronously pumped by a high power femtosecond Yb:fiber laser. The singly-resonant ring cavity, containing two periodically poled lithium niobate crystals, is capable of generating two synchronized idler wavelengths, independently tunable over 30 THz in the 2.9 - 4.2 μm wavelength region, due to the cascaded quadratic nonlinear effect. The independent tunability of the two idlers makes the optical parametric oscillator a promising source for ultrafast pulse generation towards the THz wavelength region, based on different frequency generation. In addition, the observed frequency doubled idler within the crystal indicates the possibility to realize a broadband optical self-phase locking between pump, signal, idler and higher order generated parametric lights.

  1. Effects of Temperature and X-rays on Plastic Scintillating Fiber and Infrared Optical Fiber.

    Science.gov (United States)

    Lee, Bongsoo; Shin, Sang Hun; Jang, Kyoung Won; Yoo, Wook Jae

    2015-05-11

    In this study, we have studied the effects of temperature and X-ray energy variations on the light output signals from two different fiber-optic sensors, a fiber-optic dosimeter (FOD) based on a BCF-12 as a plastic scintillating fiber (PSF) and a fiber-optic thermometer (FOT) using a silver halide optical fiber as an infrared optical fiber (IR fiber). During X-ray beam irradiation, the scintillating light and IR signals were measured simultaneously using a dosimeter probe of the FOD and a thermometer probe of the FOT. The probes were placed in a beaker with water on the center of a hotplate, under variation of the tube potential of a digital radiography system or the temperature of the water in the beaker. From the experimental results, in the case of the PSF, the scintillator light output at the given tube potential decreased as the temperature increased in the temperature range from 25 to 60 °C. We demonstrated that commonly used BCF-12 has a significant temperature dependence of -0.263 ± 0.028%/°C in the clinical temperature range. Next, in the case of the IR fiber, the intensity of the IR signal was almost uniform at each temperature regardless of the tube potential range from 50 to 150 kVp. Therefore, we also demonstrated that the X-ray beam with an energy range used in diagnostic radiology does not affect the IR signals transmitted via a silver halide optical fiber.

  2. Measurement of thermal radiation using regular glass optics and short-wave infrared detectors.

    Science.gov (United States)

    Yoon, H W; Eppeldauer, G P

    2008-01-21

    The measurement of thermal radiation from ambient-temperature objects using short-wave infrared detectors and regular glass optics is described. The detectors are chosen to operate in the 2.0 microm to 2.5 microm atmospheric window. Selection of detectors with high shunt resistance along with the 4-stage thermo-electric cooling of the detectors to -85 degrees C results in detectivity, D*, of 4 x 10(13) cm Hz(1/2)/W which is near the background limited performance at 295 K. Furthermore, the use of regular-glass commercial optics to collect the thermal radiation results in diffraction-limited imaging. The use of a radiation thermometer constructed with these elements for the measurement of a blackbody from 20 degrees C to 50 degrees C results in noise-equivalent temperature difference (NETD) of thermal sensors also leads to lower sensitivity to the emissivity of the object in determining the temperature of the object. These elements are used to construct a calibrator for an infrared collimator, and such a system demonstrates noise-equivalent irradiances of thermal infrared detectors.

  3. 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.

  4. [Study on predicting total acid content and soluble sugar of tomato juice by near infrared optical fiber spectrometer technique].

    Science.gov (United States)

    Zhang, Bing-Fang; Yuan, Li-Bo; Zhang, Bing-Xiu

    2014-02-01

    In order to explore a simple, rapid and efficient tomato quality detection method, in the present experiment near infrared spectroscopy and optical fiber sensing technology were applied to quickly measure the nutrition ingredient content in tomato juice samples. The main instrument used in this experiment was near infrared optical fiber spectrometer in a wavelength range from 900 to 2 500 nm, which measured the absorbance of the tomato juice samples; A collection of one hundred and sixty-four tomato juice samples were selected as the standard samples, the spectra and the corresponding chemical value were measured. Partial least squares (PLS) was adopted to establish the mathematical model of the total acid and soluble sugar content in tomato juice samples, and the regression equation was statistically analysed. The total acid in tomato juice prediction correlation coefficient was 0.967, calibration standard deviation (RMSEC) was 0.133, standard error of prediction (RMSEP) was 0.103; the soluble sugar prediction correlation coefficient is 0.976, calibration standard deviation (RMSEC) was 0.463, and the standard error of prediction (RMSEP) was 0. 460. The above data achieved better forecasting results, which showed that the method of quantitative analysis of tomato fruit multicomponent content was feasible. The method is rapid, simple and can do multicomponent analysis on the same sample simultaneously. It is a promising sensor and gradually becoming a international research focus in sensor field.

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

    NARCIS (Netherlands)

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

    2017-01-01

    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

  6. Micro- and nanophotonic structures in the visible and near infrared spectral region for optical devices

    Science.gov (United States)

    Pham, Van Hoi; Bui, Huy; Van Nguyen, Thuy; Nguyen, The Anh; Son Pham, Thanh; Cam Hoang, Thi Hong; Ngo, Quang Minh

    2013-06-01

    In this paper we present some research results on the micro and nano-photonic structures in the visible and near infrared spectral region for optical devices that have been done within the framework of Nanoscience and Nanotechnology Program of Institute of Materials Science. In the first part, we report the design and fabrication of 1D photonic structure based on porous silicon layers fabricated by electrochemical etching method and some of their potential applications such as optical filters, microcavity and optical sensors for distinguishing the content of bio-gasoline. In addition, we demonstrate some results on preparation of the 2D and 3D nanophotonic structures based on silica opal layers prepared by sol-gel and self-assembled methods. In the second part, we demonstrate the results of lasing emissions of erbium ions in the visible and near infrared zone from microcavity. The observation of emission of single-mode green light at the wavelength of 537 nm from erbium ions in the microcavity is interesting for the study of atom-photon interaction phenomenon. In the last part, we will show some new results of design and fabrication of nanocomposite based on nanoscale TiO2 and/or ZnO and nanoparticles of semiconductors and metals, which are oriented to the fabrication of energy conversion and photo-reactor devices. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN2012, 30 October-2 November, 2012, Ha Long, Vietnam.

  7. Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts.

    Science.gov (United States)

    Katagiri, Takashi; Shibayama, Kyosuke; Iida, Takeru; Matsuura, Yuji

    2018-03-27

    A real-time gas monitoring system based on optical absorption spectroscopy is proposed for localized carbon dioxide (CO₂) measurement in respiratory tracts. In this system, a small gas cell is attached to the end of a hollow optical fiber that delivers mid-infrared light with small transmission loss. The diameters of the fiber and the gas cell are smaller than 1.2 mm so that the probe can be inserted into a working channel of common bronchoscopes. The dimensions of the gas cell are designed based on absorption spectra of CO₂ standard gases in the 4.2 μm wavelength region, which are measured using a Fourier-transform infrared spectrometer. A miniature gas cell that is comprised of a stainless-steel tube with slots for gas inlet and a micro-mirror is fabricated. A compact probing system with a quantum cascade laser (QCL) light source is built using a gas cell with a hollow optical fiber for monitoring CO₂ concentration. Experimental results using human breaths show the feasibility of the system for in-situ measurement of localized CO₂ concentration in human airways.

  8. Optical properties in the far infrared and at low temperatures of fifteen ionic crystals

    International Nuclear Information System (INIS)

    Claudel, Jacques

    1969-01-01

    In this research thesis, the author first briefly presents the problem of interactions between electromagnetic waves and thermal agitation waves in crystal. Then, he reports an analysis of reflection spectra in the far infrared and at low temperatures for fourteen ionic crystals in order to determine their optical properties. The author presents the methods used to calculate optical and dielectric constants. Results obtained for each compound are presented and discussed. In the next part, the author reports the study of transmission spectra of two ionic compounds (caesium iodide and copper oxide) at ambient temperature and at liquid helium temperature. He reports the determination of phonon addition and difference processes which occur during caesium iodide absorption, and the search for a second active infrared frequency for the copper oxide. The author briefly describes a high resolution spectrometer, and presents in a more detailed way the use of a new antimony-based sensor which allows studies to be performed at lower temperatures. Finally, various issues are discussed: Havelock relationship, determination of the optical longitudinal mode, and Szigeti equations of compressibility

  9. High-energy infrared femtosecond pulses generated by dual-chirped optical parametric amplification.

    Science.gov (United States)

    Fu, Yuxi; Takahashi, Eiji J; Midorikawa, Katsumi

    2015-11-01

    We demonstrate high-energy infrared femtosecond pulse generation by a dual-chirped optical parametric amplification (DC-OPA) scheme [Opt. Express19, 7190 (2011)]. By employing a 100 mJ pump laser, a signal pulse energy exceeding 20 mJ at a wavelength of 1.4 μm was achieved before dispersion compensation. A total output energy of 33 mJ was recorded. Under a further energy scaling condition, the signal pulse was compressed to an almost transform-limited duration of 27 fs using a fused silica prism compressor. Since the DC-OPA scheme is efficient and energy scalable, design parameters for obtaining 100 mJ level infrared pulses are presented, which are suitable as driver lasers for the energy scaling of high-order harmonic generation with sub-keV photon energy.

  10. A twin optically-pumped far-infrared CH3OH laser for plasma diagnostics

    International Nuclear Information System (INIS)

    Yamanaka, M.; Takeda, Y.; Tanigawa, S.; Nishizawa, A.; Noda, N.

    1979-11-01

    A twin optically-pumped far-infrared CH 3 OH laser has been constructed for use in plasma diagnostics. The anti-symmetric doublet due to the Raman-type resonant two-photon transition is reproducibly observed at 118.8 μm. With the 118.8-μm line, it is obtained from the frequency separation of the anti-symmetric doublet that the CH 3 OH absorption line center is 16 +- 1 MHz higher than the pump 9.7-μm P(36) CO 2 laser line center. It is shown that the Raman-type resonant two-photon transition is useful in order to get several-MHz phase modulation for the far-infrared laser interferometer. Some preliminary performances of this twin laser for the modulated interferometer are described. (author)

  11. Discriminating red spray paints by optical microscopy, Fourier transform infrared spectroscopy and X-ray fluorescence.

    Science.gov (United States)

    Govaert, Filip; Bernard, Magali

    2004-02-10

    Red spray paints from different European suppliers were characterised to determine the discriminating power of a sequence of analysing techniques. A total of 51 red spray paints were analysed with the help of three techniques: (1) optical microscopy, (2) Fourier transform infrared spectrometry and (3) X-ray fluorescence. Infrared spectra were classified according to binder type, filler and pigment composition and a searchable spectral library was created. Due to the difference in the elemental composition of spray paints, a further discrimination was possible. The microscopic analysis was not taken into consideration for classification purposes. The structure of the substrate under a paint coating strongly affects the surface characteristics of this spray paint. Together with the spectral library, a database of information of spray paints was build.

  12. Mid-infrared optical properties of chalcogenide glasses within tin-antimony-selenium ternary system.

    Science.gov (United States)

    Lin, Ruiqiang; Chen, Feifei; Zhang, Xiaoyu; Huang, Yicong; Song, Baoan; Dai, Shixun; Zhang, Xianghua; Ji, Wei

    2017-10-16

    In this work, we investigated the mid-infrared (MIR) optical properties of selenide (Se-based) chalcogenide glasses (ChGs) within an As- and Ge-free system, namely the environment-friendly and low-cost tin-antimony-selenium (Sn-Sb-Se, SSS) ternary system, which has not been systematically studied to the best of our knowledge. As compared to ChGs within those conventional Se-based systems, SSS ChGs were found to exhibit extended infrared transmittance range as well as larger linear refractive index (n 0 ). Femtosecond Z-scan measurements show the presence of evident three-photon absorption from Urbach absorption of the SSS ChGs at MIR wavelength, which resonantly enhanced the nonlinear refractive behavior and resulted in large nonlinear refractive index (n 2 ).

  13. J-Black: a stray light coating for optical and infrared systems

    Science.gov (United States)

    Waddell, Patrick; Black, David S.

    2016-07-01

    A new stray light coating, called J-Black, has been developed for NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA). The coating is a layered composition of Nextel-Suede 3101 primers and top coats and silicon carbide grit. J-Black has been applied to large areas of the SOFIA airborne telescope and is currently operating within the open cavity environment of the Boeing 747. Over a series of discrete filter bands, from 0.4 to 21 microns, J-Black optical and infrared reflectivity performance is compared with other available coatings. Measured total reflectance values are less than 2% at the longest wavelengths, including at high incidence angles. Detailed surface structure characteristics are also compared via electron and ion microscopy. Environmental tests applicable for aerospace applications are presented, as well as the detailed steps required to apply the coating.

  14. Surface-enhanced infrared absorption studies towards a new optical biosensor

    Directory of Open Access Journals (Sweden)

    Lothar Leidner

    2016-11-01

    Full Text Available Reflectometric interference spectroscopy (RIfS, which is well-established in the visual regime, measures the optical thickness change of a sensitive layer caused, e.g., by binding an analyte. When operated in the mid-infrared range the sensor provides additional information via weak absorption spectra (fingerprints. The originally poor spectra are magnified by surface-enhanced infrared absorption (SEIRA. This is demonstrated using the broad complex fluid water band at 3300 cm−1, which is caused by superposition of symmetric, antisymmetric stretching vibration, and the first overtone of the bending vibration under the influence of H-bonds and Fermi resonance effect. The results are compared with a similar experiment performed with an ATR (attenuated total reflectance set-up.

  15. Optical and infrared properties of tetramethyltetraselenafulvalene [(TMTSF)2X] and tetramethyltetrathiafulvalene [(TMTTF)2X] compounds

    DEFF Research Database (Denmark)

    Jacobsen, Claus Schelde; Tanner, D. B.; Bechgaard, K.

    1983-01-01

    of the order 0.18-0.20 eV. No b-axis plasma edge is observable. The infrared conductivity spectra of the materials consist of a broad electronic band with superimposed vibrational fine structure. The band is centered at 300 cm-1 in the best (TMTSF)2X conductors and at 2200 cm-1 in (TMTTF)2PF6, an organic......The electronic structure of the organic conductors bis-tetramethyltetraselenafulvalene-X [(TMTSF)2X] and bis-tetramethyltetrathiafulvalene-X [(TMTTF)2X] has been investigated by means of polarized optical and infrared reflectance measurements. Analysis of plasma edges in reflectance is used...... conductor of moderate conductivity. The electron-molecular vibration coupling constants for TMTSF and TMTTF appear to be qualitatively similar to those of TTF (tetrathiafulvalene). A new feature is the observation of considerable coupling to modes involving methyl groups, suggesting that a sizable charge...

  16. Optics of Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): Delay Lines and Alignment

    Science.gov (United States)

    Dhabal, Arnab; Rinehart, Stephen A.; Rizzo, Maxime J.; Mundy, Lee; Fixsen, Dale; Sampler, Henry; Mentzell, Eric; Veach, Todd; Silverberg, Robert F.; Furst, Stephen; hide

    2016-01-01

    We present the optics of Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) as it gets ready for launch. BETTII is an 8-meter baseline far-infrared (30-90 microns) interferometer mission with capabilities of spatially resolved spectroscopy aimed at studying star formation and galaxy evolution. The instrument collects light from its two arms, makes them interfere, divides them into two science channels (30-50 microns and 60-90 microns), and focuses them onto the detectors. It also separates out the NIR light (1-2.5 microns) and uses it for tip-tilt corrections of the telescope pointing. Currently, all the optical elements have been fabricated, heat treated, coated appropriately and are mounted on their respective assemblies. We are presenting the optical design challenges for such a balloon borne spatio-spectral interferometer, and discuss how they have been mitigated. The warm and cold delay lines are an important part of this optics train. The warm delay line corrects for path length differences between the left and the right arm due to balloon pendulation, while the cold delay line is aimed at introducing a systematic path length difference, thereby generating our interferograms from where we can derive information about the spectra. The details of their design and the results of the testing of these opto-mechanical parts are also discussed. The sensitivities of different optical elements on the interferograms produced have been determined with the help of simulations using FRED software package. Accordingly, an alignment plan is drawn up which makes use of a laser tracker, a CMM, theodolites and a LUPI interferometer.

  17. Attractive Casimir effect in an infrared modified gluon bag model

    International Nuclear Information System (INIS)

    Oxman, L.E.; Amaral, R.L.P.G.; Svaiter, N.F.

    2005-01-01

    In this work, we are motivated by previous attempts to derive the vacuum contribution to the bag energy in terms of familiar Casimir energy calculations for spherical geometries. A simple infrared modified model is introduced which allows studying the effects of the analytic structure as well as the geometry in a clear manner. In this context, we show that if a class of infrared vanishing effective gluon propagators is considered, then the renormalized vacuum energy for a spherical bag is attractive, as required by the bag model to adjust hadron spectroscopy

  18. 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.

    2018-02-01

    We performed a near-infrared (NIR, ˜1.0μm-2.4μm) 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 magnitude higher than optical values. For higher resolution models, optical and NIR results tend do aggree much better, suggesting that a higher spectral resolution is fundamental to improve the quality of the results.

  19. Two-color mid-infrared spectroscopy of optically doped semiconductors

    International Nuclear Information System (INIS)

    Forcales, M.; Klik, M.A.J.; Vinh, N.Q.; Phillips, J.; Wells, J-P.R.; Gregorkiewicz, T.

    2003-01-01

    Optical doping is an attractive method to tailor photonic properties of semiconductor matrices for development of solid-state electroluminescent structures. For practical applications, thermal stability of emission obtained from these materials is required. Thermal processes can be conveniently investigated by two-color spectroscopy in the visible and the mid-infrared. Free-electron laser is a versatile high-brilliance source of radiation in the latter spectral range. In this contribution, we briefly review some of the results obtained recently by the two-color spectroscopy with a free-electron laser in different semiconductors optically doped with rare earth and transition metal ions. Effects leading to both enhancement and quenching of emission from optical dopants will be presented. For InP:Yb, Si:Er, and Si:Cu activation of particular optically induced non-radiative recombination paths will be shown. For Si:Er and Si:Ag, observation of a low temperature optical memory effect will be reported

  20. Optical models of the human eye.

    Science.gov (United States)

    Atchison, David A; Thibos, Larry N

    2016-03-01

    Optical models of the human eye have been used in visual science for purposes such as providing a framework for explaining optical phenomena in vision, for predicting how refraction and aberrations are affected by change in ocular biometry and as computational tools for exploring the limitations imposed on vision by the optical system of the eye. We address the issue of what is understood by optical model eyes, discussing the 'encyclopaedia' and 'toy train' approaches to modelling. An extensive list of purposes of models is provided. We discuss many of the theoretical types of optical models (also schematic eyes) of varying anatomical accuracy, including single, three and four refracting surface variants. We cover the models with lens structure in the form of nested shells and gradient index. Many optical eye models give accurate predictions only for small angles and small fields of view. If aberrations and image quality are important to consider, such 'paraxial' model eyes must be replaced by 'finite model' eyes incorporating features such as aspheric surfaces, tilts and decentrations, wavelength-dependent media and curved retinas. Many optical model eyes are population averages and must become adaptable to account for age, gender, ethnicity, refractive error and accommodation. They can also be customised for the individual when extensive ocular biometry and optical performance data are available. We consider which optical model should be used for a particular purpose, adhering to the principle that the best model is the simplest fit for the task. We provide a glimpse into the future of optical models of the human eye. This review is interwoven with historical developments, highlighting the important people who have contributed so richly to our understanding of visual optics. © 2016 The Authors. Clinical and Experimental Optometry © 2016 Optometry Australia.

  1. 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.

  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. Modeling of optical wireless scattering communication channels over broad spectra.

    Science.gov (United States)

    Liu, Weihao; Zou, Difan; Xu, Zhengyuan

    2015-03-01

    The air molecules and suspended aerosols help to build non-line-of-sight (NLOS) optical scattering communication links using carriers from near infrared to visible light and ultraviolet bands. This paper proposes channel models over such broad spectra. Wavelength dependent Rayleigh and Mie scattering and absorption coefficients of particles are analytically obtained first. They are applied to the ray tracing based Monte Carlo method, which models the photon scattering angle from the scatterer and propagation distance between two consecutive scatterers. Communication link path loss is studied under different operation conditions, including visibility, particle density, wavelength, and communication range. It is observed that optimum communication performances exist across the wavelength under specific atmospheric conditions. Infrared, visible light and ultraviolet bands show their respective features as conditions vary.

  4. Optical and Infrared Colors of Stars Observed by 2MASS and SDSS

    OpenAIRE

    Finlator, K.; Ivezic, Z.; Strauss, M.; Knapp, J.; Lupton, R.; Gunn, J.; Rockosi, C.

    2000-01-01

    We discuss optical and infrared photometric properties of stars matched in the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Survey (SDSS) commissioning data for 50 deg2 of sky. About 98% (63,000) of objects listed in the 2MASS Point Source Catalog in the analyzed area are matched within 2 arcsec to an SDSS source. The matched sources represent 8% of the about 800,000 SDSS sources in this area, and 15% of them are resolved in SDSS imaging data, although they are detected as poin...

  5. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

  6. 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.

  7. Optical and Near-Infrared Observations of SN 2013DX Associated with GRB 130702A

    Science.gov (United States)

    Toy, V. L.; Cenko, S. B.; Silverman, J. M.; Butler, N. R.; Cucchiara, A.; Watson, A. M.; Bersier, D.; Perley, D. A.; Margutti, R.; Bellm, E.; hide

    2016-01-01

    We present optical and near-infrared (NIR) light curves and optical spectra of SN 2013dx, associated with the nearby (redshift 0.145) gamma-ray burst GRB 130702A. The prompt isotropic gamma-ray energy released from GRB 130702A is measured to be E(sub gamma, iso) = 6.4(+1.3/-1.0) x 10(exp 50) erg (1 keV to 10 MeV in the rest frame), placing it intermediate between low-luminosity GRBs like GRB 980425/SN 1998bw and the broader cosmological population. We compare the observed g'r'i'z' light curves of SN 2013dx to a SN 1998bw template, finding that SN 2013dx evolves approx. 20% faster (steeper rise time), with a comparable peak luminosity. Spectroscopically, SN 2013dx resembles other broad-lined SNe Ic, both associated with (SN 2006aj and SN 1998bw) and lacking (SN 1997ef, SN 2007I, and SN 2010ah) gamma-ray emission, with photospheric velocities around peak of approx. 21,000 km/s. We construct a quasi-bolometric (g'r'z'yJ) light curve for SN 2013dx, only the fifth GRB-associated SN with extensive NIR coverage and the third with a bolometric light curve extending beyond (Delta)t > 40 days. Together with the measured photospheric velocity, we derive basic explosion parameters using simple analytic models. We infer a Ni-56 mass of M(sub Ni) = 0.37+/- 0.01 Stellar Mass, an ejecta mass of M(sub ej) = 3.1+/- 0.1 Stellar Mass, and a kinetic energy of E(sub K) = (8.2+/- 0.43) x 10(exp 51) erg (statistical uncertainties only), consistent with previous GRB-associated supernovae. When considering the ensemble population of GRB-associated supernovae, we find no correlation between the mass of synthesized Ni-56 and high-energy properties, despite clear predictions from numerical simulations that M(sub Ni) should correlate with the degree of asymmetry. On the other hand, M(sub Ni) clearly correlates with the kinetic energy of the supernova ejecta across a wide range of core-collapse events.

  8. Broadband and tunable optical parametric generator for remote detection of gas molecules in the short and mid-infrared.

    Science.gov (United States)

    Lambert-Girard, Simon; Allard, Martin; Piché, Michel; Babin, François

    2015-04-01

    The development of a novel broadband and tunable optical parametric generator (OPG) is presented. The OPG properties are studied numerically and experimentally in order to optimize the generator's use in a broadband spectroscopic LIDAR operating in the short and mid-infrared. This paper discusses trade-offs to be made on the properties of the pump, crystal, and seeding signal in order to optimize the pulse spectral density and divergence while enabling energy scaling. A seed with a large spectral bandwidth is shown to enhance the pulse-to-pulse stability and optimize the pulse spectral density. A numerical model shows excellent agreement with output power measurements; the model predicts that a pump having a large number of longitudinal modes improves conversion efficiency and pulse stability.

  9. An optical and near infrared search for a pulsar in Supernova 1987A

    Energy Technology Data Exchange (ETDEWEB)

    Sasseen, T.P.

    1990-12-01

    We describe a search for an optical pulsar in the remnant of Supernova 1987A. We have performed over one hundred separate observations of the supernova, covering wavelengths from 3500 angstroms to 1.8 microns, with sensitivity to pulsations as faint as magnitude 22.7. As of September 26, 1990, we have not seen evidence for pulsations due to a pulsar in the supernova. We discuss the implications of this result on predictions of pulsar optical luminosity. We have constructed for the search two photodiode detectors and a data system. We describe their design, calibration and performance. These detectors have allowed us to increase our sensitivity as much as a factor of 5 over standard photomultiplier tubes, and extend this search to near infrared wavelengths. 59 refs., 10 figs., 1 tab.

  10. Discovery, Follow-up, and Implications of the Optical/Infrared Counterpart to GW170817

    Science.gov (United States)

    Drout, Maria

    2018-01-01

    On August 17th, 2017, the field of multi-messenger, gravitational-wave, astronomy was born. On this date, Advanced LIGO and Advanced Virgo observed gravitational waves from the coalescence of a neutron star binary with a false alarm probability of 1 per 10000 years and electromagnetic counterparts were subsequently identified across the entire electromagnetic spectrum. In this talk, I will give a broad review of the optical and infrared emission associated with the binary neutron star merger, GW170817. I will describe the process of the discovery and localization of the optical counterpart, and review the extensive follow-up observations obtained over the following three weeks. Finally, I will place these results in context. I will discuss the implications of these observations on our understanding of the ejecta from neutron star mergers, the origin of r-process elements, and the prospects for the identification of similar transients in upcoming surveys.

  11. 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

  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. 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.

  14. 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.

  15. Infrared imaging systems: Design, analysis, modeling, and testing III; Proceedings of the Meeting, Orlando, FL, Apr. 23, 24, 1992

    Science.gov (United States)

    Holst, Gerald C.

    This volume discusses today's thermal imaging systems, modeling of thermal imaging systems, sampling and aliasing, and systems and testing. Individual papers are on single-frame multispectral thermal imagery, measurement of the MTF of IR staring-array imaging systems, IRC-64 infrared focal-plane-array camera, performance and application of serial-scan FLIRs, and nondestructive thermal analysis with portable pyroelectric television camera. Attention is also given to standard night vision thermal modeling parameters, the analysis of a proposed infrared sensor focal plane, spatial aliasing effects in ground vehicle IR imagery, spatial sampling effects of multipixel sensors on the guided-missile system performance, and the perception of unwanted signals in displayed imagery. Other papers are on the assessment of environment-driven infrared intensity components, measurements of optical transfer function of discretely sampled thermal imaging systems, and the status of uncooled infrared imagers.

  16. Non-linear calibration models for near infrared spectroscopy

    DEFF Research Database (Denmark)

    Ni, Wangdong; Nørgaard, Lars; Mørup, Morten

    2014-01-01

    by ridge regression (RR). The performance of the different methods is demonstrated by their practical applications using three real-life near infrared (NIR) data sets. Different aspects of the various approaches including computational time, model interpretability, potential over-fitting using the non...

  17. Land Cover Characterization for Hydrological Modeling Using Thermal Infrared Emissivities

    Science.gov (United States)

    Remote sensing with multispectral thermal infrared observations has the potential to improve regional scale estimation of evapotranspiration (ET) by constraining the land surface energy balance in a way that is not possible using more conventional remote sensing techniques. Current models use data f...

  18. Theoretical study on optical model potential

    International Nuclear Information System (INIS)

    Lim Hung Gi.

    1984-08-01

    The optical model potential of non-local effect on the rounded edge of the potential is derived. On the basis of this potential the functional form of the optical model potential, the energy dependence and relationship of its parameters, and the dependency of the values of the parameters on energy change are shown in this paper. (author)

  19. Thermophysical modeling of asteroids from WISE thermal infrared data - Significance of the shape model and the pole orientation uncertainties

    Science.gov (United States)

    Hanuš, J.; Delbo', M.; Ďurech, J.; Alí-Lagoa, V.

    2015-08-01

    In the analysis of thermal infrared data of asteroids by means of thermophysical models (TPMs) it is a common practice to neglect the uncertainty of the shape model and the rotational state, which are taken as an input for the model. Here, we present a novel method of investigating the importance of the shape model and the pole orientation uncertainties in the thermophysical modeling - the varied shape TPM (VS-TPM). Our method uses optical photometric data to generate various shape models that map the uncertainty in the shape and the rotational state. The TPM procedure is then run for all these shape models. We apply the implementation of the classical TPM as well as our VS-TPM to the convex shape models of several asteroids together with their thermal infrared data acquired by the NASA's Wide-field Infrared Survey Explorer (WISE) and compare the results. These show that the uncertainties of the shape model and the pole orientation can be very important (e.g., for the determination of the thermal inertia) and should be considered in the thermophysical analyses. We present thermophysical properties for six asteroids - (624) Hektor, (771) Libera, (1036) Ganymed, (1472) Muonio, (1627) Ivar, and (2606) Odessa.

  20. Interpreting the cosmic far-infrared background anisotropies using a gas regulator model

    Science.gov (United States)

    Wu, Hao-Yi; Doré, Olivier; Teyssier, Romain; Serra, Paolo

    2018-04-01

    Cosmic far-infrared background (CFIRB) is a powerful probe of the history of star formation rate (SFR) and the connection between baryons and dark matter across cosmic time. In this work, we explore to which extent the CFIRB anisotropies can be reproduced by a simple physical framework for galaxy evolution, the gas regulator (bathtub) model. This model is based on continuity equations for gas, stars, and metals, taking into account cosmic gas accretion, star formation, and gas ejection. We model the large-scale galaxy bias and small-scale shot noise self-consistently, and we constrain our model using the CFIRB power spectra measured by Planck. Because of the simplicity of the physical model, the goodness of fit is limited. We compare our model predictions with the observed correlation between CFIRB and gravitational lensing, bolometric infrared luminosity functions, and submillimetre source counts. The strong clustering of CFIRB indicates a large galaxy bias, which corresponds to haloes of mass 1012.5 M⊙ at z = 2, higher than the mass associated with the peak of the star formation efficiency. We also find that the far-infrared luminosities of haloes above 1012 M⊙ are higher than the expectation from the SFR observed in ultraviolet and optical surveys.

  1. The Optical-infrared Extinction Curve and Its Variation in the Milky Way

    Science.gov (United States)

    Schlafly, E. F.; Meisner, A. M.; Stutz, A. M.; Kainulainen, J.; Peek, J. E. G.; Tchernyshyov, K.; Rix, H.-W.; Finkbeiner, D. P.; Covey, K. R.; Green, G. M.; Bell, E. F.; Burgett, W. S.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Magnier, E. A.; Martin, N. F.; Metcalfe, N.; Wainscoat, R. J.; Waters, C.

    2016-04-01

    The dust extinction curve is a critical component of many observational programs and an important diagnostic of the physics of the interstellar medium. Here we present new measurements of the dust extinction curve and its variation toward tens of thousands of stars, a hundred-fold larger sample than in existing detailed studies. We use data from the APOGEE spectroscopic survey in combination with ten-band photometry from Pan-STARRS1, the Two Micron All-Sky Survey, and Wide-field Infrared Survey Explorer. We find that the extinction curve in the optical through infrared is well characterized by a one-parameter family of curves described by R(V). The extinction curve is more uniform than suggested in past works, with σ (R(V))=0.18, and with less than one percent of sight lines having R(V)\\gt 4. Our data and analysis have revealed two new aspects of Galactic extinction: first, we find significant, wide-area variations in R(V) throughout the Galactic plane. These variations are on scales much larger than individual molecular clouds, indicating that R(V) variations must trace much more than just grain growth in dense molecular environments. Indeed, we find no correlation between R(V) and dust column density up to E(B-V)≈ 2. Second, we discover a strong relationship between R(V) and the far-infrared dust emissivity.

  2. Improved optical sub-systems for intraoperative near-infrared fluorescence imaging

    Science.gov (United States)

    Gioux, Sylvain; Degrand, Alec M.; Lee, Deborah S.; Yazdanfar, Siavash; Idoine, John D.; Lomnes, Stephen J.; Frangioni, John V.

    2005-11-01

    Near-infrared light propagation through living tissue provides promising opportunities for the development of non-invasive imaging techniques for human care. We have developed a Fluorescence-Assisted Resection and Exploration (FLARE) imaging system for surgery. The FLARE system uses invisible near-infrared light to help the surgeon visualize critical structures intraoperatively and in real-time. We present here the continued optimization of our imaging system from a research prototype to an efficient and ergonomic tool to be used during human surgery. New, hands-free operation enables the surgeon to zoom, focus, recall and save images through a footswitch. A LabVIEW curve-fitting algorithm, in combination with stepper motor control, provides auto-focus capability. Cardiac and/or respiratory gating minimizes motion artifacts of moving objects in the surgical field, and permits in-focus imaging during long fluorescence integration times. Automated subtraction of the near-infrared fluorescence signal from background reflections minimizes the effect of ambient illumination and improves the contrast to noise ratio with only moderate effects on intensity precision. Taken together, this study improves several optical components of the FLARE system, and helps ready it for human clinical testing.

  3. Determination of the size of the dust torus in H0507+164 through optical and infrared monitoring

    Science.gov (United States)

    Mandal, Amit Kumar; Rakshit, Suvendu; Kurian, Kshama S.; Stalin, C. S.; Mathew, Blesson; Hoenig, Sebastian; Gandhi, Poshak; Sagar, Ram; Pandge, M. B.

    2018-04-01

    The time delay between flux variations in different wavelength bands can be used to probe the inner regions of active galactic nuclei (AGNs). Here, we present the first measurements of the time delay between optical and near-infrared (NIR) flux variations in H0507+164, a nearby Seyfert 1.5 galaxy at z = 0.018. The observations in the optical V-band and NIR J, H, and Ks bands carried over 35 epochs during the period 2016 October to 2017 April were used to estimate the inner radius of the dusty torus. From a careful reduction and analysis of the data using cross-correlation techniques, we found delayed responses of the J, H, and Ks light curves to the V-band light curve. In the rest frame of the source, the lags between optical and NIR bands are found to be 27.1^{+13.5}_{-12.0} d (V versus J), 30.4^{+13.9}_{-12.0} d (V versus H) and 34.6^{+12.1}_{-9.6} d (V versus Ks). The lags between the optical and different NIR bands are thus consistent with each other. The measured lags indicate that the inner edge of dust torus is located at a distance of 0.029 pc from the central ultraviolet/optical AGN continuum. This is larger than the radius of the broad line region of this object determined from spectroscopic monitoring observations thereby supporting the unification model of AGN. The location of H0507+164 in the τ-MV plane indicates that our results are in excellent agreement with the now known lag-luminosity scaling relationship for dust in AGN.

  4. Effects of Temperature and X-rays on Plastic Scintillating Fiber and Infrared Optical Fiber

    Directory of Open Access Journals (Sweden)

    Bongsoo Lee

    2015-05-01

    Full Text Available In this study, we have studied the effects of temperature and X-ray energy variations on the light output signals from two different fiber-optic sensors, a fiber-optic dosimeter (FOD based on a BCF-12 as a plastic scintillating fiber (PSF and a fiber-optic thermometer (FOT using a silver halide optical fiber as an infrared optical fiber (IR fiber. During X-ray beam irradiation, the scintillating light and IR signals were measured simultaneously using a dosimeter probe of the FOD and a thermometer probe of the FOT. The probes were placed in a beaker with water on the center of a hotplate, under variation of the tube potential of a digital radiography system or the temperature of the water in the beaker. From the experimental results, in the case of the PSF, the scintillator light output at the given tube potential decreased as the temperature increased in the temperature range from 25 to 60 °C. We demonstrated that commonly used BCF-12 has a significant temperature dependence of −0.263 ± 0.028%/°C in the clinical temperature range. Next, in the case of the IR fiber, the intensity of the IR signal was almost uniform at each temperature regardless of the tube potential range from 50 to 150 kVp. Therefore, we also demonstrated that the X-ray beam with an energy range used in diagnostic radiology does not affect the IR signals transmitted via a silver halide optical fiber.

  5. Compact acousto-optic imaging spectro-polarimeter for mineralogical investigations in the near infrared.

    Science.gov (United States)

    Belyaev, Denis A; Yushkov, Konstantin B; Anikin, Sergey P; Dobrolenskiy, Yuri S; Laskin, Aleksander; Mantsevich, Sergey N; Molchanov, Vladimir Ya; Potanin, Sergey A; Korablev, Oleg I

    2017-10-16

    Spectral imaging in the near infrared is a promising method for mineralogy analysis, in particular well-suited for airless celestial objects or those with faint atmospheres. Additional information about structure and composition of minerals can be obtained using spectral polarimetry with high spatial resolution. We report design and performance of laboratory prototype for a compact near infrared acousto-optic imaging spectro-polarimeter, which may be implemented for remote or close-up analysis of planetary surfaces. The prototype features telecentric optics, apochromatic design over the bandwidth of 0.8-1.75 µm, and simultaneous imaging of two orthogonal linear polarizations of the same scene with a single FPA detector. When validating the scheme, reflectance spectra of several minerals were measured with the spectral resolution of 100 cm -1 (10 nm passband at 1 µm). When imaging samples, the spatial resolution of 0.6 mm at the target distance of one meter was reached. It corresponds to 100 by 100 diffraction-limited elements resolved at the focal plane array (FPA) for each of the two light polarizations. A similar prototype is also being designed for the spectral range from 1.7 to 3.5 µm. This type of the spectro-polarimeter is considered as a potential reconnaissance and analysis tool for future planetary or moon landers and rovers.

  6. Nanocomposites for high-speed optical modulators and plasmonic thermal mid-infrared emitters

    Science.gov (United States)

    Demir, Veysi

    Demand for high-speed optical modulators and narrow-bandwidth infrared thermal emitters for numerous applications continues to rise and new optical devices are needed to deal with massive data flows, processing powers, and fabrication costs. Conventional techniques are usually hindered by material limitations or electronic interconnects and advances in organic nanocomposite materials and their integration into photonic integrated circuits (PICs) have been acknowledged as a promising alternative to single crystal techniques. The work presented in this thesis uses plasmonic and magneto-optic effects towards the development of novel optical devices for harnessing light and generating high bandwidth signals (>40GHz) at room and cryogenic temperatures (4.2°K). Several publications have resulted from these efforts and are listed at the end of the abstract. In our first published research we developed a narrow-bandwidth mid-infrared thermal emitter using an Ag/dielectric/Ag thin film structure arranged in hexagonal planar lattice structures. PECVD produced nanoamorphous carbon (NAC) is used as a dielectric layer. Spectrally tunable (>2 mum) and narrow bandwidth (resistivity of NAC from 1012 and 109 O.cm with an MoSi2 dopant and increasing the emitter lattice constant from 4 to 7 mum. This technique offers excellent flexibility for developing cost-effective mid-IR sources as compared to costly fiber and quantum cascade lasers (QCLs). Next, the effect of temperature on the Verdet constant for cobalt-ferrite polymer nanocomposites was measured for a series of temperatures ranging from 40 to 200°K with a Faraday rotation polarimeter. No visual change was observed in the films during thermal cycling, and ˜4x improvement was achieved at 40°K. The results are promising and further analysis is merited at 4.2°K to assess the performance of this material for cryogenic magneto-optic modulators for supercomputers. Finally, the dielectric constant and loss tangent of MAPTMS sol

  7. Determination of Propranolol Hydrochloride in Pharmaceutical Preparations Using Near Infrared Spectrometry with Fiber Optic Probe and Multivariate Calibration Methods

    Directory of Open Access Journals (Sweden)

    Jucelino Medeiros Marques Junior

    2015-01-01

    Full Text Available A method for determination of propranolol hydrochloride in pharmaceutical preparation using near infrared spectrometry with fiber optic probe (FTNIR/PROBE and combined with chemometric methods was developed. Calibration models were developed using two variable selection models: interval partial least squares (iPLS and synergy interval partial least squares (siPLS. The treatments based on the mean centered data and multiplicative scatter correction (MSC were selected for models construction. A root mean square error of prediction (RMSEP of 8.2 mg g−1 was achieved using siPLS (s2i20PLS algorithm with spectra divided into 20 intervals and combination of 2 intervals (8501 to 8801 and 5201 to 5501 cm−1. Results obtained by the proposed method were compared with those using the pharmacopoeia reference method and significant difference was not observed. Therefore, proposed method allowed a fast, precise, and accurate determination of propranolol hydrochloride in pharmaceutical preparations. Furthermore, it is possible to carry out on-line analysis of this active principle in pharmaceutical formulations with use of fiber optic probe.

  8. The structure of As{sub 3}Se{sub 5}Te{sub 2} infrared optical glass

    Energy Technology Data Exchange (ETDEWEB)

    Jovari, P., E-mail: jovari@sunserv.kfki.h [Research Institute for Solid State Physics and Optics, H-1525 Budapest, POB 49 (Hungary); Bureau, B. [Equipe Verres et Ceramiques, Laboratoire Sciences Chimiques de Rennes UMR-CNRS 6226, Campus de Beaulieu, Universite de Rennes 1, 35042 Rennes Cedex (France); Kaban, I. [Institut of Physics, Chemnitz University of Technology, D-09107 Chemnitz (Germany); Nazabal, V. [Equipe Verres et Ceramiques, Laboratoire Sciences Chimiques de Rennes UMR-CNRS 6226, Campus de Beaulieu, Universite de Rennes 1, 35042 Rennes Cedex (France); Beuneu, B. [Laboratoire Leon Brillouin, CEA-Saclay 91191 Gif sur Yvette Cedex (France); Ruett, U. [Hamburger Synchrotronstrahlungslabor HASYLAB am Deutschen Elektronen-Synchroton DESY, Notkestrasse 85 D-22603 Hamburg (Germany)

    2009-11-20

    The structure of As{sub 3}Se{sub 5}Te{sub 2} infrared optical glass was investigated by X-ray and neutron diffraction as well as extended X-ray absorption fine structure measurements at the As-, Se- and Te K-edges. The five datasets were modelled simultaneously by the reverse Monte Carlo simulation technique. Experimental data could be fitted satisfactorily by allowing As-Se, As-Te and Se-Te bonds only. It was revealed that the affinity of As is much higher to Se than to Te. The nearest As-Se distance is similar to that found in other vitreous As-Se based alloys, while the As-Te bond length is 0.02-0.04 A shorter in As{sub 3}Se{sub 5}Te{sub 2} than in binary As-Te glasses.

  9. Optical, Infrared, and Ultraviolet Observations of the X-Ray Flash XRF 050416A

    Science.gov (United States)

    Holland, S. T.; Boyd, P. T.; Gorosabel, J.; Hjorth, J.; Schady, P.; Thomsen, B.; Augusteijn, T.; Blustin, A. J.; Breeveld, A.; De Pasquale, M.; Fynbo, J. P. U.; Gehrels, N.; Gronwall, C.; Hunsberger, S.; Ivanushkina, M.; Landsman, W.; Laursen, P.; McGowan, K.; Mangano, V.; Markwardt, C. B.; Marshall, F.; Mason, K. O.; Moretti, A.; Page, M. J.; Poole, T.; Roming, P.; Rosen, S.; Still, M.

    2007-01-01

    We present ultraviolet, optical, and infrared photometry of the afterglow of the X-ray flash XRF 050416A taken between approximately 100 s and 36 days after the burst. We find an intrinsic spectral slope between 1930 and 22200 Å of β=-1.14+/-0.20 and a decay rate of α=-0.86+/-0.15. There is no evidence for a change in the decay rate between approximately 0.7 and 4.7 days after the burst. Our data imply that there is no spectral break between the optical and X-ray bands between 0.7 and 4.7 days after the burst and are consistent with the cooling break being redward of the Ks band (22200 Å) at 0.7 days. The combined ultraviolet/optical/infrared spectral energy distribution shows no evidence for a significant amount of extinction in the host galaxy along the line of sight to XRF 050416A. Our data suggest that the extragalactic extinction along the line of sight to the burst is only approximately AV=0.2 mag, which is significantly less than the extinction expected from the hydrogen column density inferred from X-ray observations of XRF 050416A assuming a dust-to-gas ratio similar to what is found for the Milky Way. The observed extinction, however, is consistent with the dust-to-gas ratio seen in the Small Magellanic Cloud. We suggest that XRF 050416A may have a two-component jet similar to what has been proposed for GRB 030329. If this is the case, the lack of an observed jet break between 0.7 and 42 days is an illusion due to emission from the wide jet dominating the afterglow after approximately 1.5 days.

  10. 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.

  11. Comparison of optical and electron spectra in an infra-red free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, A.M.; Gillespie, W.A.; Martin, P.F. [Univ. of Abertay, Dundee (United Kingdom)] [and others

    1995-12-31

    Time-resolved electron and optical spectra recently acquired at the FELIX facility are presented, showing the evolution of the respective macropulses. A comparison is made between the optical power output during the macropulse and the measured power extracted from the electron beam using a simple model of the cavity losses. Data are available for a wide range of operating conditions: the wavelength range is from 9 {mu}m to 28 {mu}m and detuning are between 1/4{lambda} and 2{lambda}. The effect of rapid electron beam energy changes on the optical and electron spectra will also be discussed.

  12. AGN Obscuration Through Dusty Infrared Dominated Flows. II. Multidimensional, Radiation-Hydrodynamics Modeling

    Science.gov (United States)

    Dorodnitsyn, Anton; Kallman, Tim; Bisno\\vatyiI-Kogan, Gennadyi

    2011-01-01

    We explore a detailed model in which the active galactic nucleus (AGN) obscuration results from the extinction of AGN radiation in a global ow driven by the pressure of infrared radiation on dust grains. We assume that external illumination by UV and soft X-rays of the dusty gas located at approximately 1pc away from the supermassive black hole is followed by a conversion of such radiation into IR. Using 2.5D, time-dependent radiation hydrodynamics simulations in a ux-limited di usion approximation we nd that the external illumination can support a geometrically thick obscuration via out ows driven by infrared radiation pressure in AGN with luminosities greater than 0:05 L(sub edd) and Compton optical depth, Tau(sub T) approx > & 1.

  13. 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.

  14. Transparent infrared-emitting CeF3:Yb-Er polymer nanocomposites for optical applications.

    Science.gov (United States)

    Tan, Mei Chee; Patil, Swanand D; Riman, Richard E

    2010-07-01

    Bright infrared-emitting nanocomposites of unmodified CeF(3):Yb-Er with polymethyl-methacrylate (PMMA) and polystyrene (PS), which offer a vast range of potential applications, which include optical amplifiers, waveguides, laser materials, and implantable medical devices, were developed. For the optical application of these nanocomposites, it is critical to obtain highly transparent composites to minimize absorption and scattering losses. Preparation of transparent composites typically requires powder processing approaches that include sophisticated particle size control, deagglomeration, and dispersion stabilization methods leading to an increase in process complexity and processing steps. This work seeks to prepare transparent composites with high solids loading (>5 vol%) by matching the refractive index of the inorganic particle with low cost polymers like PMMA and PS, so as to circumvent the use of any complex processing techniques or particle surface modification. PS nanocomposites were found to exhibit better transparency than the PMMA nanocomposites, especially at high solids loading (>/=10 vol%). It was found that the optical transparency of PMMA nanocomposites was more significantly affected by the increase in solids loading and inorganic particle size because of the larger refractive index mismatch of the PMMA nanocomposites compared to that of PS nanocomposites. Rayleigh scattering theory was used to provide a theoretical estimate of the scattering losses in these ceramic-polymer nanocomposites.

  15. Composition dependence of optical band gap of the Se-Ge-Te far infrared transmitting glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guoxiang, E-mail: guoxiang_8899@163.co [Faculty of Information Science and Engineering, Ningbo University (China) and State Key Laboratory Base of Novel Functional Materials and Preparation Science, Ningbo 315211 (China); Nie Qiuhua; Wang Xunsi; Dai Shixun; Xu Tiefeng; Shen Xiang [Faculty of Information Science and Engineering, Ningbo University (China); State Key Laboratory Base of Novel Functional Materials and Preparation Science, Ningbo 315211 (China); Zhang Xianghua [Laboratoire des Verres et ceramiques, Universite de Rennes I, 35042 Rennes Cedex (France)

    2010-11-01

    A systematic series of Se{sub x}Ge{sub 25-x}Te{sub 75} (x=0, 5, 10, 15, 20 at%) far infrared transmitting glasses were prepared by traditional melt-quenching method. Physical, thermal and optical properties of the glass system were analyzed. The allowed indirect transition of samples was calculated according to the classical Tauc equation. The results show the density increases with the substitution of Ge by Se and a maximum {Tau}{sub g} value of 175 {sup o}C was obtained for the Se{sub 15}Ge{sub 10}Te{sub 75} glass. The energy band gap of Se{sub 15}Ge{sub 10}Te{sub 75} glass is 1.25 eV, possessing the largest metallization criterion value (0.25) and the lowest refractive index (3.16). When the dissolved amount of Se increased from 0 to 15 at%, the values of indirect optical band gap were in the range from 0.573 to 0.679 eV. A wide optical transparent window with a cut-off wavelength beyond 18 {mu}m was shown.

  16. Near-infrared phosphorescent polymeric nanomicelles: efficient optical probes for tumor imaging and detection.

    Science.gov (United States)

    Kumar, Rajiv; Ohulchanskyy, Tymish Y; Roy, Indrajit; Gupta, Sandesh K; Borek, Carsten; Thompson, Mark E; Prasad, Paras N

    2009-07-01

    We report a formulation of near-infrared (near-IR) phosphorescent polymeric nanomicelles and their use for in vivo high-contrast optical imaging, targeting, and detection of tumors in small animals. Near-IR phosphorescent molecules of Pt(II)-tetraphenyltetranaphthoporphyrin (Pt(TPNP)) were found to maintain their near-IR phosphorescence properties when encapsulated into phospholipid nanomicelles. The prepared phosphorescent micelles are of approximately 100 nm size and are highly stable in aqueous suspensions. A large spectral separation between the Pt(TPNP) absorption, with a peak at approximately 700 nm, and its phosphorescence emission, with a peak at approximately 900 nm, allows a dramatic decrease in the level of background autofluorescence and scattered excitation light in the near-IR spectral range, where the signal from the phosphorescent probe is observed. In vivo animal imaging with subcutaneously xenografted tumor-bearing mice has resulted in high contrast optical images, indicating highly specific accumulation of the phosphorescent micelles into tumors. Using optical imaging with near-IR phosphorescent nanomicelles, detection of smaller, visually undetectable tumors has also been demonstrated.

  17. Optical design, laboratory test, and calibration of airborne long wave infrared imaging spectrometer.

    Science.gov (United States)

    Yuan, Liyin; He, Zhiping; Lv, Gang; Wang, Yueming; Li, Chunlai; Xie, Jia'nan; Wang, Jianyu

    2017-09-18

    We discuss and evaluate a long wave infrared imaging spectrometer in terms of its opto-mechanical design and analysis, alignment, testing, and calibration. The instrument is a practical airborne sensor achieving high spectral resolution and sensitive noise equivalent delta temperature. The instrument operates in the 8 to 12.5 μm spectral region with 28.85 nm spectral sampling, 1 mrad instantaneous field of view, and >40° cross track field. The instrument comprises three uniform sub-modules with identical design parameters and performances. The sub-module design is based on a refractive foreoptics feeding an all-reflective spectrometer. The optical form of the spectrometer is a double-pass reflective triplet with a flat grating, which has a fast f/2 and high optical throughput. Cryogenic optics of 100 K is implemented only for the spectrometer. Assembly and thermal deformation and focusing adjustment design are particularly considered for this low temperature. All the mirrors of the spectrometer are opto-mechanical-integrated designed and manufactured by single-point diamond turning technology. We consider the center sub-module as an example, and we present its laboratory testing results and calibration; the results indicate the instrument's potential value in airborne sensing.

  18. Infrared Radiation Assisted Stokes’ Law Based Synthesis and Optical Characterization of ZnS Nanoparticles

    Directory of Open Access Journals (Sweden)

    Beer Pal Singh

    2016-01-01

    Full Text Available The strategy and technique exploited in the synthesis of nanostructure materials have an explicit effect on the nucleation, growth, and properties of product materials. Nanoparticles of zinc sulfide (ZnS have been synthesized by new infrared radiation (IR assisted and Stokes’ law based controlled bottom-up approach without using any capping agent and stirring. IR has been used for heating the reaction surface designed in accordance with the well-known Stokes law for a free body falling in a quiescent fluid for the synthesis of ZnS nanoparticles. The desired concentration of aqueous solutions of zinc nitrate (Zn(NO32·4H2O and thioacetamide (CH3CSNH2 was reacted in a controlled manner by IR radiation heating at the reaction area (top layer of reactants solution of the solution which results in the formation of ZnS nanoparticles at ambient conditions following Stokes’ law for a free body falling in a quiescent fluid. The phase, crystal structure, and particle size of as-synthesized nanoparticles were studied by X-ray diffraction (XRD. The optical properties of as-synthesized ZnS nanoparticles were studied by means of optical absorption spectroscopic measurements. The optical energy band gap and the nature of transition have been studied using the well-known Tauc relation with the help of absorption spectra of as-synthesized ZnS nanoparticles.

  19. Near infrared phosphorescent polymeric nanomicelles: efficient optical probes for tumor imaging and detection

    Science.gov (United States)

    Kumar, Rajiv; Ohulchanskyy, Tymish Y.; Roy, Indrajit; Gupta, Sandesh K.; Borek, Carsten; Thompson, Mark E.; Prasad, Paras N.

    2013-01-01

    We report a formulation of near infrared (NIR) phosphorescent polymeric nanomicelles and their use for in vivo high contrast optical imaging, targeting and detection of tumors in small animals. NIR phosphorescent molecules of Pt(II)-tetraphenyltetranaphthoporphyrin [Pt(TPNP)] were found to maintain their NIR phosphorescence properties when encapsulated into phospholipid nanomicelles. The prepared phosphorescent micelles are of ~100 nm size and are highly stable in aqueous suspensions. A large spectral separation between Pt(TPNP) absorption, peaked at ~700 nm, and its phosphorescence emission, with peak at ~ 900 nm, allows a dramatic decrease in the level of background autofluorescence and scattered excitation light in the NIR spectral range, where the signal from phosphorescent probe is observed. In vivo animal imaging with subcutaneously xenograted tumor-bearing mice has resulted in high contrast optical images, indicating highly specific accumulation of the phosphorescent micelles into tumors. Using optical imaging with NIR phosphorescent nanomicelles, detection of smaller, visually undetectable tumors has also been demonstrated. PMID:20355951

  20. Transmission in near-infrared optical windows for deep brain imaging.

    Science.gov (United States)

    Shi, Lingyan; Sordillo, Laura A; Rodríguez-Contreras, Adrián; Alfano, Robert

    2016-01-01

    Near-infrared (NIR) radiation has been employed using one- and two-photon excitation of fluorescence imaging at wavelengths 650-950 nm (optical window I) for deep brain imaging; however, longer wavelengths in NIR have been overlooked due to a lack of suitable NIR-low band gap semiconductor imaging detectors and/or femtosecond laser sources. This research introduces three new optical windows in NIR and demonstrates their potential for deep brain tissue imaging. The transmittances are measured in rat brain tissue in the second (II, 1,100-1,350 nm), third (III, 1,600-1,870 nm), and fourth (IV, centered at 2,200 nm) NIR optical tissue windows. The relationship between transmission and tissue thickness is measured and compared with the theory. Due to a reduction in scattering and minimal absorption, window III is shown to be the best for deep brain imaging, and windows II and IV show similar but better potential for deep imaging than window I. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. MODELLING OF EXTRINSIC FIBER OPTIC SAGNAC ...

    African Journals Online (AJOL)

    ABSTRACT. Ultrasonic waves are used extensively in nondestructive testing both for characterization of material properties, in this paper, we describe a fiber optic sensor suitable for detection of ultrasonic waves. This sensor is based on an extrinsic fiber optic sagnac interferometer. The proposed sensor model can act as a ...

  2. Detection of the dusty torus in AGN with COMIC, the new infrared camera dedicated to the ESO adaptive optics system.

    Science.gov (United States)

    Marco, Olivier

    1997-10-01

    High angular resolution observation has greatly benefitted from adaptive optic systems working in the infrared. The COMIC camera, the second camera dedicated to ADONIS, the ESO 3.60 meter telescope adaptive optics system, allows observation in the spectral range 3-5 micron at the diffraction limit of the telescope. The characterization of the camera at the Meudon and Grenoble laboratories, then its performances determination on the sky in Chile constitute the first part of this dissertation. A new method for evaluating the limiting magnitudes is proposed which takes into account the various contributions to the detectivity loss between laboratory testing and real condition observations. This approach can be transferred to any other case where a priori observing conditions are known ( Strehl ratio or seeing ). Study of the central region of Active Galactic Nuclei (~1 arcsec) requires high angular resolution. In particular, warm and hot dust is emissive in the 1-5 micron spectral region. Thus, adaptive optics observations are well suited to AGN observation. It is predicted that the central engine and its neighboring environment are embedded within an optically thin dusty/molecular torus which may, along some lines of sight, obscure and even fully hide the nuclear emission leading to distinct observational properties for objects supposed to be identical. Observations made with ADONIS & COMIC of NGC7469 and NGC1068 have shown large amounts of dust located in the torus but also mixed with gas from the narrow line emission region. The high angular resolution achieved has allowed the determination of the dust temperature, mass and spatial distribution around the AGN central engine. These results are in agreement with several torus models and could help to constrain them.

  3. 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

  4. 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

  5. Comparison of Fiber Optic and Conduit Attenuated Total Reflection (ATR) Fourier Transform Infrared (FT-IR) Setup for In-Line Fermentation Monitoring.

    Science.gov (United States)

    Koch, Cosima; Posch, Andreas E; Herwig, Christoph; Lendl, Bernhard

    2016-12-01

    The performance of a fiber optic and an optical conduit in-line attenuated total reflection mid-infrared (IR) probe during in situ monitoring of Penicillium chrysogenum fermentation were compared. The fiber optic probe was connected to a sealed, portable, Fourier transform infrared (FT-IR) process spectrometer via a plug-and-play interface. The optical conduit, on the other hand, was connected to a FT-IR process spectrometer via a knuckled probe with mirrors that had to be adjusted prior to each fermentation, which were purged with dry air. Penicillin V (PenV) and its precursor phenoxyacetic acid (POX) concentrations were determined by online high-performance liquid chromatography and the obtained concentrations were used as reference to build partial least squares regression models. Cross-validated root-mean-square errors of prediction were found to be 0.2 g L -1 (POX) and 0.19 g L -1 (PenV) for the fiber optic setup and 0.17 g L -1 (both POX and PenV) for the conduit setup. Higher noise-levels and spectrum-to-spectrum variations of the fiber optic setup lead to higher noise of estimated (i.e., unknown) POX and PenV concentrations than was found for the conduit setup. It seems that trade-off has to be made between ease of handling (fiber optic setup) and measurement accuracy (optical conduit setup) when choosing one of these systems for bioprocess monitoring. © The Author(s) 2016.

  6. Gas leak detection in infrared video with background modeling

    Science.gov (United States)

    Zeng, Xiaoxia; Huang, Likun

    2018-03-01

    Background modeling plays an important role in the task of gas detection based on infrared video. VIBE algorithm is a widely used background modeling algorithm in recent years. However, the processing speed of the VIBE algorithm sometimes cannot meet the requirements of some real time detection applications. Therefore, based on the traditional VIBE algorithm, we propose a fast prospect model and optimize the results by combining the connected domain algorithm and the nine-spaces algorithm in the following processing steps. Experiments show the effectiveness of the proposed method.

  7. Electroarchitected porous platinum on metallic multijunction nanolayers to optimize their optical properties for infrared sensor application.

    Science.gov (United States)

    Stanca, Sarmiza Elena; Haenschke, Frank; Zieger, Gabriel; Dellith, Jan; Dellith, Andrea; Ihring, Andreas; Belkner, Johannes; Meyer, Hans-Georg

    2018-01-09

    Tailoring the physicochemical properties of the metallic multijunction nanolayers is a prerequisite for the development of microelectronics. From this perspective, a desired lower reflectance of infrared radiation was achieved by an electrochemical deposition of porous platinum in nonaqueous media on silver mirror supported nickel-chrom and nickel-titanium metallic films with incremental decreasing thicknesses from 80 nm to 10 nm. The electroassembled architectures were examined by means of SEM and FTIR and it was observed that the layer and sublayer thicknesses and resistivities have a substantial effect upon the porous platinum morphology and its optical properties. It is here reported that the augmentation of the metallic layer electrical conductivity determines the electroformation of more compact platinum nanolayers. Moreover, the platinum black coating of metallic nanolayers causes a considerable decrease of the reflectance in the region from 1000 cm-1 to 8000 cm-1. © 2018 IOP Publishing Ltd.

  8. Physical, thermal, infrared and optical properties of Nd3+ doped lithium–lead-germanate glasses

    International Nuclear Information System (INIS)

    Veeranna Gowda, V.C.

    2015-01-01

    The structure–property relationships of neodymium doped lithium–lead-germanate glasses were investigated. The density was found to increase with the increase of Nd 2 O 3 concentration and its variation is explained in terms of its molecular mass, structural transformation and packing density. Addition of modifier oxide to lead-germanate glass suggests a decreased free space within the glass matrix, resulting in the formation of stiff network. The increase in glass transition temperature specifies strengthening of glass by forming bridging oxygens. The optical properties of glass were measured employing UV–visible spectroscopy. The refractive index values varied nonlinearly with Nd 2 O 3 concentration and were speculated to depend on the electronic polarizability of oxide glasses. The frequencies of the infrared absorption bands were affected marginally and the absorption peaks revealed that the glass matrix consists of [GeO 4/2 ], [GeO 6/2 ] and [PbO 4/2 ] structural units

  9. Optical properties of drying wood studied by time-resolved near-infrared spectroscopy.

    Science.gov (United States)

    Konagaya, Keiji; Inagaki, Tetsuya; Kitamura, Ryunosuke; Tsuchikawa, Satoru

    2016-05-02

    We measured the optical properties of drying wood with the moisture contents ranging from 10% to 200%. By using time-resolved near-infrared spectroscopy, the reduced scattering coefficient μs' and absorption coefficient μa were determined independent of each other, providing information on the chemical and structural changes, respectively, of wood on the nanometer scale. Scattering from dry pores dominated, which allowed us to determine the drying process of large pores during the period of constant drying rate, and the drying process of smaller pores during the period of decreasing drying rate. The surface layer and interior of the wood exhibit different moisture states, which affect the scattering properties of the wood.

  10. Optoelectronic measurement system for testing the optical parameters of infrared seeker

    Science.gov (United States)

    He, Wenjun; Liu, Zhiying; Fu, Yuegang

    2018-01-01

    We propose an optoelectronic measurement system for testing the optical parameters of infrared seeker, such as the position of the image plane, the size of the diffused spot, and the diameter of the scanning circle. The measurement method and operating principle of the optoelectronic measurement system have been introduced. The source of the stray light in the optoelectronic measurement system have been analyzed by using FRED software, and the stray light have been restricted effectively by a co-centered mica plate which closes to the substrate of pinhole. Experimental results show that the test error for the size of the diffused spot is less than +/-0.01 mm, the test errors for the position of the image plane and the diameter of the scanning circle are less than +/-0.02 mm.

  11. Hyperfine spectrum measurement of an optically pumped far-infrared laser with a Michelson interferometer

    International Nuclear Information System (INIS)

    Zuo, Z G; Ling, F R; Wang, P; Liu, J S; Yao, J Q; Weng, C X

    2013-01-01

    In this letter, we present a Michelson interferometer for the hyperfine spectrum measurement of an optically pumped far-infrared laser with a highest frequency resolution of 3–5 GHz. CH 3 OH gas with a purity of 99.9%, is pumped by the CO 2 9P36 and 9R10 laser lines to generate terahertz lasers with frequencies of 2.52 and 3.11 THz, respectively. Moreover, except for the center frequency, which is in good agreement with theoretical work, some additional frequencies on both sides of the center frequency are obtained at a frequency interval of 0.15 THz. Meanwhile, the mechanism behind the observed experimental results is also investigated. (letter)

  12. 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.

  13. 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.

  14. High energy eye-safe and mid-infrared optical parametric oscillator

    International Nuclear Information System (INIS)

    Liu, J; Liu, Q; Huang, L; Gong, M

    2010-01-01

    A high energy eye-safe and mid-infrared optical parametric oscillator (OPO) is demonstrated. The nonlinear media is a Y-cut KTA crystal with the length of 20 mm, which is pumped by a Nd:YAG laser. Both eye-safe and mid-infrared laser are output with high energy. When the pump energy is 1 J and the pulse duration is 10 ns, we get 53 mJ idler at 3.632 μm and 151 mJ signal at 1.505 μm. As we know, the idler energy is the highest at the wavelength beyond 3.5 μm and the signal energy is the highest with Y-cut KTA. The results prove that the Y-cut KTA crystal can produce the signal and idler with the energies as high as these in the paper. We have tested the temperature-tuning characters and the coefficient of the idler is 0.26 nm/°C

  15. Optical and infrared spectrophotometry of the symbiotic system V1016 Cygni

    International Nuclear Information System (INIS)

    Rudy, R.J.; Rossano, G.S.; Cohen, R.D.; Puetter, R.C.

    1990-01-01

    Spectrophotometry from 0.46 to 1.3 micron of the peculiar emission-line object V1016 Cyg is presented. The optical region displays a weak continuum underlying the rich emission-line spectrum detailed in past studies. The infrared spectrum consists of prominent emission lines of H I, He I, He II, forbidden Ni, O I, and forbidden S III overlying a strong stellar continuum. The latter displays bands at 0.94 micron and 1.13 micron characteristic of a late-type, oxygen-rich giant as well as an absorption at 1.05 micron which is due to VO. The presence of these molecular features indicates a spectral class of M6 or later for the cool secondary. The reddening of the secondary does not appear to be much different from that of the emission lines. Among the infrared emission features is the rarely seen permitted transition of neutral oxygen at 1.1287 micron. Its presence at a strength comparable to O I 8446 A, together with the absence of O I 13164 A, confirms the result of Strafella that the strong O I lines arise primarily from fluorescent excitation by Ly-beta. 62 refs

  16. Optical and infrared spectroscopic studies of chemical sensing by copper phthalocyanine thin films

    International Nuclear Information System (INIS)

    Singh, Sukhwinder; Tripathi, S.K.; Saini, G.S.S.

    2008-01-01

    Thin films of copper phthalocyanine have been deposited on KBr and glass substrates by thermal evaporation method and characterized by the X-ray diffraction and optical absorption techniques. The observed X-ray pattern suggests the presence of α crystalline phase of copper phthalocyanine in the as-deposited thin films. Infrared spectra of thin films on the KBr pallet before and after exposure to the vapours of ammonia and methanol have been recorded in the wavenumber region of 400-1650 cm -1 . The observed infrared bands also confirm the α crystalline phase. On exposure, change in the intensity of some bands is observed. A new band at 1385 cm -1 , forbidden under ideal D 4h point group symmetry, is also observed in the spectra of exposed thin films. These changes in the spectra are interpreted in terms of the lowering of molecular symmetry from D 4h to C 4v . Axial ligation of the vapour molecules on fifth coordination site of the metal ion is responsible for lowering of the molecular symmetry

  17. Continuous-wave, singly resonant parametric oscillator-based mid-infrared optical vortex source.

    Science.gov (United States)

    Aadhi, A; Sharma, Varun; Singh, R P; Samanta, G K

    2017-09-15

    We report on a high-power, continuous-wave source of optical vortices tunable in the mid-infrared (mid-IR) wavelength range. Using the orbital angular momentum (OAM) conservation of the parametric processes and the threshold conditions of the cavity modes of the singly resonant optical parametric oscillator (SRO), we have transferred the OAM of the pump beam at the near-infrared wavelength to the idler beam tunable in the mid-IR. Pumped with a vortex beam of order l p =1 at 1064 nm, the SRO, configured in a four curved mirror-based ring cavity with a 50 mm long MgO-doped periodically poled LiNbO 3 crystal, produces an idler beam with an output power in excess of 2 W in a vortex spatial profile with the order l i =1, tunable across 2217-3574 nm and corresponding signal beam in Gaussian intensity distribution across 1515-2046 nm. For pump vortices of the order l p =1 and 2, and a power of 22 W, the SRO produces idler vortices of the same order as that of the pump beam with a maximum power of 5.23 and 2.3 W, corresponding to near-IR to mid-IR vortex conversion efficiency of 23.8% and 10.4%, respectively. The idler vortex beam has a spectral width, and a passive rms power stability of 101 MHz and 4.9% over 2 h, respectively.

  18. 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.

  19. 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.

  20. Mid-infrared continuous wave cavity ring down spectroscopy of molecular ions using an optical parametric oscillator

    NARCIS (Netherlands)

    Verbraak, H.; Ngai, A.K.Y.; Persijn, S.T.; Harren, F.J.M.; Linnartz, H.

    2007-01-01

    A sensitive infrared detection scheme is presented in which continuous wave cavity ring down spectroscopy is used to record rovibrational spectra of molecular ions in direct absorption through supersonically expanding planar plasma. A cw optical parametric oscillator is used as a light source and

  1. Intense Far-Infrared Free-Electron Laser-Pulses with a Length of 6 Optical Cycles

    NARCIS (Netherlands)

    Knippels, G.M.H.; R F X A M Mols,; van der Meer, A. F. G.; Oepts, D.; van Amersfoort, P. W.

    1995-01-01

    Second-order optical autocorrelation measurements are reported for a far-infrared free-electron laser. Second-harmonic generation in an 840-mu m-long CdTe crystal is used to provide the nonlinear autocorrelation signal. At wavelengths of 10.4 and 24.5 mu m, FWHM pulse durations of 220 and 500 fs,

  2. The Absolute Age of the Globular Cluster M15 Using Near-infrared Adaptive Optics Images from PISCES/LBT.

    NARCIS (Netherlands)

    Monelli, M.; Testa, V.; Bono, G.; Ferraro, I.; Iannicola, G.; Fiorentino, G.; Arcidiacono, C.; Massari, D.; Boutsia, K.; Briguglio, R.; Busoni, L.; Carini, R.; Close, L.; Cresci, G.; Esposito, S.; Fini, L.; Fumana, M.; Guerra, J. C.; Hill, J.; Kulesa, C.; Mannucci, F.; McCarthy, D.; Pinna, E.; Puglisi, A.; Quiros-Pacheco, F.; Ragazzoni, R.; Riccardi, A.; Skemer, A.; Xompero, M.

    2015-01-01

    We present deep near-infrared J, {K}{{s}} photometry of the old, metal-poor Galactic globular cluster M15 obtained with images collected with the LUCI1 and PISCES cameras available at the Large Binocular Telescope (LBT). We show how the use of First Light Adaptive Optics (FLAO) system coupled with

  3. Optical Design of a Broadband Infrared Spectrometer for Bunch Length Measurement at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kiel; /SLAC

    2012-09-07

    The electron pulses generated by the Linac Coherent Light Source at the SLAC National Accelerator Laboratory occur on the order of tens of femtoseconds and cannot be directly measured by conventional means. The length of the pulses can instead be reconstructed by measuring the spectrum of optical transition radiation emitted by the electrons as they move toward a conducting foil. Because the emitted radiation occurs in the mid-infrared from 0.6 to 30 microns a novel optical layout is required. Using a helium-neon laser with wavelength 633 nm, a series of gold-coated off-axis parabolic mirrors were positioned to direct a beam through a zinc selenide prism and to a focus at a CCD camera for imaging. Constructing this layout revealed a number of novel techniques for reducing the aberrations introduced into the system by the off-axis parabolic mirrors. The beam had a recorded radius of less than a millimeter at its final focus on the CCD imager. This preliminary setup serves as a model for the spectrometer that will ultimately measure the LCLS electron pulse duration.

  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. 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.

  6. Infrared Thermography in Serotonin-Induced Itch Model in Rats

    DEFF Research Database (Denmark)

    Jasemian, Yousef; Gazerani, Parisa; Dagnæs-Hansen, Frederik

    2012-01-01

    The study validated the application of infrared thermography in a serotonin-induced itch model in rats since the only available method in animal models of itch is the count of scratching bouts. Twenty four adult Sprague-Dawley male rats were used in 3 experiments: 1) local vasomotor response...... with no scratching reflex was investigated. Serotonin elicited significant scratching and lowered the local temperature at the site of injection. A negative dose-temperature relationship of serotonin was found by thermography. Vasoregulation at the site of serotonin injection took place in the absence of scratching...

  7. Improving optical contact for functional near‑infrared brain spectroscopy and imaging with brush optodes

    Science.gov (United States)

    Khan, Bilal; Wildey, Chester; Francis, Robert; Tian, Fenghua; Delgado, Mauricio R.; Liu, Hanli; MacFarlane, Duncan; Alexandrakis, George

    2012-01-01

    A novel brush optode was designed and demonstrated to overcome poor optical contact with the scalp that can occur during functional near infrared spectroscopy (fNIRS) and imaging due to light obstruction by hair. The brush optodes were implemented as an attachment to existing commercial flat-faced (conventional) fiber bundle optodes. The goal was that the brush optodes would thread through hair and improve optical contact on subjects with dense hair. Simulations and experiments were performed to assess the magnitude of these improvements. FNIRS measurements on 17 subjects with varying hair colors (blonde, brown, and black) and hair densities (0–2.96 hairs/mm2) were performed during a finger tapping protocol for both flat and brush optodes. In addition to reaching a study success rate of almost 100% when using the brush optode extensions, the measurement setup times were reduced by a factor of three. Furthermore, the brush optodes enabled improvements in the activation signal-to-noise ratio (SNR) by up to a factor of ten as well as significant (p faced fiber bundles and individual fibers for a given subject. PMID:22567582

  8. Infrared optical properties of a coal-fired power plant plume

    International Nuclear Information System (INIS)

    Stearns, L.P.; Pueschel, R.F.

    1983-01-01

    Infrared measurements in the 8--14-μm spectral region were made of two coal-fired power plant plumes and area haze in the Four Corners region of New Mexico from 1 to 7 Nov. 1980. The layer tranmittance, optical depth, and volume extinction coefficient derived from measurements on four nonconsecutive days show the effects of the plumes on the IR optical properties of the atmosphere. The average contribution of the plume alone to the IR extinction coefficient was 74% at the Four Corners plant; the background haze contributed 7--11%. More efficient particulate emission control at the San Juan power plant reduced the average contribution of its plume to 57% of the extinction coefficient. The haze contributed an average of 16%. The results show an increase with time of the haze bulk extinction coefficient during a persistent anticyclonic synoptic situation. Extinction coefficients of the haze showed a linearity with particulate loading, which led to estimates of IR volume extinctions of the free troposphre from aerosol measurements

  9. Optical properties of metals: Infrared emissivity in the anomalous skin effect spectral region

    Energy Technology Data Exchange (ETDEWEB)

    Echániz, T. [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, UPV/EHU, Sarriena s/n, Leioa 48940 (Spain); Pérez-Sáez, R. B., E-mail: raul.perez@ehu.es; Tello, M. J. [Departamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, UPV/EHU, Sarriena s/n, Leioa 48940 (Spain); Instituto de Síntesis y Estudio de Materiales, Universidad del País Vasco, Apdo. 644, Bilbao 48080 (Spain)

    2014-09-07

    When the penetration depth of an electromagnetic wave in a metal is similar to the mean free path of the conduction electrons, the Drude classical theory is no longer satisfied and the skin effect becomes anomalous. Physical parameters of this theory for twelve metals were calculated and analyzed. The theory predicts an emissivity peak ε{sub peak} at room temperature in the mid-infrared for smooth surface metals that moves towards larger wavelengths as temperature decreases. Furthermore, the theory states that ε{sub peak} increases with the emission angle but its position, λ{sub peak}, is constant. Copper directional emissivity measurements as well as emissivity obtained using optical constants data confirm the predictions of the theory. Considering the relationship between the specularity parameter p and the sample roughness, it is concluded that p is not the simple parameter it is usually assumed to be. Quantitative comparison between experimental data and theoretical predictions shows that the specularity parameter can be equal to one for roughness values larger than those predicted. An exhaustive analysis of the experimental optical parameters shows signs of a reflectance broad peak in Cu, Al, Au, and Mo around the wavelength predicted by the theory for p = 1.

  10. Infrared optical imaging of matrix metalloproteinases (MMPs up regulation following ischemia reperfusion is ameliorated by hypothermia

    Directory of Open Access Journals (Sweden)

    Barber Philip A

    2012-06-01

    Full Text Available Abstract Background We investigated the use of a new MMP activatable probe MMPSense™ 750 FAST (MMPSense750 for in-vivo visualization of early MMP activity in ischemic stroke. Following middle cerebral artery occlusion (MCAO optical imaging was performed. Near-infrared (NIR fluorescent images of MMPSense activation were acquired using an Olympus fluorescent microscope, 1.25x objective, a CCD camera and an appropriate filter cube for detecting the activated probe with peak excitation and emission at 749 and 775 nm, respectively. Images were acquired starting at 2 or 24 hours after reperfusion over the ipsilateral and contralateral cortex before and for 3 hours after, MMPSense750 was injected. Results Increased intensities ipsilaterally were observed following MMPSense750 injection with ischemic injury but not in sham animals. There were significant ipsilateral and contralateral differences at 15 minutes (P Conclusions Matrix-metalloproteinase upregulation in ischemia reperfusion can be imaged acutely in-vivo with NIRF using MMPSense750. Hypothermia attenuated both the optical increase in intensity after MMPSense750 and the increase in MMP-9 protein expression supporting the proof of concept that NIRF imaging using MMPSense can be used to assess potential therapeutic strategies for stroke treatment.

  11. Model study of combined electrical and near-infrared neural stimulation on the bullfrog sciatic nerve.

    Science.gov (United States)

    You, Mengxian; Mou, Zongxia

    2017-07-01

    This paper implemented a model study of combined electrical and near-infrared (808 nm) neural stimulation (NINS) on the bullfrog sciatic nerve. The model includes a COMSOL model to calculate the electric-field distribution of the surrounding area of the nerve, a Monte Carlo model to simulate light transport and absorption in the bullfrog sciatic nerve during NINS, and a NEURON model to simulate the neural electrophysiology changes under electrical stimulus and laser irradiation. The optical thermal effect is considered the main mechanism during NINS. Therefore, thermal change during laser irradiation was calculated by the Monte Carlo method, and the temperature distribution was then transferred to the NEURON model to stimulate the sciatic nerve. The effects on thermal response by adjusting the laser spot size, energy of the beam, and the absorption coefficient of the nerve are analyzed. The effect of the ambient temperature on the electrical stimulation or laser stimulation and the interaction between laser irradiation and electrical stimulation are also studied. The results indicate that the needed stimulus threshold for neural activation or inhibition is reduced by laser irradiation. Additionally, the needed laser energy for blocking the action potential is reduced by electrical stimulus. Both electrical and laser stimulation are affected by the ambient temperature. These results provide references for subsequent animal experiments and could be of great help to future basic and applied studies of infrared neural stimulation (INS).

  12. Optical properties of erbium doped antimony based glasses: Promising visible and infrared amplifiers materials

    Energy Technology Data Exchange (ETDEWEB)

    Hamzaoui, M.; Baazouzi, M. [UMR 6226- Verres et Ceramiques - Campus de Beaulieu, Universite de Rennes1, 35042 Rennes (France); Departement de physique, Faculte des sciences exactes, Universite de Biskra, BP 145, RP, 07000, Biskra (Algeria); Soltani, M.T.; Tioua, B. [Departement de physique, Faculte des sciences exactes, Universite de Biskra, BP 145, RP, 07000, Biskra (Algeria); Ivanova, Z.G. [Institute of Solid State Physics, Bulgarian Academy of Sciences, 1784 Sofia (Bulgaria); Lebullenger, R.; Poulain, M. [UMR 6226- Verres et Ceramiques - Campus de Beaulieu, Universite de Rennes1, 35042 Rennes (France); Zavadil, J. [Institute of Photonics and Electronics AS CR, 182 51 Prague 8-Kobylisy (Czech Republic)

    2012-11-15

    Highly stable glasses in the (70 - x)Sb{sub 2}O{sub 3}-20Na{sub 2}O-10ZnO-xEr{sub 2}O{sub 3} (x = 0.25, 0.5, and 1.0 mol%) system have been prepared and investigated by UV-Vis-NIR absorption, near infrared photoluminescence and time-resolved spectroscopy. Judd-Ofelt study has been used to determine the intensity parameters ({Omega}{sub 2}, {Omega}{sub 4}, and {Omega}{sub 6}), spontaneous emission probabilities, branching ratios, and radiative lifetimes ({tau}{sub R}) related to the corresponding optical transitions of Er{sup 3+} ions. Details of the emission at {proportional_to}1530 nm and spectroscopic characteristics such as the stimulated emission cross-section ({sigma}{sub e}), effectiveband width ({Delta}{lambda}{sub eff}), quantum efficiency, and the optical gain have been summarized, accounting the role of the increased Er content. The obtained results indicate that these new low phonon energy glasses could be used as a laser medium and for optical amplification in the 1.5 {mu}m region. In particular, the composition containing 0.5 mol% Er{sub 2}O{sub 3} exhibits optimal values of {Omega}{sub 2} (4.5 x 10{sup -20} cm{sup 2}), {Delta}{lambda}{sub eff} = 57 nm, {sigma}{sub e} = 7.28 x 10{sup -21} cm{sup 2}, {tau}{sub meas} (3.36 ms), and quantum efficiency of the {sup 4}I{sub 13/2} level of Er{sup 3+} ions {proportional_to}71%. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Molded, wafer level optics for long wave infra-red applications

    Science.gov (United States)

    Franks, John

    2016-05-01

    For many years, the Thermal Imaging market has been driven by the high volume consumer market. The first signs of this came with the launch of night vision systems for cars, first by Cadillac and Honda and then, more successfully by BMW, Daimler and Audi. For the first time, simple thermal imaging systems were being manufactured at the rate of more than 10,000 units a year. This step change in volumes enabled a step change in system costs, with thermal imaging moving into the consumer's price range. Today we see that the consumer awareness and the consumer market continues to increase with the launch of a number of consumer focused smart phone add-ons. This has brought a further step change in system costs, with the possibility to turn your mobile phone into a thermal imager for under $250. As the detector technology has matured, the pixel pitches have dropped from 50μm in 2002 to 12 μm or even 10μm in today's detectors. This dramatic shrinkage in size has had an equally dramatic effect on the optics required to produce the image on the detector. A moderate field of view that would have required a focal length of 40mm in 2002 now requires a focal length of 8mm. For wide field of view applications and small detector formats, focal lengths in the range 1mm to 5mm are becoming common. For lenses, the quantity manufactured, quality and costs will require a new approach to high volume Infra-Red (IR) manufacturing to meet customer expectations. This, taken with the SwaP-C requirements and the emerging requirement for very small lenses driven by the new detectors, suggests that wafer scale optics are part of the solution. Umicore can now present initial results from an intensive research and development program to mold and coat wafer level optics, using its chalcogenide glass, GASIR®.

  14. High-efficiency mid-infrared optical parametric amplifier with approximate uniform rectangular pump distribution

    Science.gov (United States)

    Wei, Xingbin; Peng, Yuefeng; Luo, Xingwang; Zhou, Tangjian; Peng, Jue; Nie, Zan; Gao, Jianrong

    2017-10-01

    We present a high-efficiency mid-infrared optical parametric amplifier (OPA) pumped by a Nd:YAG slab laser with rectangular beam distribution. To improve the conversion efficiency of OPA, we used an approximate uniform pump beam, which helped most of the pump area maintain the optimal intensity to reduce the back conversion effect. The uniform pump distribution without any peak intensity also reduced the damage chances of the nonlinear crystal of PPMgOLN and increased its pump power capability in power-scaling operations. To make sufficient usage of the narrow and small interface of PPMgOLN, we chose a rectangular pump shape whose size was adjusted to match the maximum effective interface of PPMgOLN. The idler laser of 3.82 μm from an optical parametric oscillator (OPO) was powerscaled in the following OPA system. We used two 1.064 μm lasers to pump the OPO and OPA separately. The pulsewidth adjustment and pulse synchronization of the 1 μm pump laser and 3.82 μm seed laser were realized by changing the parameters of the two acoustic-optical Q-switches in the two pump lasers. With the input pump power of 293.4 W, the amplified 3.82 μm laser power was 40.3 W deducting the injected seed laser power of 2.9 W from OPO. The corresponding conversion efficiency from the pump to the idler was 13.7% for the PPMgOLN OPA.

  15. Nanowire assembly, e.g. for optical probes, comprises optically trapping high aspect ratio semiconductor nanowire with infrared single-beam optical trap and attaching nanowire to organic or inorganic structure

    OpenAIRE

    Pauzauskie, P.; Radenovic, A.; Trepagnier, E.; Liphardt, J.; Yang, P.

    2007-01-01

    NOVELTY - A nanowire assembly method comprises optically trapping a semiconductor nanowire with an infrared single-beam optical trap and attaching the nanowire to an organic or inorganic structure by laser fusing. The nanowire is further trapped in a fluid environment. The optical trap has a beam wavelength of 1064 nm. The nanowire has an aspect ratio greater than 100 and a diameter less than 100 (preferably less than 80) nm. The nanowire and the organic or inorganic structure form a heterost...

  16. Characterization and control of the electro-optic phase dispersion in lithium niobate modulators for wide spectral band interferometry applications in the mid-infrared.

    Science.gov (United States)

    Heidmann, S; Ulliac, G; Courjal, N; Martin, G

    2017-05-10

    Mid-infrared wideband modulation (3.2-3.7 μm) is achieved in an electro-optic Y-junction using lithium niobate waveguides in TE polarized light. Comparison between external (scanning mirror) and internal (electro-optical) modulation allows studying the chromatic polynomial dependence of the relative phase. Internal modulation consists on a V AC ramp up to 370 V at 0.25 Hz, applied over 14 mm long electrodes with 14 μm separation. The overall V π L π obtained is 17.5 V·cm, meaning that using a 300 V generator we can actively scan and track the whole L-band (3.4-4.1 μm) wideband fringes. We observe a dramatic reduction of the coherence length under electro-optic modulation, which is attributed to a strong nonlinear dependence of the electro-optic effect on the wavelength upon application of such high voltages. We study the effect of applying a V DC offset, from -50  V to 200 V (50 V step). We characterize this dispersion and propose an improved dispersion model that is used to show active dispersion compensation in wideband fringe modulation in the mid-infrared. This can be useful for long baseline interferometry or pulse compression applications when light propagates along fibers, in order to compensate for chromatic effects that induce differential dispersion or pulse spreading, respectively.

  17. Behavioral Model of High Performance Camera for NIF Optics Inspection

    International Nuclear Information System (INIS)

    Hackel, B M

    2007-01-01

    The purpose of this project was to develop software that will model the behavior of the high performance Spectral Instruments 1000 series Charge-Coupled Device (CCD) camera located in the Final Optics Damage Inspection (FODI) system on the National Ignition Facility. NIF's target chamber will be mounted with 48 Final Optics Assemblies (FOAs) to convert the laser light from infrared to ultraviolet and focus it precisely on the target. Following a NIF shot, the optical components of each FOA must be carefully inspected for damage by the FODI to ensure proper laser performance during subsequent experiments. Rapid image capture and complex image processing (to locate damage sites) will reduce shot turnaround time; thus increasing the total number of experiments NIF can conduct during its 30 year lifetime. Development of these rapid processes necessitates extensive offline software automation -- especially after the device has been deployed in the facility. Without access to the unique real device or an exact behavioral model, offline software testing is difficult. Furthermore, a software-based behavioral model allows for many instances to be running concurrently; this allows multiple developers to test their software at the same time. Thus it is beneficial to construct separate software that will exactly mimic the behavior and response of the real SI-1000 camera

  18. Target recognition: fusing long-wave infrared and electro-optical imagery for detection of humans in a scene

    Science.gov (United States)

    Woodyard, R. L.; Skipper, J. A.; Repperger, D. W.

    2009-05-01

    We aim to identify humans in multimodal imagery by predicting the human long-wave infrared (LWIR) signature in a variety of scenarios. By adapting Tanabe's thermocomfort model, we simulate human body heat flow both between tissue layers (core, muscle, fat and skin) and between body segments (head, chest, upper arm, etc.). To assess the validity of our implementation, we simulated the conditions described in actual human subject studies, and compared our results to values reported in the literature. Inputs to the model include age, height, weight, clothing, physical activity and ambient conditions, including temperature, humidity and wind velocity. Iteration of heat transport equations and a thermoregulatory component yields temporal data of segment surface temperature. Our model was found to be in close agreement with experimentally collected data, with a maximum deviation from literature values of approximately 0.80%. By comparing the predicted human thermal signature to deblurred LWIR images and then fusing this information at the feature level with high-resolution electro-optical image data, we can facilitate identity detection of objects in a scene acquired under different conditions. Ultimately, our goal is to differentiate humans from their surroundings and label non-human objects as thermal clutter.

  19. Optimal hemodynamic response model for functional near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Muhammad Ahmad Kamran

    2015-06-01

    Full Text Available Functional near-infrared spectroscopy (fNIRS is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650-950 nm wavelengths. The cortical hemodynamic response (HR differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF is modeled by using two Gamma functions with six unknown parameters. The HRF model is supposed to be linear combination of HRF, baseline and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown. An objective function is developed as a square of the residuals with constraints on twelve free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using ten real and fifteen simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis, i.e., (t-value >tcritical and p-value < 0.05.

  20. Optical Evaluation of the Rear Contacts of Crystalline Silicon Solar Cells by Coupled Electromagnetic and Statistical Ray-Optics Modeling

    KAUST Repository

    Dabirian, Ali

    2017-02-15

    High-efficiency crystalline silicon (c-Si) solar cells increasingly feature sophisticated electron and hole contacts aimed at minimizing electronic losses. At the rear of photovoltaic devices, such contacts—usually consisting of stacks of functional layers—offer opportunities to enhance the infrared response of the solar cells. Here, we propose an accurate and simple modeling procedure to evaluate the infrared performance of rear contacts in c-Si solar cells. Our method combines full-wave electromagnetic modeling of the rear contact with a statistical ray optics model to obtain the fraction of optical energy dissipated from the rear contact relative to that absorbed by the Si wafer. Using this technique, we study the impact of the refractive index, extinction coefficient, and thickness of the rear-passivating layer and establish basic design rules. In addition, we evaluate novel optical structures, including stratified thin films, nanoparticle composites, and conductive nanowires embedded in a low-index dielectric matrix, for integration into advanced rear contacts in c-Si photovoltaic devices. From an optical perspective, nanowire structures preserving low contact resistance appear to be the most effective approach to mitigating dissipation losses from the rear contact.

  1. Estrogen receptor-targeted optical imaging of breast cancer cells with near-infrared fluorescent dye

    Science.gov (United States)

    Jose, Iven; Deodhar, Kodand; Chiplunkar, Shuba V.; Patkar, Meena

    2010-02-01

    Molecular imaging provides the in vivo characterization of cellular molecular events involved in normal and pathologic processes. With the advent of optical molecular imaging, specific molecules, proteins and genes may be tagged with a luminescent reporter and visualized in small animals. This powerful new tool has pushed in vivo optical imaging to the forefront as it allows for direct determination of drug bio-distribution and uptake kinetics as well as an indicator of biochemical activity and drug efficacy. Although optical imaging encompasses diverse techniques and makes use of various wavelengths of light, a great deal of excitement in molecular research lies in the use of tomographic and fluorescence techniques to image living tissues with near-infrared (NIR) light. Nonionizing, noninvasive near-infrared optical imaging has great potential to become promising alternative for breast cancer detection. Fluorescence spectroscopy studies of human tissue suggest that a variety of lesions show distinct fluorescence spectra compared to those of normal tissue. It has also been shown that exogenous dyes exhibit selective uptake in neoplastic lesions and may offer the best contrast for optical imaging. Use of exogenous agents would provide fluorescent markers, which could serve to detect embedded tumors in the breast. In particular, the ability to monitor the fluorescent yield and lifetime may also enable biochemical specificity if the fluorophore is sensitive to a specific metabolite, such as oxygen. As a first step, we have synthesized and characterized one such NIR fluorescent dye conjugate, which could potentially be used to detect estrogen receptors (ER)[2] . The conjugate was synthesized by ester formation between 17-β estradiol and a hydrophilic derivative of indocyanine green (ICG) cyanine dye, bis-1, 1-(4-sulfobutyl) indotricarbocyanine-5- carboxylic acid, sodium salt. The ester formed was found to have an extra binding ability with the receptor cites as

  2. Modeling and optimization of LCD optical performance

    CERN Document Server

    Yakovlev, Dmitry A; Kwok, Hoi-Sing

    2015-01-01

    The aim of this book is to present the theoretical foundations of modeling the optical characteristics of liquid crystal displays, critically reviewing modern modeling methods and examining areas of applicability. The modern matrix formalisms of optics of anisotropic stratified media, most convenient for solving problems of numerical modeling and optimization of LCD, will be considered in detail. The benefits of combined use of the matrix methods will be shown, which generally provides the best compromise between physical adequacy and accuracy with computational efficiency and optimization fac

  3. Constraints on the brown dwarf mass function from optical and infrared searches

    International Nuclear Information System (INIS)

    Probst, R.G.

    1986-01-01

    Photometric surveys of faint proper motion stars and searches for infrared binary companions have identified a few very low luminosity objects. The author considers how these searches may constrain the brown dwarf mass function. An astrophysically plausible brown dwarf population is defined which yields a dark mass density = 0.5 x the observed density. Using the sensitivity and other limits of various surveys, the expected numbers of observable brown dwarfs are obtained from the model population for comparison with actual results. Reasonable improvement in search protocol could yield statistically significant tests of the brown dwarf mass function. (author)

  4. Overhead longwave infrared hyperspectral material identification using radiometric models

    Energy Technology Data Exchange (ETDEWEB)

    Zelinski, M. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2018-01-09

    Material detection algorithms used in hyperspectral data processing are computationally efficient but can produce relatively high numbers of false positives. Material identification performed as a secondary processing step on detected pixels can help separate true and false positives. This paper presents a material identification processing chain for longwave infrared hyperspectral data of solid materials collected from airborne platforms. The algorithms utilize unwhitened radiance data and an iterative algorithm that determines the temperature, humidity, and ozone of the atmospheric profile. Pixel unmixing is done using constrained linear regression and Bayesian Information Criteria for model selection. The resulting product includes an optimal atmospheric profile and full radiance material model that includes material temperature, abundance values, and several fit statistics. A logistic regression method utilizing all model parameters to improve identification is also presented. This paper details the processing chain and provides justification for the algorithms used. Several examples are provided using modeled data at different noise levels.

  5. 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.

  6. 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.

  7. Review: Model particles in atmospheric optics

    International Nuclear Information System (INIS)

    Kahnert, Michael; Nousiainen, Timo; Lindqvist, Hannakaisa

    2014-01-01

    This review paper provides an overview over model geometries for computing light scattering by small particles. The emphasis is on atmospheric optics, although much of this review will also be relevant to neighbouring fields, in particular to astronomy. Various morphological particle properties are discussed, such as overall nonsphericity, pristine shapes, aggregation, and different forms of inhomogeneity, e.g. porous and compact inhomogeneous morphologies, as well as encapsulated aggregates. Models employed to reproduce the optical properties of complex particles range from strongly simplified to highly realistic and morphologically sophisticated model geometries. Besides reviewing the most recent literature, we discuss the idea behind models of varying degree of complexity with regard to the intended use of the models. Applications range from fundamental studies of light scattering processes to routine applications of particle optics look-up tables in operational modelling systems. - Highlights: • Particle models in atmospheric optics are reviewed. • Review of recent literature on nonspherical particles. • Applications of particle models are discussed

  8. Completely integrable models of nonlinear optics

    Indian Academy of Sciences (India)

    Abstract. The models of the nonlinear optics in which solitons appeared are considered. These models are of paramount importance in studies of nonlinear wave phenomena. The classical ex- amples of phenomena of this kind are the self-focusing, self-induced transparency and parametric interaction of three waves.

  9. Optical Coherence Tomography: Advanced Modeling

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Thrane, Lars; Yura, Harold T.

    2013-01-01

    - and multiple-scattering regimes is derived. An advanced Monte Carlo model for calculating the OCT signal is also derived, and the validity of this model is shown through a mathematical proof based on the extended Huygens-Fresnel principle. From the analytical model, an algorithm for enhancing OCT images...

  10. Multiple Scattering Model for Optical Coherence Tomography with Rytov Approximation

    KAUST Repository

    Li, Muxingzi

    2017-04-24

    Optical Coherence Tomography (OCT) is a coherence-gated, micrometer-resolution imaging technique that focuses a broadband near-infrared laser beam to penetrate into optical scattering media, e.g. biological tissues. The OCT resolution is split into two parts, with the axial resolution defined by half the coherence length, and the depth-dependent lateral resolution determined by the beam geometry, which is well described by a Gaussian beam model. The depth dependence of lateral resolution directly results in the defocusing effect outside the confocal region and restricts current OCT probes to small numerical aperture (NA) at the expense of lateral resolution near the focus. Another limitation on OCT development is the presence of a mixture of speckles due to multiple scatterers within the coherence length, and other random noise. Motivated by the above two challenges, a multiple scattering model based on Rytov approximation and Gaussian beam optics is proposed for the OCT setup. Some previous papers have adopted the first Born approximation with the assumption of small perturbation of the incident field in inhomogeneous media. The Rytov method of the same order with smooth phase perturbation assumption benefits from a wider spatial range of validity. A deconvolution method for solving the inverse problem associated with the first Rytov approximation is developed, significantly reducing the defocusing effect through depth and therefore extending the feasible range of NA.

  11. 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.

  12. 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

    2018-03-02

    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 WO 3 (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.

  13. 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.

  14. FDTD method and models in optical education

    Science.gov (United States)

    Lin, Xiaogang; Wan, Nan; Weng, Lingdong; Zhu, Hao; Du, Jihe

    2017-08-01

    In this paper, finite-difference time-domain (FDTD) method has been proposed as a pedagogical way in optical education. Meanwhile, FDTD solutions, a simulation software based on the FDTD algorithm, has been presented as a new tool which helps abecedarians to build optical models and to analyze optical problems. The core of FDTD algorithm is that the time-dependent Maxwell's equations are discretized to the space and time partial derivatives, and then, to simulate the response of the interaction between the electronic pulse and the ideal conductor or semiconductor. Because the solving of electromagnetic field is in time domain, the memory usage is reduced and the simulation consequence on broadband can be obtained easily. Thus, promoting FDTD algorithm in optical education is available and efficient. FDTD enables us to design, analyze and test modern passive and nonlinear photonic components (such as bio-particles, nanoparticle and so on) for wave propagation, scattering, reflection, diffraction, polarization and nonlinear phenomena. The different FDTD models can help teachers and students solve almost all of the optical problems in optical education. Additionally, the GUI of FDTD solutions is so friendly to abecedarians that learners can master it quickly.

  15. Analytical model of the optical vortex microscope.

    Science.gov (United States)

    Płocinniczak, Łukasz; Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

    2016-04-20

    This paper presents an analytical model of the optical vortex scanning microscope. In this microscope the Gaussian beam with an embedded optical vortex is focused into the sample plane. Additionally, the optical vortex can be moved inside the beam, which allows fine scanning of the sample. We provide an analytical solution of the whole path of the beam in the system (within paraxial approximation)-from the vortex lens to the observation plane situated on the CCD camera. The calculations are performed step by step from one optical element to the next. We show that at each step, the expression for light complex amplitude has the same form with only four coefficients modified. We also derive a simple expression for the vortex trajectory of small vortex displacements.

  16. THE ROLE OF STARBURST-ACTIVE GALACTIC NUCLEUS COMPOSITES IN LUMINOUS INFRARED GALAXY MERGERS: INSIGHTS FROM THE NEW OPTICAL CLASSIFICATION SCHEME

    International Nuclear Information System (INIS)

    Yuan, T.-T.; Kewley, L. J.; Sanders, D. B.

    2010-01-01

    We investigate the fraction of starbursts, starburst-active galactic nucleus (AGN) composites, Seyferts, and low-ionization narrow emission-line region galaxies (LINERs) as a function of infrared luminosity (L IR ) and merger progress for ∼500 infrared (IR)-selected galaxies. Using the new optical classifications afforded by the extremely large data set of the Sloan Digital Sky Survey, we find that the fraction of LINERs in IR-selected samples is rare ( IR > 10 12 L sun ), starburst-AGN composite galaxies dominate at early-intermediate stages of the merger, and AGN galaxies dominate during the final merger stages. Our results are consistent with models for IR-luminous galaxies where mergers of gas-rich spirals fuel both starburst and AGN, and where the AGN becomes increasingly dominant during the final merger stages of the most luminous IR objects.

  17. Optimal hemodynamic response model for functional near-infrared spectroscopy.

    Science.gov (United States)

    Kamran, Muhammad A; Jeong, Myung Yung; Mannan, Malik M N

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650-950 nm wavelengths. The cortical hemodynamic response (HR) differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF) is modeled by two Gamma functions with six unknown parameters (four of them to model the shape and other two to scale and baseline respectively). The HRF model is supposed to be a linear combination of HRF, baseline, and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown). An objective function is developed as a square of the residuals with constraints on 12 free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using 10 real and 15 simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis (i.e., t-value > t critical and p-value < 0.05).

  18. Mid-infrared materials and devices on a Si platform for optical sensing

    Directory of Open Access Journals (Sweden)

    Vivek Singh

    2014-01-01

    Full Text Available In this article, we review our recent work on mid-infrared (mid-IR photonic materials and devices fabricated on silicon for on-chip sensing applications. Pedestal waveguides based on silicon are demonstrated as broadband mid-IR sensors. Our low-loss mid-IR directional couplers demonstrated in SiNx waveguides are useful in differential sensing applications. Photonic crystal cavities and microdisk resonators based on chalcogenide glasses for high sensitivity are also demonstrated as effective mid-IR sensors. Polymer-based functionalization layers, to enhance the sensitivity and selectivity of our sensor devices, are also presented. We discuss the design of mid-IR chalcogenide waveguides integrated with polycrystalline PbTe detectors on a monolithic silicon platform for optical sensing, wherein the use of a low-index spacer layer enables the evanescent coupling of mid-IR light from the waveguides to the detector. Finally, we show the successful fabrication processing of our first prototype mid-IR waveguide-integrated detectors.

  19. Study on the defects detection in composites by using optical position and infrared thermography

    Energy Technology Data Exchange (ETDEWEB)

    Kwn, Koo Ahn; Choi, Man Yong; Park, Jeong Hak; Choi, Won Jae [Safety Measurement Center, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Park, Hee Sang [Dept. of Research and Development, Korea Research Institute of Smart Material and Structures System Association, Daejeon (Korea, Republic of)

    2016-04-15

    Non-destructive testing methods for composite materials (e.g., carbon fiber-reinforced and glass fiber-reinforced plastic) have been widely used to detect damage in the overall industry. This study detects defects using optical infrared thermography. The transient heat transport in a solid body is characterized by two dynamic quantities, namely, thermal diffusivity and thermal effusivity. The first quantity describes the speed with thermal energy diffuses through a material, whereas the second one represents a type of thermal inertia. The defect detection rate is increased by utilizing a lock-in method and performing a comparison of the defect detection rates. The comparison is conducted by dividing the irradiation method into reflection and transmission methods and the irradiation time into 50 mHz and 100 mHz. The experimental results show that detecting defects at 50 mHz is easy using the transmission method. This result implies that low-frequency thermal waves penetrate a material deeper than the high-frequency waves.

  20. The Large UV/Optical/Infrared Surveyor (LUVOIR): Decadal Mission concept technology development overview

    Science.gov (United States)

    Bolcar, Matthew R.

    2017-09-01

    The Large Ultraviolet / Optical / Infrared (LUVOIR) Surveyor is one of four large mission concept studies being developed by NASA for consideration in the 2020 Astrophysics Decadal Survey. LUVOIR will support 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. The LUVOIR Science and Technology Definition Team (STDT) has tasked a Technology Working Group (TWG), with more than 60 members from NASA centers, academia, industry, and international partners, with identifying technologies that enable or enhance the LUVOIR science mission. The TWG has identified such technologies in the areas of Coronagraphy, Ultra-Stable Opto-mechanical Systems, Detectors, Coatings, Starshades, and Instrument Components, and has completed a detailed assessment of the state-of-the-art. We present here a summary of this technology assessment effort, as well as the current progress in defining a technology development plan to mature these technologies to the required technology readiness level (TRL).

  1. Synthesis and Optical Properties of Near-Infrared meso-Phenyl-Substituted Symmetric Heptamethine Cyanine Dyes

    Directory of Open Access Journals (Sweden)

    Andrew Levitz

    2018-01-01

    Full Text Available Heptamethine cyanine dyes are a class of near infrared fluorescence (NIRF probes of great interest in bioanalytical and imaging applications due to their modifiability, allowing them to be tailored for particular applications. Generally, modifications at the meso-position of these dyes are achieved through Suzuki-Miyaura C-C coupling and SRN1 nucleophilic substitution of the chlorine atom at the meso-position of the dye. Herein, a series of 15 meso phenyl-substituted heptamethine cyanines was synthesized utilizing a modified dianil linker. Their optical properties, including molar absorptivity, fluorescence, Stokes shift, and quantum yield were measured. The HSA binding affinities of two representative compounds were measured and compared to that of a series of trimethine cyanines previously synthesized by our lab. The results indicate that the binding of these compounds to HSA is not only dependent on hydrophobicity, but may also be dependent on steric interferences in the binding site and structural dynamics of the NIRF compounds.

  2. Electrical and Infrared Optical Properties of Vanadium Oxide Semiconducting Thin-Film Thermometers

    Science.gov (United States)

    Zia, Muhammad Fakhar; Abdel-Rahman, Mohamed; Alduraibi, Mohammad; Ilahi, Bouraoui; Awad, Ehab; Majzoub, Sohaib

    2017-10-01

    A synthesis method has been developed for preparation of vanadium oxide thermometer thin film for microbolometer application. The structure presented is a 95-nm thin film prepared by sputter-depositing nine alternating multilayer thin films of vanadium pentoxide (V2O5) with thickness of 15 nm and vanadium with thickness of 5 nm followed by postdeposition annealing at 300°C in nitrogen (N2) and oxygen (O2) atmospheres. The resulting vanadium oxide (V x O y ) thermometer thin films exhibited temperature coefficient of resistance (TCR) of -3.55%/°C with room-temperature resistivity of 2.68 Ω cm for structures annealed in N2 atmosphere, and TCR of -3.06%/°C with room-temperature resistivity of 0.84 Ω cm for structures annealed in O2 atmosphere. Furthermore, optical measurements of N2- and O2-annealed samples were performed by Fourier-transform infrared ellipsometry to determine their dispersion curves, refractive index ( n), and extinction coefficient ( k) at wavelength from 7000 nm to 14,000 nm. The results indicate the possibility of applying the developed materials in thermometers for microbolometers.

  3. Tunable optical coherence tomography in the infrared range using visible photons

    Science.gov (United States)

    Paterova, Anna V.; Yang, Hongzhi; An, Chengwu; Kalashnikov, Dmitry A.; Krivitsky, Leonid A.

    2018-04-01

    Optical coherence tomography (OCT) is an appealing technique for bio-imaging, medicine, and material analysis. For many applications, OCT in mid- and far-infrared (IR) leads to significantly more accurate results. Reported mid-IR OCT systems require light sources and photodetectors which operate in mid-IR range. These devices are expensive and need cryogenic cooling. Here, we report a proof-of-concept demonstration of a wavelength tunable IR OCT technique with detection of only visible range photons. Our method is based on the nonlinear interference of frequency correlated photon pairs. The nonlinear crystal, introduced in the Michelson-type interferometer, generates photon pairs with one photon in the visible and another in the IR range. The intensity of detected visible photons depends on the phase and loss of IR photons, which interact with the sample under study. This enables us to characterize sample properties and perform imaging in the IR range by detecting visible photons. The technique possesses broad wavelength tunability and yields a fair axial and lateral resolution, which can be tailored to the specific application. The work contributes to the development of versatile 3D imaging and material characterization systems working in a broad range of IR wavelengths, which do not require the use of IR-range light sources and photodetectors.

  4. Cerebral monitoring during carotid endarterectomy using near-infrared diffuse optical spectroscopies and electroencephalogram

    Energy Technology Data Exchange (ETDEWEB)

    Shang Yu; Cheng Ran; Dong Lixin; Yu Guoqiang [Center for Biomedical Engineering, University of Kentucky, KY (United States); Ryan, Stephen J [Department of Neurology, University of Kentucky, KY (United States); Saha, Sibu P, E-mail: guoqiang.yu@uky.edu [Division of Cardiothoracic Surgery, University of Kentucky, KY (United States)

    2011-05-21

    Intraoperative monitoring of cerebral hemodynamics during carotid endarterectomy (CEA) provides essential information for detecting cerebral hypoperfusion induced by temporary internal carotid artery (ICA) clamping and post-CEA hyperperfusion syndrome. This study tests the feasibility and sensitivity of a novel dual-wavelength near-infrared diffuse correlation spectroscopy technique in detecting cerebral blood flow (CBF) and cerebral oxygenation in patients undergoing CEA. Two fiber-optic probes were taped on both sides of the forehead for cerebral hemodynamic measurements, and the instantaneous decreases in CBF and electroencephalogram (EEG) alpha-band power during ICA clamping were compared to test the measurement sensitivities of the two techniques. The ICA clamps resulted in significant CBF decreases (-24.7 {+-} 7.3%) accompanied with cerebral deoxygenation at the surgical sides (n = 12). The post-CEA CBF were significantly higher (+43.2 {+-} 16.9%) than the pre-CEA CBF. The CBF responses to ICA clamping were significantly faster, larger and more sensitive than EEG responses. Simultaneous monitoring of CBF, cerebral oxygenation and EEG power provides a comprehensive evaluation of cerebral physiological status, thus showing potential for the adoption of acute interventions (e.g., shunting, medications) during CEA to reduce the risks of severe cerebral ischemia and cerebral hyperperfusion syndrome.

  5. Testing the AGN unification model in the infrared. First results with GTC/CanariCam

    Science.gov (United States)

    Ramos Almeida, C.

    2015-05-01

    The unified model for Active Galactic Nuclei (AGN) accounts for a variety of observational differences in terms of viewing geometry alone. However, from the fitting of high spatial resolution infrared (IR) data with clumpy torus models, it has been hinted that the immediate dusty surroundings of Type-1 and 2 Seyfert nuclei might be intrinsically different in terms of covering factor (torus width and number of clouds). Moreover, these torus covering factors also showed variations among objects belonging to the same type, in contradiction with simple unification. Interestingly, these intrinsic differences in Seyfert tori could explain, for example, the lack of broad optical lines in the polarized spectra of about half of the brightest Seyfert 2 galaxies. On the other hand, recent IR interferometry studies have revealed that, in at least four Seyfert galaxies, the mid-IR emission is elongated in the polar direction. These results are difficult to reconcile with unified models, which claim that the bulk of the mid-IR emission comes from the torus. In this invited contribution I summarize the latest results on high angular resolution IR studies of AGN, which constitute a crucial test for AGN unification. These results include those from the mid-infrared instrument CanariCam on the 10.4 m Gran Telescopio CANARIAS (GTC), which are starting to be published by the CanariCam AGN team, Los Piratas (https://sites.google.com/site/piratasrelatedpublications).

  6. Infrared Cloud Imager Development for Atmospheric Optical Communication Characterization, and Measurements at the JPL Table Mountain Facility

    Science.gov (United States)

    Nugent, P. W.; Shaw, J. A.; Piazzolla, S.

    2013-02-01

    The continuous demand for high data return in deep space and near-Earth satellite missions has led NASA and international institutions to consider alternative technologies for high-data-rate communications. One solution is the establishment of wide-bandwidth Earth-space optical communication links, which require (among other things) a nearly obstruction-free atmospheric path. Considering the atmospheric channel, the most common and most apparent impairments on Earth-space optical communication paths arise from clouds. Therefore, the characterization of the statistical behavior of cloud coverage for optical communication ground station candidate sites is of vital importance. In this article, we describe the development and deployment of a ground-based, long-wavelength infrared cloud imaging system able to monitor and characterize the cloud coverage. This system is based on a commercially available camera with a 62-deg diagonal field of view. A novel internal-shutter-based calibration technique allows radiometric calibration of the camera, which operates without a thermoelectric cooler. This cloud imaging system provides continuous day-night cloud detection with constant sensitivity. The cloud imaging system also includes data-processing algorithms that calculate and remove atmospheric emission to isolate cloud signatures, and enable classification of clouds according to their optical attenuation. Measurements of long-wavelength infrared cloud radiance are used to retrieve the optical attenuation (cloud optical depth due to absorption and scattering) in the wavelength range of interest from visible to near-infrared, where the cloud attenuation is quite constant. This article addresses the specifics of the operation, calibration, and data processing of the imaging system that was deployed at the NASA/JPL Table Mountain Facility (TMF) in California. Data are reported from July 2008 to July 2010. These data describe seasonal variability in cloud cover at the TMF site

  7. Solvothermally Synthesized Sb2Te3 Platelets Show Unexpected Optical Contrasts in Mid-Infrared Near-Field Scanning Microscopy.

    Science.gov (United States)

    Hauer, Benedikt; Saltzmann, Tobias; Simon, Ulrich; Taubner, Thomas

    2015-05-13

    We report nanoscale-resolved optical investigations on the local material properties of Sb2Te3 hexagonal platelets grown by solvothermal synthesis. Using mid-infrared near-field microscopy, we find a highly symmetric pattern, which is correlated to a growth spiral and which extends over the entire platelet. As the origin of the optical contrast, we identify domains with different densities of charge carriers. On Sb2Te3 samples grown by other means, we did not find a comparable domain structure.

  8. 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.

  9. Analytical modeling of mid-infrared silicon Raman lasers

    Science.gov (United States)

    Ma, J.; Fathpour, S.

    2012-01-01

    Silicon photonics has significantly matured in the near-infrared (telecommunication) wavelength range with several commercial products already in the market. More recently, the technology has been extended into the mid-infrared (mid- IR) regime with potential applications in biochemical sensing, tissue photoablation, environmental monitoring and freespace communications. The key advantage of silicon in the mid-IR, as compared with near-IR, is the absence of twophoton absorption (TPA) and free-carrier absorption (FCA). The absence of these nonlinear losses would potentially lead to high-performance nonlinear devices based on Raman and Kerr effects. Also, with the absence of TPA and FCA, the coupled-wave equations that are usually numerically solved to model these nonlinear devices lend themselves to analytical solutions in the mid-IR. In this paper, an analytical model for mid-IR silicon Raman lasers is developed. The validity of the model is confirmed by comparing it with numerical solutions of the coupled-wave equations. The developed model can be used as a versatile and efficient tool for analysis, design and optimization of mid-IR silicon Raman lasers, or to find good initial guesses for numerical methods. The effects of cavity parameters, such as cavity length and facet reflectivities, on the lasing threshold and input-output characteristics of the Raman laser are studied. For instance, for a propagation loss of 0.5 dB/cm, conversion efficiencies as high as 56% is predicted. The predicted optimum cavity (waveguide) length at 2.0 dB/cm propagation loss is { 3.4 mm. The results of this study predict strong prospects for mid-IR silicon Raman lasers for the mentioned applications.

  10. Modelling Diverse Soil Attributes with Visible to Longwave Infrared Spectroscopy Using PLSR Employed by an Automatic Modelling Engine

    Directory of Open Access Journals (Sweden)

    Veronika Kopačková

    2017-02-01

    Full Text Available The study tested a data mining engine (PARACUDA® to predict various soil attributes (BC, CEC, BS, pH, Corg, Pb, Hg, As, Zn and Cu using reflectance data acquired for both optical and thermal infrared regions. The engine was designed to utilize large data in parallel and automatic processing to build and process hundreds of diverse models in a unified manner while avoiding bias and deviations caused by the operator(s. The system is able to systematically assess the effect of diverse preprocessing techniques; additionally, it analyses other parameters, such as different spectral resolutions and spectral coverages that affect soil properties. Accordingly, the system was used to extract models across both optical and thermal infrared spectral regions, which holds significant chromophores. In total, 2880 models were evaluated where each model was generated with a different preprocessing scheme of the input spectral data. The models were assessed using statistical parameters such as coefficient of determination (R2, square error of prediction (SEP, relative percentage difference (RPD and by physical explanation (spectral assignments. It was found that the smoothing procedure is the most beneficial preprocessing stage, especially when combined with spectral derivation (1st or 2nd derivatives. Automatically and without the need of an operator, the data mining engine enabled the best prediction models to be found from all the combinations tested. Furthermore, the data mining approach used in this study and its processing scheme proved to be efficient tools for getting a better understanding of the geochemical properties of the samples studied (e.g., mineral associations.

  11. Parametric uncertainty in optical image modeling

    Science.gov (United States)

    Potzick, James; Marx, Egon; Davidson, Mark

    2006-10-01

    Optical photomask feature metrology and wafer exposure process simulation both rely on optical image modeling for accurate results. While it is fair to question the accuracies of the available models, model results also depend on several input parameters describing the object and imaging system. Errors in these parameter values can lead to significant errors in the modeled image. These parameters include wavelength, illumination and objective NA's, magnification, focus, etc. for the optical system, and topography, complex index of refraction n and k, etc. for the object. In this paper each input parameter is varied over a range about its nominal value and the corresponding images simulated. Second order parameter interactions are not explored. Using the scenario of the optical measurement of photomask features, these parametric sensitivities are quantified by calculating the apparent change of the measured linewidth for a small change in the relevant parameter. Then, using reasonable values for the estimated uncertainties of these parameters, the parametric linewidth uncertainties can be calculated and combined to give a lower limit to the linewidth measurement uncertainty for those parameter uncertainties.

  12. 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.

  13. 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.

  14. Kilonova from post-merger ejecta as an optical and near-Infrared counterpart of GW170817

    Science.gov (United States)

    Tanaka, Masaomi; Utsumi, Yousuke; Mazzali, Paolo A.; Tominaga, Nozomu; Yoshida, Michitoshi; Sekiguchi, Yuichiro; Morokuma, Tomoki; Motohara, Kentaro; Ohta, Kouji; Kawabata, Koji S.; Abe, Fumio; Aoki, Kentaro; Asakura, Yuichiro; Baar, Stefan; Barway, Sudhanshu; Bond, Ian A.; Doi, Mamoru; Fujiyoshi, Takuya; Furusawa, Hisanori; Honda, Satoshi; Itoh, Yoichi; Kawabata, Miho; Kawai, Nobuyuki; Kim, Ji Hoon; Lee, Chien-Hsiu; Miyazaki, Shota; Morihana, Kumiko; Nagashima, Hiroki; Nagayama, Takahiro; Nakaoka, Tatsuya; Nakata, Fumiaki; Ohsawa, Ryou; Ohshima, Tomohito; Okita, Hirofumi; Saito, Tomoki; Sumi, Takahiro; Tajitsu, Akito; Takahashi, Jun; Takayama, Masaki; Tamura, Yoichi; Tanaka, Ichi; Terai, Tsuyoshi; Tristram, Paul J.; Yasuda, Naoki; Zenko, Tetsuya

    2017-12-01

    Recent detection of gravitational waves from a neutron star (NS) merger event GW170817 and identification of an electromagnetic counterpart provide a unique opportunity to study the physical processes in NS mergers. To derive properties of ejected material from the NS merger, we perform radiative transfer simulations of kilonova, optical and near-infrared emissions powered by radioactive decays of r-process nuclei synthesized in the merger. We find that the observed near-infrared emission lasting for >10 d is explained by 0.03 M⊙ of ejecta containing lanthanide elements. However, the blue optical component observed at the initial phases requires an ejecta component with a relatively high electron fraction (Ye). We show that both optical and near-infrared emissions are simultaneously reproduced by the ejecta with a medium Ye of ˜0.25. We suggest that a dominant component powering the emission is post-merger ejecta, which exhibits that the mass ejection after the first dynamical ejection is quite efficient. Our results indicate that NS mergers synthesize a wide range of r-process elements and strengthen the hypothesis that NS mergers are the origin of r-process elements in the Universe.

  15. Effects of thermal treatment on infrared optical properties of SiO{sub 2} films on Si Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yiqin, E-mail: jiyiqin@gmail.com [National Key Laboratory of Science and Technology on Tunable Laser, Institute of Optical-electronics, Harbin Institute of Technology, Harbin, 150080 (China); Tianjin Key Laboratory of Optical Thin Film, Tianjin Jinhang Institute of Technical Physics, Tianjin 300192 (China); Jiang, Yugang [Tianjin Key Laboratory of Optical Thin Film, Tianjin Jinhang Institute of Technical Physics, Tianjin 300192 (China); Key Laboratory of Advanced Micro-structure Materials, Ministry of Education, Department of Physics, Tongji University, Shanghai, 200092 (China); Liu, Huasong; Wang, Lishuan; Liu, Dandan; Jiang, Chenghui [Tianjin Key Laboratory of Optical Thin Film, Tianjin Jinhang Institute of Technical Physics, Tianjin 300192 (China); Fan, Rongwei; Chen, Deying [National Key Laboratory of Science and Technology on Tunable Laser, Institute of Optical-electronics, Harbin Institute of Technology, Harbin, 150080 (China)

    2013-10-31

    The effects of thermal treatment on infrared optical properties of SiO{sub 2} films on Si substrates by ion beam sputtering technology were investigated. Complex refractive index of SiO{sub 2} films was calculated from Fourier transform infrared transmission spectrum from 400 to 4000 cm{sup −1}. Absorption band properties associated with Si-O-Si stretching, bending, rocking mode at about 1080 cm{sup −1}, 816 cm{sup −1}, 460 cm{sup −1} were analyzed. With the increase of thermal annealing temperature, the absorption peak with Si-O-Si stretching, rocking mode shift to long wave number, but the bending mode shifts to short. After thermal treatment, the infrared optical constants are close to the value of the more stabilized thermal grown SiO{sub 2}. So, it can be concluded that the structure of Si-O-Si network in SiO{sub 2} films deposited on Si was modified to the stable structure of thermal grown SiO{sub 2}. - Highlights: • Effects of annealing on IR optical properties of SiO{sub 2} films are achieved. • Complex dielectric functions of SiO{sub 2} films in the IR wave band are calculated. • Absorption bands properties with three modes are analyzed with thermal treatment.

  16. 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.

  17. Modelling of nectarine drying under near infrared - Vacuum conditions.

    Science.gov (United States)

    Alaei, Behnam; Chayjan, Reza Amiri

    2015-01-01

    Drying of nectarine slices was performed to determine the thermal and physical properties in order to reduce product deterioration due to chemical reactions, facilitate storage and lower transportation costs. Because nectarine slices are sensitive to heat with long drying period, the selection of a suitable drying approach is a challenging task. Infrared-vacuum drying can be used as an appropriate method for susceptible materials with high moisture content such as nectarine slices. Modelling of nectarine slices drying was carried out in a thin layer near infraredvacuum conditions. Drying of the samples was implemented at the absolute pressures of 20, 40 and 60 kPa and drying temperatures of 50, 60 and 70°C. Drying behaviour of nectarine slices, as well as the effect of drying conditions on moisture loss trend, drying rate, effective diffusion coefficient, activation energy, shrinkage, colour and energy consumption of nectarine slices, dried in near infrared-vacuum dryer are discussed in this study. Six mathematical models were used to predict the moisture ratio of the samples in thin layer drying. The Midilli model had supremacy in prediction of nectarine slices drying behaviour. The maximum drying rates of the samples were between 0.014-0.047 gwater/gdry material·min. Effective moisture diffusivity of the samples was estimated in the ranges of 2.46·10-10 to 6.48·10-10 m2/s. Activation energy were computed between 31.28 and 35.23 kJ/mol. Minimum shrinkage (48.4%) and total colour difference (15.1) were achieved at temperature of 50°C and absolute pressure of 20 kPa. Energy consumption of the tests was estimated in the ranges of 0.129 to 0.247 kWh. Effective moisture diffusivity was increased with decrease of vacuum pressure and increase of drying temperature but effect of drying temperature on effective moisture diffusivity of nectarine slices was more than vacuum pressure. Activation energy was decreased with decrease in absolute pressure. Total colour

  18. Optical characterization of free electron concentration in heteroepitaxial InN layers using Fourier transform infrared spectroscopy and a 2 × 2 transfer-matrix algebra

    International Nuclear Information System (INIS)

    Katsidis, C. C.; Ajagunna, A. O.; Georgakilas, A.

    2013-01-01

    Fourier Transform Infrared (FTIR) reflectance spectroscopy has been implemented as a non-destructive, non-invasive, tool for the optical characterization of a set of c-plane InN single heteroepitaxial layers spanning a wide range of thicknesses (30–2000 nm). The c-plane (0001) InN epilayers were grown by plasma-assisted molecular beam epitaxy (PAMBE) on GaN(0001) buffer layers which had been grown on Al 2 O 3 (0001) substrates. It is shown that for arbitrary multilayers with homogeneous anisotropic layers having their principal axes coincident with the laboratory coordinates, a 2 × 2 matrix algebra based on a general transfer-matrix method (GTMM) is adequate to interpret their optical response. Analysis of optical reflectance in the far and mid infrared spectral range has been found capable to discriminate between the bulk, the surface and interface contributions of free carriers in the InN epilayers revealing the existence of electron accumulation layers with carrier concentrations in mid 10 19 cm −3 at both the InN surface and the InN/GaN interface. The spectra could be fitted with a three-layer model, determining the different electron concentration and mobility values of the bulk and of the surface and the interface electron accumulation layers in the InN films. The variation of these values with increasing InN thickness could be also sensitively detected by the optical measurements. The comparison between the optically determined drift mobility and the Hall mobility of the thickest sample reveals a value of r H = 1.49 for the Hall factor of InN at a carrier concentration of 1.11 × 10 19 cm −3 at 300°Κ.

  19. EVOLVING STARBURST MODELING OF FAR-INFRARED/SUBMILLIMETER/MILLIMETER LINE EMISSION. III. APPLICATION TO NEARBY LUMINOUS INFRARED GALAXIES

    International Nuclear Information System (INIS)

    Yao Lihong

    2010-01-01

    In a previous work, we showed that the observed far-infrared/submillimeter/millimeter line spectra of a starburst galaxy (M82) can be successfully modeled in terms of the evolutionary scheme of an ensemble of giant molecular clouds (GMCs) and shells, and such studies can usefully constrain the age(s) or star formation history of a starburst galaxy. In this paper, we present a preliminary study of using the template of an ensemble of evolving GMCs/shells we developed for M82. We apply the model to represent various stages of starburst evolution in a well-known sample of nearby luminous infrared galaxies. In this way, we attempt to interpret the relationship between the degree of molecular excitation and ratio of far-infrared (FIR) to 12 CO (or simply CO) luminosity to possibly reflect different stages of the evolution of star-forming activity within their nuclear regions.

  20. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol Optical Thickness (AOT) and Aerosol Particle Size Parameter (APSP) Environmental Data Record (EDR) from IDPS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of Aerosol Optical Thickness (AOT) from the Visible Infrared Imaging Radiometer...

  1. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol Optical Depth and Aerosol Particle Size Distribution Environmental Data Record (EDR) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of aerosol optical depth (AOD) and particle size from the Visible Infrared Imaging...

  2. Improving the optical efficiency and concentration of a single-plate quantum dot solar concentrator using near infra-red emitting quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, M.; McCormack, S.J.; Doran, J.; Norton, B. [Dublin Energy Lab., Dublin Institute of Technology, Focas Institute, DIT - Kevin Street, Dublin 8, Dublin (Ireland)

    2009-07-15

    Low luminescent quantum yields and large overlap between quantum dot (QD) emission and absorption spectra of present commercially-available visible-emitting QDs have led to low optical efficiencies for single-plate quantum dot solar concentrators (QDSCs). It is shown that using near infra-red (NIR) emitting QDs, re-absorption of QD emitted photons can be reduced greatly, thereby diminishing escape cone losses thus improving optical efficiencies and concentration ratios. Using Monte-Carlo ray-trace modelling, escape cone losses are quantified for different types of QD. A minimum 25% escape cone loss would be expected for a plate with refractive index of 1.5 containing QDs with no spectral overlap. It is shown that escape cone losses account for {proportional_to}57% of incident photons absorbed in QDSCs containing commercially-available visible-emitting QDs. (author)

  3. FY 2006 Infrared Photonics Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C.; Allen, Paul J.; Bernacki, Bruce E.; Ho, Nicolas; Krishnaswami, Kannan; Qiao, Hong (Amy); Schultz, John F.

    2006-12-28

    Research done by the Infrared Photonics team at Pacific Northwest National Laboratory (PNNL) is focused on developing miniaturized integrated optics and optical fiber processing methods for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications by exploiting the unique optical and material properties of chalcogenide glass. PNNL has developed thin-film deposition capabilities, direct laser writing techniques, infrared photonic device demonstration, holographic optical element design and fabrication, photonic device modeling, and advanced optical metrology—all specific to chalcogenide glass. Chalcogenide infrared photonics provides a pathway to quantum cascade laser (QCL) transmitter miniaturization. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors that are particularly useful for nuclear nonproliferation missions.

  4. Modelling Nonlinear Optics in the CERN SPS

    CERN Document Server

    Zimmermann, Frank; Faus-Golfe, A; Collier, Paul

    2002-01-01

    Nonlinear fields arising from eddy currents in the vac-uum chamber and remanent fields in the magnets of the CERN SPS vary with time and with the acceleration cycle. We describe a procedure of constructing a nonlinear op-tics model for the SPS, by considering sextupolar, octupo-lar, and decapolar field errors in the dipole and quadrupole magnets, respectively, whose strengths are adjusted so as to best reproduce the measured nonlinear chromaticities up to third order in the momentum deviation. Applying this procedure to SPS chromaticity measurements taken at 26 GeV/c, we have obtained a refined optics model. The tune shifts with the transverse amplitude predicted by this model are consistent with a direct measurement.

  5. 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.

  6. 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

  7. 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.

  8. Anatomically accurate, finite model eye for optical modeling.

    Science.gov (United States)

    Liou, H L; Brennan, N A

    1997-08-01

    There is a need for a schematic eye that models vision accurately under various conditions such as refractive surgical procedures, contact lens and spectacle wear, and near vision. Here we propose a new model eye close to anatomical, biometric, and optical realities. This is a finite model with four aspheric refracting surfaces and a gradient-index lens. It has an equivalent power of 60.35 D and an axial length of 23.95 mm. The new model eye provides spherical aberration values within the limits of empirical results and predicts chromatic aberration for wavelengths between 380 and 750 nm. It provides a model for calculating optical transfer functions and predicting optical performance of the eye.

  9. Fourier transform infrared for noninvasive optical diagnosis of oral, oropharyngeal, and laryngeal cancer.

    Science.gov (United States)

    Menzies, Georgina E; Fox, Hannah R; Marnane, Conor; Pope, Laysan; Prabhu, Vinod; Winter, Stuart; Derrick, Anna V; Lewis, Paul D

    2014-01-01

    The 5-year survival rate for advanced head and neck cancers is 50%. There is currently no noninvasive method or effective screening procedure available to diagnose head and neck cancer at the earliest stages when it is still highly curable. This study aims to show how Fourier transform infrared (FTIR) spectroscopy could be used as a sensitive, noninvasive, low cost technique to diagnose head and neck cancer at an earlier stage and, thus, increase the likelihood of survival. Sputum samples were collected from 16 cases with oral or oropharyngeal cancer, 8 cases with laryngeal cancer patients and 15 normal controls. Cell pellets were produced from each of these samples and used to generate FTIR spectra within the 'biochemical fingerprint' wavenumber region of 1800 to 950 cm(-1). Discrimination between cancer and normal sputum was achieved using infrared wavenumbers 1650 cm(-1), 1550 cm(-1), and 1042 cm(-1) determined by robust feature selection. These 3 wavenumbers were used to develop potential models to discriminate both oropharyngeal and laryngeal cancer from normal control. In cancer cases, the absorbance levels for 1550 cm(-1) were increased relative to controls, whereas 1042 cm(-1) absorbance was decreased suggesting changes to protein and glycoprotein structure within sputa cells. This preliminary study shows potential for how FTIR could be developed into a simplistic diagnostic tool that could easily be implemented by a nonspecialist to diagnose and monitor head and neck cancer. The method could especially provide a means for detecting laryngeal cancer hidden from noninvasive observation. Copyright © 2014 Mosby, Inc. All rights reserved.

  10. Recognition of stimulus-evoked neuronal optical response by identifying chaos levels of near-infrared spectroscopy time series.

    Science.gov (United States)

    Hu, Xiao-Su; Hong, Keum-Shik; Ge, Shuzhi Sam

    2011-10-24

    Near-infrared spectroscopy (NIRS) can detect two different kinds of signals from the human brain: the hemodynamic response (slow) and the neuronal response (fast). This paper explores a nonlinear aspect in the tactile-stimulus-evoked neuronal optical response over a NIRS time series (light intensity variation). The existence of the fast optical responses (FORs) over the time series recorded in stimulus sessions is confirmed by event-related averaging. The chaos levels of the NIRS time series recorded both in stimulus and in rest sessions are then identified according to the estimated largest Lyapunov exponent. The obtained results ascertain that stimulus-evoked neuronal optical responses can be detected in the somatosensory cortex using continuous-wave NIRS equipment. Further, the results strongly suggest that the chaos level can be used to recognize the FORs in NIRS time series and, thereby, the state of the pertinent brain activity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Green Network Planning Model for Optical Backbones

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Riaz, M. Tahir; Jensen, Michael

    2010-01-01

    Communication networks are becoming more essential for our daily lives and critically important for industry and governments. The intense growth in the backbone traffic implies an increment of the power demands of the transmission systems. This power usage might have a significant negative effect...... on the environment in general. In network planning there are existing planning models focused on QoS provisioning, investment minimization or combinations of both and other parameters. But there is a lack of a model for designing green optical backbones. This paper presents novel ideas to be able to define...... an analytical model to consider environmental aspects in the planning stage of backbones design....

  12. Effect of environmental temperature on diffraction efficiency for multilayer diffractive optical elements in Mid-wave infrared

    Science.gov (United States)

    Piao, Mingxu; Cui, Qingfeng; Zhu, Hao; Zhang, Bo

    2014-11-01

    In this paper, the effect of environmental temperature change on multilayer diffractive optical elements (MLDOEs) is evaluated from the viewpoint of the diffraction efficiency and the polychromatic integral diffraction efficiency (PIDE). As environmental temperature changes, the microstructure heights of MLDOEs expand or contract, and refractive indices of substrate materials also change. Based on the changes in microstructure height and substrate material index with environmental temperature, the theoretical relation between diffraction efficiency of MLDOEs and environmental temperature is deduced. A practical 3-5μm Mid-wave infrared (MWIR) optical system designed with a MLDOE, which made of ZNSE and GE, is discussed to illustrate the influence of environmental temperature change. The result shows that diffraction efficiency reduction is no more than 85% and PIDE reduction is less than 50% when environmental temperature ranges from -20°C to 60°C. According to the calculated diffraction efficiency in different environmental temperatures, the MTF of hybrid optical system is modified and the modified MTF curve is compared with the original MTF curve. Although the hybrid optical system achieved passive athermalization in above environmental temperature range, the modified MTF curve also remarkably decline in environmental temperature extremes after the consideration of diffraction efficiency change of MLDOE. It is indicated that the image quality of hybrid optical system with ZNSE-GE MLDOE is significantly sensitive to environmental temperature change. The analysis result can be used for optical engineering design with MLDOEs in MWIR.

  13. Optical wavelength selection for portable hemoglobin determination by near-infrared spectroscopy method

    Science.gov (United States)

    Tian, Han; Li, Ming; Wang, Yue; Sheng, Dinggao; Liu, Jun; Zhang, Linna

    2017-11-01

    Hemoglobin concentration is commonly used in clinical medicine to diagnose anemia, identify bleeding, and manage red blood cell transfusions. The golden standard method for determining hemoglobin concentration in blood requires reagent. Spectral methods were advantageous at fast and non-reagent measurement. However, model calibration with full spectrum is time-consuming. Moreover, it is necessary to use a few variables considering size and cost of instrumentation, especially for a portable biomedical instrument. This study presents different wavelength selection methods for optical wavelengths for total hemoglobin concentration determination in whole blood. The results showed that modelling using only two wavelengths combination (1143 nm, 1298 nm) can keep on the fine predictability with full spectrum. It appears that the proper selection of optical wavelengths can be more effective than using the whole spectra for determination hemoglobin in whole blood. We also discussed the influence of water absorptivity on the wavelength selection. This research provides valuable references for designing portable NIR instruments determining hemoglobin concentration, and may provide some experience for noninvasive hemoglobin measurement by NIR methods.

  14. A Thermo-Optic Propagation Modeling Capability.

    Energy Technology Data Exchange (ETDEWEB)

    Schrader, Karl; Akau, Ron

    2014-10-01

    A new theoretical basis is derived for tracing optical rays within a finite-element (FE) volume. The ray-trajectory equations are cast into the local element coordinate frame and the full finite-element interpolation is used to determine instantaneous index gradient for the ray-path integral equation. The FE methodology (FEM) is also used to interpolate local surface deformations and the surface normal vector for computing the refraction angle when launching rays into the volume, and again when rays exit the medium. The method is implemented in the Matlab(TM) environment and compared to closed- form gradient index models. A software architecture is also developed for implementing the algorithms in the Zemax(TM) commercial ray-trace application. A controlled thermal environment was constructed in the laboratory, and measured data was collected to validate the structural, thermal, and optical modeling methods.

  15. A Novel Gradient Vector Flow Snake Model Based on Convex Function for Infrared Image Segmentation.

    Science.gov (United States)

    Zhang, Rui; Zhu, Shiping; Zhou, Qin

    2016-10-21

    Infrared image segmentation is a challenging topic because infrared images are characterized by high noise, low contrast, and weak edges. Active contour models, especially gradient vector flow, have several advantages in terms of infrared image segmentation. However, the GVF (Gradient Vector Flow) model also has some drawbacks including a dilemma between noise smoothing and weak edge protection, which decrease the effect of infrared image segmentation significantly. In order to solve this problem, we propose a novel generalized gradient vector flow snakes model combining GGVF (Generic Gradient Vector Flow) and NBGVF (Normally Biased Gradient Vector Flow) models. We also adopt a new type of coefficients setting in the form of convex function to improve the ability of protecting weak edges while smoothing noises. Experimental results and comparisons against other methods indicate that our proposed snakes model owns better ability in terms of infrared image segmentation than other snakes models.

  16. Infrared ship signature prediction, model validation and sky radiance

    NARCIS (Netherlands)

    Neele, F.P.

    2005-01-01

    The increased interest during the last decade in the infrared signature of (new) ships results in a clear need of validated infrared signature prediction codes. This paper presents the results of comparing an in-house developed signature prediction code with measurements made in the 3-5 μm band in

  17. Intra-Body Optical Channel Modeling for In Vivo Wireless Nanosensor Networks.

    Science.gov (United States)

    Guo, Hongzhi; Johari, Pedram; Jornet, Josep Miquel; Sun, Zhi

    2016-01-01

    In vivo wireless nanosensor networks (iWNSNs) consist of nanosized communicating devices, which can operate inside the human body in real time. iWNSNs are at the basis of transformative healthcare techniques, ranging from intra-body health-monitoring systems to drug-delivery applications. Plasmonic nanoantennas are expected to enable the communication among nanosensors in the near infrared and optical transmission window. This result motivates the analysis of the phenomena affecting the propagation of such electromagnetic (EM) signals inside the human body. In this paper, a channel model for intra-body optical communication among nanosensors is developed. The total path loss is computed by taking into account the absorption from different types of molecules and the scattering by different types of cells. In particular, first, the impact of a single cell on the propagation of an optical wave is analytically obtained, by modeling a cell as a multi-layer sphere with complex permittivity. Then, the impact of having a large number of cells with different properties arranged in layered tissues is analyzed. The analytical channel model is validated by means of electromagnetic simulations and extensive numerical results are provided to understand the behavior of the intra-body optical wireless channel. The result shows that, at optical frequencies, the scattering loss introduced by cells is much larger than the absorption loss from the medium. This result motivates the utilization of the lower frequencies of the near-infrared window for communication in iWNSNs.

  18. Infrared galaxies evolution. From cosmological observations with ISO to a mid-infrared to sub-millimetric modeling

    International Nuclear Information System (INIS)

    Dole, Herve

    2000-01-01

    This thesis deals with the analysis of the FIRBACK deep survey performed in the far infrared at λ=170 μm with the Infrared Space Observatory whose aim is the study of the galaxies contributing to the Cosmic Infrared Background, and with the modelling of galaxy evolution in the mid-infrared to submillimeter range. The FIRBACK survey covers 3. 89 Sq. Deg. in 3 high galactic latitude and low foreground emission fields (2 of which are in the northern sky). I first present the techniques of reduction, processing and calibration of the ISOPHOT cosmological data. I show that there is a good agreement between PHOT and DIRBE on extended emission, thanks to the derivation of the PHOT footprint. Final maps are created, and the survey is confusion limited at σc=45 mJy. I present then the techniques of source extraction and the simulations for photometry needed to build the final catalog of 106 sources between 180 mJy (4σ) and 2.4 Jy. The complementary catalog is made of 90 sources between 135 and 180 mJy. Galaxy counts show a large excess with respect to local counts or models (with and without evolution), only compatible with strong evolution scenarios. The Cosmic Infrared Background (CIB) is resolved at 4 % at 170 μm. The identifications of the sources at other wavelengths suggest that most of the sources are local, but a non-negligible part lies above redshift 1. I have developed a phenomenological model of galaxy evolution in order to constrain galaxy evolution in the infrared and to have a better understanding of what the FIRBACK sources are. Using the local Luminosity Function (LF), and template spectra of starburst galaxies, it is possible to constrain the evolution of the LF using all the available data: deep source counts at 15, 170 and 850 μm and the CIB spectrum. I show that galaxy evolution is dominated by a high infrared luminosity population, peaking at L=2.0*10 11 Redshift distributions are in agreement with available observations. Predictions are possible

  19. Robust visual tracking of infrared object via sparse representation model

    Science.gov (United States)

    Ma, Junkai; Liu, Haibo; Chang, Zheng; Hui, Bin

    2014-11-01

    In this paper, we propose a robust tracking method for infrared object. We introduce the appearance model and the sparse representation in the framework of particle filter to achieve this goal. Representing every candidate image patch as a linear combination of bases in the subspace which is spanned by the target templates is the mechanism behind this method. The natural property, that if the candidate image patch is the target so the coefficient vector must be sparse, can ensure our algorithm successfully. Firstly, the target must be indicated manually in the first frame of the video, then construct the dictionary using the appearance model of the target templates. Secondly, the candidate image patches are selected in following frames and the sparse coefficient vectors of them are calculated via l1-norm minimization algorithm. According to the sparse coefficient vectors the right candidates is determined as the target. Finally, the target templates update dynamically to cope with appearance change in the tracking process. This paper also addresses the problem of scale changing and the rotation of the target occurring in tracking. Theoretic analysis and experimental results show that the proposed algorithm is effective and robust.

  20. Infrared Analysis Of Enzymes Adsorbed Onto Model Surfaces

    Science.gov (United States)

    Story, Gloria M.; Rauch, Deborah S.; Brode, Philip F.; Marcott, Curtis A.

    1989-12-01

    The adsorption of the enzymes, subtilisin BPN' and lysozyme, onto model surfaces was examined using attenuated total reflectance (ATR) infrared (IR) spectroscopy. Using a cylindrical internal reflection (CIRcle) cell with a Germanium (Ge) internal reflection element (IRE), model hydrophilic surfaces were made by plasma cleaning the IRE and model hydrophobic surfaces were made by precoating the IRE with a thin film of polystyrene. Gas chromatography (GC)-IR data collection software was used to monitor adsorption kinetics during the first five minutes after injection of the enzyme into the CIRcle cell. It was found that for both lysozyme and BPN', most of the enzyme that was going to adsorb onto the model surface did so within ten seconds after injection. Nearly an order-of-magnitude more BPN' adsorbed on the hydrophobic Ge surface than the hydrophilic one, while lysozyme adsorbed somewhat more strongly to the hydrophilic Ge surface. Overnight, the lysozyme layer continued to increase in thickness, while BPN' maintained its initial coverage. The appearance of carboxylate bands in some of the adsorbed BPN' spectra suggests the occurrence of peptide bond hydrolysis. A Au/Pd coating on the CIRcle cell o-rings had a significant effect on the adsorption of BPN'. (This coating was applied in an attempt to eliminate interfering Teflon absorption bands.) An apparent electrochemical reaction occurred, involving BPN', Ge, Au/Pd, and the salt solution used to stabilize BPN'. The result of this reaction was enhanced adsorption of the enzyme around the coated o-rings, etching of the Ge IRE at the o-ring site, and some autolysis of the enzyme. No such reaction was observed with lysozyme.

  1. Optical Coherence Tomography: Modeling and Applications

    DEFF Research Database (Denmark)

    Thrane, Lars

    An analytical model is presented that is able to describe the performance of OCT systems in both the single and multiple scattering regimes simultaneously. This model inherently includes the shower curtain effect, well-known for light propagation through the atmosphere. This effect has been omitted...... in previous theoretical models of OCT systems. It is demonstrated that the shower curtain effect is of utmost importance in the theoretical description of an OCT system. The analytical model, together with proper noise analysis of the OCT system, enables calculation of the SNR, where the optical properties...... geometry, i.e., reflection geometry, is developed. As in the new OCT model, multiple scattered photons has been taken into account together with multiple scattering effects. As an important result, a novel method of creating images based on measurements of the momentum width of the Wigner phase...

  2. 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

  3. A study on ultra-precision machining technique for Al6061-T6 to fabricate space infrared optics

    Science.gov (United States)

    Ryu, Geun-man; Lee, Gil-jae; Hyun, Sang-won; Sung, Ha-yeong; Chung, Euisik; Kim, Geon-hee

    2014-08-01

    In this paper, analysis of variance on designed experiments with full factorial design was applied to determine the optimized machining parameters for ultra-precision fabrication of the secondary aspheric mirror, which is one of the key elements of the space cryogenic infrared optics. A single point diamond turning machine (SPDTM, Nanotech 4μpL Moore) was adopted to fabricate the material, AL6061-T6, and the three machining parameters of cutting speed, feed rate and depth of cut were selected. With several randomly assigned experimental conditions, surface roughness of each condition was measured by a non-contact optical profiler (NT2000; Vecco). As a result of analysis using Minitab, the optimum cutting condition was determined as following; cutting speed: 122 m/min, feed rate: 3 mm/min and depth of cut: 1 μm. Finally, a 120 mm diameter aspheric secondary mirror was attached to a particularly designed jig by using mixture of paraffin and wax and successfully fabricated under the optimum machining parameters. The profile of machined surface was measured by a high-accuracy 3-D profilometer(UA3P; Panasonic) and we obtained the geometrical errors of 30.6 nm(RMS) and 262.4 nm(PV), which satisfy the requirements of the space cryogenic infrared optics.

  4. FY 2005 Infrared Photonics Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C.; Allen, Paul J.; Ho, Nicolas; Krishnaswami, Kannan; Johnson, Bradley R.; Sundaram, S. K.; Riley, Bradley M.; Martinez, James E.; Qiao, Hong (Amy); Schultz, John F.

    2005-12-01

    Research done by the Infrared Photonics team at Pacific Northwest National Laboratory (PNNL) is focused on developing miniaturized integrated optics for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications by exploiting the unique optical and material properties of chalcogenide glass. PNNL has developed thin-film deposition capabilities, direct laser writing techniques, infrared photonic device demonstration, holographic optical element design and fabrication, photonic device modeling, and advanced optical metrology—all specific to chalcogenide glass. Chalcogenide infrared photonics provides a pathway to quantum cascade laser (QCL) transmitter miniaturization. QCLs provide a viable infrared laser source for a new class of laser transmitters capable of meeting the performance requirements for a variety of national security sensing applications. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors that are particularly useful for nuclear nonproliferation missions. During FY 2005, PNNL’s Infrared Photonics research team made measurable progress exploiting the extraordinary optical and material properties of chalcogenide glass to develop miniaturized integrated optics for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications. We investigated sulfur purification methods that will eventually lead to routine production of optical quality chalcogenide glass. We also discovered a glass degradation phenomenon and our investigation uncovered the underlying surface chemistry mechanism and developed mitigation actions. Key research was performed to understand and control the photomodification properties. This research was then used to demonstrate several essential infrared photonic devices, including LWIR single-mode waveguide devices and

  5. Two-crystal mid-infrared optical parametric oscillator for absorption and dispersion dual-comb spectroscopy.

    Science.gov (United States)

    Jin, Yuwei; Cristescu, Simona M; Harren, Frans J M; Mandon, Julien

    2014-06-01

    We present a femtosecond optical parametric oscillator (OPO) containing two magnesium-doped periodically poled lithium niobate crystals in a singly resonant ring cavity, pumped by two mode-locked Yb-fiber lasers. As such, the OPO generates two idler combs (up to 220 mW), covering a wavelength range from 2.7 to 4.2 μm, from which a mid-infrared dual-comb Fourier transform spectrometer is constructed. By detecting the heterodyning signal between the two idler beams a full broadband spectrum of a molecular gas can be observed over 250  cm(-1) within 70 μs with a spectral resolution of 15 GHz. The absorption and dispersion spectra of acetylene and methane have been measured around 3000  cm(-1), indicating that this OPO represents an ideal broadband mid-infrared source for fast chemical sensing.

  6. Electro-architected porous platinum on metallic multijunction nanolayers to optimize their optical properties for infrared sensor application

    Science.gov (United States)

    Stanca, Sarmiza Elena; Hänschke, Frank; Zieger, Gabriel; Dellith, Jan; Dellith, Andrea; Ihring, Andreas; Belkner, Johannes; Meyer, Hans-Georg

    2018-03-01

    Tailoring the physicochemical properties of the metallic multijunction nanolayers is a prerequisite for the development of microelectronics. From this perspective, a desired lower reflectance of infrared radiation was achieved by an electrochemical deposition of porous platinum in nonaqueous media on silver mirror supported nickel-chrome and nickel-titanium metallic films with incremental decreasing thicknesses from 80-10 nm. The electro-assembled architectures were examined by means of scanning electron microscopy and Fourier transform infrared spectroscopy and it was observed that the layer and sublayer thicknesses and resistivities have a substantial effect upon the porous platinum morphology and its optical properties. It is here reported that the augmentation of the metallic layer electrical conductivity determines the electroformation of more compact platinum nanolayers. Moreover, the platinum black coating of metallic nanolayers causes a considerable decrease of the reflectance in the region from 1000-8000 cm-1.

  7. Predicting ambient aerosol thermal-optical reflectance measurements from infrared spectra: elemental carbon

    Science.gov (United States)

    Dillner, A. M.; Takahama, S.

    2015-10-01

    Elemental carbon (EC) is an important constituent of atmospheric particulate matter because it absorbs solar radiation influencing climate and visibility and it adversely affects human health. The EC measured by thermal methods such as thermal-optical reflectance (TOR) is operationally defined as the carbon that volatilizes from quartz filter samples at elevated temperatures in the presence of oxygen. Here, methods are presented to accurately predict TOR EC using Fourier transform infrared (FT-IR) absorbance spectra from atmospheric particulate matter collected on polytetrafluoroethylene (PTFE or Teflon) filters. This method is similar to the procedure developed for OC in prior work (Dillner and Takahama, 2015). Transmittance FT-IR analysis is rapid, inexpensive and nondestructive to the PTFE filter samples which are routinely collected for mass and elemental analysis in monitoring networks. FT-IR absorbance spectra are obtained from 794 filter samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites collected during 2011. Partial least squares regression is used to calibrate sample FT-IR absorbance spectra to collocated TOR EC measurements. The FT-IR spectra are divided into calibration and test sets. Two calibrations are developed: one developed from uniform distribution of samples across the EC mass range (Uniform EC) and one developed from a uniform distribution of Low EC mass samples (EC normalized error (21 %). These performance metrics can be achieved with various degrees of spectral pretreatment (e.g., including or excluding substrate contributions to the absorbances) and are comparable in precision and accuracy to collocated TOR measurements. Only the normalized error is higher for the FT-IR EC measurements than for collocated TOR. FT-IR spectra are also divided into calibration and test sets by the ratios OC/EC and ammonium/EC to determine the impact of OC and ammonium on EC prediction. We conclude that FT-IR analysis with

  8. Infrared emission from four Be stars optical counterparts of galactic X-ray sources

    International Nuclear Information System (INIS)

    Persi, P.; Ferrari-Toniolo, M.

    1982-01-01

    Preliminary results of our infrared observations from 2.3 up to 10 and 20 microns of the Be-X-ray stars X Per, γ Cas and HDE 245770, indicate the presence of an ionized circumstellar disk with an electron density law of the type nsub(e) proportional to rsup(-3.5). X Per and γ Cas show besides, variable infrared excess at 10μ suggesting variability in the stellar wind. LS I+65 0 010 presents an anomalous infrared energy distribution for a Be star. (Auth.)

  9. Infrared optical responses of wurtzite In{sub x}Ga{sub 1−x}N thin films with porous surface morphology

    Energy Technology Data Exchange (ETDEWEB)

    Yew, P., E-mail: paulinevcu@hotmail.com [Institute of Nano-Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 Minden, Penang (Malaysia); School of Physics, Universiti Sains Malaysia, 11800 Minden, Penang (Malaysia); Lee, S.C. [School of Physics, Universiti Sains Malaysia, 11800 Minden, Penang (Malaysia); Centre of Excellence for Pre-University Studies, INTI International College Penang, Laureate International University, 1-Z, Lebuh Bukit Jambul, 11900 Penang (Malaysia); Ng, S.S. [Institute of Nano-Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia, 11800 Minden, Penang (Malaysia); Hassan, H. Abu [School of Physics, Universiti Sains Malaysia, 11800 Minden, Penang (Malaysia); Chen, W.L. [Department of Electronic Engineering, National Changhua University of Education, 500, Taiwan, ROC (China); Osipowicz, T.; Ren, M.Q. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 119260 (Singapore)

    2016-03-31

    Room temperature infrared (IR) optical responses of wurtzite indium gallium nitride (In{sub x}Ga{sub 1−x}N) in the composition range of 0.174 ≤ x ≤ 0.883 were investigated by the polarized IR reflectance spectroscopy. Analyses of the amplitudes of oscillation fringes in the non-reststrahlen region revealed that the high frequency dielectric constants of the samples were unusually smaller than the values predicted from the Clausius–Mossotti relation. This odd behavior was attributed to the porous surface morphology of the In{sub x}Ga{sub 1−x}N samples. The E{sub 1} optical phonon modes of the In{sub x}Ga{sub 1−x}N were deduced from the composition dependent reststrahlen features. The obtained values were compared to those calculated through the modified random element iso-displacement (MREI) model. The deviation between the measured data and the MREI model prediction were explained in detail from the aspects of strain, thermal expansion and anharmonic phonon-coupling. Finally, it was found that the large discrepancy of the E{sub 1}(LO) mode is mainly attributed to the effects of the longitudinal phonon–plasmon coupling. - Highlights: • Composition dependence of E{sub 1} modes of In{sub x}Ga{sub 1−x}N alloys (x = 0.174 to 0.883) • Dependence of porous morphology on infrared (IR) optical properties • Longitudinal phonon–plasmon coupling obscures determination of E{sub 1}(LO) mode.

  10. Design of Rose Bengal/FTO optical thin film system as a novel nonlinear media for infrared blocking windows

    Directory of Open Access Journals (Sweden)

    S.M. El-Bashir

    Full Text Available Rose Bengal (RB is a new organic semiconductor with the highly stable layer, was deposited on highly cleaned conductive glass substrate known as (FTO glass with different thickness in the range from 80 to 292 nm. XRD showed an entirely amorphous structure of the studied film thicknesses. The observed peaks are the indexed peaks for FTO layer. Spectrophotometric data as transmittance, reflectance, and absorbance were used for the analysis the optical constant of RB/FTO optical thin film system. Refractive index was calculated using Fresnel’s equation with the aid of reflectance and absorption index. The dielectric constant, dielectric loss and dissipation factor were discussed and analyzed according to the applied optical theories. Nonlinear parameters such as third order nonlinear optical susceptibility and the nonlinear refractive index were calculated based on the linear refractive index of the applications of this material in nonlinear media. The results showed that Rose Bengal is a proving material for wide scale optoelectronic applications such as infrared blocking windows. Keywords: Rose Bengal, Dielectric parameters, Linear/nonlinear optics, Dye/FTO, IR blocking windows

  11. Performance of visible and mid-infrared scattering-type near-field optical microscopes.

    Science.gov (United States)

    Taubner, T; Hillenbrand, R; Keilmann, F

    2003-06-01

    We describe the principles of two scattering-type near-field optical microscopes (s-SNOMs), one operating at 633 nm wavelength, the other at selectable wavelengths in the range 7.3-11.3 micro m, and compare the measurement experience. Both use interferometric detection of scattered radiation, and are therefore capable of amplitude and phase-contrast imaging. In this study both instruments use the same or even identical commercial probe tips, and measure a single, three-component, test sample. Our results show that the imaging process of s-SNOM is wavelength-independent, namely, that the resolution is determined by the properties of the tip only, and that the contrast is given by the complex refractive index of the sample, predictable from a simple, analytical model of tip-sample interaction. A novel, 'edge-darkening' artefact is described which may appear in s-SNOM and that is wavelength-independent.

  12. Near-Field Imaging of Optical Fibers in the Mid-Infrared for New Mid-Wave Infrared Fiber Science

    Science.gov (United States)

    2017-03-17

    diverse as: combustion gases (giving potential for controlling energy efficiency); ground, water and air pollutants and greenhouse gases (for...controlling the environment); pharmaceuticals; toxic agents (for security); soft materials such as plastics and biological tissue (for laser machining and...Spontaneous Emission (ASE) was not included in the laser model. According to Quimby ASE can be neglected in the laser model due to fact that for a laser

  13. Using late-time optical and near-infrared spectra to constrain Type Ia supernova explosion properties

    Science.gov (United States)

    Maguire, K.; Sim, S. A.; Shingles, L.; Spyromilio, J.; Jerkstrand, A.; Sullivan, M.; Chen, T.-W.; Cartier, R.; Dimitriadis, G.; Frohmaier, C.; Galbany, L.; Gutiérrez, C. P.; Hosseinzadeh, G.; Howell, D. A.; Inserra, C.; Rudy, R.; Sollerman, J.

    2018-03-01

    The late-time spectra of Type Ia supernovae (SNe Ia) are powerful probes of the underlying physics of their explosions. We investigate the late-time optical and near-infrared spectra of seven SNe Ia obtained at the VLT with XShooter at >200 d after explosion. At these epochs, the inner Fe-rich ejecta can be studied. We use a line-fitting analysis to determine the relative line fluxes, velocity shifts, and line widths of prominent features contributing to the spectra ([Fe II], [Ni II], and [Co III]). By focussing on [Fe II] and [Ni II] emission lines in the ˜7000-7500 Å region of the spectrum, we find that the ratio of stable [Ni II] to mainly radioactively-produced [Fe II] for most SNe Ia in the sample is consistent with Chandrasekhar-mass delayed-detonation explosion models, as well as sub-Chandrasekhar mass explosions that have metallicity values above solar. The mean measured Ni/Fe abundance of our sample is consistent with the solar value. The more highly ionised [Co III] emission lines are found to be more centrally located in the ejecta and have broader lines than the [Fe II] and [Ni II] features. Our analysis also strengthens previous results that SNe Ia with higher Si II velocities at maximum light preferentially display blueshifted [Fe II] 7155 Å lines at late times. Our combined results lead us to speculate that the majority of normal SN Ia explosions produce ejecta distributions that deviate significantly from spherical symmetry.

  14. James Webb Telescope's Near Infrared Camera: Making Models, Building Understanding

    Science.gov (United States)

    Lebofsky, Larry A.; McCarthy, D. W.; Higgins, M. L.; Lebofsky, N. R.

    2010-10-01

    The Astronomy Camp for Girl Scout Leaders is a science education program sponsored by NASA's next large space telescope: The James Webb Space Telescope (JWST). The E/PO team for JWST's Near Infrared Camera (NIRCam), in collaboration with the Sahuaro Girl Scout Council, has developed a long-term relationship with adult leaders from all GSUSA Councils that directly benefits troops of all ages, not only in general science education but also specifically in the astronomical and technology concepts relating to JWST. We have been training and equipping these leaders so they can in turn teach young women essential concepts in astronomy, i.e., the night sky environment. We model what astronomers do by engaging trainers in the process of scientific inquiry, and we equip them to host troop-level astronomy-related activities. It is GSUSA's goal to foster girls’ interest and creativity in Science, Technology, Engineering, and Math, creating an environment that encourages their interests early in their lives while creating a safe place for girls to try and fail, and then try again and succeed. To date, we have trained over 158 leaders in 13 camps. These leaders have come from 24 states, DC, Guam, and Japan. While many of the camp activities are related to the "First Light” theme, many of the background activities relate to two of the other JWST and NIRCam themes: "Birth of Stars and Protoplanetary Systems” and "Planetary Systems and the Origin of Life.” The latter includes our own Solar System. Our poster will highlight the Planetary Systems theme: 1. Earth and Moon: Day and Night; Rotation and Revolution. 2. Earth/Moon Comparisons. 3. Size Model: The Diameters of the Planets. 4. Macramé Planetary (Solar) Distance Model. 5.What is a Planet? 6. Planet Sorting Cards. 7. Human Orrery 8. Lookback Time in Our Daily Lives NIRCam E/PO website: http://zeus.as.arizona.edu/ dmccarthy/GSUSA

  15. 730-nm optical parametric conversion from near- to short-wave infrared band

    DEFF Research Database (Denmark)

    Boggio, J.M.C.; Windmiller, J.R.; Knutzen, M.

    2008-01-01

    A record 730 nm parametric conversion in silica fiber from the near-infrared to the short-wave infrared band is reported and analyzed. A parametric gain in excess of 30 dB was measured for a signal at 1300 nm (with corresponding idler at 2030 nm). This conversion was performed in a travelling sin...... single-pass one-pump parametric architecture and high efficiency is achieved by a combination of high peak power and a nonlinear fiber with a reduced fourth-order dispersion coefficient.......A record 730 nm parametric conversion in silica fiber from the near-infrared to the short-wave infrared band is reported and analyzed. A parametric gain in excess of 30 dB was measured for a signal at 1300 nm (with corresponding idler at 2030 nm). This conversion was performed in a travelling...

  16. Near-infrared spectroscopy (NIRS) in a piglet model

    DEFF Research Database (Denmark)

    Clausen, Nicola Groes; Spielmann, Nelly; Ringer, Simone K.

    2017-01-01

    Near-infrared spectroscopy (NIRS) in a piglet model: readings are influenced by the colour of the cover Clausen NG1,2, Spielmann N1,3, Weiss M1,3, Ringer SK4 1Children’s Research Center, University Children’s Hospital of Zurich, Switzerland; 2Department of Anaesthesiology and Intensive Care, Odense...... from rSO2-UC and rSO2-SC (rSO2-UC2: 57.4 ± 6.8; rSO2-SC: 57.5 ± 6.4; rSO2-SD: 52 ± 5.9 %) (preadings can be influenced by covering of the sensors. The colour of the cover seems to be of importance....... This variability is likely to reflect a source of error rather than an actual change in rSO2 and should be considered, when interpreting rSO2 in a clinical setting. We suggest application of a black sensor cover to avoid the influence of light. Acknowledgement: An INVOS Oximetry monitor was provided with courtesy...

  17. Effects of Infrared Optical Trapping on Saccharomyces cerevisiae in a Microfluidic System

    Czech Academy of Sciences Publication Activity Database

    Pilát, Zdeněk; Jonáš, A.; Ježek, Jan; Zemánek, Pavel

    2017-01-01

    Roč. 17, NOV (2017), s. 1-12, č. článku 2640. ISSN 1424-8220 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : optical trapping * microfluidics * phototoxicity * laser * Saccharomyces cerevisiae Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 2.677, year: 2016 http://www.mdpi.com/1424-8220/17/11/2640

  18. 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.

  19. Optical modeling of Fresnel zoneplate microscopes.

    Science.gov (United States)

    Naulleau, Patrick P; Mochi, Iacopo; Goldberg, Kenneth A

    2011-07-10

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community. © 2011 Optical Society of America

  20. The Application of Infrared Imaging and Optical Coherence Tomography of the Lacrimal Punctum in Patients Undergoing Punctoplasty for Epiphora.

    Science.gov (United States)

    Timlin, Hannah M; Keane, Pearse A; Rose, Geoffrey E; Ezra, Daniel G

    2017-06-01

    To determine the application of imaging the stenotic lacrimal punctum with infrared photographs and optical coherence tomography (OCT) and to identify characteristics of the lacrimal punctum in patients who benefit from punctoplasty. Case-control study. Twenty patients with epiphora who were listed for punctoplasty and 20 healthy controls. Prospectively, 20 patients listed for punctoplasty were asked to rate their epiphora, using the Munk score, before and after punctoplasty. They also underwent preoperative OCT and infrared imaging of the affected punctum. They were divided into 2 groups, depending on whether the epiphora improved, and were compared with 20 healthy controls. Measurements of puncta from infrared and OCT images were obtained along with Munk scores of patient epiphora. The infrared image measurements were significantly smaller in those patients whose epiphora improved compared with those whose did not in both the area of the punctal aperture and in the maximum punctal diameter. Additionally, those patients with improvement in epiphora had a significantly smaller preoperative punctal diameter at 100 μm depth on OCT compared with healthy controls; this was not observed in patients whose epiphora failed to improve. There was no significant difference in the punctum diameter among the 3 groups at the punctum surface entrance or at 500 μm depth. Patients with epiphora had a higher tear meniscus within the punctum compared with healthy controls. Lacrimal punctum infrared and OCT imaging may be helpful in predicting patients more likely to benefit symptomatically from punctoplasty, with patients with smaller puncta having greater symptomatic improvement. However, the results suggest that inner punctum diameter (not readily measurable by slit-lamp examination), rather than the surface diameter, is correlated with outcome. Additionally, OCT measurements of the tear meniscus height within the punctum may be related to the degree of epiphora. Copyright

  1. Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph

    Science.gov (United States)

    Sugai, Hajime; Tamura, Naoyuki; Karoji, Hiroshi; Shimono, Atsushi; Takato, Naruhisa; Kimura, Masahiko; Ohyama, Youichi; Ueda, Akitoshi; Aghazarian, Hrand; de Arruda, Marcio V.; Barkhouser, Robert H.; Bennett, Charles L.; Bickerton, Steve; Bozier, Alexandre; Braun, David F.; Bui, Khanh; Capocasale, Christopher M.; Carr, Michael A.; Castilho, Bruno; Chang, Yin-Chang; Chen, Hsin-Yo; Chou, Richard C. Y.; Dawson, Olivia R.; Dekany, Richard G.; Ek, Eric M.; Ellis, Richard S.; English, Robin J.; Ferrand, Didier; Ferreira, Décio; Fisher, Charles D.; Golebiowski, Mirek; Gunn, James E.; Hart, Murdock; Heckman, Timothy M.; Ho, Paul T. P.; Hope, Stephen; Hovland, Larry E.; Hsu, Shu-Fu; Hu, Yen-Sang; Huang, Pin Jie; Jaquet, Marc; Karr, Jennifer E.; Kempenaar, Jason G.; King, Matthew E.; Le Fèvre, Olivier; Le Mignant, David; Ling, Hung-Hsu; Loomis, Craig; Lupton, Robert H.; Madec, Fabrice; Mao, Peter; Marrara, Lucas S.; Ménard, Brice; Morantz, Chaz; Murayama, Hitoshi; Murray, Graham J.; de Oliveira, Antonio Cesar; de Oliveira, Claudia M.; de Oliveira, Ligia S.; Orndorff, Joe D.; de Paiva Vilaça, Rodrigo; Partos, Eamon J.; Pascal, Sandrine; Pegot-Ogier, Thomas; Reiley, Daniel J.; Riddle, Reed; Santos, Leandro; dos Santos, Jesulino B.; Schwochert, Mark A.; Seiffert, Michael D.; Smee, Stephen A.; Smith, Roger M.; Steinkraus, Ronald E.; Sodré, Laerte; Spergel, David N.; Surace, Christian; Tresse, Laurence; Vidal, Clément; Vives, Sebastien; Wang, Shiang-Yu; Wen, Chih-Yi; Wu, Amy C.; Wyse, Rosie; Yan, Chi-Hung

    2014-07-01

    The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 μm to 1.26 μm, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 μm to 0.89 μm also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts (SuMIRe) project, while Hyper Suprime-Cam (HSC) works on the imaging part. HSC's excellent image qualities have proven the high quality of the Wide Field Corrector (WFC), which PFS shares with HSC. The PFS collaboration has succeeded in the project Preliminary Design Review and is now in a phase of subsystem Critical Design Reviews and construction. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated microlens is glued to each fiber tip. The microlenses are molded glass, providing uniform lens dimensions and a variety of refractive-index selection. After successful production of mechanical and optical samples, mass production is now complete. Following careful investigations including Focal Ratio Degradation (FRD) measurements, a higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. After evaluating the statistics of positioning accuracies, collision avoidance software, and interferences (if any) within/between electronics boards, mass production will commence. Fiber

  2. 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.

  3. Quantum optical signatures in strong-field laser physics: Infrared photon counting in high-order-harmonic generation.

    Science.gov (United States)

    Gonoskov, I A; Tsatrafyllis, N; Kominis, I K; Tzallas, P

    2016-09-07

    We analytically describe the strong-field light-electron interaction using a quantized coherent laser state with arbitrary photon number. We obtain a light-electron wave function which is a closed-form solution of the time-dependent Schrödinger equation (TDSE). This wave function provides information about the quantum optical features of the interaction not accessible by semi-classical theories. With this approach we can reveal the quantum optical properties of high harmonic generation (HHG) process in gases by measuring the photon statistics of the transmitted infrared (IR) laser radiation. This work can lead to novel experiments in high-resolution spectroscopy in extreme-ultraviolet (XUV) and attosecond science without the need to measure the XUV light, while it can pave the way for the development of intense non-classical light sources.

  4. Optical modeling and simulation of thin-film photovoltaic devices

    CERN Document Server

    Krc, Janez

    2013-01-01

    In wafer-based and thin-film photovoltaic (PV) devices, the management of light is a crucial aspect of optimization since trapping sunlight in active parts of PV devices is essential for efficient energy conversions. Optical modeling and simulation enable efficient analysis and optimization of the optical situation in optoelectronic and PV devices. Optical Modeling and Simulation of Thin-Film Photovoltaic Devices provides readers with a thorough guide to performing optical modeling and simulations of thin-film solar cells and PV modules. It offers insight on examples of existing optical models

  5. Infrared and Optical Observations of GRB 030115 and its Extremely Red Host Galaxy: Implications for Dark Bursts

    International Nuclear Information System (INIS)

    Levan, Andrew; Fruchter, Andrew; Rhoads, James; Mobasher, Bahram; Tanvir, Nial; Gorosabel, Javier; Rol, Evert; Kouveliotou, Chryssa; Dell'Antonio, Ian; Merrill, Michael; Bergeron, Eddie; Castro Ceron, JosMar a; Masetti, Nicola; Vreeswijk, Paul; Antonelli, Angelo; Bersier, David; Castro-Tirado, Alberto; Fynbo, Johan; Garnavich, Peter; Holland, Stephen; Hjorth, Jens; Nugent, Peter; Pian, Elena; Smette, Alain; Thomsen, Bjarne; Thorsett, Stephen E.; Wijers, Ralph

    2006-01-01

    We present near-infrared (NIR) and optical observations of the afterglow of GRB 030115. Discovered in an infrared search at Kitt Peak5 hr after the burst trigger, this afterglow is the faintest ever observed in the R band at such an early epoch and exhibits very red colors, with R-K∼6. The optical magnitude of the afterglow of GRB 030115 is fainter than many upper limits for other bursts, suggesting that without early NIR observations it would have been classified as a 'dark' burst. Both the color and optical magnitude of the afterglow are likely due to dust extinction at moderate redshift z>2 and indicate that at least some optical afterglows are very faint due to dust along the line of sight. Multicolor Hubble Space Telescope observations were also taken of the host galaxy and the surrounding field. Photometric redshifts imply that the host and a substantial number of faint galaxies in the field are at z 2:5. The overdensity of galaxies is sufficiently great that GRB030115 may have occurred in a rich high-red shift cluster. The host galaxy shows extremely red colors (R-K = 5) and is the first GRB host to be classified as an extremely red object (ERO). Some of the galaxies surrounding the host also show very red colors, while the majority of the cluster are much bluer, indicating ongoing unobscured star formation. As it is thought that much of high-redshift star formation occurs in highly obscured environments, it may well be that GRB 030115 represents a transition object, between the relatively unobscured afterglows seen to date and a population of objects that are very heavily extinguished, even in the NIR

  6. The forward tracking, an optical model method

    CERN Document Server

    Benayoun, M

    2002-01-01

    This Note describes the so-called Forward Tracking, and the underlying optical model, developed in the context of LHCb-Light studies. Starting from Velo tracks, cheated or found by real pattern recognition, the tracks are found in the ST1-3 chambers after the magnet. The main ingredient to the method is a parameterisation of the track in the ST1-3 region, based on the Velo track parameters and an X seed in one ST station. Performance with the LHCb-Minus and LHCb-Light setups is given.

  7. Optical Model and Cross Section Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.

    2009-10-05

    Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.

  8. Using Molecular Modeling in Teaching Group Theory Analysis of the Infrared Spectra of Organometallic Compounds

    Science.gov (United States)

    Wang, Lihua

    2012-01-01

    A new method is introduced for teaching group theory analysis of the infrared spectra of organometallic compounds using molecular modeling. The main focus of this method is to enhance student understanding of the symmetry properties of vibrational modes and of the group theory analysis of infrared (IR) spectra by using visual aids provided by…

  9. MEMS-based optical mini- and microspectrometers for the visible and infrared spectral range

    Science.gov (United States)

    Wolffenbuttel, R. F.

    2005-07-01

    Miniaturized free-field based optical microspectrometers have huge potential for application in industry, science, medicine, agriculture and biology. State-of-the-art is the micro-assembly of micromachined optical components on a mini-bench and the trend is towards fully integrated optical microsystems. Complete silicon IC compatible MEMS-based opto-electrical microsystems on a single chip may offer huge cost benefits in these potentially high-volume applications. On-chip integration does, however, impose limitations. The required process compatibility and limited choice of acceptable materials does not necessarily give optimum optical performance. Also, the dimensional downscaling is not generally an optical advantage. This overview discusses grating-based and interferometer-based mini- and microspectrometers, shows performances already reported, the trends, the potential, the limitations and approaches to obtain a sufficient optical performance, in terms of spectral resolution and throughput, for serving the majority of applications.

  10. Developments Toward Diagnostic Breast Cancer Imaging Using Near-Infrared Optical Measurements and Fluorescent Contrast Agents1

    Directory of Open Access Journals (Sweden)

    Daniel J. Hawrysz

    2000-09-01

    Full Text Available The use of near-infrared (NIR light to interrogate deep tissues has enormous potential for molecular-based imaging when coupled with NIR excitable dyes. More than a decade has now passed since the initial proposals for NIR optical tomography for breast cancer screening using time-dependent measurements of light propagation in the breast. Much accomplishment in the development of optical mammography has been demonstrated, most recently in the application of time-domain, frequency-domain, and continuous-wave measurements that depend on endogenous contrast owing to angiogenesis and increased hemoglobin absorbance for contrast. Although exciting and promising, the necessity of angiogenesis-mediated absorption contrast for diagnostic optical mammography minimizes the potential for using NIR techniques to assess sentinel lymph node staging, metastatic spread, and multifocality of breast disease, among other applications. In this review, we summarize the progress made in the development of optical mammography, and focus on the emerging work underway in the use of diagnostic contrast agents for the molecular-based, diagnostic imaging of breast.

  11. Design of Rose Bengal/FTO optical thin film system as a novel nonlinear media for infrared blocking windows

    Science.gov (United States)

    El-Bashir, S. M.; Yahia, I. S.; Binhussain, M. A.; AlSalhi, M. S.

    Rose Bengal (RB) is a new organic semiconductor with the highly stable layer, was deposited on highly cleaned conductive glass substrate known as (FTO glass) with different thickness in the range from 80 to 292 nm. XRD showed an entirely amorphous structure of the studied film thicknesses. The observed peaks are the indexed peaks for FTO layer. Spectrophotometric data as transmittance, reflectance, and absorbance were used for the analysis the optical constant of RB/FTO optical thin film system. Refractive index was calculated using Fresnel's equation with the aid of reflectance and absorption index. The dielectric constant, dielectric loss and dissipation factor were discussed and analyzed according to the applied optical theories. Nonlinear parameters such as third order nonlinear optical susceptibility and the nonlinear refractive index were calculated based on the linear refractive index of the applications of this material in nonlinear media. The results showed that Rose Bengal is a proving material for wide scale optoelectronic applications such as infrared blocking windows.

  12. Optical properties of nanostructured TiO2 thin films and their application as antireflection coatings on infrared detectors.

    Science.gov (United States)

    Jayasinghe, R C; Perera, A G U; Zhu, H; Zhao, Y

    2012-10-15

    Oblique-angle deposited titanium dioxide (TiO(2)) nanorods have attracted much attention as good antireflection (AR) coating material due to their low n profile. Therefore, it is necessary to better understand the optical properties of these nanorods. TiO(2) nanorods grown on glass and Si substrates were characterized in the visible (0.4-0.8 μm) and infrared (2-12 μm) regions to extract their complex n profiles empirically. Application of these nanorods in multilayer AR coatings on infrared detectors is also discussed. Optimization of graded index profile of these AR coatings in the broad infrared region (2-12 μm) even at oblique angles of incidence is discussed. The effective coupling between the incoming light and multiple nanorod layers for reducing the reflection is obtained by optimizing the effect from Fabry-Perot oscillations. An optimized five-layer AR coating on GaN shows the reflectance less than 3.3% for normal incidence and 10.5% at 60° across the whole 2-8 μm spectral range.

  13. Predicting ambient aerosol thermal-optical reflectance (TOR) measurements from infrared spectra: organic carbon

    Science.gov (United States)

    Dillner, A. M.; Takahama, S.

    2015-03-01

    Organic carbon (OC) can constitute 50% or more of the mass of atmospheric particulate matter. Typically, organic carbon is measured from a quartz fiber filter that has been exposed to a volume of ambient air and analyzed using thermal methods such as thermal-optical reflectance (TOR). Here, methods are presented that show the feasibility of using Fourier transform infrared (FT-IR) absorbance spectra from polytetrafluoroethylene (PTFE or Teflon) filters to accurately predict TOR OC. This work marks an initial step in proposing a method that can reduce the operating costs of large air quality monitoring networks with an inexpensive, non-destructive analysis technique using routinely collected PTFE filter samples which, in addition to OC concentrations, can concurrently provide information regarding the composition of organic aerosol. This feasibility study suggests that the minimum detection limit and errors (or uncertainty) of FT-IR predictions are on par with TOR OC such that evaluation of long-term trends and epidemiological studies would not be significantly impacted. To develop and test the method, FT-IR absorbance spectra are obtained from 794 samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites collected during 2011. Partial least-squares regression is used to calibrate sample FT-IR absorbance spectra to TOR OC. The FTIR spectra are divided into calibration and test sets by sampling site and date. The calibration produces precise and accurate TOR OC predictions of the test set samples by FT-IR as indicated by high coefficient of variation (R2; 0.96), low bias (0.02 μg m-3, the nominal IMPROVE sample volume is 32.8 m3), low error (0.08 μg m-3) and low normalized error (11%). These performance metrics can be achieved with various degrees of spectral pretreatment (e.g., including or excluding substrate contributions to the absorbances) and are comparable in precision to collocated TOR measurements. FT-IR spectra are also

  14. Predicting ambient aerosol Thermal Optical Reflectance (TOR) measurements from infrared spectra: elemental carbon

    Science.gov (United States)

    Dillner, A. M.; Takahama, S.

    2015-06-01

    Elemental carbon (EC) is an important constituent of atmospheric particulate matter because it absorbs solar radiation influencing climate and visibility and it adversely affects human health. The EC measured by thermal methods such as Thermal-Optical Reflectance (TOR) is operationally defined as the carbon that volatilizes from quartz filter samples at elevated temperatures in the presence of oxygen. Here, methods are presented to accurately predict TOR EC using Fourier Transform Infrared (FT-IR) absorbance spectra from atmospheric particulate matter collected on polytetrafluoroethylene (PTFE or Teflon) filters. This method is similar to the procedure tested and developed for OC in prior work (Dillner and Takahama, 2015). Transmittance FT-IR analysis is rapid, inexpensive, and non-destructive to the PTFE filter samples which are routinely collected for mass and elemental analysis in monitoring networks. FT-IR absorbance spectra are obtained from 794 filter samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites collected during 2011. Partial least squares regression is used to calibrate sample FT-IR absorbance spectra to collocated TOR EC measurements. The FTIR spectra are divided into calibration and test sets. Two calibrations are developed, one which is developed from uniform distribution of samples across the EC mass range (Uniform EC) and one developed from a~uniform distribution of low EC mass samples (EC TOR EC samples in the same mass range and an estimate of the minimum detection limit (MDL) that is on par with TOR EC MDL. For all samples, this hybrid approach leads to precise and accurate TOR EC predictions by FT-IR as indicated by high coefficient of variation (R2; 0.96), no bias (0.00 μg m-3, concentration value based on the nominal IMPROVE sample volume of 32.8 m-3), low error (0.03 μg m-3) and reasonable normalized error (21 %). These performance metrics can be achieved with various degrees of spectral pretreatment

  15. 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.

  16. The Evolving Sociology of Ground-Based Optical and Infrared Astronomy at the Start of the 21ST Century

    Science.gov (United States)

    Roy, Jean-Rene; Mountain, Matt

    2006-01-01

    By looking back at the last half century and beyond, an understanding emerges in the patterns and influences of the social, fiscal and institutional development of astronomical institutions and observatories. In this paper, the authors review many changes that have transformed how astronomers build and use their "great telescopes"; they also examine the evolving process that maximizes the productivity and impact of undertaking modern ground-based optical/infrared astronomy. The integration of modern engineering and experimental practices, broadened access to largescale funding and international competition, all have a role in these changes. A changing social paradigm has moved these ventures from the scientific elite into the realm and structure of tightly managed projects involving close partnerships between engineers and scientists. Astronomer's observational methods have changed in fundamental ways as well, driven by the complexity of the instruments used and their tremendous cost. The conclusion of this paper is that optical/infrared ground-based astronomy is in transition. "Hundred-million-dollar-scale" 8m to 10m telescopes have been erected and now our communities have billion-dollar-scale ambitions. To realize these ambitions, the same communities need to relinquish cherished notions of individual and even institutional dominance and merge into large, productive consortia consisting of institutions and multi-national agencies.

  17. 730-nm optical parametric conversion from near- to short-wave infrared band.

    Science.gov (United States)

    Chavez Boggio, J M; Windmiller, J R; Knutzen, M; Jiang, R; Bres, C; Alic, N; Stossel, B; Rottwitt, K; Radic, S

    2008-04-14

    A record 730 nm parametric conversion in silica fiber from the near-infrared to the short-wave infrared band is reported and analyzed. A parametric gain in excess of 30 dB was measured for a signal at 1300 nm (with corresponding idler at 2030 nm). This conversion was performed in a travelling single-pass one-pump parametric architecture and high efficiency is achieved by a combination of high peak power and a nonlinear fiber with a reduced fourth-order dispersion coefficient.

  18. Dynamic modeling method for infrared smoke based on enhanced discrete phase model

    Science.gov (United States)

    Zhang, Zhendong; Yang, Chunling; Zhang, Yan; Zhu, Hongbo

    2018-03-01

    The dynamic modeling of infrared (IR) smoke plays an important role in IR scene simulation systems and its accuracy directly influences the system veracity. However, current IR smoke models cannot provide high veracity, because certain physical characteristics are frequently ignored in fluid simulation; simplifying the discrete phase as a continuous phase and ignoring the IR decoy missile-body spinning. To address this defect, this paper proposes a dynamic modeling method for IR smoke, based on an enhanced discrete phase model (DPM). A mathematical simulation model based on an enhanced DPM is built and a dynamic computing fluid mesh is generated. The dynamic model of IR smoke is then established using an extended equivalent-blackbody-molecule model. Experiments demonstrate that this model realizes a dynamic method for modeling IR smoke with higher veracity.

  19. Integrated modeling of the Canadian Very Large Optical Telescope

    Science.gov (United States)

    Roberts, Scott C.; Pazder, John S.; Fitzsimmons, Joeleff T.; Herriot, Glen; Loewen, Nathan; Smith, Malcolm J.; Dunn, Jennifer; Saddlemyer, Leslie K.

    2004-07-01

    We describe the VLOT integrated model, which simulates the telescope optical performance under the influence of external disturbances including wind. Details of the implementation in the MATLAB/SIMULINK environment are given, and the data structures are described. The structural to optical interface is detailed, including a discussion of coordinate transformations. The optical model includes both an interface with ZEMAX to perform raytracing analysis and an efficient Linear Optics Model for producing telescope optical path differences from within MATLAB. An extensive set of optical analysis routines has been developed for use with the integrated model. The telescope finite element model, state-space formulation and the high fidelity 1500 mode modal state-space structural dynamics model are presented. Control systems and wind models are described. We present preliminary results, showing the delivered image quality under the influence of wind on the primary mirror, with and without primary mirror control.

  20. Kinetics of infrared stimulated luminescence from feldspars

    DEFF Research Database (Denmark)

    Jain, Mayank; Sohbati, Reza; Guralnik, Benny

    2015-01-01

    thermal and optical, of the infrared stimulated luminescence signal from feldspar. Based on the application of this model, it is concluded that different infra-red stimulated luminescence emissions (UV, blue, yellow and far-red) follow the same kinetics, and, therefore, involve participation of the same...... in feldspar. © 2015 Elsevier Ltd. All rights reserved....

  1. Mid-infrared Spectroscopy/Bioimaging: Moving toward MIR optical biopsy

    DEFF Research Database (Denmark)

    Seddon, Angela B.; Napier, Bruce; Lindsay, Ian

    2016-01-01

    Limited availability of tests to diagnose cancer in its early stages has contributed to an unfortunate prevalence of late-stage diagnoses and metastatic spread. For this reason, emerging technologies that promise early diagnosis constitute a key focus of research. Mid-infrared imaging (MIR), with...

  2. ITER-like wide-angle infrared thermography and visible observation diagnostic using reflective optics

    NARCIS (Netherlands)

    Gauthier, E.; Roche, H.; Thomas, E.; Droineau, S.; Bertrand, B.; Migozzi, J.B.; Vliegenthart, W.A.; Dague, L.; Andrew, P.; Tiscornia, T.; Sands, D.

    2007-01-01

    Control of the plasma-wall interaction during transient events will be a critical issue in ITER. A new ITER-like wide-angle infrared and visible diagnostic, allowing to observe plasma wall interaction in the main chamber, has been installed on JET. The design and the manufacture of the diagnostic

  3. Diffractive Optics in the Infrared (DiOptIR) LDRD 67109 final report.

    Energy Technology Data Exchange (ETDEWEB)

    Alford, Charles Fred; Vawter, Gregory Allen; Wendt, Joel Robert; Kemme, Shanalyn A.; Samora, Sally; Carter, Tony Ray; Peters, David William; Shields, Eric A.

    2005-10-01

    This diffractive optical element (DOE) LDRD is divided into two tasks. In Task 1, we develop two new DOE technologies: (1) a broad wavelength band effective anti-reflection (AR) structure and (2) a design tool to encode dispersion and polarization information into a unique diffraction pattern. In Task 2, we model, design, and fabricate a subwavelength polarization splitter. The first technology is an anti-reflective (AR) layer that may be etched into the DOE surface. For many wavelengths of interest, transmissive silicon DOEs are ideal. However, a significant portion of light (30% from each surface) is lost due to Fresnel reflection. To address this issue, we investigate a subwavelength, surface relief structure that acts as an effective AR coating. The second DOE component technology in Task 1 is a design tool to determine the optimal DOE surface relief structure that can encode the light's degree of dispersion and polarization into a unique spatial pattern. Many signals of interest have unique spatial, temporal, spectral, and polarization signatures. The ability to disperse the signal into a unique diffraction pattern would result in improved signal detection sensitivity with a simultaneous reduction in false alarm. Task 2 of this LDRD project is to investigate the modeling, design, and fabrication of subwavelength birefringent devices for polarimetric spectral sensing and imaging applications. Polarimetric spectral sensing measures the spectrum of the light and polarization state of light at each wavelength simultaneously. The capability to obtain both polarization and spectral information can help develop target/object signature and identify the target/object for several applications in NP&MC and national security.

  4. Optical and FT Infrared spectral studies of vanadium ions in cadmium borate glass and effects of gamma irradiation.

    Science.gov (United States)

    AbdelAziz, T D; EzzElDin, F M; El Batal, H A; Abdelghany, A M

    2014-10-15

    Combined optical and infrared absorption spectra of V2O5-doped cadmium borate glasses were investigated before and after gamma irradiation with a dose of 8 Mrad (=8×10(4) Gy). The undoped base cadmium borate glass reveals a spectrum consisting of strong charge transfer UV absorption bands which are related to the presence of unavoidable contaminated trace iron impurities (mainly Fe(3+)). The V2O5-doped glasses reveal an extra band at 380nm and the high V2O5-content glass also shows a further band at about 420nm. The observed optical spectrum indicates the presence of vanadium ions mainly in the pentavalent state (d(0) configuration). The surplus band at 420nm shows that some trivalent vanadium ions are identified at high V2O5 content. The optical spectra of the glasses after gamma irradiation show small decrease of the intensity of the UV absorption which are interpreted by assuming the transformation of some Fe(3+) ions by photochemical reactions with the presence of high content (45mol%) of heavy massive CdO causing some shielding behavior. FT infrared absorption spectra of the glasses show vibrational bands due to collective presence of triangular and tetrahedral borate groups in their specific wavenumbers. The FTIR spectra are observed to be slightly affected by both the V2O5-dopants being present in modifying low percent or gamma irradiation due to the presence of high content heavy CdO. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Modeling of aircraft exhaust emissions and infrared spectra for remote measurement of nitrogen oxides

    Directory of Open Access Journals (Sweden)

    K. Beier

    Full Text Available Infrared (IR molecular spectroscopy is proposed to perform remote measurements of NOx concentrations in the exhaust plume and wake of aircraft. The computer model NIRATAM is applied to simulate the physical and chemical properties of the exhaust plume and to generate low resolution IR spectra and synthetical thermal images of the aircraft in its natural surroundings. High-resolution IR spectra of the plume, including atmospheric absorption and emission, are simulated using the molecular line-by-line radiation model FASCODE2. Simulated IR spectra of a Boeing 747-400 at cruising altitude for different axial and radial positions in the jet region of the exhaust plume are presented. A number of spectral lines of NO can be identified that can be discriminated from lines of other exhaust gases and the natural atmospheric background in the region around 5.2 µm. These lines can be used to determine NO concentration profiles in the plume. The possibility of measuring nitrogen dioxide NO2 is also discussed briefly, although measurements turn out to be substantially less likely than those of NO. This feasibility study compiles fundamental data for the optical and radiometric design of an airborne Fourier transform spectrometer and the preparation of in-flight measurements for monitoring of aircraft pollutants.

  6. Modeling of aircraft exhaust emissions and infrared spectra for remote measurement of nitrogen oxides

    Directory of Open Access Journals (Sweden)

    K. Beier

    1994-08-01

    Full Text Available Infrared (IR molecular spectroscopy is proposed to perform remote measurements of NOx concentrations in the exhaust plume and wake of aircraft. The computer model NIRATAM is applied to simulate the physical and chemical properties of the exhaust plume and to generate low resolution IR spectra and synthetical thermal images of the aircraft in its natural surroundings. High-resolution IR spectra of the plume, including atmospheric absorption and emission, are simulated using the molecular line-by-line radiation model FASCODE2. Simulated IR spectra of a Boeing 747-400 at cruising altitude for different axial and radial positions in the jet region of the exhaust plume are presented. A number of spectral lines of NO can be identified that can be discriminated from lines of other exhaust gases and the natural atmospheric background in the region around 5.2 µm. These lines can be used to determine NO concentration profiles in the plume. The possibility of measuring nitrogen dioxide NO2 is also discussed briefly, although measurements turn out to be substantially less likely than those of NO. This feasibility study compiles fundamental data for the optical and radiometric design of an airborne Fourier transform spectrometer and the preparation of in-flight measurements for monitoring of aircraft pollutants.

  7. Dynamic ray tracing for modeling optical cell manipulation

    Science.gov (United States)

    Sraj, Ihab; Szatmary, Alex C.; Marr, David W. M.; Eggleton, Charles D.

    2010-01-01

    Current methods for predicting stress distribution on a cell surface due to optical trapping forces are based on a traditional ray optics scheme for fixed geometries. Cells are typically modeled as solid spheres as this facilitates optical force calculation. Under such applied forces however, real and non-rigid cells can deform, so assumptions inherent in traditional ray optics methods begin to break down. In this work, we implement a dynamic ray tracing technique to calculate the stress distribution on a deformable cell induced by optical trapping. Here, cells are modeled as three-dimensional elastic capsules with a discretized surface with associated hydrodynamic forces calculated using the Immersed Boundary Method. We use this approach to simulate the transient deformation of spherical, ellipsoidal and biconcave capsules due to external optical forces induced by a single diode bar optical trap for a range of optical powers. PMID:20721060

  8. Characterization of silver halide fiber optics and hollow silica waveguides for use in the construction of a mid-infrared attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy probe.

    Science.gov (United States)

    Damin, Craig A; Sommer, André J

    2013-11-01

    Advances in fiber optic materials have allowed for the construction of fibers and waveguides capable of transmitting infrared radiation. An investigation of the transmission characteristics associated with two commonly used types of infrared-transmitting fibers/waveguides for prospective use in a fiber/waveguide-coupled attenuated total internal reflection (ATR) probe was performed. Characterization of silver halide polycrystalline fiber optics and hollow silica waveguides was done on the basis of the transmission of infrared light using a conventional fiber optic coupling accessory and an infrared microscope. Using the fiber optic coupling accessory, the average percent transmission for three silver halide fibers was 18.1 ± 6.1% relative to a benchtop reflection accessory. The average transmission for two hollow waveguides (HWGs) using the coupling accessory was 8.0 ± 0.3%. (Uncertainties in the relative percent transmission represent the standard deviations.) Reduced transmission observed for the HWGs was attributed to the high numerical aperture of the coupling accessory. Characterization of the fibers/waveguides using a zinc selenide lens objective on an infrared microscope indicated 24.1 ± 7.2% of the initial light input into the silver halide fibers was transmitted. Percent transmission obtained for the HWGs was 98.7 ± 0.1%. Increased transmission using the HWGs resulted from the absence or minimization of insertion and scattering losses due to the hollow air core and a better-matched numerical aperture. The effect of bending on the transmission characteristics of the fibers/waveguides was also investigated. Significant deviations in the transmission of infrared light by the solid-core silver halide fibers were observed for various bending angles. Percent transmission greater than 98% was consistently observed for the HWGs at the bending angles. The combined benefits of high percent transmission, reproducible instrument responses, and increased bending

  9. Thin ice clouds in the Arctic: cloud optical depth and particle size retrieved from ground-based thermal infrared radiometry

    Directory of Open Access Journals (Sweden)

    Y. Blanchard

    2017-06-01

    Full Text Available Multiband downwelling thermal measurements of zenith sky radiance, along with cloud boundary heights, were used in a retrieval algorithm to estimate cloud optical depth and effective particle diameter of thin ice clouds in the Canadian High Arctic. Ground-based thermal infrared (IR radiances for 150 semitransparent ice clouds cases were acquired at the Polar Environment Atmospheric Research Laboratory (PEARL in Eureka, Nunavut, Canada (80° N, 86° W. We analyzed and quantified the sensitivity of downwelling thermal radiance to several cloud parameters including optical depth, effective particle diameter and shape, water vapor content, cloud geometric thickness and cloud base altitude. A lookup table retrieval method was used to successfully extract, through an optimal estimation method, cloud optical depth up to a maximum value of 2.6 and to separate thin ice clouds into two classes: (1 TIC1 clouds characterized by small crystals (effective particle diameter  ≤  30 µm, and (2 TIC2 clouds characterized by large ice crystals (effective particle diameter  >  30 µm. The retrieval technique was validated using data from the Arctic High Spectral Resolution Lidar (AHSRL and Millimeter Wave Cloud Radar (MMCR. Inversions were performed over three polar winters and results showed a significant correlation (R2 =  0.95 for cloud optical depth retrievals and an overall accuracy of 83 % for the classification of TIC1 and TIC2 clouds. A partial validation relative to an algorithm based on high spectral resolution downwelling IR radiance measurements between 8 and 21 µm was also performed. It confirms the robustness of the optical depth retrieval and the fact that the broadband thermal radiometer retrieval was sensitive to small particle (TIC1 sizes.

  10. Infrared optical constants of liquid palm oil and palm oil biodiesel determined by the combined ellipsometry-transmission method.

    Science.gov (United States)

    Wang, C C; Tan, J Y; Ma, Y Q; Liu, L H

    2017-06-20

    The optical constants of vegetable oils and biodiesels are the basic input parameters in the study of the thermal radiation transfer and monitoring the productivity of vegetable oils converting to biodiesels. In this work, a combined ellipsometry-transmission method is presented to obtain the optical constants of palm oil and palm oil biodiesel between 20°C and 150°C in the spectral range 600-4100  cm -1 and to study the temperature effect on the optical constants. In the combined method, a modified ellipsometry method is used to measure the optical constants of palm oil and palm oil biodiesel for the whole researched wave bands. For the weak absorption regions in which the ellipsometry method cannot give precise absorption indices, the transmission method is conducted to get the absorption indices using the refractive indices obtained by the proposed ellipsometry method. Deionized water and methanol are taken as examples to verify the combined ellipsometry-transmission method. It is shown that the combined method can overcome the deficiencies of the traditional ellipsometry and transmission method, which can be used for the measurements of both strong and weak absorption wave bands. The experimental analyses indicate that temperature exerts a noticeable influence on the infrared optical constants of palm oil and palm oil biodiesel. With the increase of temperature, the refractive indices at certain wavenumbers decrease nearly linearly, and the amplitudes of dominant absorption peaks show a decreasing trend. The absorption peaks located around 3550  cm -1 show blueshift trends as temperature increases. Comparing these two kinds of oils, palm oil presents larger values in refractive indices and dominant absorption peaks.

  11. Optical modeling of Fresnel zoneplate microscopes

    International Nuclear Information System (INIS)

    Naulleau, Patrick P.; Mochi, Iacopo; Goldberg, Kenneth A.

    2011-01-01

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community.

  12. Functional near infrared brain imaging with a brush-fiber optode to improve optical contact on subjects with dense hair

    Science.gov (United States)

    Khan, Bilal; Wildey, Chester; Francis, Robert; Tian, Fenghua; Romero, Mario I.; Delgado, Mauricio R.; Clegg, Nancy J.; Smith, Linsley; Liu, Hanli; MacFarlane, Duncan L.; Alexandrakis, George

    2011-03-01

    A major obstacle in functional near infrared spectroscopy (fNIRS) and imaging is poor optical contact of the optodes with the scalp due to obstruction by hair. To overcome this problem a novel brush-fiber extension was made as an attachment to existing commercial flat-face fiber bundle optodes. The goal was that the brush-fiber extension would thread through hair and improve optical contact on subjects with dense hair. Simulations and experiments were performed to assess the magnitude of these improvements. Firstly, a Monte Carlo (MC) simulation of photon propagation through the scalp with hair and hair follicles was performed showing a drop in light transmission for different hair densities in the range of 3 to 9 dB. Similar levels of signal loss at individual optodes were determined experimentally in preliminary measurements on a human subject, when comparisons were made for finger tapping activation measurements with and without the brush-fiber extensions. The effects of such losses on reconstructed images were also simulated by using neutral density filters during tissue phantom measurements. As brush-fibers attenuated the signal by approximately 2.5 dB due to imperfect optical contact with the flat-face optode tips we explored the idea of using larger diameter brush-fibers to overcome that loss.

  13. 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.

  14. 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.

  15. A New Method Based on Graphics Processing Units for Fast Near-Infrared Optical Tomography.

    Science.gov (United States)

    Jiang, Jingjing; Ahnen, Linda; Kalyanov, Alexander; Lindner, Scott; Wolf, Martin; Majos, Salvador Sanchez

    2017-01-01

    The accuracy of images obtained by Diffuse Optical Tomography (DOT) could be substantially increased by the newly developed time resolved (TR) cameras. These devices result in unprecedented data volumes, which present a challenge to conventional image reconstruction techniques. In addition, many clinical applications require taking photons in air regions like the trachea into account, where the diffusion model fails. Image reconstruction techniques based on photon tracking are mandatory in those cases but have not been implemented so far due to computing demands. We aimed at designing an inversion algorithm which could be implemented on commercial graphics processing units (GPUs) by making use of information obtained with other imaging modalities. The method requires a segmented volume and an approximately uniform value for the reduced scattering coefficient in the volume under study. The complex photon path is reduced to a small number of partial path lengths within each segment resulting in drastically reduced memory usage and computation time. Our approach takes advantage of wavelength normalized data which renders it robust against instrumental biases and skin irregularities which is critical for realistic clinical applications. The accuracy of this method has been assessed with both simulated and experimental inhomogeneous phantoms showing good agreement with target values. The simulation study analyzed a phantom containing a tumor next to an air region. For the experimental test, a segmented cuboid phantom was illuminated by a supercontinuum laser and data were gathered by a state of the art TR camera. Reconstructions were obtained on a GPU-installed computer in less than 2 h. To our knowledge, it is the first time Monte Carlo methods have been successfully used for DOT based on TR cameras. This opens the door to applications such as accurate measurements of oxygenation in neck tumors where the presence of air regions is a problem for conventional approaches.

  16. Affibody-DyLight conjugates for in vivo assessment of HER2 expression by near-infrared optical imaging.

    Science.gov (United States)

    Zielinski, Rafal; Hassan, Moinuddin; Lyakhov, Ilya; Needle, Danielle; Chernomordik, Victor; Garcia-Glaessner, Alejandra; Ardeshirpour, Yasaman; Capala, Jacek; Gandjbakhche, Amir

    2012-01-01

    Amplification of the HER2/neu gene and/or overexpression of the corresponding protein have been identified in approximately 20% of invasive breast carcinomas. Assessment of HER2 expression in vivo would advance development of new HER2-targeted therapeutic agents and, potentially, facilitate choice of the proper treatment strategy offered to the individual patient. We present novel HER2-specific probes for in vivo evaluation of the receptor status by near-infrared (NIR) optical imaging. Affibody molecules were expressed, purified, and labeled with NIR-fluorescent dyes. The binding affinity and specificity of the obtained probe were tested in vitro. For in vivo validation, the relationship of the measured NIR signal and HER2 expression was characterized in four breast cancer xenograft models, expressing different levels of HER2. Accumulation of Affibody molecules in tumor tissue was further confirmed by ex vivo analysis. Affibody-DyLight conjugates showed high affinity to HER2 (K(D) = 3.66±0.26). No acute toxicity resulted from injection of the probes (up to 0.5 mg/kg) into mice. Pharmacokinetic studies revealed a relatively short (37.53±2.8 min) half-life of the tracer in blood. Fluorescence accumulation in HER2-positive BT-474 xenografts was evident as soon as a few minutes post injection and reached its maximum at 90 minutes. On the other hand, no signal retention was observed in HER2-negative MDA-MB-468 xenografts. Immunostaining of extracted tumor tissue confirmed penetration of the tracer into tumor tissue. The results of our studies suggest that Affibody-DyLight-750 conjugate is a powerful tool to monitor HER2 status in a preclinical setting. Following clinical validation, it might provide complementary means for assessment of HER2 expression in breast cancer patients (assuming availability of proper NIR scanners) and/or be used to facilitate detection of HER2-positive metastatic lesions during NIR-assisted surgery.

  17. Novel High Temperature and Radiation Resistant Infrared Glasses and Optical Fibers for Sensing in Advanced Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ballato, John [Clemson Univ., SC (United States)

    2018-01-22

    One binary and three series of ternary non-oxide pure sulfide glasses compositions were investigated with the goal of synthesizing new glasses that exhibit high glass transition (Tg) and crystallization (Tc) temperatures, infrared transparency, and reliable glass formability. The binary glass series consisted of Ges2 and La2S3 and the three glass series in the x(nBaS + mLa2S3) + (1-2x)GeS2 ternary system have BaS:La2S3 modifier ratios of 1:1, 1:2, and 2:1 with . With these glasses, new insights were realized as to how ionic glasses form and how glass modifiers affect both structure and glass formability. All synthesized compositions were characterized by Infrared (IR) and Raman spectroscopies and differential thermal analysis (DTA) to better understand the fundamental structure, optical, and thermal characteristics of the glasses. After a range of these glasses were synthesized, optimal compositions were formed into glass disks and subjected to gamma irradiation. Glass disks were characterized both before and after irradiation by microscope imaging, measuring the refractive index, density, and UV-VIS-IR transmission spectra. The final total dose the samples were subjected to was ~2.5 MGy. Ternary samples showed a less than 0.4% change in density and refractive index and minimal change in transmission window. The glasses also resisted cracking as seen in microscope images. Overall, many glass compositions were developed that possess operating temperatures above 500 °C, where conventional chalcogenide glasses such as As2S3 and have Tgs from ~200-300 °C, and these glasses have a greater than Tc – Tg values larger than 100 °C and this shows that these glasses have good thermal stability of Tg such that they can be fabricated into optical fibers and as such can be considered candidates for high temperature infrared fiber optics. Initial fiber fabrication efforts showed that selected glasses could be drawn but larger

  18. The infrared optical absorption spectra of the functionalized nanocrystalline diamond surface

    Czech Academy of Sciences Publication Activity Database

    Remeš, Zdeněk; Kromka, Alexander; Kozak, Halyna; Vaněček, Milan; Haenen, K.; Wenmackers, S.

    2009-01-01

    Roč. 18, 5-8 (2009), s. 772-775 ISSN 0925-9635 R&D Projects: GA MŠk LC510; GA AV ČR KJB100100623 Institutional research plan: CEZ:AV0Z10100521 Keywords : nanocrystalline diamond * photochemical functionalization * spin coating * polymer * infrared spectroscopy * fluorescence microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.822, year: 2009

  19. Infrared Radiation Assisted Stokes’ Law Based Synthesis and Optical Characterization of ZnS Nanoparticles

    OpenAIRE

    Singh, Beer Pal; Upadhyay, Ravish Kumar; Kumar, Rakesh; Yadav, Kamna; Areizaga-Martinez, Hector I.

    2016-01-01

    The strategy and technique exploited in the synthesis of nanostructure materials have an explicit effect on the nucleation, growth, and properties of product materials. Nanoparticles of zinc sulfide (ZnS) have been synthesized by new infrared radiation (IR) assisted and Stokes’ law based controlled bottom-up approach without using any capping agent and stirring. IR has been used for heating the reaction surface designed in accordance with the well-known Stokes law for a free body falling in a...

  20. An inter-comparison of far-infrared line-by-line radiative transfer models

    International Nuclear Information System (INIS)

    Kratz, D.P.; Mlynczak, M.G.; Mertens, C.J.Christopher J.; Brindley, Helen; Gordley, L.L.; Martin-Torres, Javier; Miskolczi, F.M.; Turner, D.D.

    2005-01-01

    A considerable fraction (>40%) of the outgoing longwave radiation escapes from the Earth's atmosphere-surface system within a region of the spectrum known as the far-infrared (wave-numbers less than 650 cm -1 ). Dominated by the line and continuum spectral features of the pure rotation band of water vapor, the far-infrared has a strong influence upon the radiative balance of the troposphere, and hence upon the climate of the Earth. Despite the importance of the far-infrared contribution, however, very few spectrally resolved observations have been made of the atmosphere for wave-numbers less than 650 cm -1 . The National Aeronautics and Space Administration (NASA), under its Instrument Incubator Program (IIP), is currently developing technology that will enable routine, space-based spectral measurements of the far-infrared. As part of NASA's IIP, the Far-Infrared Spectroscopy of the Troposphere (FIRST) project is developing an instrument that will have the capability of measuring the spectrum over the range from 100 to 1000 cm -1 at a resolution of 0.6 cm -1 . To properly analyze the data from the FIRST instrument, accurate radiative transfer models will be required. Unlike the mid-infrared, however, no inter-comparison of codes has been performed for the far-infrared. Thus, in parallel with the development of the FIRST instrument, an investigation has been undertaken to inter-compare radiative transfer models for potential use in the analysis of far-infrared measurements. The initial phase of this investigation has focused upon the inter-comparison of six distinct line-by-line models. The results from this study have demonstrated remarkably good agreement among the models, with differences being of order 0.5%, thereby providing a high measure of confidence in our ability to accurately compute spectral radiances in the far-infrared

  1. Optical nanoantennas for multiband surface-enhanced infrared and raman spectroscopy

    KAUST Repository

    D'Andrea, Cristiano

    2013-04-23

    In this article we show that linear nanoantennas can be used as shared substrates for surface-enhanced Raman and infrared spectroscopy (SERS and SEIRS, respectively). This is done by engineering the plasmonic properties of the nanoantennas, so to make them resonant in both the visible (transversal resonance) and the infrared (longitudinal resonance), and by rotating the excitation field polarization to selectively take advantage of each resonance and achieve SERS and SEIRS on the same nanoantennas. As a proof of concept, we have fabricated gold nanoantennas by electron beam lithography on calcium difluoride (1-2 μm long, 60 nm wide, 60 nm high) that exhibit a transverse plasmonic resonance in the visible (640 nm) and a particularly strong longitudinal dipolar resonance in the infrared (tunable in the 1280-3100 cm -1 energy range as a function of the length). SERS and SEIRS detection of methylene blue molecules adsorbed on the nanoantenna\\'s surface is accomplished, with signal enhancement factors of 5 × 102 for SERS (electromagnetic enhancement) and up to 105 for SEIRS. Notably, we find that the field enhancement provided by the transverse resonance is sufficient to achieve SERS from single nanoantennas. Furthermore, we show that by properly tuning the nanoantenna length the signals of a multitude of vibrational modes can be enhanced with SEIRS. This simple concept of plasmonic nanosensor is highly suitable for integration on lab-on-a-chip schemes for label-free chemical and biomolecular identification with optimized performances. © 2013 American Chemical Society.

  2. 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.

  3. Modeling the Infrared Reverberation Response of the Circumnuclear Dusty Torus in AGNs: The Effects of Cloud Orientation and Anisotropic Illumination

    International Nuclear Information System (INIS)

    Almeyda, Triana; Robinson, Andrew; Richmond, Michael; Vazquez, Billy; Nikutta, Robert

    2017-01-01

    The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN continuum luminosity, a technique known as reverberation mapping. The IR response is the convolution of the AGN ultraviolet/optical light curve with a transfer function that contains information about the size, geometry, and structure of the torus. Here, we describe a new computer model that simulates the reverberation response of a clumpy torus. Given an input optical light curve, the code computes the emission of a 3D ensemble of dust clouds as a function of time at selected IR wavelengths, taking into account light travel delays. We present simulated dust emission responses at 3.6, 4.5, and 30 μ m that explore the effects of various geometrical and structural properties, dust cloud orientation, and anisotropy of the illuminating radiation field. We also briefly explore the effects of cloud shadowing (clouds are shielded from the AGN continuum source). Example synthetic light curves have also been generated, using the observed optical light curve of the Seyfert 1 galaxy NGC 6418 as input. The torus response is strongly wavelength-dependent, due to the gradient in cloud surface temperature within the torus, and because the cloud emission is strongly anisotropic at shorter wavelengths. Anisotropic illumination of the torus also significantly modifies the torus response, reducing the lag between the IR and optical variations.

  4. Modeling the Infrared Reverberation Response of the Circumnuclear Dusty Torus in AGNs: The Effects of Cloud Orientation and Anisotropic Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Almeyda, Triana; Robinson, Andrew; Richmond, Michael; Vazquez, Billy [School of Physics and Astronomy, Rochester Institute of Technology, Rochester, NY 14623 (United States); Nikutta, Robert, E-mail: tra3595@rit.edu [National Optical Astronomy Observatory, 950 N Cherry Ave, Tucson, AZ 85719 (United States)

    2017-07-01

    The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN continuum luminosity, a technique known as reverberation mapping. The IR response is the convolution of the AGN ultraviolet/optical light curve with a transfer function that contains information about the size, geometry, and structure of the torus. Here, we describe a new computer model that simulates the reverberation response of a clumpy torus. Given an input optical light curve, the code computes the emission of a 3D ensemble of dust clouds as a function of time at selected IR wavelengths, taking into account light travel delays. We present simulated dust emission responses at 3.6, 4.5, and 30 μ m that explore the effects of various geometrical and structural properties, dust cloud orientation, and anisotropy of the illuminating radiation field. We also briefly explore the effects of cloud shadowing (clouds are shielded from the AGN continuum source). Example synthetic light curves have also been generated, using the observed optical light curve of the Seyfert 1 galaxy NGC 6418 as input. The torus response is strongly wavelength-dependent, due to the gradient in cloud surface temperature within the torus, and because the cloud emission is strongly anisotropic at shorter wavelengths. Anisotropic illumination of the torus also significantly modifies the torus response, reducing the lag between the IR and optical variations.

  5. A modelling error approach for the estimation of optical absorption in the presence of anisotropies

    Energy Technology Data Exchange (ETDEWEB)

    Heino, Jenni [Helsinki University of Technology, Laboratory of Biomedical Engineering, PO Box 2200, FIN-02015 HUT (Finland); Somersalo, Erkki [Helsinki University of Technology, Institute of Mathematics, PO Box 1100, FIN-02015 HUT (Finland)

    2004-10-21

    Optical tomography is an emerging method for non-invasive imaging of human tissues using near-infrared light. Generally, the tissue is assumed isotropic, but this may not always be true. In this paper, we present a method for the estimation of optical absorption coefficient allowing the background to be anisotropic. To solve the forward problem, we model the light propagation in tissue using an anisotropic diffusion equation. The inverse problem consists of the estimation of the absorption coefficient based on boundary measurements. Generally, the background anisotropy cannot be assumed to be known. We treat the uncertainties in the background anisotropy parameter values as modelling error, and include this in our model and reconstruction. We present numerical examples based on simulated data. For reference, examples using an isotropic inversion scheme are also included. The estimates are qualitatively different for the two methods.

  6. 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.

  7. The optical properties of different temperature deposited ZnS film in visible to near-infrared region

    Science.gov (United States)

    Zhou, Ming; Liu, Dingquan; Yu, Tianyan; Cai, Qingyuan

    2012-10-01

    In this paper, Zinc Sulfide (ZnS) single-layer films were deposited on Germanium (Ge) substrate by thermal evaporation with film thickness about 1600 nm, and deposition temperature were 115°C, 155°C and 230°C. Reflective index of Ge substrate and ZnS film were measured by infrared spectroscopy and Spectroscopic Ellipsometry (SE). Additionally, Scanning Electron Microscopy (SEM) was used to observe the thin film structure graphics. The experiment results indicate that the prepared conditions have a great influence on optical constants of film, appropriately increase the deposition temperature will be helpful for increasing the packing density, and the refractive index is closely related to the surface micro-structure of film.

  8. Theoretical emission line ratios for [Fe III] and [Fe VII] applicable to the optical and infrared spectra of gaseous nebulae.

    Science.gov (United States)

    Keenan, F P; Aller, L H; Ryans, R S; Hyung, S

    2001-08-14

    Recent calculations of electron impact excitation rates and Einstein A-coefficients for transitions among the 3d(6) levels of Fe III and among the 3d(2) levels of Fe VII are used to derive theoretical emission line ratios applicable to the optical and infrared spectra of gaseous nebulae. Results for [Fe III] are generated for electron temperatures T(e) = 7,000-20,000 K and densities N(e) = 10(2)-10(8) cm(-3), whereas those for [Fe VII] are provided for T(e) = 10,000-30,000 K and N(e) = 10(2)-10(8) cm(-3). The theoretical line ratios are significantly different in some instances from earlier calculations and resolve discrepancies between theory and observation found for the planetary nebulae IC 4997 and NGC 7027.

  9. Off-axis quartz-enhanced photoacoustic spectroscopy using a pulsed nanosecond mid-infrared optical parametric oscillator.

    Science.gov (United States)

    Lassen, Mikael; Lamard, Laurent; Feng, Yuyang; Peremans, Andre; Petersen, Jan C

    2016-09-01

    A trace-gas sensor, based on quartz-enhanced photoacoustic spectroscopy (QEPAS), consisting of two acoustically coupled micro-resonators (mR) with an off-axis 20 kHz quartz tuning fork (QTF) is demonstrated. The complete acoustically coupled mR system is optimized based on finite-element simulations and is experimentally verified. The QEPAS sensor is pumped resonantly by a nanosecond pulsed single-mode mid-infrared optical parametric oscillator. The sensor is used for spectroscopic measurements on methane in the 3.1-3.5 μm wavelength region with a resolution bandwidth of 1  cm-1 and a detection limit of 0.8 ppm. An Allan deviation analysis shows that the detection limit at the optimum integration time for the QEPAS sensor is 32 ppbv at 190 s, and that the background noise is due solely to the thermal noise of the QTF.

  10. Gluing interface qualification test results and gluing process development of the EUCLID near-infrared spectro-photometer optical assembly

    Science.gov (United States)

    Mottaghibonab, A.; Thiele, H.; Gubbini, E.; Dubowy, M.; Gal, C.; Mecsaci, A.; Gawlik, K.; Vongehr, M.; Grupp, F.; Penka, D.; Wimmer, C.; Bender, R.

    2016-07-01

    The Near Infrared Spectro-Photometer Optical assembly (NIOA) of EUCLID satellite requires high precision large lens holders with different lens materials, shapes and diameters. The aspherical lenses are glued into their separate CTE matched lens holder. The gluing of the lenses in their holder with 2K epoxy is selected as bonding process to minimize the stress in the lenses to achieve the required surface form error (SFE) performance (32nm) and lens position stability (+/-10μm) due to glue shrinkage. Adhesive shrinkage stress occurs during the glue curing at room temperature and operation in cryogenic temperatures, which might overstress the lens, cause performance loss, lens breakage or failure of the gluing interface. The selection of the suitable glue and required bonding parameters, design and qualification of the gluing interface, development and verification of the gluing process was a great challenge because of the low TRL and heritage of the bonding technology. The different material combinations (CaF2 to SS316L, LF5G15 and S-FTM16 to Titanium, SUPRASIL3001 to Invar M93), large diameter (168mm) and thin edge of the lenses, cryogenic nonoperational temperature (100K) and high performance accuracy of the lenses were the main design driver of the development. The different coefficients of thermal expansion (CTE) between lens and lens holder produce large local mechanical stress. As hygroscopic crystal calcium fluoride (CaF2) is very sensitive to moisture therefore an additional surface treatment of the gluing area is necessary. Extensive tests e.g glue handling and single lap shear tests are performed to select the suitable adhesive. Interface connection tests are performed to verify the feasibility of selected design (double pad design), injection channel, the roughness and treatment of the metal and lens interfaces, glue thickness, glue pad diameter and the gluing process. CTE and dynamic measurements of the glue, thermal cycling, damp- heat, connection

  11. Optical phase locking of two infrared continuous wave lasers separated by 100 THz

    Czech Academy of Sciences Publication Activity Database

    Chiodo, N.; Du-Burck, F.; Hrabina, Jan; Lours, M.; Chea, E.; Acef, O.

    2014-01-01

    Roč. 39, č. 10 (2014), s. 2936-2939 ISSN 0146-9592 R&D Projects: GA ČR GPP102/11/P820; GA MŠk ED0017/01/01; GA MŠk EE2.4.31.0016; GA MŠk(CZ) LO1212; GA MŠk(CZ) 7AMB14FR040 Institutional support: RVO:68081731 Keywords : Continuous wave lasers * Frequency allocation * Harmonic generation * Laser optics Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.292, year: 2014

  12. 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.

  13. 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.

  14. Fiber-optic Fourier transform infrared spectroscopy for remote label-free sensing of medical device surface contamination

    Science.gov (United States)

    Hassan, Moinuddin; Tan, Xin; Welle, Elissa; Ilev, Ilko

    2013-05-01

    As a potential major source of biochemical contamination, medical device surfaces are of critical safety concerns in the clinical practice and public health. The development of innovative sensing methods for accurate and real-time detection of medical device surface contamination is essential to protect patients from high risk infection. In this paper, we demonstrate an alternative fiber-optic Fourier Transform Infrared (FTIR) spectroscopy based sensing approach for remote, non-contact, and label-free detection of biochemical contaminants in the mid-infrared (mid-IR) region. The sensing probe is designed using mid-IR hollow fibers and FTIR measurements are carried out in reflection mode. Bovine Serum Albumin (BSA) and bacterial endotoxin of different concentrations under thoroughly dry condition are used to evaluate the detection sensitivity. The devised system can identify ≤0.0025% (≤4 × 1011 molecules) BSA and 0.5% (0.5 EU/ml) endotoxin concentration. The developed sensing approach may be applied to detect various pathogens that pose public health threats.

  15. Optical, phonon and efficient visible and infrared photocatalytic activity of Cu doped ZnS micro crystals

    Science.gov (United States)

    Prasad, Neena; Balasubramanian, Karthikeyan

    2017-02-01

    We report, the enhanced photocatalytic behaviour of Cu doped ZnS micro crystals. ZnS and different concentrations of Cu doped ZnS microcrystals were prepared. X-ray diffraction confirms the crystalline and phase of the particles. Morphology and sizes were studied using Scanning Electron Microscopy (SEM). Recorded optical absorption spectra show a band for around 365 nm for pure ZnS, but there is a broad band in the near infrared regime for the Cu-doped ZnS microcrystals which are attributed to the d-d transitions of Cu2 + ions. Phonon properties of as-prepared samples were investigated using Raman spectroscopy. Present work we investigate the potential of ZnS and Cu doped ZnS as a photocatalyst. For this from the degradation of methylene blue dye in aqueous media the photocatalytic activity of pure and highest doped ZnS samples with the irradiation of white light and infrared, enhanced photocatalytic activity were observed. Mechanism of white light an IR light based photocatalytic activity is explained based on the electron-hole pair production.

  16. 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.

  17. Optical constants of ammonium sulfate in the infrared. [stratospheric aerosol refractive and absorption indices

    Science.gov (United States)

    Downing, H. D.; Pinkley, L. W.; Sethna, P. P.; Williams, D.

    1977-01-01

    The infrared spectral reflectance at near normal incidence has been measured for 3.2 M, 2.4 M, and 1.6 M solutions of ammonium sulfate, an aerosol abundant in the stratosphere and also present in the troposphere. Kramers-Kronig analysis was used to determine values of the refractive and absorption indices from the measured spectral reflectance. A synthetic spectrum of crystalline ammonium sulfate was obtained by extrapolation of the absorption index obtained for the solution to the absorber number densities of the NH4 and SO4 ions characteristic of the crystal.

  18. Near-infrared optical coherence tomography for the inspection of fiber composites

    NARCIS (Netherlands)

    Liu, P.; Yao, L.; Groves, R.M.

    2015-01-01

    Optical coherence tomography (OCT) is a non-invasive imaging method, which allows the econstruction of three dimensional depth-resolved images with microscale resolution. Originally developed for biomedical diagnostics, nowadays it also shows a high potential for applications in the field of

  19. Near-infrared and optical broadband surface photometry of 86 face-on disk dominated galaxies .4. Using color profiles to study stellar and dust content of galaxies

    NARCIS (Netherlands)

    deJong, RS

    The stellar and dust content of spiral galaxies as function of radius has been investigated using near-infrared and optical broadband surface photometry of 86 face-on spiral galaxies. Colors of galaxies correlate with the azimuthally averaged local surface brightness both within and among galaxies,

  20. In vivo trans-rectal ultrasound coupled trans-rectal near-infrared optical tomography of canine prostate bearing transmissible venereal tumor

    Science.gov (United States)

    Jiang, Zhen; Holyoak, G. Reed; Bartels, Kenneth E.; Ritchey, Jerry W.; Xu, Guan; Bunting, Charles F.; Slobodov, Gennady; Krasinski, Jerzy S.; Piao, Daqing

    2009-02-01

    In vivo trans-rectal near-infrared (NIR) optical tomography is conducted on a tumor-bearing canine prostate with the assistance of trans-rectal ultrasound (TRUS). The canine prostate tumor model is made possible by a unique round cell neoplasm of dogs, transmissible venereal tumor (TVT) that can be transferred from dog to dog regardless of histocompatibility. A characterized TVT cell line was homogenized and passed twice in subcutaneous tissue of NOD/SCID mice. Following the second passage, the tumor was recovered, homogenized and then inoculated by ultrasound guidance into the prostate gland of a healthy dog. The dog was then imaged with a combined trans-rectal NIR and TRUS imager using an integrated trans-rectal NIR/US applicator. The image was taken by NIR and US modalities concurrently, both in sagittal view. The trans-rectal NIR imager is a continuous-wave system that illuminates 7 source channels sequentially by a fiber switch to deliver sufficient light power to the relatively more absorbing prostate tissue and samples 7 detection channels simultaneously by a gated intensified high-resolution CCD camera. This work tests the feasibility of detecting prostate tumor by trans-rectal NIR optical tomography and the benefit of augmenting TRUS with trans-rectal NIR imaging.

  1. Self-consistent Non-LTE Model of Infrared Molecular Emissions and Oxygen Dayglows in the Mesosphere and Lower Thermosphere

    Science.gov (United States)

    Feofilov, Artem G.; Yankovsky, Valentine A.; Pesnell, William D.; Kutepov, Alexander A.; Goldberg, Richard A.; Mauilova, Rada O.

    2007-01-01

    We present the new version of the ALI-ARMS (for Accelerated Lambda Iterations for Atmospheric Radiation and Molecular Spectra) model. The model allows simultaneous self-consistent calculating the non-LTE populations of the electronic-vibrational levels of the O3 and O2 photolysis products and vibrational level populations of CO2, N2,O2, O3, H2O, CO and other molecules with detailed accounting for the variety of the electronic-vibrational, vibrational-vibrational and vibrational-translational energy exchange processes. The model was used as the reference one for modeling the O2 dayglows and infrared molecular emissions for self-consistent diagnostics of the multi-channel space observations of MLT in the SABER experiment It also allows reevaluating the thermalization efficiency of the absorbed solar ultraviolet energy and infrared radiative cooling/heating of MLT by detailed accounting of the electronic-vibrational relaxation of excited photolysis products via the complex chain of collisional energy conversion processes down to the vibrational energy of optically active trace gas molecules.

  2. Global phenomenological and microscopic optical model potentials for alpha

    Science.gov (United States)

    Guo, Hairui; Su, Xinwu; Liang, Haiying; Xu, Yongli; Han, Yinlu; Shen, Qingbiao

    2017-09-01

    The global phenomenological and microscopic optical model potentials for alpha with the incident energy up to 400 MeV are obtained. The global phenomenological optical model potential is extracted by simultaneously fitting the experimental data of total reaction cross sections and elastic scattering angular distributions in the mass range of target nuclei 20 ≤ A ≤ 209. The microscopic optical model potential is obtained by the Green function method through nuclear matter approximation and local density approximation based on the effective Skyrme nucleon-nucleon interaction. Both optical model potentials are used to calculate the reaction cross sections and elastic scattering angular distributions for the target nuclei in the mass range 12 ≤ A ≤ 209 at incident alpha energies up to 400 MeV. The calculated results are compared with the experimental data, and the calculated results by phenomenological and microscopic optical model potentials are also compared with each other.

  3. Global phenomenological and microscopic optical model potentials for alpha

    Directory of Open Access Journals (Sweden)

    Guo Hairui

    2017-01-01

    Full Text Available The global phenomenological and microscopic optical model potentials for alpha with the incident energy up to 400 MeV are obtained. The global phenomenological optical model potential is extracted by simultaneously fitting the experimental data of total reaction cross sections and elastic scattering angular distributions in the mass range of target nuclei 20 ≤ A ≤ 209. The microscopic optical model potential is obtained by the Green function method through nuclear matter approximation and local density approximation based on the effective Skyrme nucleon-nucleon interaction. Both optical model potentials are used to calculate the reaction cross sections and elastic scattering angular distributions for the target nuclei in the mass range 12 ≤ A ≤ 209 at incident alpha energies up to 400 MeV. The calculated results are compared with the experimental data, and the calculated results by phenomenological and microscopic optical model potentials are also compared with each other.

  4. 'Ivory': Optomechanical modeling of an optical image correlator

    Science.gov (United States)

    Hatheway, Alson E.

    2005-09-01

    "Ivory" is a computer code that generates Optomechanical Constraint Equations (OCE) from the optical physical prescription data. The OCE predict the translation, rotation and size change of an optical image from the motions, temperature changes and other factors affecting the optical elements forming the image. An airborne optical image correlator has been designed and built for UAV applications. Commercially available optical components were used throughout. The centerpiece of the mechanical design was control of the manufacturing and assembly tolerances to assure precise alignment and stable image registration for high performance operation. Control was maintained during the design and manufacturing process by the use of optomechanical models based upon the Optomechanical Constraint Equations (OCE). The equations provided a comprehensive optomechanical model that related the critical optical functions (images and diffraction patterns) to the translation and rotation (dimensions and tolerances) of all the piece-parts. The equations also modeled the thermal and wavelength stability of the correlator. Engineers may generate the OCE by longhand calculations or in a computer spreadsheet. For larger optical systems this can be very time consuming. Ivory automates the generation of the OCE for the engineer making timely and accurate calculations of the image registration errors possible, even for very complex optical systems. This paper shows the application of the OCE to a variety of challenges in the optical image correlator: athermalization, alignment procedures, optical and mechanical tolerance budgets, optimizing the folded geometry and sizing alignment mechanisms.

  5. 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.

  6. Numerous applications of fiber optic evanescent wave Fourier transform infrared (FEW-FTIR) spectroscopy for subsurface structural analysis

    Science.gov (United States)

    Afanasyeva, Natalia I.; Welser, Leslie; Bruch, Reinhard F.; Kano, Angelique; Makhine, Volodymyr

    1999-10-01

    A new infrared (IR) interferometric method has been developed in conjunction with low-loss, flexible optical fibers, sensors, and probes. This combination of fiber optical sensors and Fourier Transform (FT) spectrometers can be applied to many fields, including (1) noninvasive medical diagnostics of cancer and other different diseases in vivo, (2) minimally invasive bulk diagnostics of tissue, (3) remote monitoring of tissue, chemical processes, and environment, (4) surface analysis of polymers and other materials, (5) characterization of the quality of food, pharmacological products, cosmetics, paper, and other wood-related products, as well as (6) agricultural, forensic, geological, mining, and archeological field measurements. In particular, our nondestructive, fast, compact, portable, remote and highly sensitive diagnostics tools are very promising for subsurface analysis at the molecular level without sample preparation. For example, this technique is ideal for different types of soft porous foams, rough polymers, and rock surfaces. Such surfaces, as well as living tissue, are very difficult to investigate by traditional FTIR methods. We present here FEW-FTIR spectra of polymers, banana and grapefruit peels, and living tissues detected directly at surfaces. In addition, results on the vibrational spectral analysis of normal and pathological skin tissue in the region of 850 - 4000 cm-1 are discussed.

  7. Self-organized, effective medium black silicon antireflection structures for silicon optics in the mid-infrared

    Science.gov (United States)

    Steglich, Martin; Käsebier, Thomas; Kley, Ernst-Bernhard; Tünnermann, Andreas

    2016-09-01

    Thanks to its high quality and low cost, silicon is the material of choice for optical devices operating in the mid-infrared (MIR; 2 μm to 6 μm wavelength). Unfortunately in this spectral region, the refractive index is comparably high (about 3.5) and leads to severe reflection losses of about 30% per interface. In this work, we demonstrate that self-organized, statistical Black Silicon structures, fabricated by Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE), can be used to effectively suppress interface reflection. More importantly, it is shown that antireflection can be achieved in an image-preserving, non-scattering way. This enables Black Silicon antireflection structures (ARS) for imaging applications in the MIR. It is demonstrated that specular transmittances of 97% can be easily achieved on both flat and curved substrates, e.g. lenses. Moreover, by a combined optical and morphological analysis of a multitude of different Black Silicon ARS, an effective medium criterion for the examined structures is derived that can also be used as a design rule for maximizing sample transmittance in a desired wavelength range. In addition, we show that the mechanical durability of the structures can be greatly enhanced by coating with hard dielectric materials like diamond-like carbon (DLC), hence enabling practical applications. Finally, the distinct advantages of statistical Black Silicon ARS over conventional AR layer stacks are discussed: simple applicability to topological substrates, absence of thermal stress and cost-effectiveness.

  8. Polarization sensitive subcutaneous and muscular imaging based on common path optical coherence tomography using near infrared source.

    Science.gov (United States)

    Han, Jae-Ho; Kang, Jin U; Song, Chul Gyu

    2011-08-01

    In this paper, we describe a polarization sensitive (PS) subcutaneous and muscular imaging system based on common path optical coherence tomography (CP-OCT) using a near infrared source. The axial and lateral resolutions of the PS-OCT system are 9 and 6 μm, respectively. The main goal of this work is to build a high-resolution and minimally invasive optical imager for examining various kinds of cutaneous substructures with intrinsic or form birefringence. The internal structural information is extracted by the real-time signal analysis (Fourier Transform) of the modulated spectral intensity depending on the beam and tissue birefringence. The preliminary results using fresh beef longissimus muscle and in vivo Rattus norvegicus (rat) show that it is possible to visualize the birefringence effect of the tissue collagen fibers in the samples in order to achieve superior image contrast and sensitivity for the detection of hidden dermal structures. Compared to conventional CP-OCT, the proposed PS-OCT system provides depth-resolved images, which reflect the tissue birefringence.

  9. 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.

  10. A broadly tunable autocorrelator for ultra-short, ultra-high power infrared optical pulses

    Energy Technology Data Exchange (ETDEWEB)

    Szarmes, E.B.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)

    1995-12-31

    We describe the design of a crossed-beam, optical autocorrelator that uses an uncoated, birefringent beamsplitter to split a linearly polarized incident pulse into two orthogonally polarized pulses, and a Type II, SHG crystal to generate the intensity autocorrelation function. The uncoated beamsplitter accommodates extremely broad tunability while precluding any temporal distortion of ultrashort optical pulses at the dielectric interface, and the specific design provides efficient operation between 1 {mu}m and 4 {mu}m. Furthermore, the use of Type II SHG completely eliminates any single-beam doubling, so the autocorrelator can be operated at very shallow crossed-beam angles without generating a background pedestal. The autocorrelator has been constructed and installed in the Mark III laboratory at Duke University as a broadband diagnostic for ongoing compression experiments on the chirped-pulse FEL.

  11. Femtosecond infrared intrastromal ablation and backscattering-mode adaptive-optics multiphoton microscopy in chicken corneas.

    Science.gov (United States)

    Gualda, Emilio J; Vázquez de Aldana, Javier R; Martínez-García, M Carmen; Moreno, Pablo; Hernández-Toro, Juan; Roso, Luis; Artal, Pablo; Bueno, Juan M

    2011-11-01

    The performance of femtosecond (fs) laser intrastromal ablation was evaluated with backscattering-mode adaptive-optics multiphoton microscopy in ex vivo chicken corneas. The pulse energy of the fs source used for ablation was set to generate two different ablation patterns within the corneal stroma at a certain depth. Intrastromal patterns were imaged with a custom adaptive-optics multiphoton microscope to determine the accuracy of the procedure and verify the outcomes. This study demonstrates the potential of using fs pulses as surgical and monitoring techniques to systematically investigate intratissue ablation. Further refinement of the experimental system by combining both functions into a single fs laser system would be the basis to establish new techniques capable of monitoring corneal surgery without labeling in real-time. Since the backscattering configuration has also been optimized, future in vivo implementations would also be of interest in clinical environments involving corneal ablation procedures.

  12. Report on the Radiation Effects Testing of the Infrared and Optical Transition Radiation Camera Systems

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-20

    Presented in this report are the results tests performed at Argonne National Lab in collaboration with Los Alamos National Lab to assess the reliability of the critical 99Mo production facility beam monitoring diagnostics. The main components of the beam monitoring systems are two cameras that will be exposed to radiation during accelerator operation. The purpose of this test is to assess the reliability of the cameras and related optical components when exposed to operational radiation levels. Both X-ray and neutron radiation could potentially damage camera electronics as well as the optical components such as lenses and windows. This report covers results of the testing of component reliability when exposed to X-ray radiation. With the information from this study we provide recommendations for implementing protective measures for the camera systems in order to minimize the occurrence of radiation-induced failure within a ten month production run cycle.

  13. Optical Approach To The Measurement Of Delignification In Kraft Pulping: Part B: Using Infrared Spectroscopy.

    Science.gov (United States)

    Adam, E.; Sugden, N.

    1986-10-01

    A study of the infrared (IR) absorption characteristics of dried kraft pulp sheets was made. This was done in order to assess the potential of using this approach as the basis for determining residual lignin, or Kappa number, in pulp after cooking. Strong positive linear correlations were obtained between Kappa number and IR absorbance at 1509 cm-for pulps made from different wood species, produced in different mills and having a Kappa number range of 13-37. For pulps from some mills, made from the same wood furnish and having a small Kappa number range, the degree of correlation was seriously reduced. The method requires the use of moisture-free pulp specimens in the measurement of absorbance. It is suggested that it would be more suitable as the basis for a laboratory instrument than for an on-line, process Kappa number sensor.

  14. 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.

  15. Comparison Between Infrared Optical and Stereoscopic X-Ray Technologies for Patient Setup in Image Guided Stereotactic Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tagaste, Barbara, E-mail: tagaste@cnao.it [Division of Radiation Oncology, European Institute of Oncology, Milano (Italy); Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); Riboldi, Marco [Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); TBM Lab, Department of Bioengineering, Politecnico di Milano University, Milano (Italy); Spadea, Maria F. [TBM Lab, Department of Bioengineering, Politecnico di Milano University, Milano (Italy); Department of Experimental and Clinical Medicine, Universita degli Studi Magna Graecia, Catanzaro (Italy); Bellante, Simone [TBM Lab, Department of Bioengineering, Politecnico di Milano University, Milano (Italy); Baroni, Guido [Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); TBM Lab, Department of Bioengineering, Politecnico di Milano University, Milano (Italy); Cambria, Raffaella; Garibaldi, Cristina [Medical Physics, European Institute of Oncology, Milano (Italy); Ciocca, Mario [Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); Medical Physics, European Institute of Oncology, Milano (Italy); Catalano, Gianpiero [Division of Radiation Oncology, European Institute of Oncology, Milano (Italy); Unit of Radiotherapy, Multimedica Holding Clinical Institute, Castellanza (Italy); Alterio, Daniela [Division of Radiation Oncology, European Institute of Oncology, Milano (Italy); Orecchia, Roberto [Division of Radiation Oncology, European Institute of Oncology, Milano (Italy); Centro Nazionale di Adroterapia Oncologica, Pavia (Italy); Department of Science and Biomedical Technologies, Universita di Milano, Milano (Italy)

    2012-04-01

    Purpose: To compare infrared (IR) optical vs. stereoscopic X-ray technologies for patient setup in image-guided stereotactic radiotherapy. Methods and Materials: Retrospective data analysis of 233 fractions in 127 patients treated with hypofractionated stereotactic radiotherapy was performed. Patient setup at the linear accelerator was carried out by means of combined IR optical localization and stereoscopic X-ray image fusion in 6 degrees of freedom (6D). Data were analyzed to evaluate the geometric and dosimetric discrepancy between the two patient setup strategies. Results: Differences between IR optical localization and 6D X-ray image fusion parameters were on average within the expected localization accuracy, as limited by CT image resolution (3 mm). A disagreement between the two systems below 1 mm in all directions was measured in patients treated for cranial tumors. In extracranial sites, larger discrepancies and higher variability were observed as a function of the initial patient alignment. The compensation of IR-detected rotational errors resulted in a significantly improved agreement with 6D X-ray image fusion. On the basis of the bony anatomy registrations, the measured differences were found not to be sensitive to patient breathing. The related dosimetric analysis showed that IR-based patient setup caused limited variations in three cases, with 7% maximum dose reduction in the clinical target volume and no dose increase in organs at risk. Conclusions: In conclusion, patient setup driven by IR external surrogates localization in 6D featured comparable accuracy with respect to procedures based on stereoscopic X-ray imaging.

  16. Mathematical Model of the One-stage Magneto-optical Sensor Based on Faraday Effect

    Science.gov (United States)

    Babaev, O. G.; Paranin, V. D.; Sinitsin, L. I.

    2018-01-01

    The aim of this work is to refine a model of magneto-optical sensors based on Faraday’s longitudinal magneto-optical effect. The tasks of the study include computer modeling and analysis of the transfer characteristic of a single-stage magneto-optical sensor for various polarization of the input beam and non-ideal optical components. The proposed mathematical model and software make it possible to take into account the non-ideal characteristics of film polaroids observed in operation in the near infrared region and at increased temperatures. On the basis of the results of the model analysis it was found that the dependence of normalized transmission T(γ2) has periodic nature. Choosing the angle (γ 2-γ 1) makes it possible to shift the initial operation point and change the sensitivity dT/dγ 2. The influence of the input beam polarization increases with the increase of polaroid parameter deviation from ideal and shows itself as reduction of modulation depth and angular shift of the sensor conversion response.

  17. Optical imaging to trace near infrared fluorescent zinc oxide nanoparticles following oral exposure

    Directory of Open Access Journals (Sweden)

    Lee CM

    2012-06-01

    Full Text Available Chang-Moon Lee,1–4,* Hwan-Jeong Jeong,1–4,* Kuk-No Yun,1–3 Dong Wook Kim,1–4 Myung-Hee Sohn,1–4 Jong Kwon Lee,5 Jayoung Jeong,5 Seok Tae Lim1–4 *These authors contributed equally to this work.1Department of Nuclear Medicine; 2Cyclotron Research Center; 3Research Institute of Clinical Medicine; 4Institute for Medical Sciences, Chonbuk National University Medical School and Hospital, Jeonju, Jeollabuk-Do, Republic of Korea; 5Toxicological Research Division, National Institute of Food and Drug Safety Evaluation, Osong-Eup, Chungchungbuk-Do, Republic of KoreaBackground: Understanding how nanomaterials are distributed in the body after exposure is important for assessing whether they are safe. In this study, we investigated the behavior and accumulation of nanoscaled and submicron-scaled zinc oxide (ZnO particles in the body using optical imaging following oral exposure.Methods: To trace these nanoparticles in the body, ZnO nanoparticles were conjugated with a monoreactive hydroxysuccinimide ester of Cy5.5 (Cy5.5-NHS, and the conjugation-stabilizing effect of Cy5.5 on the nanoparticles was evaluated in simulated gastric fluid (pH 1.2 for 7 hours. To compare the distribution of Cy5.5-NHS and Cy5.5-conjugated ZnO nanoparticles, Cy5.5-NHS 0.5 mg/kg and Cy5.5-conjugated ZnO nanoparticles 250 mg/kg were administered orally to healthy rats. We collected blood from the rats at predesignated time points for 7 hours after administration, and optical imaging studies were performed at 1, 2, 3, 5, and 7 hours after dosing. To investigate the extent of nanoparticle accumulation in the organs and tissues, the mice were sacrificed at 23 hours after administration, and the organs were removed and imaged.Results: Cy5.5-conjugated ZnO nanoparticles were stable in simulated gastric fluid for 7 hours. The signal intensity of Cy5.5-NHS in blood was highest 3 hours after oral administration, and Cy5.5-conjugated ZnO nanoparticles showed the highest signal

  18. Near-infrared diffuse interstellar bands in APOGEE telluric standard star spectra . Weak bands and comparisons with optical counterparts

    Science.gov (United States)

    Elyajouri, M.; Lallement, R.; Monreal-Ibero, A.; Capitanio, L.; Cox, N. L. J.

    2017-04-01

    Aims: Information on the existence and properties of diffuse interstellar bands (DIBs) outside the optical domain is still limited. Additional infra-red (IR) measurements and IR-optical correlative studies are needed to constrain DIB carriers and locate various absorbers in 3D maps of the interstellar matter. Methods: We extended our study of H-band DIBs in Apache Point Observatory Galactic Evolution Experiment (APOGEE) Telluric Standard Star (TSS) spectra. We used the strong λ15273 band to select the most and least absorbed targets. We used individual spectra of the former subsample to extract weaker DIBs, and we searched the two stacked series for differences that could indicate additional bands. High-resolution NARVAL and SOPHIE optical spectra for a subsample of 55 TSS targets were additionally recorded for NIR/optical correlative studies. Results: From the TSS spectra we extract a catalog of measurements of the poorly studied λλ15617, 15653, and 15673 DIBs in ≃300 sightlines, we obtain a first accurate determination of their rest wavelength and constrained their intrinsic width and shape. In addition, we studied the relationship between these weak bands and the strong λ15273 DIB. We provide a first or second confirmation of several other weak DIBs that have been proposed based on different instruments, and we add new constraints on their widths and locations. We finally propose two new DIB candidates. Conclusions: We compared the strength of the λ15273 absorptions with their optical counterparts λλ5780, 5797, 6196, 6283, and 6614. Using the 5797-5780 ratio as a tracer of shielding against the radiation field, we showed that the λ15273 DIB carrier is significantly more abundant in unshielded (σ-type) clouds, and it responds even more strongly than the λ5780 band carrier to the local ionizing field. Full Table 5 is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  19. Thermal piston model for the optoacoustic effect: Sound generation in an optically thick gas

    International Nuclear Information System (INIS)

    Stewart, R.B.; Diebold, G.J.

    1987-01-01

    At high concentrations of an infrared absorbing gas, the optical absorption length for the incident radiation can become small compared with the thermal diffusion length in the gas. A description of the optoacoustic effect consequently must include thermal conduction of heat to the cell window since sound generation takes place in a thin layer of gas adjacent to the entrance window. A piston model is given here for the optoacoustic effect generated in a highly absorbing gas; in addition, experiments are reported that show new phase and amplitude dependences of the acoustic signal on gas concentrations, and modulation frequency

  20. MRGC performance evaluation model of gas leak infrared imaging detection system.

    Science.gov (United States)

    Li, Jiakun; Jin, Weiqi; Wang, Xia; Zhang, Xu

    2014-12-15

    Gas leak infrared imaging detection technology has become one of the most effective means to detect gas leaks. We propose a novel MRGC (minimum resolvable gas concentration) model that is suitable for evaluating the performance of passive GLIIDSs (gas leak infrared imaging detection systems). An MRGC equivalent calculation method and a direct MRGC measurement method based on the MRTD (minimum resolvable temperature difference) model are also proposed. The MRGC measurement system is designed and built. The measured and calculated results are in good agreement, which verifies the MRGC model's correctness and demonstrates the effectiveness of the MRGC performance evaluation method.

  1. Optical Fibres in the Modeling of Translucent Concrete Blocks

    OpenAIRE

    M.N.V.Padma Bhushan, D.Johnson, Md. Afzal Basheer Pasha And Ms. K. Prasanthi

    2013-01-01

    Translucent concrete is a concrete based material with light-transmissive properties, obtained due to embedded light optical elements like Optical fibers in it. Light is conducted through the stone from one end to the other. This results into a certain light pattern on the other surface, depending on the fibre structure. Optical fibres transmit light so effectively that there is virtually no loss of light conducted through the fibres. Our paper deals with the modelling of such translucent or ...

  2. Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy

    Science.gov (United States)

    Hallacoglu, Bertan; Sassaroli, Angelo; Wysocki, Michael; Guerrero-Berroa, Elizabeth; Schnaider Beeri, Michal; Haroutunian, Vahram; Shaul, Merav; Rosenberg, Irwin H.; Troen, Aron M.; Fantini, Sergio

    2012-08-01

    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 available multi-distance frequency-domain system and analyzed using a diffusion theory model for a semi-infinite, homogeneous medium with semi-infinite boundary conditions. Our study included repeat measurements, taken five months apart, on 16 elderly volunteers that demonstrate intra-subject reproducibility of the absolute measurements with cross-correlation coefficients of 0.9 for absorption coefficient (μa), oxy-hemoglobin concentration ([HbO2]), and total hemoglobin concentration ([HbT]), 0.7 for deoxy-hemoglobin concentration ([Hb]), 0.8 for hemoglobin oxygen saturation (StO2), and 0.7 for reduced scattering coefficient (). We found significant differences between the two age groups. Compared to young subjects, elderly subjects had lower cerebral [HbO2], [Hb], [HbT], and StO2 by 10±4 μM, 4±3 μM, 14±5 μM, and 6%±5%, respectively. Our results demonstrate the reliability and robustness of multi-distance near-infrared spectroscopy measurements based on a homogeneous model in the human forehead on a large sample of human subjects. Absolute, non-invasive optical measurements on the brain, such as those presented here, can significantly advance the development of NIRS technology as a tool for monitoring resting/basal cerebral perfusion, hemodynamics, oxygenation, and metabolism.

  3. Optically pumped tunable HBr laser in the mid-infrared region.

    Science.gov (United States)

    Koen, Wayne; Jacobs, Cobus; Bollig, Christoph; Strauss, Hencharl J; Esser, M J Daniel; Botha, Lourens R

    2014-06-15

    An optically pumped tunable HBr laser has been demonstrated for the first time. The pump source was a single-frequency Ho:YLF laser and amplifier system, which was locked to the 2064 nm absorption line of HBr. Laser oscillation was demonstrated on 19 molecular transition lines, which included both the R-branch (3870-4015 nm) and the P-branch (4070-4453 nm), by the use of an intra-cavity diffraction grating. The highest output energy was 2.4 mJ at 4133 nm.

  4. Infra-red laser source using Tm:Ho optical fibre for potential sensor applications

    International Nuclear Information System (INIS)

    Chen, S Y; Yeo, T L; Leighton, J; Sun, T; Grattan, K T V; Lade, R; Powell, B; Foster-Turner, G; Osborne, M

    2007-01-01

    In this work, a 1600nm Er fibre laser, which demonstrates a high pumping efficiency, has been used to pump an efficient all-fibre Tm:Ho laser system using a 0.3 m length of optical fibre. A low threshold of 33 mW and a slope efficiency of 0.6% have been achieved with operation at a wavelength of ∼1870 nm. A cross-comparison has been made with the output of a device pumped by a 785 nm laser diode. The focus of the work is better and more compact sources for gas sensing in the near infra red region of the spectrum

  5. Optical feedback in dfb quantum cascade laser for mid-infrared cavity ring-down spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Terabayashi, Ryohei, E-mail: terabayashi.ryouhei@h.mbox.nagoya-u.ac.jp; Sonnenschein, Volker, E-mail: volker@nagoya-u.jp; Tomita, Hideki, E-mail: tomita@nagoya-u.jp; Hayashi, Noriyoshi, E-mail: hayashi.noriyoshi@h.mbox.nagoya-u.ac.jp; Kato, Shusuke, E-mail: katou.shuusuke@f.mbox.nagoya-u.ac.jp; Jin, Lei, E-mail: kin@nuee.nagoya-u.ac.jp; Yamanaka, Masahito, E-mail: yamanaka@nuee.nagoya-u.ac.jp; Nishizawa, Norihiko, E-mail: nishizawa@nuee.nagoya-u.ac.jp [Nagoya University, Department of Quantum Engineering, Graduate School of Engineering (Japan); Sato, Atsushi, E-mail: atsushi.sato@sekisui.com; Nozawa, Kohei, E-mail: kohei.nozawa@sekisui.com; Hashizume, Kenta, E-mail: kenta.hashizume@sekisui.com; Oh-hara, Toshinari, E-mail: toshinari.ohara@sekisui.com [Sekisui Medical Co., Ltd., Drug Development Solutions Center (Japan); Iguchi, Tetsuo, E-mail: t-iguchi@nucl.nagoya-u.ac.jp [Nagoya University, Department of Quantum Engineering, Graduate School of Engineering (Japan)

    2017-11-15

    A simple external optical feedback system has been applied to a distributed feedback quantum cascade laser (DFB QCL) for cavity ring-down spectroscopy (CRDS) and a clear effect of feedback was observed. A long external feedback path length of up to 4m can decrease the QCL linewidth to around 50kHz, which is of the order of the transmission linewidth of our high finesse ring-down cavity. The power spectral density of the transmission signal from high finesse cavity reveals that the noise at frequencies above 20kHz is reduced dramatically.

  6. Discovering Bright Quasars at Intermediate Redshifts Based on Optical/Near-infrared Colors

    Science.gov (United States)

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

    2013-10-01

    The identification of quasars at intermediate redshifts (2.2 list of 105 unidentified bright targets with i 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 candidates than when selecting lower redshift candidates (z 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-band data satisfy our criterion. With some available samples of red quasars and type II quasars, we find that 88% and 96.5% of these objects can be selected by the Y - K/g - z criterion, respectively, which supports our claim that using the Y - K/g - z criterion efficiently selects both unobscured and obscured quasars. We discuss the implications of our results on the ongoing and upcoming large optical and near-IR sky surveys.

  7. The Infrared & Electro-Optical Systems Handbook. Emerging Systems and Technologies, Volume 8

    Science.gov (United States)

    1993-01-01

    IEEE 703(11), 1721-1743 (1990). 475. T. H. Jeys, R. M. Heinrichs, K. F. Wall, J. Korn, T. C. Hotaling , and E. Kibblewhite, "Ob- 164 IR/EO HANDBOOK...Jeys, R. M. Heinrichs, K. F. Wall, J. Korn, T. C. Hotaling , and E. Kibblewhite, "Optical pumping of mesospheric sodium" Laser Guide Star Adaptive...lasers have been used for many years in industrial processes (welding, etc.). High-power CO 2 lasers typically use an electrical discharge through a

  8. 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

  9. Wave-Optics Modeling of the Optical-Transport Line for Passive Optical Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Andorf, M. B. [NICADD, DeKalb; Lebedev, V. A. [Fermilab; Piot, P. [Fermilab; Ruan, J. [Fermilab

    2018-03-01

    Optical stochastic cooling (OSC) is expected to enable fast cooling of dense particle beams. Transition from microwave to optical frequencies enables an achievement of stochastic cooling rates which are orders of magnitude higher than ones achievable with the classical microwave based stochastic cooling systems. A subsytem critical to the OSC scheme is the focusing optics used to image radiation from the upstream "pickup" undulator to the downstream "kicker" undulator. In this paper, we present simulation results using wave-optics calculation carried out with the {\\sc Synchrotron Radiation Workshop} (SRW). Our simulations are performed in support to a proof-of-principle experiment planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab. The calculations provide an estimate of the energy kick received by a 100-MeV electron as it propagates in the kicker undulator and interacts with the electromagnetic pulse it radiated at an earlier time while traveling through the pickup undulator.

  10. Wave-optics modeling of the optical-transport line for passive optical stochastic cooling

    Science.gov (United States)

    Andorf, M. B.; Lebedev, V. A.; Piot, P.; Ruan, J.

    2018-03-01

    Optical stochastic cooling (OSC) is expected to enable fast cooling of dense particle beams. Transition from microwave to optical frequencies enables an achievement of stochastic cooling rates which are orders of magnitude higher than ones achievable with the classical microwave based stochastic cooling systems. A subsystemcritical to the OSC scheme is the focusing optics used to image radiation from the upstream "pickup" undulator to the downstream "kicker" undulator. In this paper, we present simulation results using wave-optics calculation carried out with the SYNCHROTRON RADIATION WORKSHOP (SRW). Our simulations are performed in support to a proof-of-principle experiment planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab. The calculations provide an estimate of the energy kick received by a 100-MeV electron as it propagates in the kicker undulator and interacts with the electromagnetic pulse it radiated at an earlier time while traveling through the pickup undulator.

  11. Optical constants of silica glass from extreme ultraviolet to far infrared at near room temperature

    Science.gov (United States)

    Kitamura, Rei; Pilon, Laurent; Jonasz, Miroslaw

    2007-11-01

    We thoroughly and critically review studies reporting the real (refractive index) and imaginary (absorption index) parts of the complex refractive index of silica glass over the spectral range from 30 nm to 1000 μm. The general features of the optical constants over the electromagnetic spectrum are relatively consistent throughout the literature. In particular, silica glass is effectively opaque for wavelengths shorter than 200 nm and larger than 3.5-4.0 μm. Strong absorption bands are observed (i) below 160 nm due to the interaction with electrons, absorption by impurities, and the presence of OH groups and point defects; (ii) at ~2.73-2.85, 3.5, and 4.3 μm also caused by OH groups; and (iii) at ~9-9.5, 12.5, and 21-23 μm due to SiOSi resonance modes of vibration. However, the actual values of the refractive and absorption indices can vary significantly due to the glass manufacturing process, crystallinity, wavelength, and temperature and to the presence of impurities, point defects, inclusions, and bubbles, as well as to the experimental uncertainties and approximations in the retrieval methods. Moreover, new formulas providing comprehensive approximations of the optical properties of silica glass are proposed between 7 and 50 μm. These formulas are consistent with experimental data and substantially extend the spectral range of 0.21-7 μm covered by existing formulas and can be used in various engineering applications.

  12. Thermal analysis of fused deposition modeling process using infrared thermography imaging and finite element modeling

    Science.gov (United States)

    Zhou, Xunfei; Hsieh, Sheng-Jen

    2017-05-01

    After years of development, Fused Deposition Modeling (FDM) has become the most popular technique in commercial 3D printing due to its cost effectiveness and easy-to-operate fabrication process. Mechanical strength and dimensional accuracy are two of the most important factors for reliability of FDM products. However, the solid-liquid-solid state changes of material in the FDM process make it difficult to monitor and model. In this paper, an experimental model was developed to apply cost-effective infrared thermography imaging method to acquire temperature history of filaments at the interface and their corresponding cooling mechanism. A three-dimensional finite element model was constructed to simulate the same process using element "birth and death" feature and validated with the thermal response from the experimental model. In 6 of 9 experimental conditions, a maximum of 13% difference existed between the experimental and numerical models. This work suggests that numerical modeling of FDM process is reliable and can facilitate better understanding of bead spreading and road-to-road bonding mechanics during fabrication.

  13. Compound Quantum Dot-Perovskite Optical Absorbers on Graphene Enhancing Short-Wave Infrared Photodetection.

    Science.gov (United States)

    Bessonov, Alexander A; Allen, Mark; Liu, Yinglin; Malik, Surama; Bottomley, Joseph; Rushton, Ashley; Medina-Salazar, Ivonne; Voutilainen, Martti; Kallioinen, Sami; Colli, Alan; Bower, Chris; Andrew, Piers; Ryhänen, Tapani

    2017-06-27

    Colloidal quantum dots (QDs) combined with a graphene charge transducer promise to provide a photoconducting platform with high quantum efficiency and large intrinsic gain, yet compatible with cost-efficient polymer substrates. The response time in these devices is limited, however, and fast switching is only possible by sacrificing the high sensitivity. Furthermore, tuning the QD size toward infrared absorption using conventional organic capping ligands progressively reduces the device performance characteristics. Here we demonstrate methods to couple large QDs (>6 nm in diameter) with organometal halide perovskites, enabling hybrid graphene phototransistor arrays on plastic foils that simultaneously exhibit a specific detectivity of 5 × 10 12 Jones and high video-frame-rate performance. PbI 2 and CH 3 NH 3 I co-mediated ligand exchange in PbS QDs improves surface passivation and facilitates electronic transport, yielding faster charge recovery, whereas PbS QDs embedded into a CH 3 NH 3 PbI 3 matrix produce spatially separated photocarriers leading to large gain.

  14. Development of optical ceramic materials for infrared applications by optimizing sintering conditions

    Science.gov (United States)

    Isogai, Masafumi; Sano, Masahiko

    2017-05-01

    The authors developed production process of polycrystalline Zinc Sulfide (ZnS) materials which have been widely applied to windows and domes for infrared sensor systems. Commercially available ZnS powders of ca. 5 um particle sizes were used as a starting material and Spark Plasma Sintering method (SPS) was applied to the powders for firing process. It was found that the densification of the sintered materials was inhibited by outgassing from ZnS powders during the sintering process (ca. 400 Celsius). Thermal desorption spectroscopy analyses revealed the components of outgassing, such as hydrogen sulfide, sulfur oxide and organic molecules. Based on these analyses, the optimum conditions on heating rate and starting temperature of uniaxial pressurization were investigated to remove the outgassing. The polycrystalline ZnS materials fired under the optimized SPS conditions have such characteristics as better transmittance than 65 % and good uniformity in both 3 - 5 um and 8 - 12 um wavelength regions. These results show the importance of removing outgassing from starting materials.

  15. The Maxwell-Lorentz Model for optical Pulses

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter; Brio, Moysey

    2007-01-01

    Dynamics of optical pulses, especially of ultra short femtosecond pulses, are of great technological and theoretical interest. The dynamics of optical pulses is usually studied using the nonlinear Schrodinger (NLS) equation model. While such approach works surprisingly well for description of pulse...

  16. Modelling of Extrinsic Fiber Optic Sagnac Ultrasound Interferometer ...

    African Journals Online (AJOL)

    Ultrasonic waves are used extensively in nondestructive testing both for characterization of material properties, in this paper, we describe a fiber optic sensor suitable for detection of ultrasonic waves. This sensor is based on an extrinsic fiber optic sagnac interferometer. The proposed sensor model can act as a conventional ...

  17. Infrared image enhancement based on atmospheric scattering model and histogram equalization

    Science.gov (United States)

    Li, Yi; Zhang, Yunfeng; Geng, Aihui; Cao, Lihua; Chen, Juan

    2016-09-01

    Infrared images are fuzzy due to the special imaging technology of infrared sensor. In order to achieve contrast enhancement and gain clear edge details from a fuzzy infrared image, we propose an efficient enhancement method based on atmospheric scattering model and histogram equalization. The novel algorithm optimizes and improves the visual image haze remove method which combines the characteristics of the fuzzy infrared images. Firstly, an average filtering operation is presented to get the estimation of coarse transmission rate. Then we get the fuzzy free image through self-adaptive transmission rate calculated with the statistics information of original infrared image. Finally, to deal with low lighting problem of fuzzy free image, we propose a sectional plateau histogram equalization method which is capable of background suppression. Experimental results show that the performance and efficiency of the proposed algorithm are pleased, compared to four other algorithms in both subjective observation and objective quantitative evaluation. In addition, the proposed algorithm is competent to enhance infrared image for different applications under different circumstances.

  18. Optical wireless communications system and channel modelling with Matlab

    CERN Document Server

    Ghassemlooy, Z

    2012-01-01

    Detailing a systems approach, Optical Wireless Communications: System and Channel Modelling with MATLAB(R), is a self-contained volume that concisely and comprehensively covers the theory and technology of optical wireless communications systems (OWC) in a way that is suitable for undergraduate and graduate-level students, as well as researchers and professional engineers. Incorporating MATLAB(R) throughout, the authors highlight past and current research activities to illustrate optical sources, transmitters, detectors, receivers, and other devices used in optical wireless communications. The

  19. Trace explosives detection using photo-thermal infrared imaging spectroscopy (PT-IRIS): theory, modeling, and detection algorithms

    Science.gov (United States)

    Furstenberg, Robert; Kendziora, Christopher A.; Papantonakis, Michael R.; Nguyen, Viet; Byers, Jeff; McGill, R. Andrew

    2015-05-01

    We are developing a technology for stand-off detection based on photo-thermal infrared imaging spectroscopy (PT-IRIS). In this approach, one or more infrared (IR) quantum cascade lasers are tuned to strong absorption bands in the analytes and directed at the sample while an IR focal plane array is used to image the subsequent thermal emissions. In this paper we present recent advances in the theory and numerical modeling of photo-thermal imaging and spectroscopy of particulates on flat substrates. We compare the theoretical models with experimental data taken on our mobile cart-based PT-IRIS system. Synthetic data of the photo-thermal response was calculated for a wide range of analytes, substrates, particle sizes, and analyte mass loadings using their known thermo-physical and optical properties. These synthetic data sets can now be generated quickly and were used to accelerate the development of detection algorithms. The performance of detection algorithms will also be discussed.

  20. Far-infrared optical conductivity gap in superconducting MgB2 films.

    Science.gov (United States)

    Kaindl, Robert A; Carnahan, Marc A; Orenstein, Joseph; Chemla, Daniel S; Christen, Hans M; Zhai, Hong-Ying; Paranthaman, Mariappan; Lowndes, Doug H

    2002-01-14

    We report the first study of the optical conductivity of MgB2 covering the range of its lowest-energy superconducting gap. Terahertz time-domain spectroscopy is utilized to determine the complex, frequency-dependent conductivity sigma(omega) of thin films. The imaginary part reveals an inductive response due to the emergence of the superconducting condensate. The real part exhibits a strong depletion of oscillator strength near 5 meV resulting from the opening of a superconducting energy gap. The gap ratio of 2Delta0/k(B)TC approximately 1.9 is well below the weak-coupling value, pointing to complex behavior in this novel superconductor.

  1. Broadening and Amplification of an Infrared Femtosecond Pulse for Optical Parametric Chirped-Pulse Amplification

    International Nuclear Information System (INIS)

    Wang He-Lin; Yang Ai-Jun; Leng Yu-Xin

    2011-01-01

    A high-average-power diode-pumped narrowband regenerative chirped pulse amplifier is developed using the thin-rod Nd:YAG laser architecture for optical parametric chirped-pulse amplification (OPCPA). The effect of the etalons on the amplified pulse in the regenerative cavity is studied experimentally and theoretically. By inserting glass etalons of thickness 1 mm and 5 mm into the regenerative cavity, the pre-stretching pulse from an Öffner stretcher is further broadened to above 200ps, which matches the amplification windows of the signal pulses in OPCPA and is suitable for use as a pump source in the OPCPA system. The bandwidth of the amplified pulse is 1.5 nm, and an output energy of 2mJ is achieved at a repetition rate of 10Hz. (fundamental areas of phenomenology (including applications))

  2. Analytical models of optical response in one-dimensional semiconductors

    International Nuclear Information System (INIS)

    Pedersen, Thomas Garm

    2015-01-01

    The quantum mechanical description of the optical properties of crystalline materials typically requires extensive numerical computation. Including excitonic and non-perturbative field effects adds to the complexity. In one dimension, however, the analysis simplifies and optical spectra can be computed exactly. In this paper, we apply the Wannier exciton formalism to derive analytical expressions for the optical response in four cases of increasing complexity. Thus, we start from free carriers and, in turn, switch on electrostatic fields and electron–hole attraction and, finally, analyze the combined influence of these effects. In addition, the optical response of impurity-localized excitons is discussed. - Highlights: • Optical response of one-dimensional semiconductors including excitons. • Analytical model of excitonic Franz–Keldysh effect. • Computation of optical response of impurity-localized excitons

  3. Optical properties of LiYF4:U3+. Infrared laser use

    International Nuclear Information System (INIS)

    Louis, M.

    1995-01-01

    In this study are proposed a complete interpretation of the optical spectra of trivalent uranium in LiYF 4 (LYF). Single crystals of uranium doped LYF were grown by Czochralski method with different concentration (0.05%-0.20%). The obtained crystals have pale green color, characteristic of tetravalent uranium. The absorption spectra show that effectively only U 4+ is present in this crystal. In order to reduce the oxidation state of the U 4+ , the pale green crystal containing 0.07% of U 4+ was exposed to gamma irradiation. The sample becomes orange brown and the absorption spectrum is characteristic of U 3+ . The irradiation technology is an efficient method to convert 100% of U 4+ in U 3+ . From the analysis of the polarized optical absorption and emission spectra the spectroscopic parameters have been determined. The Judd-Ofelt theory was applied in order to simulate the intensity of the 5 f 3 →5 f 3 transitions between Stark levels of U 3+ in LYF. Because of the large crystal field splitting of the J multiplet in the actinides a set of phenomenological intensity parameters is introduced to describe the transition probabilities between crystal field sublevels. A continuous laser emission of an actinide ion at ambient temperature has been revealed. In the last part of this thesis the fundamental aspect of the energy transfer process that takes place in laser crystal LYF codoped with an 4 f element Nd 3+ and an 5 f one U 3+ has been investigated. (author). 111 refs., 69 figs., 19 tabs

  4. Improving optical properties of silicon nitride films to be applied in the middle infrared optics by a combined high-power impulse/unbalanced magnetron sputtering deposition technique.

    Science.gov (United States)

    Liao, Bo-Huei; Hsiao, Chien-Nan

    2014-02-01

    Silicon nitride films are prepared by a combined high-power impulse/unbalanced magnetron sputtering (HIPIMS/UBMS) deposition technique. Different unbalance coefficients and pulse on/off ratios are applied to improve the optical properties of the silicon nitride films. The refractive indices of the Si3N4 films vary from 2.17 to 2.02 in the wavelength ranges of 400-700 nm, and all the extinction coefficients are smaller than 1×10(-4). The Fourier transform infrared spectroscopy and x-ray diffractometry measurements reveal the amorphous structure of the Si3N4 films with extremely low hydrogen content and very low absorption between the near IR and middle IR ranges. Compared to other deposition techniques, Si3N4 films deposited by the combined HIPIMS/UBMS deposition technique possess the highest refractive index, the lowest extinction coefficient, and excellent structural properties. Finally a four-layer coating is deposited on both sides of a silicon substrate. The average transmittance from 3200 to 4800 nm is 99.0%, and the highest transmittance is 99.97% around 4200 nm.

  5. Deriving Total Suspended Matter Concentration from the Near-Infrared-Based Inherent Optical Properties over Turbid Waters: A Case Study in Lake Taihu

    Directory of Open Access Journals (Sweden)

    Wei Shi

    2018-02-01

    Full Text Available Normalized water-leaving radiance spectra nLw(λ, particle backscattering coefficients bbp(λ in the near-infrared (NIR wavelengths, and total suspended matter (TSM concentrations over turbid waters are analytically correlated. To demonstrate the use of bbp(λ in the NIR wavelengths in coastal and inland waters, we used in situ optics and TSM data to develop two TSM algorithms from measurements of the Visible Infrared Imaging Radiometer Suite (VIIRS onboard the Suomi National Polar-orbiting Partnership (SNPP using backscattering coefficients at the two NIR bands bbp(745 and bbp(862 for Lake Taihu. The correlation coefficients between the modeled TSM concentrations from bbp(745 and bbp(862 and the in situ TSM are 0.93 and 0.92, respectively. A different in situ dataset acquired between 2012 and 2016 for Lake Taihu was used to validate the performance of the NIR TSM algorithms for VIIRS-SNPP observations. TSM concentrations derived from VIIRS-SNPP observations with these two NIR bbp(λ-based TSM algorithms matched well with in situ TSM concentrations in Lake Taihu between 2012 and 2016. The normalized root mean square errors (NRMSEs for the two NIR algorithms are 0.234 and 0.226, respectively. The two NIR-based TSM algorithms are used to compute the satellite-derived TSM concentrations to study the seasonal and interannual variability of the TSM concentration in Lake Taihu between 2012 and 2016. In fact, the NIR-based TSM algorithms are analytically based with minimal in situ data to tune the coefficients. They are not sensitive to the possible nLw(λ saturation in the visible bands for highly turbid waters, and have the potential to be used for estimation of TSM concentrations in turbid waters with similar NIR nLw(λ spectra as those in Lake Taihu.

  6. Thirty Meter Telescope (TMT) Narrow Field Infrared Adaptive Optics System (NFIRAOS) real-time controller preliminary architecture

    Science.gov (United States)

    Kerley, Dan; Smith, Malcolm; Dunn, Jennifer; Herriot, Glen; Véran, Jean-Pierre; Boyer, Corinne; Ellerbroek, Brent; Gilles, Luc; Wang, Lianqi

    2016-08-01

    The Narrow Field Infrared Adaptive Optics System (NFIRAOS) is the first light Adaptive Optics (AO) system for the Thirty Meter Telescope (TMT). A critical component of NFIRAOS is the Real-Time Controller (RTC) subsystem which provides real-time wavefront correction by processing wavefront information to compute Deformable Mirror (DM) and Tip/Tilt Stage (TTS) commands. The National Research Council of Canada - Herzberg (NRC-H), in conjunction with TMT, has developed a preliminary design for the NFIRAOS RTC. The preliminary architecture for the RTC is comprised of several Linux-based servers. These servers are assigned various roles including: the High-Order Processing (HOP) servers, the Wavefront Corrector Controller (WCC) server, the Telemetry Engineering Display (TED) server, the Persistent Telemetry Storage (PTS) server, and additional testing and spare servers. There are up to six HOP servers that accept high-order wavefront pixels, and perform parallelized pixel processing and wavefront reconstruction to produce wavefront corrector error vectors. The WCC server performs low-order mode processing, and synchronizes and aggregates the high-order wavefront corrector error vectors from the HOP servers to generate wavefront corrector commands. The Telemetry Engineering Display (TED) server is the RTC interface to TMT and other subsystems. The TED server receives all external commands and dispatches them to the rest of the RTC servers and is responsible for aggregating several offloading and telemetry values that are reported to other subsystems within NFIRAOS and TMT. The TED server also provides the engineering GUIs and real-time displays. The Persistent Telemetry Storage (PTS) server contains fault tolerant data storage that receives and stores telemetry data, including data for Point-Spread Function Reconstruction (PSFR).

  7. Detecting ship targets in spaceborne infrared image based on modeling radiation anomalies

    Science.gov (United States)

    Wang, Haibo; Zou, Zhengxia; Shi, Zhenwei; Li, Bo

    2017-09-01

    Using infrared imaging sensors to detect ship target in the ocean environment has many advantages compared to other sensor modalities, such as better thermal sensitivity and all-weather detection capability. We propose a new ship detection method by modeling radiation anomalies for spaceborne infrared image. The proposed method can be decomposed into two stages, where in the first stage, a test infrared image is densely divided into a set of image patches and the radiation anomaly of each patch is estimated by a Gaussian Mixture Model (GMM), and thereby target candidates are obtained from anomaly image patches. In the second stage, target candidates are further checked by a more discriminative criterion to obtain the final detection result. The main innovation of the proposed method is inspired by the biological mechanism that human eyes are sensitive to the unusual and anomalous patches among complex background. The experimental result on short wavelength infrared band (1.560 - 2.300 μm) and long wavelength infrared band (10.30 - 12.50 μm) of Landsat-8 satellite shows the proposed method achieves a desired ship detection accuracy with higher recall than other classical ship detection methods.

  8. The accuracy of heavy ion optical model calculations

    International Nuclear Information System (INIS)

    Kozik, T.

    1980-01-01

    There is investigated in detail the sources and magnitude of numerical errors in heavy ion optical model calculations. It is shown on example of 20 Ne + 24 Mg scattering at Esub(LAB)=100 MeV. (author)

  9. Mark formation modeling in optical rewritable recording

    NARCIS (Netherlands)

    Brusche, J.H.; Segal, A.; Vuik, C.; Urbach, H.P.

    2006-01-01

    In optical rewritable recording media, such as the Blu-ray Disc, amorphous marks are formed on a crystalline background of a phase-change layer, by means of short, high power laser pulses. In order to improve this data storage concept, it is of great importance to understand the mark formation

  10. Preliminary optical design of AIRES: an airborne infrared echelle spectrometer for SOFIA

    Science.gov (United States)

    Haas, Michael R.; Erickson, Edwin F.; Baltz, James A.; Colgan, Sean W.; Lynch, Dana H.; McGuire, James P.; Pina, Robert K.; Roellig, Thomas L.; Simpson, Janet P.; Telesco, Charles M.; Wolf, Juergen; Young, Erick T.

    1998-08-01

    NASA's Stratospheric Observatory for IR Astronomy (SOFIA) will enable unprecedented IR acuity at wavelengths obscured from the ground. To help open this new chapter in the exploration of the IR universe, we are developing the Airborne IR Echelle Spectrometer (AIRES) as a facility science instrument. Full funding was awarded for a four year development in October, 1997. The instrument is scheduled to come on-line with the observatory in the Fall of 2001. It will be used to investigate a broad range of phenomena that occur in the interstellar medium. AIRES will use a 1200 mm long, 76 degree blaze angle echelle to combine high resolution spectroscopy with diffraction-limited imaging in the cross-dispersion direction. Its three 2D detector arrays will prove good sensitivity over a decade in wavelength. An additional array will be used as a slit viewer for (lambda) optical design and packaging, focal plane configuration, echelle prototyping, and cryostat layout are described.

  11. Visible-infrared remote-sensing model and applications for ocean waters. Ph.D. Thesis

    Science.gov (United States)

    Lee, Zhongping

    1994-01-01

    Remote sensing has become important in the ocean sciences, especially for research involving large spatial scales. To estimate the in-water constituents through remote sensing, whether carried out by satellite or airplane, the signal emitted from beneath the sea surface, the so called water-leaving radiance (L(w)), is of prime importance. The magnitude of L(w) depends on two terms: one is the intensity of the solar input, and the other is the reflectance of the in-water constituents. The ratio of the water-leaving radiance to the downwelling irradiance (E(d)) above the sear surface (remote-sensing reflectance, R(sub rs)) is independent of the intensity of the irradiance input, and is largely a function of the optical properties of the in-water constituents. In this work, a model is developed to interpret r(sub rs) for ocean water in the visible-infrared range. In addition to terms for the radiance scattered from molecules and particles, the model includes terms that describe contributions from bottom reflectance, fluorescence of gelbstoff or colored dissolved organic matter (CDOM), and water Raman scattering. By using this model, the measured R(sub rs) of waters from the West Florida Shelf to the Mississippi River plume, which covered a (concentration of chlorophyll a) range of 0.07 - 50 mg/cu m, were well interpreted. The average percentage difference (a.p.d.) between the measured and modeled R(sub rs) is 3.4%, and, for the shallow waters, the model-required water depth is within 10% of the chart depth. Simple mathematical simulations for the phytoplankton pigment absorption coefficient (a(sub theta)) are suggested for using the R(sub rs) model. The inverse problem of R(sub rs), which is to analytically derive the in-water constituents from R(sub rs) data alone, can be solved using the a(sub theta) functions without prior knowledge of the in-water optical properties. More importantly, this method avoids problems associated with a need for knowledge of the shape

  12. Future Retrievals of Water Column Bio-Optical Properties using the Hyperspectral Infrared Imager (HyspIRI

    Directory of Open Access Journals (Sweden)

    Emmanuel Devred

    2013-12-01

    Full Text Available Interpretation of remote sensing reflectance from coastal waters at different wavelengths of light yields valuable information about water column constituents, which in turn, gives information on a variety of processes occurring in coastal waters, such as primary production, biogeochemical cycles, sediment transport, coastal erosion, and harmful algal blooms. The Hyperspectral Infrared Imager (HyspIRI is well suited to produce global, seasonal maps and specialized observations of coastal ecosystems and to improve our understanding of how phytoplankton communities are spatially distributed and structured, and how they function in coastal and inland waters. This paper draws from previously published studies on high-resolution, hyperspectral remote sensing of coastal and inland waters and provides an overview of how the HyspIRI mission could enable the retrieval of new aquatic biophysical products or improve the retrieval accuracy of existing satellite-derived products (e.g., inherent optical properties, phytoplankton functional types, pigment composition, chlorophyll-a concentration, etc.. The intent of this paper is to introduce the development of the HyspIRI mission to the coastal and inland remote sensing community and to provide information regarding several potential data products that were not originally part of the HyspIRI mission objectives but could be applicable to research related to coastal and inland waters. Further work toward quantitatively determining the extent and quality of these products, given the instrument and mission characteristics, is recommended.

  13. Mid-infrared optical properties of thin films of aluminum oxide, titanium dioxide, silicon dioxide, aluminum nitride, and silicon nitride.

    Science.gov (United States)

    Kischkat, Jan; Peters, Sven; Gruska, Bernd; Semtsiv, Mykhaylo; Chashnikova, Mikaela; Klinkmüller, Matthias; Fedosenko, Oliana; Machulik, Stephan; Aleksandrova, Anna; Monastyrskyi, Gregorii; Flores, Yuri; Masselink, W Ted

    2012-10-01

    The complex refractive index components, n and k, have been studied for thin films of several common dielectric materials with a low to medium refractive index as functions of wavelength and stoichiometry for mid-infrared (MIR) wavelengths within the range 1.54-14.29 μm (700-6500 cm(-1)). The materials silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, and titanium oxide are prepared using room temperature reactive sputter deposition and are characterized using MIR variable angle spectroscopic ellipsometry. The investigation shows how sensitive the refractive index functions are to the O2 and N2 flow rates, and for which growth conditions the materials deposit homogeneously. It also allows conclusions to be drawn on the degree of amorphousness and roughness. To facilitate comparison of the materials deposited in this work with others, the index of refraction was also determined and provided for the near-IR and visible ranges of the spectrum. The results presented here should serve as a useful information base for designing optical coatings for the MIR part of the electromagnetic spectrum. The results are parameterized to allow them to be easily used for coating design.

  14. INFRARED AND OPTICAL IMAGINGS OF THE COMET 2P/ENCKE DUST CLOUD IN THE 2003 RETURN

    Energy Technology Data Exchange (ETDEWEB)

    Sarugaku, Yuki; Ueno, Munetaka [Kiso Observatory, Institute of Astronomy, School of Science, The University of Tokyo, 10762-30 Mitake, Kiso-machi, Kiso-gun, Nagano 397-0101 (Japan); Ishiguro, Masateru [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Usui, Fumihiko [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Reach, William T., E-mail: sarugaku@kiso.ioa.s.u-tokyo.ac.jp [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2015-05-10

    We report contemporaneous imaging observations of the short-period comet 2P/Encke in infrared and optical wavelengths during the 2003 return. Both images show the same unique morphology consisting of a spiky dust cloud near the nucleus and a dust trail extending along the orbit. We conducted a dynamical simulation of dust particles to characterize the morphology and found that dust particles were ejected intensively for a short duration (≲10 days) a few days after perihelion passage. The maximum particle size is at least on the order of 1 cm in radius following a differential power-law size distribution with an index of −3.2 to −3.6. The total mass ejected in the 2003 return is at least 1.5 × 10{sup 9}–1.2 × 10{sup 10} kg, which corresponds to 0.003%–0.03% of the nucleus mass. We derived the albedo of the dust cloud as 0.01–0.04 at a solar phase angle of 26.°2, which is consistent with or possibly greater than that of the nucleus. We suppose that impulsive activity such as an outburst is a key to understanding the peculiar appearance of 2P/Encke.

  15. Noninvasive near infrared autofluorescence imaging of retinal pigment epithelial cells in the human retina using adaptive optics.

    Science.gov (United States)

    Liu, Tao; Jung, HaeWon; Liu, Jianfei; Droettboom, Michael; Tam, Johnny

    2017-10-01

    The retinal pigment epithelial (RPE) cells contain intrinsic fluorophores that can be visualized using infrared autofluorescence (IRAF). Although IRAF is routinely utilized in the clinic for visualizing retinal health and disease, currently, it is not possible to discern cellular details using IRAF due to limits in resolution. We demonstrate that the combination of adaptive optics (AO) with IRAF (AO-IRAF) enables higher-resolution imaging of the IRAF signal, revealing the RPE mosaic in the living human eye. Quantitative analysis of visualized RPE cells in 10 healthy subjects across various eccentricities demonstrates the possibility for in vivo density measurements of RPE cells, which range from 6505 to 5388 cells/mm 2 for the areas measured (peaking at the fovea). We also identified cone photoreceptors in relation to underlying RPE cells, and found that RPE cells support on average up to 18.74 cone photoreceptors in the fovea down to an average of 1.03 cone photoreceptors per RPE cell at an eccentricity of 6 mm. Clinical application of AO-IRAF to a patient with retinitis pigmentosa illustrates the potential for AO-IRAF imaging to become a valuable complementary approach to the current landscape of high resolution imaging modalities.

  16. 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.

  17. A mid-infrared carbon monoxide sensor system using wideband absorption spectroscopy and a single-reflection spherical optical chamber

    Science.gov (United States)

    Dong, Ming; Zheng, Chuantao; Miao, Shuzhuo; Song, Fang; Wang, Yiding

    2017-09-01

    A mid-infrared carbon monoxide (CO) sensor system based on a dual-channel differential detection method was developed using a broadband light source in the 4.60 μm wavelength region and a single-reflection spherical optical chamber with ∼0.373 m absorption path length. CO detection was realized by targeting the wideband strong absorption lines within 4.55-4.65 μm. A dual-channel pyroelectric detector as well as a self-developed digital signal processor (DSP) based orthogonal lock-in amplifier was employed to process CO sensing signal. A minimum detection limit of ∼0.5 ppm in volume (ppmv) was achieved with a measurement time of 6 s, based on an Allan deviation analysis of the sensor system. The response time (1000 → 0 ppmv) was determined to be ∼7 s for the CO sensor operation. Due to the characteristics of low detection limit, fast response time and high cost performance, the proposed sensor has relatively good prospect in coal-mining operation.

  18. 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.

  19. 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.

  20. Optimization of image reconstruction for magnetic resonance imaging-guided near-infrared diffuse optical spectroscopy in breast

    Science.gov (United States)

    Zhao, Yan; Mastanduno, Michael A.; Jiang, Shudong; EI-Ghussein, Fadi; Gui, Jiang; Pogue, Brian W.; Paulsen, Keith D.

    2015-05-01

    An optimized approach to nonlinear iterative reconstruction of magnetic resonance imaging (MRI)-guided near-infrared spectral tomography (NIRST) images was developed using an L-curve-based algorithm for the choice of regularization parameter. This approach was applied to clinical exam data to maximize the reconstructed values differentiating malignant and benign lesions. MRI/NIRST data from 25 patients with abnormal breast readings (BI-RADS category 4-5) were analyzed using this optimal regularization methodology, and the results showed enhanced p values and area under the curve (AUC) for the task of differentiating malignant from benign lesions. Of the four absorption parameters and two scatter parameters, the most significant differences for benign versus malignant were total hemoglobin (HbT) and tissue optical index (TOI) with p values=0.01 and 0.001, and AUC values=0.79 and 0.94, respectively, in terms of HbT and TOI. This dramatically improved the values relative to fixed regularization (p value=0.02 and 0.003; AUC=0.75 and 0.83) showing that more differentiation was possible with the optimal method. Through a combination of both biomarkers, HbT and TOI, the AUC increased from 82.9% (fixed regulation=0.1) to 94.3% (optimal method).

  1. Thermo-mechanical analysis of ITER first mirrors and its use for the ITER equatorial visible/infrared wide angle viewing system optical design

    International Nuclear Information System (INIS)

    Joanny, M.; Salasca, S.; Dapena, M.; Cantone, B.; Travère, J. M.; Thellier, C.; Fermé, J. J.; Marot, L.; Buravand, O.; Perrollaz, G.; Zeile, C.

    2012-01-01

    ITER first mirrors (FMs), as the first components of most ITER optical diagnostics, will be exposed to high plasma radiation flux and neutron load. To reduce the FMs heating and optical surface deformation induced during ITER operation, the use of relevant materials and cooling system are foreseen. The calculations led on different materials and FMs designs and geometries (100 mm and 200 mm) show that the use of CuCrZr and TZM, and a complex integrated cooling system can limit efficiently the FMs heating and reduce their optical surface deformation under plasma radiation flux and neutron load. These investigations were used to evaluate, for the ITER equatorial port visible/infrared wide angle viewing system, the impact of the FMs properties change during operation on the instrument main optical performances. The results obtained are presented and discussed.

  2. Predictive modeling of infrared radiative heating in tomato dry-peeling process: Part II. Model validation and sensitivity analysis

    Science.gov (United States)

    A predictive mathematical model was developed to simulate heat transfer in a tomato undergoing double sided infrared (IR) heating in a dry-peeling process. The aims of this study were to validate the developed model using experimental data and to investigate different engineering parameters that mos...

  3. Optically pumped ultraviolet and infrared lasers driven by exploding metal films and wires

    International Nuclear Information System (INIS)

    Jones, C.R.; Ware, K.D.

    1983-01-01

    The 342-nm molecular iodine and 1315-nm atomic iodine lasers have been optically pumped by intense light from exploding-metal-film and exploding-wire discharges. Brightness temperatures for the exploding-film discharges were approx. 25,000 K and for the wire discharges were approx. 30,000 K. For the I 2 laser the 3.5-cm-diameter by 40-cm-long pumped volume lies adjacent to the wire or film of the same length. Pressures of 1 to 6 torr I 2 and 1 to 3 atm SF, CF 4 , or Ar were used in the stainless-steel cell. Using 20-μF capacitance charged to 40 kV, a 0.25-mm tungsten wire, 3-torr I 2 , and a 2-atm SF 6 , an energy of 2 J was obtained from the laser in a pulse of 8-μs duration. The specific output energy was 7 J/l. Substitution of a cylindrical Al film for the wire, under otherwise similar conditions, led to a X10 output energies and efficiencies were obtained with similar input energy. An output pulse of 12 J and 12-μs duration was measured for a specific output energy of 18 J/l. A laser energy of 110 J in a 20-us-long pulse has been measured from atomic iodine using a wire discharge along the axis of a larger cell. The active volume available was 20 cm in diameter and 80 cm in length. Input energy was 32 kJ. In similar measurements using a cylindrical Al film for discharge initiation, the measured output energy was 40 J

  4. Multimodal optical characterisation of collagen photodegradation by femtosecond infrared laser ablation.

    Science.gov (United States)

    Manickavasagam, A; Hirvonen, L M; Melita, L N; Chong, E Z; Cook, R J; Bozec, L; Festy, F

    2014-12-07

    Collagen is a structural component of the human body, as a connective tissue it can become altered as a result of pathophysiological conditions. Although the collagen degradation mechanism is not fully understood, it plays an important role in ageing, disease progression and applications in therapeutic laser treatments. To fully understand the mechanism of collagen alteration, in our study photo-disruptive effects were induced in collagen I matrix by point-irradiation with a femtosecond Ti-sapphire laser under controlled laser ablation settings. This was followed by multi-modal imaging of the irradiated and surrounding areas to analyse the degradation mechanism. Our multi-modal methodology was based on second harmonic generation (SHG), scanning electron microscope (SEM), autofluorescence (AF) average intensities and the average fluorescence lifetime. This allowed us to quantitatively characterise the degraded area into four distinct zones: (1) depolymerised zone in the laser focal spot as indicated by the loss of SHG signal, (2) enhanced crosslinking zone in the inner boundary of the laser induced cavity as represented by the high fluorescence ring, (3) reduced crosslinking zone formed the outer boundary of the cavity as marked by the increased SHG signal and (4) native collagen. These identified distinct zones were in good agreement with the expected photochemical changes shown using Raman spectroscopy. In addition, imaging using polarisation-resolved SHG (p-SHG) revealed both a high degree of fibre re-orientation and a SHG change in tensor ratios around the irradiation spot. Our multi-modal optical imaging approach can provide a new methodology for defining distinct zones that can be used in a clinical setting to determine suitable thresholds for applying safe laser treatments without affecting the surrounding tissues. Furthermore this technique can be extended to address challenges observed in collagen based tissue engineering and used as a minimally invasive

  5. Examination of Bond Properties through Infrared Spectroscopy and Molecular Modeling in the General Chemistry Laboratory

    Science.gov (United States)

    Csizmar, Clifford M.; Force, Dee Ann; Warner, Don L.

    2012-01-01

    A concerted effort has been made to increase the opportunities for undergraduate students to address scientific problems employing the processes used by practicing chemists. As part of this effort, an infrared (IR) spectroscopy and molecular modeling experiment was developed for the first-year general chemistry laboratory course. In the…

  6. Laboratory-based grain-shape models for simulating dust infrared spectra

    NARCIS (Netherlands)

    Mutschke, H.; Min, M.; Tamanai, A.

    2009-01-01

    Context. Analysis of thermal dust emission spectra for dust mineralogy and physical grain properties depends on comparison spectra, which are either laboratory-measured infrared extinction spectra or calculated extinction cross sections based on certain grain models. Often, the agreement between

  7. Regional calibration models for predicting loblolly pine tracheid properties using near-infrared spectroscopy

    Science.gov (United States)

    Mohamad Nabavi; Joseph Dahlen; Laurence Schimleck; Thomas L. Eberhardt; Cristian Montes

    2018-01-01

    This study developed regional calibration models for the prediction of loblolly pine (Pinus taeda) tracheid properties using near-infrared (NIR) spectroscopy. A total of 1842 pith-to-bark radial strips, aged 19–31 years, were acquired from 268 trees from 109 stands across the southeastern USA. Diffuse reflectance NIR spectra were collected at 10-mm...

  8. Proton transport in a membrane protein channel: two-dimensional infrared spectrum modeling.

    NARCIS (Netherlands)

    Liang, C.; Knoester, J.; Jansen, T.L.Th.A.

    2012-01-01

    We model the two-dimensional infrared (2DIR) spectrum of a proton channel to investigate its applicability as a spectroscopy tool to study the proton transport process in biological systems. Proton transport processes in proton channels are involved in numerous fundamental biochemical reactions.

  9. Tuning direct bandgap GeSn/Ge quantum dots' interband and intraband useful emission wavelength: Towards CMOS compatible infrared optical devices

    Science.gov (United States)

    Baira, Mourad; Salem, Bassem; Madhar, Niyaz Ahamad; Ilahi, Bouraoui

    2018-05-01

    In this work, interband and intraband optical transitions from direct bandgap strained GeSn/Ge quantum dots are numerically tuned by evaluating the confined energies for heavy holes and electrons in Г-and L-valley. The practically exploitable emission wavelength ranges for efficient use in light emission and sensing should fulfill specific criteria imposing the electrons confined states in Г-valley to be sufficiently below those in L-valley. This study shows that GeSn quantum dots offer promising opportunity towards high efficient group IV based infrared optical devices operating in the mid-IR and far-IR wavelength regions.

  10. Mathematical modeling of heat transfer in production premises heated by gas infrared emitters

    Directory of Open Access Journals (Sweden)

    Maksimov Vyacheslav I.

    2017-01-01

    Full Text Available The results of numerical modeling of the process of free convective heat transfer in the regime of turbulent convection in a closed rectangular region heated by an infrared radiator are presented. The system of Navier-Stokes equations in the Boussinesq approximation is solved, the energy equation for the gas and the heat conduction equations for the enclosing vertical and horizontal walls. A comparative analysis of the heat transfer regimes in the considered region for different Grashof numbers is carried out. The features of the formation of heated air flows relative to the infrared emitter located at some distance from the upper horizontal boundary of the region are singled out.

  11. Optical Propagation Modeling for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Williams, W H; Auerbach, J M; Henesian, M A; Jancaitis, K S; Manes, K R; Mehta, N C; Orth, C D; Sacks, R A; Shaw, M J; Widmayer, C C

    2004-01-12

    Optical propagation modeling of the National Ignition Facility has been utilized extensively from conceptual design several years ago through to early operations today. In practice we routinely (for every shot) model beam propagation starting from the waveform generator through to the target. This includes the regenerative amplifier, the 4-pass rod amplifier, and the large slab amplifiers. Such models have been improved over time to include details such as distances between components, gain profiles in the laser slabs and rods, transient optical distortions due to the flashlamp heating of laser slabs, measured transmitted and reflected wavefronts for all large optics, the adaptive optic feedback loop, and the frequency converter. These calculations allow nearfield and farfield predictions in good agreement with measurements.

  12. Study of Optical Models Regarding the Human Eye

    Directory of Open Access Journals (Sweden)

    Maryam Abolmasoomi

    2011-03-01

    Full Text Available Introduction: Until now, many models have been presented for optical study of the human eye. In recent years, surgery on the anterior section of the eye (such as cataract and photo-refractive surgery has increased, so a study on the optics of the eye and evaluation of vision quality has become more important. Material and Methods: In this article, some of these models are considered. They include models with spherical and conic-section surfaces (for cornea and lens, simple models and new models with complex surfaces. Results: Evaluation of the optical models of the eye provides the possibility of enhancing the representation of human vision and also increasing the accuracy of surgery on the anterior section of the eye to enable higher quality vision.

  13. Fringes in FTIR spectroscopy revisited: understanding and modelling fringes in infrared spectroscopy of thin films.

    Science.gov (United States)

    Konevskikh, Tatiana; Ponossov, Arkadi; Blümel, Reinhold; Lukacs, Rozalia; Kohler, Achim

    2015-06-21

    The appearance of fringes in the infrared spectroscopy of thin films seriously hinders the interpretation of chemical bands because fringes change the relative peak heights of chemical spectral bands. Thus, for the correct interpretation of chemical absorption bands, physical properties need to be separated from chemical characteristics. In the paper at hand we revisit the theory of the scattering of infrared radiation at thin absorbing films. Although, in general, scattering and absorption are connected by a complex refractive index, we show that for the scattering of infrared radiation at thin biological films, fringes and chemical absorbance can in good approximation be treated as additive. We further introduce a model-based pre-processing technique for separating fringes from chemical absorbance by extended multiplicative signal correction (EMSC). The technique is validated by simulated and experimental FTIR spectra. It is further shown that EMSC, as opposed to other suggested filtering methods for the removal of fringes, does not remove information related to chemical absorption.

  14. Optical clocks and their contribution to gravity modeling

    Science.gov (United States)

    Naeimi, Mohammad; Mohamadhosseini, Babak; Hatami, Mohsen

    2016-04-01

    Optical clocks, as one of the latest achievements in atomic and molecular physics, have applications more than timing, due to their accuracy and stability. In general relativity, gravitational potential differences in space and time, cause frequency difference in optical clocks. Hence, ultra precise optical clocks can be used as a tool to observe potential differences and consequently as a new gravimetry technique. In this contribution, we investigate the latest optical clocks based on atomic transition in Al+ and derive a simple equation for frequency change related to geo-potential differences. Moreover, we consider the capability of optical clocks for gravity modeling in combination with other gravity observations. Finally, the possibility to detect potential changes in geo-dynamically active zones, such as East-Asia and the requirements for such studies are discussed.

  15. Quantitative in situ monitoring of an elevated temperature reaction using a water-cooled mid-infrared fiber-optic probe.

    Science.gov (United States)

    Maclaurin, P; Crabb, N C; Wells, I; Worsfold, P J; Coombs, D

    1996-04-01

    A novel water-cooled mid-infrared fiber-optic probe is described which is heatable to 230 °C. The probe has chalcogenide fibers and a ZnSe internal reflection element and is compact and fully flexible, allowing access to a wide range of standard laboratory reaction vessels and fume cupboard arrangements. Performance is demonstrated via the in situ analysis of an acid-catalyzed esterification reaction in toluene at 110 °C, and the results are compared with those from a conventional extractive sampling loop flow cell arrangement. Particular emphasis is given to the quantitative interpretation of the spectroscopic data, using gas chromatographic reference data. Calibration data are presented for univariate and partial least squares models, with an emphasis on procedures for improving the quality of interpreparation calibration and prediction through the use of focused reference analysis regimes. Subset univariate procedures are presented that yield relative errors of spectroscopy combined with bias correction partial least squares procedures for the efficient in situ quantitative analysis of laboratory scale reactions.

  16. Investigation of the optical properties of InAs/InGaAs/GaAs quantum dot in quantum well multilayer structures for infrared photodetectors

    KAUST Repository

    Ivanov, Ts

    2012-03-29

    A detailed study of InAs/InGaAs quantum dots in quantum well (DWELL) structures grown on GaAs substrates for infrared photodetectors was performed using surface photovoltage (SPV) spectroscopy. Three types of samples were investigated: as-grown, and annealed with dielectric coating SiO 2 or SiN. The annealing resulted in intermixing of the material components. The amplitude and phase SPV spectra were measured at room temperature under various experimental conditions. The comparison of the SPV with the photoluminescence (PL) spectra allows one to conclude that the spectral features are due to optical transitions in the DWELL structure. The blueshift observed of these features in the intermixed samples implies that the energy levels responsible for the transitions change correspondingly due to the intermixing process. The interface band-bending in the samples and the mechanisms of the carrier dynamics were determined by a comparative analysis of the SPV amplitude and phase spectra, using our vector model for representation of the SPV signal. © Published under licence by IOP Publishing Ltd.

  17. Modeling of a bimetallic MEMS-based infrared detector

    Science.gov (United States)

    Pevtsov, E. Ph; Breev, S. V.; Demenkova, T. A.

    2018-01-01

    In work techniques of calculations of the key parameters of the bimetal capacitive IR detectors matrix are presented. Sensitivity characteristics of the bimetal detector were calculated and prototype model of detector in the form of bimetallic console was produced. The possibility of use of capacitive MEMS-receivers on basis of bimetallic effect as an alternative to pyroelectric and microbolometer IR detectors is shown.

  18. Photonic encryption : modeling and functional analysis of all optical logic.

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jason D.; Schroeppel, Richard Crabtree; Robertson, Perry J.

    2004-10-01

    With the build-out of large transport networks utilizing optical technologies, more and more capacity is being made available. Innovations in Dense Wave Division Multiplexing (DWDM) and the elimination of optical-electrical-optical conversions have brought on advances in communication speeds as we move into 10 Gigabit Ethernet and above. Of course, there is a need to encrypt data on these optical links as the data traverses public and private network backbones. Unfortunately, as the communications infrastructure becomes increasingly optical, advances in encryption (done electronically) have failed to keep up. This project examines the use of optical logic for implementing encryption in the photonic domain to achieve the requisite encryption rates. This paper documents the innovations and advances of work first detailed in 'Photonic Encryption using All Optical Logic,' [1]. A discussion of underlying concepts can be found in SAND2003-4474. In order to realize photonic encryption designs, technology developed for electrical logic circuits must be translated to the photonic regime. This paper examines S-SEED devices and how discrete logic elements can be interconnected and cascaded to form an optical circuit. Because there is no known software that can model these devices at a circuit level, the functionality of S-SEED devices in an optical circuit was modeled in PSpice. PSpice allows modeling of the macro characteristics of the devices in context of a logic element as opposed to device level computational modeling. By representing light intensity as voltage, 'black box' models are generated that accurately represent the intensity response and logic levels in both technologies. By modeling the behavior at the systems level, one can incorporate systems design tools and a simulation environment to aid in the overall functional design. Each black box model takes certain parameters (reflectance, intensity, input response), and models the optical ripple

  19. A new and reliable animal model for optic nerve injury.

    Science.gov (United States)

    Yan, Hua; Li, Fengling; Zhang, Linlin

    2012-10-01

    To create an animal (rat) model of force percussion injury (FPI) to the optic nerve for clinical and experimental research. Seventy-one healthy female Wister rats, with no ocular disorders, were used in this study. Sixty-six rats were subjected to bilateral blunt trauma to the eyes via FPI; five rats were not subjected to trauma. According to the degree of optic nerve injury, injured eyes were divided into two groups: severe optic nerve injury group, with beat pressures of 699.14 ± 60.79 kPa and mild optic nerve injury group, with beat pressures of 243.18 ± 20.26 kPa. Eight rats were examined using flash visual-evoked potential (F-VEP) monitoring and magnetic resonance imaging (MRI) before, 1 and 3 days, and 1, 2, 4, 6, and 8 weeks after optic nerve injury. Fifty-six rats were examined by histopathology and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay for apoptosis at 1 and 3 days, and 1, 2, 4, 6, and 8 weeks after optic nerve injury. Two rats were examined by transmission electron microscopy (TEM) 4 and 8 weeks after optic nerve injury. The presence or absence of optic nerve injury was evaluated in all trauma eyes. Latency was prolonged in the severe injury group compared with controls 1 day after optic nerve injury (p nerve injury (p .05). Latency was prolonged in the mild optic nerve injury group compared with controls 1 day after optic nerve injury (p injury and then stabilized (p > .05). As measured by MRI, an abnormally high signal was seen 1 day after injury and remained significantly high 8 weeks after injury. A ruptured capillary was detected in the ganglion cell layer (GCL) 1 day after injury. Acellular regions in the ganglion cell layer were observed 4 weeks after optic nerve injury. TUNEL-positive cells were present in each layer of the retina 3 days after injury. The number of TUNEL-positive cells began to increase 1-2 weeks after injury, and then gradually decreased 4 weeks after injury (p nerve injury using

  20. Modeling illumination performance of plastic optical fiber passive daylighting system

    International Nuclear Information System (INIS)

    Sulaiman, F.; Ahmad, A.; Ahmed, A.Z.

    2006-01-01

    One of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings