WorldWideScience

Sample records for mid-infrared spectral survey

  1. Mid-Infrared Spectral Diagnostics of Luminous Infrared Galaxies

    CERN Document Server

    Petric, A O; Howell, J; Chan, B; Mazzarella, J M; Evans, A S; Surace, J A; Sanders, D; Appleton, P; Charmandaris, V; Santos, T Diaz; Frayer, D; Lord, S; Haan, S; Inami, H; Iwasawa, K; Kim, D; Madore, B; Marshall, J; Spoon, H; Stierwalt, S; Sturm, E; U, V; Vavilkin, T; Veilleux, S

    2010-01-01

    We present a statistical analysis of the mid-infrared (MIR) spectra of 248 luminous infrared (IR) galaxies (LIRGs) which comprise the Great Observatories All-sky LIRG Survey (GOALS) observed with the Infrared Spectrograph (IRS) on-board the Spitzer Space Telescope. The GOALS sample enables a direct measurement of the relative contributions of star-formation and active galactic nuclei (AGN) to the total IR emission from a large sample of local LIRGs. The AGN contribution to the MIR emission (f-AGN) is estimated by employing several diagnostics based on the properties of the [NeV], [OIV] and [NeII] fine structure gas emission lines, the 6.2 microns PAH and the shape of the MIR continuum. We find that 18% of all LIRGs contain an AGN and that in 10% of all sources the AGN contributes more than 50% of the total IR luminosity. Summing up the total IR luminosity contributed by AGN in all our sources suggests that AGN supply ~12% of the total energy emitted by LIRGs. The average spectrum of sources with an AGN looks ...

  2. Predictions for surveys with the SPICA Mid-infrared Instrument

    CERN Document Server

    Bonato, M; Cai, Z -Y; De Zotti, G; Bressan, A; Wada, T; Kohno, K; Maiolino, R; Gruppioni, C; Pozzi, F; Lapi, A

    2015-01-01

    We present predictions for number counts and redshift distributions of galaxies detectable in continuum and in emission lines with the Mid-infrared (MIR) Instrument (SMI) proposed for the Space Infrared Telescope for Cosmology and Astrophysics (SPICA). We have considered 24 MIR fine-structure lines, four Polycyclic Aromatic Hydrocarbon (PAH) bands (at 6.2, 7.7, 8.6 and 11.3$\\mu$m) and two silicate bands (in emission and in absorption) at 9.7$\\mu$m and 18.0$\\mu$m. Six of these lines are primarily associated with Active Galactic Nuclei (AGNs), the others with star formation. A survey with the SMI spectrometers of 1 hour integration per field-of-view (FoV) over an area of $1\\,\\hbox{deg}^2$ will yield $5\\,\\sigma$ detections of $\\simeq 140$ AGN lines and of $\\simeq 5.2\\times10^{4}$ star-forming galaxies, $\\simeq 1.6\\times10^{4}$ of which will be detected in at least two lines. The combination of a shallow ($20.0\\,\\hbox{deg}^{2}$, $1.4\\times10^{-1}$ h integration per FoV) and a deep survey ($6.9\\times10^{-3}\\,\\hbox...

  3. NIR Capturing images with spectral information in the mid-infrared

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    We demonstrate a method to capture images containing spectral information in the infrared. The method is based on sum frequency mixing of light, which allows for transformation of mid-infrared radiation to near visible light, allowing for use of a regular silicon based camera for detection. Combi...

  4. Spectral calibration in the mid-infrared: Challenges and solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sloan, G. C. [Cornell University, Center for Radiophysics and Space Research, Ithaca, NY 14853-6801 (United States); Herter, T. L.; Houck, J. R. [Cornell University, Astronomy Department, Ithaca, NY 14853-6801 (United States); Charmandaris, V. [Department of Physics and ITCP, University of Crete, GR-71003, Heraklion (Greece); Sheth, K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Burgdorf, M., E-mail: sloan@isc.astro.cornell.edu [HE Space Operations, Flughafenallee 24, D-28199 Bremen (Germany)

    2015-01-01

    We present spectra obtained with the Infrared Spectrograph on the Spitzer Space Telescope of 33 K giants and 20 A dwarfs to assess their suitability as spectrophotometric standard stars. The K giants confirm previous findings that the strength of the SiO absorption band at 8 μm increases for both later optical spectral classes and redder (B–V){sub 0} colors, but with considerable scatter. For K giants, the synthetic spectra underpredict the strengths of the molecular bands from SiO and OH. For these reasons, the assumed true spectra for K giants should be based on the assumption that molecular band strengths in the infrared can be predicted accurately from neither optical spectral class or color nor synthetric spectra. The OH bands in K giants grow stronger with cooler stellar temperatures, and they are stronger than predicted by synthetic spectra. As a group, A dwarfs are better behaved and more predictable than the K giants, but they are more likely to show red excesses from debris disks. No suitable A dwarfs were located in parts of the sky continuously observable from Spitzer, and with previous means of estimating the true spectra of K giants ruled out, it was necessary to use models of A dwarfs to calibrate spectra of K giants from observed spectral ratios of the two groups and then use the calibrated K giants as standards for the full database of infrared spectra from Spitzer. We also describe a lingering artifact that affects the spectra of faint blue sources at 24 μm.

  5. Spectral Calibration in the Mid-Infrared: Challenges and Solutions

    CERN Document Server

    Sloan, G C; Charmandaris, V; Sheth, K; Burgdorf, M; Houck, J R

    2014-01-01

    We present spectra obtained with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope of 33 K giants and 20 A dwarfs to assess their suitability as spectrophotometric standard stars. The K giants confirm previous findings that the strength of the SiO absorption band at 8 um increases for both later optical spectral classes and redder (B-V)_0 colors, but with considerable scatter. For K giants, the synthetic spectra underpredict the strengths of the molecular bands from SiO and OH. For these reasons, the assumed true spectra for K giants should be based on neither the assumption that molecular band strengths in the infrared can be predicted accurately from optical spectral class or color nor synthetric spectra. The OH bands in K giants grow stronger with cooler stellar temperatures, and they are stronger than predicted by synthetic spectra. As a group, A dwarfs are better behaved and more predictable than the K giants, but they are more likely to show red excesses from debris disks. No suitable A dwa...

  6. Spatio-temporal characterization of mid-infrared laser pulses with spatially encoded spectral shearing interferometry

    CERN Document Server

    Witting, Tobias; Tisch, John W G; Marangos, Jonathan P

    2012-01-01

    We report on the spatially resolved full amplitude and phase characterization of mid-infrared high intensity laser pulses generated in a three stage OPA. We use a spatially-encoded arrangement (SEA-)SPIDER with spectral filters for ancilla generation for spatially resolved characterization. Using five interchangeable filter sets we are able to characterize pulses from 1 to 2{\\mu}m with one single device with minimal adjustments.

  7. Spectral principal component analysis of mid-infrared spectra of a sample of PG QSOs

    CERN Document Server

    Bian, Wei-Hao; Green, Richard; Shi, Yong; Ge, Xue; Liu, Wen-Shuai

    2015-01-01

    A spectral principal component analysis (SPCA) of a sample of 87 PG QSOs at $z < 0.5$ is presented for their mid-infrared spectra from Spitzer Space Telescope. We have derived the first five eigenspectra, which account for 85.2\\% of the mid-infrared spectral variation. It is found that the first eigenspectrum represents the mid-infrared slope, forbidden emission line strength and $9.7~\\mu m$ silicate feature, the 3rd and 4th eigenspectra represent the silicate features at $18~ \\mu m$ and $9.7~\\mu m$, respectively. With the principal components (PC) from optical PCA, we find that there is a medium strong correlation between spectral SPC1 and PC2 (accretion rate). It suggests that more nuclear contribution to the near-IR spectrum leads to the change of mid-IR slope. We find mid-IR forbidden lines are suppressed with higher accretion rate. A medium strong correlation between SPC3 and PC1 (Eddington ratio) suggests a connection between the silicate feature at $18~\\mu m$ and the Eddington ratio. For the ratio o...

  8. Inference of Surface Chemical and Physical Properties Using Mid-Infrared (MIR) Spectral Observations

    Science.gov (United States)

    Roush, Ted L.

    2016-01-01

    Reflected or emitted energy from solid surfaces in the solar system can provide insight into thermo-physical and chemical properties of the surface materials. Measurements have been obtained from instruments located on Earth-based telescopes and carried on several space missions. The characteristic spectral features commonly observed in Mid-Infrared (MIR) spectra of minerals will be reviewed, along with methods used for compositional interpretations of MIR emission spectra. The influence of surface grain size, and space weathering processes on MIR emissivity spectra will also be discussed. Methods used for estimating surface temperature, emissivity, and thermal inertias from MIR spectral observations will be reviewed.

  9. The Bolocam Galactic Plane Survey. VIII. A Mid-Infrared Kinematic Distance Discrimination Method

    CERN Document Server

    Ellsworth-Bowers, Timothy P; Rosolowsky, Erik; Mairs, Steven; Evans, Neal J; Battersby, Cara; Ginsburg, Adam; Shirley, Yancy L; Bally, John

    2013-01-01

    We present a new distance estimation method for dust-continuum-identified molecular cloud clumps. Recent (sub-)millimeter Galactic plane surveys have cataloged tens of thousands of these objects, but detailed study of their physical properties requires robust distance determinations. We derive Bayesian distance probability density functions (DPDFs) for 770 objects from the Bolocam Galactic Plane Survey in the longitude range 7.5 < l < 65. The DPDF formalism is based on kinematic distances, and uses external data sets to place prior distance probabilities to resolve the kinematic distance ambiguity (KDA) for objects in the inner Galaxy. We present priors related to the mid-infrared absorption of dust in dense molecular regions and the Galactic distribution of molecular gas. By assuming a numerical model of Galactic mid-infrared emission and simple radiative transfer, we match the morphology of millimeter thermal dust emission with mid-infrared absorption to compute a prior DPDF for distance discriminatio...

  10. THE BOLOCAM GALACTIC PLANE SURVEY. VIII. A MID-INFRARED KINEMATIC DISTANCE DISCRIMINATION METHOD

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth-Bowers, Timothy P.; Glenn, Jason; Battersby, Cara; Ginsburg, Adam; Bally, John [CASA, University of Colorado, UCB 389, University of Colorado, Boulder, CO 80309 (United States); Rosolowsky, Erik [Department of Physics and Astronomy, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7 (Canada); Mairs, Steven [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 1A1 (Canada); Evans, Neal J. II [Department of Astronomy, University of Texas, 1 University Station C1400, Austin, TX 78712 (United States); Shirley, Yancy L., E-mail: timothy.ellsworthbowers@colorado.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2013-06-10

    We present a new distance estimation method for dust-continuum-identified molecular cloud clumps. Recent (sub-)millimeter Galactic plane surveys have cataloged tens of thousands of these objects, plausible precursors to stellar clusters, but detailed study of their physical properties requires robust distance determinations. We derive Bayesian distance probability density functions (DPDFs) for 770 objects from the Bolocam Galactic Plane Survey in the Galactic longitude range 7. Degree-Sign 5 {<=} l {<=} 65 Degree-Sign . The DPDF formalism is based on kinematic distances, and uses any number of external data sets to place prior distance probabilities to resolve the kinematic distance ambiguity (KDA) for objects in the inner Galaxy. We present here priors related to the mid-infrared absorption of dust in dense molecular regions and the distribution of molecular gas in the Galactic disk. By assuming a numerical model of Galactic mid-infrared emission and simple radiative transfer, we match the morphology of (sub-)millimeter thermal dust emission with mid-infrared absorption to compute a prior DPDF for distance discrimination. Selecting objects first from (sub-)millimeter source catalogs avoids a bias towards the darkest infrared dark clouds (IRDCs) and extends the range of heliocentric distance probed by mid-infrared extinction and includes lower-contrast sources. We derive well-constrained KDA resolutions for 618 molecular cloud clumps, with approximately 15% placed at or beyond the tangent distance. Objects with mid-infrared contrast sufficient to be cataloged as IRDCs are generally placed at the near kinematic distance. Distance comparisons with Galactic Ring Survey KDA resolutions yield a 92% agreement. A face-on view of the Milky Way using resolved distances reveals sections of the Sagittarius and Scutum-Centaurus Arms. This KDA-resolution method for large catalogs of sources through the combination of (sub-)millimeter and mid-infrared observations of molecular

  11. An Atlas of Galaxy Spectral Energy Distributions from the Ultraviolet to the Mid-Infrared

    CERN Document Server

    Brown, Michael J I; Smith, J -D T; da Cunha, Elisabete; Jarrett, T H; Imanishi, Masatoshi; Armus, Lee; Brandl, Bernhard R; Peek, J E G

    2013-01-01

    We present an atlas of 129 spectral energy distributions for nearby galaxies, with wavelength coverage spanning from the UV to the mid-infrared. Our atlas spans a broad range of galaxy types, including ellipticals, spirals, merging galaxies, blue compact dwarfs and luminous infrared galaxies. We have combined ground-based optical drift-scan spectrophotometry with infrared spectroscopy from Spitzer and Akari, with gaps in spectral coverage being filled using MAGPHYS spectral energy distribution models. The spectroscopy and models were normalized, constrained and verified with matched-aperture photometry measured from Swift, GALEX, SDSS, 2MASS, Spitzer and WISE images. The availability of 26 photometric bands allowed us to identify and mitigate systematic errors present in the data. Comparison of our spectral energy distributions with other template libraries and the observed colors of galaxies indicates that we have smaller systematic errors than existing atlases, while spanning a broader range of galaxy types...

  12. Mid-infrared observations of O-type stars: spectral morphology

    Science.gov (United States)

    Marcolino, W. L. F.; Bouret, J.-C.; Lanz, T.; Maia, D. S.; Audard, M.

    2017-09-01

    We present mid-infrared (mid-IR) observations for a sample of 16 O-type stars. The data were acquired with the NASA Spitzer Space Telescope, using the IRS instrument at moderate resolution (R ∼ 600), covering the range of ∼10-37 μm. Our sample includes early, mid and late O supergiants and dwarfs. We explore for the first time their mid-IR spectral morphology in a quantitative way. We use NLTE expanding atmosphere models to help with line identifications, analyse profile contributions and line-formation regions. The O supergiants present a rich emission line spectra. The most intense features are from hydrogen - 6 α, 7 α and 8 α - that have non-negligible contributions of He i or He ii lines, depending on the spectral type. The spectrum of early O supergiants is a composite of H i and He ii lines, He i lines being absent. On the other hand, late O supergiants present features composed mainly by H i and He i lines. All emission lines are formed throughout the stellar wind. We found that O dwarfs exhibit a featureless mid-IR spectrum. Two stars of our sample exhibit very similar mid-IR features, despite having a very different optical spectral classification. The analysis of O-type stars based on mid-IR spectra alone to infer spectral classes or to estimate physical parameters may thus be prone to substantial errors. Our results may therefore inform spectroscopic observations of massive stars located in heavily obscured regions and help establish an initial framework for observations of massive stars using the Mid-Infrared Instrument on the James Webb Space Telescope.

  13. Analytical modeling and ATLAS simulation for a homojunction LED in the mid-infrared spectral region

    Institute of Scientific and Technical Information of China (English)

    Sanjeev; P. Chakrabarti

    2009-01-01

    A generic analytical model and the ATLAS simulation of a homojunction light emitting diode (LED) based on p+-InAso0 91Sb0.09/n0-InAs0.91Sb0.09/n+-InAs0.91Sb0.09 materials grown on lattice matched p+-GaSb substrate are presented. This LED is suitable for use as source in the optical absorption gas spectroscopy in the mid-infrared spectral region at 300 K. The various electro-optical properties of the homojunction LED are evaluated using analytical techniques and ATLAS device simulation software. The current-voltage characteristics of the structure are computed analytically and simulated, and the results are found to be in good agreement. The output power of the homojunction LED is estimated as a function of bias current under high carrier injection and compared with the reported experimental results.

  14. Spectral cullet classification in the mid-infrared field for ceramic glass contaminants detection.

    Science.gov (United States)

    Serranti, Silvia; Bonifazi, Giuseppe; Pohl, Roland

    2006-02-01

    The presence of glass-like contaminants inside waste glass products, usually resulting from both industrial and differentiated urban waste collection, has greatly increased in recent years, due to the introduction to the market of a large amount of goods manufactured from ceramic glass. The presence of contaminants in the glass recycling streams reduces product quality and increases production costs. The detection of ceramic glass detection is an unresolved problem, as such material looks like normal glass and can only be detected by trained personnel. In this study an innovative approach to ceramic glass recognition, based on the spectral signature in the mid-infrared (MIR) field, was proposed and investigated. The study specifically addressed the spectral characterization of glass and ceramic glass fragments collected in a real recycling plant from two different production lines: coloured container glass and white container glass. To define suitable inspection strategies to separate the useful (glass) from the polluting (ceramic glass) materials at the recycling plants, fragments presenting different colour, thickness, size, shape and manufacturing were selected. Both dirty and clean cullet was considered. The analyses, carried out in the MIR spectral field (2280-4480 nm), show that ceramic glass and glass fragments can be recognized according to their different spectral signature. In particular, by selecting a specific wavelength ratio the two classes of materials can be rapidly recognized, suggesting the possibility of developing an integrated hardware and software sorting system for 'on-line' ceramic glass separation.

  15. A Ground-Based Mid-Infrared Imaging Survey of Embedded Young Stellar Objects in the Rho Ophiuchi Cloud Core

    Science.gov (United States)

    Barsony, M.; Ressler, M. E.; Marsh, K. A.

    2004-12-01

    Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the ρ Ophiuchi cloud are presented. Data were acquired at the Palomar 5-m and at the Keck 10-m telescopes with the MIRLIN and LWS instruments, at 0.5'' and 0.25'' resolutions, respectively. Of 172 survey objects, 85 were detected. A plot of the frequency distribution of the detected objects with SED spectral slope shows that YSOs spend ˜ 3 × 105 yr in the Flat Spectrum phase, clearing out their remnant infall envelopes. Mid-infrared variability is found among a significant fraction of the surveyed objects and is found to occur for all SED classes with optically thick disks. Large amplitude near-infrared variability, also found for all SED classes with optically thick disks, seems to occur with somewhat higher frequency at the earlier evolutionary stages. The highly variable value of K-band veiling that a single source can exhibit in any of the SED classes in which active disk accretion can take place is striking, and is direct observational evidence for highly time-variable accretion activity in disks. Finallly, by comparing mid-infrared vs. near-infrared excesses in a subsample with well-determined effective temperatures and extinction values, disk clearing mechanisms are explored. Financial support for this project through NSF grants AST 00-96087 (CAREER), AST 97-53229 (POWRE), and AST 02-06146 is gratefully acknowledged. MB further thanks the NASA/ASEE Summer Faculty Fellowship program at JPL, that made this work possible.

  16. A Mid-Infrared Imaging Survey of Embedded Young Stellar Objects in the Rho Ophiuchi Cloud Core

    CERN Document Server

    Barsony, M; Marsh, K A; Barsony, Mary; Ressler, Michael E.; Marsh, Kenneth A.

    2005-01-01

    Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the Rho Ophiuchi cloud are presented. Data were acquired at the Palomar 5-m and at the Keck 10-m telescopes with the MIRLIN and LWS instruments, at 0.25 arcsec and 0.25 arcsec resolutions, respectively. Of 172 survey objects, 85 were detected. Among the 22 multiple systems observed, 15 were resolved and their individual component fluxes determined. A plot of the frequency distribution of the detected objects with SED spectral slope shows that YSOs spend ~400,000 yr in the Flat Spectrum phase, clearing out their remnant infall envelopes. Mid-infrared variability is found among a significant fraction of the surveyed objects, and is found to occur for all SED classes with optically thick disks. Large-amplitude near-infrared variability, also found for all SED classes with optically thick disks, seems to occur with somewhat higher frequency at the earlier evolutionary stages. Although a general trend of mi...

  17. The Spitzer mid-infrared AGN survey. I - optical and near-infrared spectroscopy of candidate obscured and normal AGN selected in the mid-infrared

    CERN Document Server

    Lacy, M; Gates, E L; Nielsen, D M; Petric, A O; Sajina, A; Urrutia, T; Drews, S Cox; Harrison, C; Seymour, N; Storrie-Lombardi, L J

    2013-01-01

    We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate Active Galactic Nuclei (AGN) selected in the mid-infrared. This survey selects both normal and obscured AGN closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L_bol~10^10L_sun, to highly luminous quasars (L_bol~10^14L_sun), and with redshifts from 0-4.3. Samples of candidate AGN were selected through mid-infrared color cuts at several different 24 micron flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGN and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type-1 AGN with blue continua, 294 (44%) are type-2 objects with extinctions A_V>~5 towards their AGN, 96 (14%) are AGN with lower extinctions (A_V~1) and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. 50% of the survey objects have L_bol >10^12L_sun, in the quasar ...

  18. Mid-Infrared Luminosity Function of Local Star-Forming Galaxies in the NEP-Wide Survey Field of AKARI

    CERN Document Server

    Kim, Seong Jin; Jeong, Woong-Seob; Goto, Tomotsugu; Matsuhara, Hideo; Im, Myungshin; Shim, Hyunjin; Kim, Min Gyu; Lee, Myung Gyoon

    2015-01-01

    We present mid-infrared (MIR) luminosity functions (LFs) of local star-forming (SF) galaxies in the AKARI NEP-Wide Survey field. In order to derive more accurate luminosity function, we used spectroscopic sample only. Based on the NEP-Wide point source catalogue containing a large number of infrared (IR) sources distributed over the wide (5.4 sq. deg.) field, we incorporated the spectroscopic redshift data for about 1790 selected targets obtained by optical follow-up surveys with MMT/Hectospec and WIYN/Hydra. The AKARI continuous 2 to 24 micron wavelength coverage as well as photometric data from optical u band to NIR H-band with the spectroscopic redshifts for our sample galaxies enable us to derive accurate spectral energy distributions (SEDs) in the mid-infrared. We carried out SED fit analysis and employed 1/Vmax method to derive the MIR (8, 12, and 15 micron rest-frame) luminosity functions. We fit our 8 micron LFs to the double power-law with the power index of alpha= 1.53 and beta= 2.85 at the break lu...

  19. Group delay dispersion measurements in the mid-infrared spectral range of 2-20 µm.

    Science.gov (United States)

    Habel, Florian; Trubetskov, Michael; Pervak, Vladimir

    2016-07-25

    We present two measurement devices which both allow the direct measurement of the group delay (GD) and group delay dispersion (GDD) of laser optics, covering the near- and mid-infrared (MIR) spectral range from 2 to 20 µm (500-5,000 cm-1). Two different kinds of devices were developed to measure the GDD of multilayer interference coatings. One is a resonant scanning interferometer (RSI) and the other is a white light interferometer (WLI). The WLI is also capable of measuring the GDD in transmission, for instance of bulk material. GDD measurements of a high dispersive mirror for wavelengths from 2.0 to 2.15 µm and one of a multilayer mirror from 8.5 to 12.0 µm are presented. A measurement of a zinc selenide (ZnSe) substrate in transmission was made with the WLI demonstrating the full bandwidth of the device from 1.9 to 20 µm. The comparison of all measurements with their related theoretical values shows a remarkable correspondence.

  20. Mid-Infrared Spectral Indicators of Star-Formation and AGN Activity in Normal Galaxies

    CERN Document Server

    Treyer, Marie; Schiminovich, David; O'Dowd, Matt

    2010-01-01

    We investigate the use of mid-infrared PAH bands, continuum and emission lines as probes of star-formation and AGN activity in a sample of 100 `normal' and local (z~0.1) galaxies. The MIR spectra were obtained with the Spitzer IRS as part of the Spitzer-SDSS-GALEX Spectroscopic Survey (SSGSS) which includes multi-wavelength photometry from the UV to the FIR and optical spectroscopy. The spectra were decomposed using PAHFIT (Smith et al. 2007), which we find to yield PAH equivalent widths (EW) up to ~30 times larger than the commonly used spline methods. Based on correlations between PAH, continuum and emission line properties and optically derived physical properties (gas phase metallicity, radiation field hardness), we revisit the diagnostic diagram relating PAH EWs and [NeII]/[OIV] and find it more efficient as distinguishing weak AGNs from star-forming galaxies than when spline decompositions are used. The luminosity of individual MIR component (PAH, continuum, Ne and molecular hydrogen lines) are found to...

  1. CONSTRAINING THE EXOZODIACAL LUMINOSITY FUNCTION OF MAIN-SEQUENCE STARS: COMPLETE RESULTS FROM THE KECK NULLER MID-INFRARED SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Mennesson, B.; Serabyn, E.; Colavita, M. M.; Bryden, G.; Doré, O.; Traub, W. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Millan-Gabet, R. [NASA Exoplanet Science Center, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Absil, O. [Département d' Astrophysique, Géophysique et Océanographie, Université de Liège, 17 Allée du Six Août, 4000 Liège (Belgium); Wyatt, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Danchi, W.; Kuchner, M.; Stapelfeldt, K. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Defrère, D.; Hinz, P. [Steward Observatory, Department of Astronomy, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Ragland, S. [Keck Observatory, 65-1120 Mamalahoa Highway, Kamuela, HI 96743 (United States); Scott, N. [Center for High Angular Resolution Astronomy, Georgia State University, Mount Wilson, CA 91023 (United States); Woillez, J., E-mail: Bertrand.Mennesson@jpl.nasa.gov [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Munchen (Germany)

    2014-12-20

    Forty-seven nearby main-sequence stars were surveyed with the Keck Interferometer mid-infrared Nulling instrument (KIN) between 2008 and 2011, searching for faint resolved emission from exozodiacal dust. Observations of a subset of the sample have already been reported, focusing essentially on stars with no previously known dust. Here we extend this previous analysis to the whole KIN sample, including 22 more stars with known near- and/or far-infrared excesses. In addition to an analysis similar to that of the first paper of this series, which was restricted to the 8-9 μm spectral region, we present measurements obtained in all 10 spectral channels covering the 8-13 μm instrumental bandwidth. Based on the 8-9 μm data alone, which provide the highest signal-to-noise measurements, only one star shows a large excess imputable to dust emission (η Crv), while four more show a significant (>3σ) excess: β Leo, β UMa, ζ Lep, and γ Oph. Overall, excesses detected by KIN are more frequent around A-type stars than later spectral types. A statistical analysis of the measurements further indicates that stars with known far-infrared (λ ≥ 70 μm) excesses have higher exozodiacal emission levels than stars with no previous indication of a cold outer disk. This statistical trend is observed regardless of spectral type and points to a dynamical connection between the inner (zodi-like) and outer (Kuiper-Belt-like) dust populations. The measured levels for such stars are clustering close to the KIN detection limit of a few hundred zodis and are indeed consistent with those expected from a population of dust that migrated in from the outer belt by Poynting-Robertson drag. Conversely, no significant mid-infrared excess is found around sources with previously reported near-infrared resolved excesses, which typically have levels of the order of 1% over the photospheric flux. If dust emission is really at play in these near-infrared detections, the absence of a strong mid-infrared

  2. A Spitzer survey of mid-infrared molecular emission from protoplanetary disks I: Detection rates

    CERN Document Server

    Pontoppidan, Klaus M; Blake, Geoffrey A; Meijerink, Rowin; Carr, John S; Najita, Joan

    2010-01-01

    We present a Spitzer InfraRed Spectrometer search for 10-36 micron molecular emission from a large sample of protoplanetary disks, including lines from H2O, OH, C2H2, HCN and CO2. This paper describes the sample and data processing and derives the detection rate of mid-infrared molecular emission as a function of stellar mass. The sample covers a range of spectral type from early M to A, and is supplemented by archival spectra of disks around A and B stars. It is drawn from a variety of nearby star forming regions, including Ophiuchus, Lupus and Chamaeleon. In total, we identify 22 T Tauri stars with strong mid-infrared H2O emission. Integrated water line luminosities, where water vapor is detected, range from 5x10^-4 to 9x10^-3 Lsun, likely making water the dominant line coolant of inner disk surfaces in classical T Tauri stars. None of the 5 transitional disks in the sample show detectable gaseous molecular emission with Spitzer upper limits at the 1% level in terms of line-to-continuum ratios (apart from H...

  3. Prediction of Soil Fertility Properties from a Globally Distributed Soil Mid-Infrared Spectral Library

    NARCIS (Netherlands)

    Terhoeven-Urselmans, T.; Vagen, T.G.; Spaargaren, O.; Shepherd, K.D.

    2010-01-01

    Globally applicable calibrations to predict standard soil properties based on infrared spectra may increase the use of this reliable technique. The objective of this study was to evaluate the ability of mid-infrared diffuse reflectance spectroscopy (4000-602 cm(-1)) to predict chemical and textural

  4. Mid-infrared Spectral Indicators of Star Formation and Active Galactic Nucleus Activity in Normal Galaxies

    NARCIS (Netherlands)

    Treyer, Marie; Schiminovich, David; Johnson, Benjamin D.; O'Dowd, Matt; Martin, Christopher D.; Wyder, Ted; Charlot, Stephane; Heckman, Timothy; Martins, Lucimara; Seibert, Mark; van der Hulst, J. M.

    2010-01-01

    We investigate the use of mid-infrared (MIR) polycyclic aromatic hydrocarbon (PAH) bands, the continuum, and emission lines as probes of star formation (SF) and active galactic nucleus (AGN) activity in a sample of 100 "normal" and local (z similar to 0.1) emission-line galaxies. The MIR spectra wer

  5. Study on the mechanism of human blood glucose concentration measuring using mid-infrared spectral analysis technology

    Science.gov (United States)

    Li, Xiang

    2016-10-01

    All forms of diabetes increase the risk of long-term complications. Blood glucose monitoring is of great importance for controlling diabetes procedure, preventing the complications and improving the patient's life quality. At present, the clinical blood glucose concentration measurement is invasive and could be replaced by noninvasive spectroscopy analytical techniques. The mid-infrared spectral region contains strong characteristic and well-defined absorption bands. Therefore, mid-infrared provides an opportunity for monitoring blood glucose invasively with only a few discrete bonds. Although the blood glucose concentration measurement using mid-infrared spectroscopy has a lot of advantages, the disadvantage is also obvious. The absorption in this infrared region is fundamental molecular group vibration. Absorption intensity is very strong, especially for biological molecules. In this paper, it figures out that the osmosis rate of glucose has a certain relationship with the blood glucose concentration. Therefore, blood glucose concentration could be measured indirectly by measuring the glucose exudate in epidermis layer. Human oral glucose tolerance tests were carried out to verify the correlation of glucose exudation in shallow layer of epidermis layer and blood glucose concentration. As it has been explained above, the mid-infrared spectral region contains well-defined absorption bands, the intensity of absorption peak around 1123 cm-1 was selected to measure the glucose and that around 1170 cm-1 was selected as reference. Ratio of absorption peak intensity was recorded for each set of measurement. The effect and importance of the cleaning the finger to be measured before spectrum measuring are discussed and also verified by experiment.

  6. Mid-Infrared Lasers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mid Infrared DIAL systems can provide vital data needed by atmospheric scientists to understand atmospheric chemistry. The Decadal Survey recommended missions, such...

  7. A Mid-Infrared Census of Star Formation Activity in Bolocam Galactic Plane Survey Sources

    CERN Document Server

    Dunham, Miranda K; Evans, Neal J; Schlingman, Wayne M; Cyganowski, Claudia J; Urquhart, James

    2011-01-01

    We present the results of a search for mid-infrared signs of star formation activity in the 1.1 mm sources in the Bolocam Galactic Plane Survey (BGPS). We have correlated the BGPS catalog with available mid-IR Galactic plane catalogs based on the Spitzer Space Telescope GLIMPSE legacy survey and the Midcourse Space Experiment (MSX) Galactic plane survey. We find that 44% (3,713 of 8,358) of the BGPS sources contain at least one mid-IR source, including 2,458 of 5,067 (49%) within the area where all surveys overlap (10 deg < l < 65 deg). Accounting for chance alignments between the BGPS and mid-IR sources, we conservatively estimate that 20% of the BPGS sources within the area where all surveys overlap show signs of active star formation. We separate the BGPS sources into four groups based on their probability of star formation activity. Extended Green Objects (EGOs) and Red MSX Sources (RMS) make up the highest probability group, while the lowest probability group is comprised of "starless" BGPS sources...

  8. The AKARI/IRC Mid-Infrared All-Sky Survey

    CERN Document Server

    Ishihara, Daisuke; Kataza, Hirokazu; Salama, Alberto; Alfageme, Carlos; Cassatella, Angelo; Cox, Nick; Garcia-Lario, Pedro; Stephenson, Craig; Cohen, Martin; Fujishiro, Naofumi; Fujiwara, Hideaki; Hasegawa, Sunao; Ita, Yoshifusa; Kim, Woojung; Matsuhara, Hideo; Murakami, Hiroshi; Muller, Thomas G; Nakagawa, Takao; Ohyama, Youichi; Oyabu, Shinki; Pyo, Jeonghyun; Sakon, Itsuki; Shibai, Hiroshi; Takita, Satoshi; Tanabe, Toshihiko; Uemizu, Kazunori; Ueno, Munetaka; Usui, Fumihiko; Wada, Takehiko; Watarai, Hiden ori; Yamamura, Issei; Yamauchi, Chisato

    2010-01-01

    Context : AKARI is the first Japanese astronomical satellite dedicated to infrar ed astronomy. One of the main purposes of AKARI is the all-sky survey performed with six infrared bands between 9 and 200um during the period from 2006 May 6 to 2007 August 28. In this paper, we present the mid-infrared part (9um and 18um b ands) of the survey carried out with one of the on-board instruments, the Infrar ed Camera (IRC). Aims : We present unprecedented observational results of the 9 and 18um AKARI al l-sky survey and detail the operation and data processing leading to the point s ource detection and measurements. Methods : The raw data are processed to produce small images for every scan and point sources candidates, above the 5-sigma noise level per single scan, are der ived. The celestial coordinates and fluxes of the events are determined statisti cally and the reliability of their detections is secured through multiple detect ions of the same source within milli-seconds, hours, and months from each other. Resu...

  9. Mid-Infrared Variability from the Spitzer Deep, Wide-Field Survey

    CERN Document Server

    Kozlowski, Szymon; Stern, Daniel; Ashby, Matthew L N; Assef, Roberto J; Bock, J J; Borys, C; Brand, K; Brodwin, M; Brown, M J I; Cool, R; Cooray, A; Croft, S; Dey, Arjun; Eisenhardt, P R; Gonzalez, A; Gorjian, V; Griffith, R; Grogin, N; Ivison, R; Jacob, J; Jannuzi, B T; Mainzer, A; Moustakas, L; Rottgering, H; Seymour, N; Smith, H A; Stanford, S A; Stauffer, J R; Sullivan, I S; van Breugel, W; Willner, S P; Wright, E L

    2010-01-01

    We use the multi-epoch, mid-infrared Spitzer Deep, Wide-Field Survey to investigate the variability of 474,179 objects in 8.1 deg^2 of the NDWFS Bootes field. We perform a Difference Image Analysis of the four available epochs between 2004 and 2008, focusing on the deeper 3.6 and 4.5 micron bands. We find that 1.1% of the studied sample meet our standard selection criteria for being classed as a variable source. We require that the 3.6 and 4.5 micron light-curves are strongly correlated (r>0.8) and that their joint variance exceeds that for all sources with the same magnitude by 2 sigma. We then examine the mid-IR colors of the variable sources and match them with X-ray sources from the XBootes survey, radio catalogs, 24 micron-selected AGN candidates, and spectroscopically identified AGNs from the AGN and Galaxy Evolution Survey (AGES). Based on their mid-IR colors, most of the variable sources are AGNs (76%), with smaller contributions from stars (11%), galaxies (6%), and unclassified objects. Most of the s...

  10. Spectral and Imaging Observations of a White-light Flare in the Mid-Infrared

    CERN Document Server

    Penn, M; Hudson, H; Jhabvala, M; Jennings, D; Lunsford, A; Kaufmann, P

    2015-01-01

    We report high-resolution observations at mid-infrared wavelengths of a minor solar flare, SOL2014-09-24T17T17:50 (C7.0), using Quantum Well Infrared Photodetector (QWIP) cameras at an auxiliary of the McMath-Pierce telescope. The flare emissions, the first simultaneous observations in two mid-infrared bands at $5\\ \\mu$m and $8\\ \\mu$m with white-light and hard X-ray coverage, revealed impulsive time variability with increases on time scales of $\\sim 4$~s followed by exponential decay at $\\sim$10 s in two bright regions separated by about 13$"$. The brightest source is compact, unresolved spatially at the diffraction limit ($1.3"$ at $5\\ \\mu$m). We identify the IR sources as flare ribbons also seen in white-light emission at 6173~\\AA~observed by SDO/HMI, with twin hard X-ray sources observed by RHESSI, and with EUV sources (e.g., 94~\\AA) observed by SDO/AIA. The two infrared points have closely the same flux density ($f_\

  11. AcuA: the AKARI/IRC Mid-infrared Asteroid Survey

    CERN Document Server

    Usui, Fumihiko; Mueller, Thomas G; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; Ishihara, Daisuke; Kataza, Hirokazu; Takita, Satoshi; Oyabu, Shinki; Ueno, Munetaka; Matsuhara, Hideo; Onaka, Takashi

    2011-01-01

    We present the results of an unbiased asteroid survey in the mid-infrared wavelength with the Infrared Camera (IRC) onboard the Japanese infrared satellite AKARI. About 20% of the point source events recorded in the AKARI All-Sky Survey observations are not used for the IRC Point Source Catalog (IRC-PSC) in its production process because of the lack of multiple detection by position. Asteroids, which are moving objects on the celestial sphere, remain in these "residual events". We identify asteroids out of the residual events by matching them with the positions of known asteroids. For the identified asteroids, we calculate the size and albedo based on the Standard Thermal Model. Finally we have a brand-new catalog of asteroids, named the Asteroid Catalog Using Akari (AcuA), which contains 5,120 objects, about twice as many as the IRAS asteroid catalog. The catalog objects comprise 4,953 main belt asteroids, 58 near Earth asteroids, and 109 Jovian Trojan asteroids. The catalog will be publicly available via th...

  12. Towards the mid-infrared optical biopsy

    DEFF Research Database (Denmark)

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

    2016-01-01

    We are establishing a new paradigm in mid-infrared molecular sensing, mapping and imaging to open up the mid-infrared spectral region for in vivo (i.e. in person) medical diagnostics and surgery. Thus, we are working towards the mid-infrared optical biopsy ('opsy' look at, bio the biology) in situ...... of a bright mid-infrared wideband source in a portable package as a first step for medical fiber-based systems operating in the mid-infrared. Moreover, mid-infrared molecular mapping and imaging is potentially a disruptive technology to give improved monitoring of the environment, energy efficiency, security...

  13. Identification of Spectral Regions for Quantification of Red Wine Tannins with Fourier Transform Mid-Infrared Spectroscopy

    DEFF Research Database (Denmark)

    Jensen, Jacob Skibsted; Egebo, Max; Meyer, Anne S.

    2008-01-01

    Accomplishment of fast tannin measurements is receiving increased interest as tannins are important for the mouthfeel and color properties of red wines. Fourier transform mid-infrared spectroscopy allows fast measurement of different wine components, but quantification of tannins is difficult due...... to interferences from spectral responses of other wine components. Four different variable selection tools were investigated for the identification of the most important spectral regions which would allow quantification of tannins from the spectra using partial least-squares regression. The study included...... to be particularly important for tannin quantification. The spectral regions identified from the variable selection methods were used to develop calibration models. All four variable selection methods identified regions that allowed an improved quantitative prediction of tannins (RMSEP = 69−79 mg of CE/L; r = 0...

  14. Bridging the Mid-Infrared-to-Telecom Gap with Silicon Nanophotonic Spectral Translation

    CERN Document Server

    Liu, Xiaoping; Roelkens, Gunther; Baets, Roel; Osgood, Richard M; Green, William M J

    2012-01-01

    Expanding far beyond traditional applications in optical interconnects at telecommunications wavelengths, the silicon nanophotonic integrated circuit platform has recently proven its merits for working with mid-infrared (mid-IR) optical signals in the 2-8 {\\mu}m range. Mid-IR integrated optical systems are capable of addressing applications including industrial process and environmental monitoring, threat detection, medical diagnostics, and free-space communication. Rapid progress has led to the demonstration of various silicon components designed for the on-chip processing of mid-IR signals, including waveguides, vertical grating couplers, microcavities, and electrooptic modulators. Even so, a notable obstacle to the continued advancement of chip-scale systems is imposed by the narrow-bandgap semiconductors, such as InSb and HgCdTe, traditionally used to convert mid-IR photons to electrical currents. The cryogenic or multi-stage thermo-electric cooling required to suppress dark current noise, exponentially d...

  15. Spectral and Imaging Observations of a White-light Solar Flare in the Mid-infrared

    Science.gov (United States)

    Penn, Matt; Krucker, Säm; Hudson, Hugh; Jhabvala, Murzy; Jennings, Don; Lunsford, Allen; Kaufmann, Pierre

    2016-03-01

    We report high-resolution observations at mid-infrared wavelengths of a minor solar flare, SOL2014-09-24T17:50 (C7.0), using Quantum Well Infrared Photodetector cameras at an auxiliary of the McMath-Pierce telescope. The flare emissions, the first simultaneous observations in two mid-infrared bands at 5.2 and 8.2 μ {{m}} with white-light and hard X-ray coverage, revealed impulsive time variability with increases on timescales of ˜4 s followed by exponential decay at ˜10 s in two bright regions separated by about 13\\prime\\prime . The brightest source is compact, unresolved spatially at the diffraction limit (1\\_\\_AMP\\_\\_farcs;72 at 5.2 μ {{m}}). We identify the IR sources as flare ribbons also seen in white-light emission at 6173 Å observed by SDO/HMI, with twin hard X-ray sources observed by Reuven Ramaty High Energy Solar Spectroscopic Imager, and with EUV sources (e.g., 94 Å) observed by SDO/AIA. The two infrared points have nearly the same flux density (fν, W m-2 Hz) and extrapolate to a level of about an order of magnitude below that observed in the visible band by HMI, but with a flux of more than two orders of magnitude above the free-free continuum from the hot (˜15 MK) coronal flare loop observed in the X-ray range. The observations suggest that the IR emission is optically thin; this constraint and others suggest major contributions from a density less than about 4× {10}13 cm-3. We tentatively interpret this emission mechanism as predominantly free-free emission in a highly ionized but cool and rather dense chromospheric region.

  16. Mid-infrared Variability from the Spitzer Deep Wide-field Survey

    Science.gov (United States)

    Kozłowski, Szymon; Kochanek, Christopher S.; Stern, Daniel; Ashby, Matthew L. N.; Assef, Roberto J.; Bock, J. J.; Borys, C.; Brand, K.; Brodwin, M.; Brown, M. J. I.; Cool, R.; Cooray, A.; Croft, S.; Dey, Arjun; Eisenhardt, P. R.; Gonzalez, A.; Gorjian, V.; Griffith, R.; Grogin, N.; Ivison, R.; Jacob, J.; Jannuzi, B. T.; Mainzer, A.; Moustakas, L.; Röttgering, H.; Seymour, N.; Smith, H. A.; Stanford, S. A.; Stauffer, J. R.; Sullivan, I. S.; van Breugel, W.; Willner, S. P.; Wright, E. L.

    2010-06-01

    We use the multi-epoch, mid-infrared Spitzer Deep Wide-Field Survey to investigate the variability of objects in 8.1 deg2 of the NOAO Deep Wide Field Survey Boötes field. We perform a Difference Image Analysis of the four available epochs between 2004 and 2008, focusing on the deeper 3.6 and 4.5 μm bands. Out of 474, 179 analyzed sources, 1.1% meet our standard variability selection criteria that the two light curves are strongly correlated (r>0.8) and that their joint variance (σ12) exceeds that for all sources with the same magnitude by 2σ. We then examine the mid-IR colors of the variable sources and match them with X-ray sources from the XBoötes survey, radio catalogs, 24 μm selected active galactic nucleus (AGN) candidates, and spectroscopically identified AGNs from the AGN and Galaxy Evolution Survey (AGES). Based on their mid-IR colors, most of the variable sources are AGNs (76%), with smaller contributions from stars (11%), galaxies (6%), and unclassified objects, although most of the stellar, galaxy, and unclassified sources are false positives. For our standard selection criteria, 11%-12% of the mid-IR counterparts to X-ray sources, 24 μm AGN candidates, and spectroscopically identified AGNs show variability. The exact fractions depend on both the search depth and the selection criteria. For example, 12% of the 1131 known z>1 AGNs in the field and 14%-17% of the known AGNs with well-measured fluxes in all four Infrared Array Camera bands meet our standard selection criteria. The mid-IR AGN variability can be well described by a single power-law structure function with an index of γ ≈ 0.5 at both 3.6 and 4.5 μm, and an amplitude of S 0 ~= 0.1 mag on rest-frame timescales of 2 yr. The variability amplitude is higher for shorter rest-frame wavelengths and lower luminosities.

  17. Two-dimensional hetero-spectral mid-infrared and near-infrared correlation spectroscopy for discrimination adulterated milk.

    Science.gov (United States)

    Yang, Renjie; Liu, Rong; Dong, Guimei; Xu, Kexin; Yang, Yanrong; Zhang, Weiyu

    2016-03-15

    A new approach for discriminant analysis of adulterated milk is proposed based on two-dimensional (2D) hetero-spectral near-infrared (NIR) and mid-infrared (IR) correlation spectroscopy along with multi-way partial least squares discriminant analysis (NPLS-DA). NIR transmittance spectra and IR attenuated total reflection spectra of pure milk and adulterated milk with level of melamine varying from 0.03 to 3 g·L(-1) were collected at room temperature. The synchronous 2D hetero-spectral IR/NIR correlation spectra of all samples were calculated to build a discriminant model to classify adulterated milk and pure milk. Also, the NPLS-DA models were built based on synchronous 2D homo-spectral NIR/NIR and IR/IR correlation spectra, respectively. Comparison results showed that the NPLS-DA model could provide better results using 2D hetero-spectral IR/NIR correlation spectra than using 2D homo-spectral NIR/NIR and 2D IR/IR correlation spectra.

  18. Two-dimensional hetero-spectral mid-infrared and near-infrared correlation spectroscopy for discrimination adulterated milk

    Science.gov (United States)

    Yang, Renjie; Liu, Rong; Dong, Guimei; Xu, Kexin; Yang, Yanrong; Zhang, Weiyu

    2016-03-01

    A new approach for discriminant analysis of adulterated milk is proposed based on two-dimensional (2D) hetero-spectral near-infrared (NIR) and mid-infrared (IR) correlation spectroscopy along with multi-way partial least squares discriminant analysis (NPLS-DA). NIR transmittance spectra and IR attenuated total reflection spectra of pure milk and adulterated milk with level of melamine varying from 0.03 to 3 g·L- 1 were collected at room temperature. The synchronous 2D hetero-spectral IR/NIR correlation spectra of all samples were calculated to build a discriminant model to classify adulterated milk and pure milk. Also, the NPLS-DA models were built based on synchronous 2D homo-spectral NIR/NIR and IR/IR correlation spectra, respectively. Comparison results showed that the NPLS-DA model could provide better results using 2D hetero-spectral IR/NIR correlation spectra than using 2D homo-spectral NIR/NIR and 2D IR/IR correlation spectra.

  19. The mid-infrared environments of 6.7 GHz Methanol Masers from the Methanol Multi-Beam Survey

    CERN Document Server

    Gallaway, M; Lucas, P W; Fuller, G A; Caswell, J L; Green, J A; Voronkov, M A; Breen, S L; Quinn, L; Ellingsen, S P; Avison, A; Ward-Thompson, D; Cox, J

    2012-01-01

    We present a study of the mid-infrared environments and association with star formation tracers of 6.7 GHz methanol masers taken from the Methanol Multi-Beam (MMB) Survey. Our ultimate goal is to establish the mass of the host star and its evolutionary stage for each maser site. As a first step, the GLIMPSE survey of the Galactic Plane is utilised to investigate the environment of 776 methanol masers and we find that while the majority of the masers are associated with mid-infrared counterparts, a significant fraction (17%) are not associated with any detectable mid-infrared emission. A number of the maser counterparts are clearly extended with respect to the GLIMPSE point spread function and we implement an adaptive non-circular aperture photometry (ANCAP) technique to determine the fluxes of the maser counterparts. The ANCAP technique doubles the number of masers with flux information at all four wavelengths compared to the number of the corresponding counterparts obtained from the GLIMPSE Point Source Cata...

  20. A Precise Determination of the Mid-Infrared Interstellar Extinction Law Based on the APOGEE Spectroscopic Survey

    CERN Document Server

    Xue, Mengyao; Gao, Jian; Liu, Jiaming; Wang, Shu; Li, Aigen

    2016-01-01

    A precise measure of the mid-infrared interstellar extinction law is crucial to the investigation of the properties of interstellar dust, especially of the grains in the large size end. Based on the stellar parameters derived from the SDSS-III/APOGEE spectroscopic survey, we select a large sample of G- and K-type giants as the tracers of the Galactic mid-infrared extinction. We calculate the intrinsic stellar color excesses from the stellar effective temperatures and use them to determine the mid-infrared extinction for a given line of sight. For the entire sky of the Milky Way surveyed by APOGEE, we derive the extinction (relative to the K$_{\\rm S}$ band at wavelength $\\lambda=2.16\\mu$m) for the four \\emph{WISE} bands at 3.4, 4.6, 12 and 22$\\mu$m, the four \\emph{Spitzer}/IRAC bands at 3.6, 4.5, 5.8 and 8$\\mu$m, the \\emph{Spitzer}/MIPS24 band at 23.7$\\mu$m and for the first time, the \\emph{AKARI}/S9W band at 8.23$\\mu$m. Our results agree with previous works in that the extinction curve is flat in the ~3--8$\\m...

  1. SPECTRAL CHARACTERISTICS OF MID-INFRARED LIGHT-EMITTING DIODES BASED ON InAs (Sb,P

    Directory of Open Access Journals (Sweden)

    N. K. Zhumashev

    2016-01-01

    Full Text Available Subject of Study. We consider spectral characteristics of mid-infrared light-emitting diodes with heterostructures based on InAs(Sb,P emitting at T=300 K in the wavelength range 3.4–4.1 micrometers. The aim of the study was to search for the ways of increasing the diode efficiency. Methods. The heterostructures were grown from metal-organic chemical compounds with the use of vapor-phase epitaxial technique. The spectra were recorded under pulse excitation with the use of computer-controlled installation employing MDR-23 grating monochromator and a lock-in amplifier. InSb photodiode was used as a detector. Comparative study of electroluminescence spectra of the diodes was carried out at the temperatures equal to 300 K and 77 K. We compared the obtained data with the calculation results of the band diagrams of the heterostructures. Main Results. As a result of comparative study of the electroluminescence spectra of the diodes recorded at 300 K and 77 K we have established that increasing of their efficiency is hindered by substantial influence of Auger recombination. For the first time at 77 К we have observed the effect of stimulated emission from InAsSb active layer in light-emitting structures made of InAs/InAsSb/InAsSbP. For heterostructures with quantum wells InAs/(InAs/InAsSb/InAsSbP we have found out that at 77 К the carrier recombination occurs outside quantum wells, which points out to the insufficient carrier localization in the active layer. Thus, we have shown that the efficiency of mid-infrared light-emitting diodes based on InAs(Sb,P can be increased via suppression of Auger-recombination and improvement of carrier localization in the active region. Practical Relevance. The results of the study can be used for development of heterostructures for mid-infrared light-emitting diodes.

  2. Mid-infrared interferometry on spectral lines III. Ammonia and Silane around IRC+10216 and VY CMa

    CERN Document Server

    Monnier, J D; Hale, D S; Tuthill, P G; Townes, C H

    2000-01-01

    Using the U.C. Berkeley Infrared Spatial Interferometer with an RF filterbank, the first interferometric observations of mid-infrared molecular absorption features of ammonia (NH_3) and silane (SiH_4) with very high spectral resolution (R ~ 100000) were made. Under the assumptions of spherical symmetry and uniform outflow, these new data permitted the molecular stratification around carbon star IRC+10216 and red supergiant VY CMa to be investigated. For IRC+10216, both ammonia and silane were found to form in the dusty outflow significantly beyond both the dust formation and gas acceleration zones. Specifically, ammonia was found to form before silane in a region of decaying gas turbulence (>~ 20 R_star), while the silane is produced in a region of relatively smooth gas flow much further from the star (>~ 80 R_star). The depletion of gas-phase SiS onto grains soon after dust formation may fuel silane-producing reactions on the grain surfaces. For VY CMa, a combination of interferometric and spectral observati...

  3. Improved mid infrared detector for high spectral or spatial resolution and synchrotron radiation use

    Science.gov (United States)

    Faye, Mbaye; Bordessoule, Michel; Kanouté, Brahim; Brubach, Jean-Blaise; Roy, Pascale; Manceron, Laurent

    2016-06-01

    When using bright, small effective size sources, such as synchrotron radiation light beam, for broadband spectroscopy at spectral or spatial high resolution for mid-IR FTIR measurements, a marked detectivity improvement can be achieved by setting up a device matching the detector optical étendue to that of the source. Further improvement can be achieved by reducing the background unmodulated flux and other intrinsic noise sources using a lower temperature cryogen, such as liquid helium. By the combined use of cooled apertures, cold reimaging optics, filters and adapted detector polarization, and preamplification electronics, the sensitivity of a HgCdTe photoconductive IR detector can be improved by a significant factor with respect to standard commercial devices (more than one order of magnitude on average over 6-20 μm region) and the usable spectral range extended to longer wavelengths. The performances of such an optimized detector developed on the AILES Beamline at SOLEIL are presented here.

  4. RESOLVING THE ACTIVE GALACTIC NUCLEUS AND HOST EMISSION IN THE MID-INFRARED USING A MODEL-INDEPENDENT SPECTRAL DECOMPOSITION

    Energy Technology Data Exchange (ETDEWEB)

    Hernán-Caballero, Antonio; Alonso-Herrero, Almudena [Instituto de Física de Cantabria, CSIC-UC, Avenida de los Castros s/n, E-39005, Santander (Spain); Hatziminaoglou, Evanthia [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Spoon, Henrik W. W. [Cornell University, CRSR, Space Sciences Building, Ithaca, NY 14853 (United States); Almeida, Cristina Ramos [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Santos, Tanio Díaz [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Hönig, Sebastian F. [School of Physics and Astronomy, University of Southampton, Southampton SO18 1BJ (United Kingdom); González-Martín, Omaira [Centro de Radioastronomía y Astrofísica (CRyA-UNAM), 3-72 (Xangari), 8701, Morelia (Mexico); Esquej, Pilar, E-mail: ahernan@ifca.unican.es [Departamento de Astrofísica, Facultad de CC. Físicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2015-04-20

    We present results on the spectral decomposition of 118 Spitzer Infrared Spectrograph (IRS) spectra from local active galactic nuclei (AGNs) using a large set of Spitzer/IRS spectra as templates. The templates are themselves IRS spectra from extreme cases where a single physical component (stellar, interstellar, or AGN) completely dominates the integrated mid-infrared emission. We show that a linear combination of one template for each physical component reproduces the observed IRS spectra of AGN hosts with unprecedented fidelity for a template fitting method with no need to model extinction separately. We use full probability distribution functions to estimate expectation values and uncertainties for observables, and find that the decomposition results are robust against degeneracies. Furthermore, we compare the AGN spectra derived from the spectral decomposition with sub-arcsecond resolution nuclear photometry and spectroscopy from ground-based observations. We find that the AGN component derived from the decomposition closely matches the nuclear spectrum with a 1σ dispersion of 0.12 dex in luminosity and typical uncertainties of ∼0.19 in the spectral index and ∼0.1 in the silicate strength. We conclude that the emission from the host galaxy can be reliably removed from the IRS spectra of AGNs. This allows for unbiased studies of the AGN emission in intermediate- and high-redshift galaxies—currently inaccesible to ground-based observations—with archival Spitzer/IRS data and in the future with the Mid-InfraRed Instrument of the James Webb Space Telescope. The decomposition code and templates are available at http://denebola.org/ahc/deblendIRS.

  5. The ultraviolet-to-mid-infrared spectral energy distribution of weak emission line quasars

    NARCIS (Netherlands)

    Lane, R.A.; Shemmer, O.; Diamond-Stanic, A.M.; Fan, X.; Anderson, S.F.; Brandt, W.N.; Plotkin, R.M.; Richards, G.T.; Schneider, D.P.; Strauss, M.A.

    2011-01-01

    We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 ≤ z ≤ 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS

  6. [Two-Dimensional Hetero-Spectral Near-Infrared and Mid-Infrared Correlation Spectroscopy for Discrimination Adulterated Milk].

    Science.gov (United States)

    Yu, Ge; Yang, Ren-jie; Lü, Ai-jun; Tan, En-zhong

    2015-08-01

    New approach for discriminant analysis of adulterated milk is proposed based on combining hetero-spectral two-dimensional (2D) near-infrared (NIR) and mid-infrared (IR) correlation spectroscopy along with multi-way partial least squares discriminant analysis (NPLS-DA). Firstly, 36 pure milk samples were collected and 36 adulterated milk with starch samples (0.01 to 1 g · L(-1)) were prepared by adding appropriate mass of starch into pure milk. Then, one-dimensional NIR transmittance spectra and IR attenuated total reflection spectra of pure milk and adulterated milk with starch were measured at room temperature. And the synchronous 2D NIR-IR (4200~4800 vs. 900~1700 cm(-1)) correlation spectra of all samples were calculated. Due to the trace of adulterants, the synchronous 2D IR-NIR correlation spectral differences between adulterated milk with starch and pure milk are very subtle. Consequently, it was impossible to directly distinguish whether the sample was pure milk or adulterated milk. Finally, 2D IR-NIR correlation spectra were to build a discriminant model to classify adulterated milk and pure milk. The classification accuracy rates of samples in calibration set and in prediction set were 95.8% and 100% respectively. Also, the NPLS-DA models were built based on 2D NIR and 2D IR correlation spectra, respectively. The classification accuracy rates of samples in prediction set were 95.8%. Comparison results showed that the NPLS-DA model could provide better results using 2D NIR-IR correlation spectra than using 2D NIR, and 2D IR correlation spectra. The proposed method can not only effectively extract the feature information of adulterants in milk, but also explores a new perspective method for detection of adulterated food.

  7. Mid-Infrared Spectral Measures of Star-Formation and AGN Activity in Normal Galaxies

    CERN Document Server

    Treyer, Marie; Johnson, B D; O'Dowd, M; Martin, C D; Wyder, T; Charlot, S; Heckman, T; Martins, L; Seibert, M; van der Hulst, J M

    2010-01-01

    We investigate the use of MIR PAH bands, continuum and emission lines as probes of star-formation and AGN activity in a sample of 100 'normal' and local (z~0.1) emission-line galaxies. The MIR spectra were obtained with the Spitzer Space Telescope Infrared Spectrograph (IRS) as part of the Spitzer-SDSS-GALEX Spectroscopic Survey (SSGSS) which includes multi-wavelength photometry from the UV to the FIR and optical spectroscopy. The continuum and features were extracted using PAHFIT (Smith et al. 2007), a decomposition code which we find to yield PAH equivalent widths up to ~30 times larger than the commonly used spline methods. Despite the lack of extreme objects in our sample (such as strong AGNs, low metallicity galaxies or ULIRGs), we find significant variations in PAH, continuum and emission line properties and systematic trends between these MIR properties and optically derived physical properties such as age, metallicity and radiation field hardness. We revisit the diagnostic diagram relating PAH equival...

  8. 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.

  9. Towards the mid-infrared optical biopsy

    Science.gov (United States)

    Seddon, Angela B.; Benson, Trevor M.; Sujecki, Slawomir; Abdel-Moneim, Nabil; Tang, Zhuoqi; Furniss, David; Sojka, Lukasz; Stone, Nick; Jayakrupakar, Nallala; Lloyd, Gavin R.; Lindsay, Ian; Ward, Jon; Farries, Mark; Moselund, Peter M.; Napier, Bruce; Lamrini, Samir; Møller, Uffe; Kubat, Irnis; Petersen, Christian R.; Bang, Ole

    2016-03-01

    We are establishing a new paradigm in mid-infrared molecular sensing, mapping and imaging to open up the midinfrared spectral region for in vivo (i.e. in person) medical diagnostics and surgery. Thus, we are working towards the mid-infrared optical biopsy (`opsy' look at, bio the biology) in situ in the body for real-time diagnosis. This new paradigm will be enabled through focused development of devices and systems which are robust, functionally designed, safe, compact and cost effective and are based on active and passive mid-infrared optical fibers. In particular, this will enable early diagnosis of 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 portable, bright sources. We set a record in demonstrating extreme broad-band supercontinuum generated light 1.4 to 13.3 microns in a specially engineered, high numerical aperture mid-infrared optical fiber. The active mid-infrared fiber broadband supercontinuum for the first time offers the possibility of a bright mid-infrared wideband source in a portable package as a first step for medical fiber-based systems operating in the mid-infrared. Moreover, mid-infrared molecular mapping and imaging is potentially a disruptive technology to give improved monitoring of the environment, energy efficiency, security, 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).

  10. Spectral Characterization of RDX, ETN, PETN, TATP, HMTD, HMX, and C-4 in the Mid-Infrared Region

    Science.gov (United States)

    2014-04-01

    Plant HMTD Hexamethylene triperoxide HMX Cyclotrimethylene tetranitrate IED Improvised explosive device IR Infrared IRE Internal reflection... chromatography MIR Mid-infrared n Real refractive index PBA Poly(1,4-butylene adipate) PETN Pentaerythritol tetranitrate PIB Poly(isobutylene) PMMA...was removed from the holder, the anti-reflection coated surfaces were gently cleaned with lens paper and solvent to remove any traces of contamination

  11. The Herschel Orion Protostar Survey: Constraining Protostellar Models with Mid-Infrared Spectroscopy

    Science.gov (United States)

    Furlan, Elise; HOPS Team

    2013-01-01

    During the protostellar stage of star formation, a young star is surrounded by a large infalling envelope of dust and gas; the material falls onto a circumstellar disk and is eventually accreted by the central star. The dust in the disk and envelope emits prominently at mid- to far-infrared wavelengths; at 10 micron, absorption by small silicate grains causes a broad absorption feature. By modeling the near- to far-IR spectral energy distributions (SEDs) of protostars, properties of their disks and envelopes can be derived; in particular, mid-IR spectroscopy reveals the detailed emission around the silicate absorption feature and thus provides additional constraints for the models. Here we present results from modeling a sample of protostars in the Orion star-forming region that were observed as part of the Herschel Orion Protostar Survey (HOPS). These protostars represent a subsample of HOPS; they have Spitzer/IRS spectra, which cover the mid-IR SED from 5 to 35 micron, and photometry in the near-IR (2MASS), mid-IR (Spitzer/IRAC and MIPS), and far-IR (Herschel/PACS). We show the importance of adding Spitzer/IRS spectra with appropriate weights in determining the best fit to the SED from a large grid of protostellar models. The 10 micron silicate absorption feature and the mid- to far-IR SED slope provide key constraints for the inclination angle of the object and its envelope density, with a deep absorption feature and steep SED slope for the most embedded and highly inclined objects. We show a few examples that illustrate our SED fitting method and present preliminary results from our fits.

  12. The extended High A(V) Quasar Survey: Searching for dusty absorbers toward mid-infrared selected quasars

    CERN Document Server

    Krogager, J -K; Heintz, K E; Geier, S; Ledoux, C; Møller, P; Noterdaeme, P; Venemans, B P; Vestergaard, M

    2016-01-01

    We present the results of a new spectroscopic survey for dusty intervening absorption systems, particularly damped Ly$\\alpha$ absorbers (DLAs), towards reddened quasars. The candidate quasars are selected from mid-infrared photometry from the Wide-field Infrared Survey Explorer combined with optical and near-infrared photometry. Out of 1073 candidates, we secure low-resolution spectra for 108 using the Nordic Optical Telescope on La Palma, Spain. Based on the spectra, we are able to classify 100 of the 108 targets as quasars. A large fraction (50 %) is observed to have broad absorption lines (BALs). Moreover, we find 6 quasars with strange breaks in their spectra, which are not consistent with regular dust reddening. Using template fitting we infer the amount of reddening along each line of sight ranging from A(V)$\\approx$0.1 mag to 1.2 mag (assuming an SMC extinction curve). In four cases, the reddening is consistent with dust exhibiting the 2175{\\AA} feature caused by an intervening absorber, and for two of...

  13. The North Ecliptic Pole Wide survey of AKARI: a near- and mid-infrared source catalog

    CERN Document Server

    Kim, Seong Jin; Matsuhara, Hideo; Wada, Takehiko; Oyabu, Shinki; Im, Myungshin; Jeon, Yiseul; Kang, Eugene; Ko, Jongwan; Lee, Myung Gyoon; Takagi, Toshinobu; Pearson, Chris; White, Glenn J; Jeong, Woong-Seob; Serjeant, Stephen; Nakagawa, Takao; Ohyama, Youichi; Goto, Tomotsugu; Takeuchi, Tsutomu T; Pollo, Agnieszka; Solarz, Aleksandra; Pepiak, Agata

    2012-01-01

    We present a photometric catalog of infrared (IR) sources based on the North Ecliptic PoleWide field (NEP-Wide) survey of AKARI, which is an infrared space telescope launched by Japan. The NEP-Wide survey covered 5.4 deg2 area, a nearly circular shape centered on the North Ecliptic Pole, using nine photometric filter-bands from 2 - 25 {\\mu}m of the Infrared Camera (IRC). Extensive efforts were made to reduce possible false objects due to cosmic ray hits, multiplexer bleeding phenomena around bright sources, and other artifacts. The number of detected sources varied depending on the filter band: with about 109,000 sources being cataloged in the near-IR bands at 2 - 5 {\\mu}m, about 20,000 sources in the shorter parts of the mid-IR bands between 7 - 11 {\\mu}m, and about 16,000 sources in the longer parts of the mid-IR bands, with \\sim 4,000 sources at 24 {\\mu}m. The estimated 5? detection limits are approximately 21 magnitude (mag) in the 2 - 5 {\\mu}m bands, 19.5 - 19 mag in the 7 - 11 {\\mu}m, and 18.8 - 18.5 ma...

  14. The Taurus Spitzer Survey: New Candidate Taurus Members Selected Using Sensitive Mid-Infrared Photometry

    CERN Document Server

    Rebull, L M; McCabe, C -E; Hillenbrand, L A; Stapelfeldt, K R; Noriega-Crespo, A; Carey, S J; Brooke, T; Huard, T; Terebey, S; Audard, M; Monin, J -L; Fukagawa, M; Guedel, M; Knapp, G R; Menard, F; Allen, L E; Angione, J R; Baldovin-Saavedra, C; Bouvier, J; Briggs, K; Dougados, C; Evans, N J; Flagey, N; Guieu, S; Grosso, N; Glauser, A M; Harvey, P; Hines, D; Latter, W B; Skinner, S L; Strom, S; Tromp, J; Wolf, S

    2009-01-01

    We report on the properties of pre-main-sequence objects in the Taurus molecular clouds as observed in 7 mid- and far-infrared bands with the Spitzer Space Telescope. There are 215 previously-identified members of the Taurus star-forming region in our ~44 square degree map; these members exhibit a range of Spitzer colors that we take to define young stars still surrounded by circumstellar dust (noting that ~20% of the bonafide Taurus members exhibit no detectable dust excesses). We looked for new objects in the survey field with similar Spitzer properties, aided by extensive optical, X-ray, and ultraviolet imaging, and found 148 candidate new members of Taurus. We have obtained follow-up spectroscopy for about half the candidate sample, thus far confirming 34 new members, 3 probable new members, and 10 possible new members, an increase of 15-20% in Taurus members. Of the objects for which we have spectroscopy, 7 are now confirmed extragalactic objects, and one is a background Be star. The remaining 93 candida...

  15. New laboratory intercomparison of the ozone absorption coefficients in the mid-infrared (10 μm) and ultraviolet (300-350 nm) spectral regions.

    Science.gov (United States)

    Gratien, A; Picquet-Varrault, B; Orphal, J; Doussin, J-F; Flaud, J-M

    2010-09-23

    Knowing the ozone absorption cross sections in the ultraviolet and infrared spectral range, with an accuracy of better than 1%, is of the utmost importance for atmospheric remote-sensing applications. For this reason, various ozone intensity intercomparisons and measurements have been published these last years. However, the corresponding results proved not to be consistent and thus have raised a controversial discussion in the community of atmospheric remote-sensing. This study, where great care has been taken to avoid any possible error, reports a new laboratory intercomparison of the ozone absorption coefficients in the mid-infrared (10 μm) and ultraviolet (300-350 nm) spectral regions. It gives a new piece of information to the puzzling problem concerning the ozone IR and UV cross sections and confirms that the IR and UV cross sections recommended in the literature are in disagreement of about 4%.

  16. THE SPITZER INTERACTING GALAXIES SURVEY: A MID-INFRARED ATLAS OF STAR FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Brassington, N. J. [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Zezas, A.; Ashby, M. L. N.; Lanz, L.; Smith, Howard A.; Willner, S. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Klein, C., E-mail: n.brassington@herts.ac.uk [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2015-05-15

    The Spitzer Interacting Galaxies Survey is a sample of 103 nearby galaxies in 48 systems, selected using association likelihoods and therefore free from disturbed morphology biases. All galaxies have been observed with Infrared Array Camera and MIPS 24 μm bands from the Spitzer Space Telescope. This catalog presents the global flux densities and colors of all systems and correlations between the interacting systems and their specific star formation rate (sSFR). This sample contains a wide variety of galaxy interactions with systems ranging in mass, mass ratios, and gas-content as well as interaction strength. This study seeks to identify the process of triggering star formation in galaxy interactions, therefore, we focus on the non-active galactic nucleus spiral galaxies only. From this subset of 70 spiral galaxies we have determined that this sample has enhanced sSFR compared to a sample of non-interacting field galaxies. Through optical data we have classified each system by “interaction strength”; the strongly interacting (Stage 4) galaxies have higher sSFR values than the weakly (Stage 2) and moderately (Stage 3) interacting systems. However, the Stage 2 and 3 systems have statistically identical sSFR properties, despite the lack of optical interaction signatures exhibited by the Stage 2 galaxies. We suggest that the similarity of sSFR in these stages could be a consequence of some of these Stage 2 systems actually being post-perigalactic and having had sufficient time for their tidal features to fade to undetectable levels. This interpretation is consistent with the correlation of sSFR with separation, which we have determined to have little variation up to 100 kpc.

  17. Mid-infrared silicon photonic devices

    Science.gov (United States)

    Mashanovich, Goran Z.; Milosevic, Milan M.; Nedeljkovic, Milos; Owens, Nathan; Headley, William R.; Teo, Ee Jin; Xiong, Boqian; Yang, Pengyuan; Hu, Youfang

    2011-01-01

    The mid-infrared spectral region is interesting for bio-chemical sensing, environmental monitoring, free space communications, or military applications. Silicon is relatively low-loss from 1.2 to 8 μm and from 24 to 100 μm, and therefore silicon photonic circuits can be used in mid- and far- infrared wavelength ranges. In this paper we investigate several silicon based waveguide structures for mid-infrared wavelength region.

  18. Mid-infrared, super-flat, supercontinuum generation covering the 2–5 μm spectral band using a fluoroindate fibre pumped with picosecond pulses

    Science.gov (United States)

    Michalska, Maria; Mikolajczyk, Janusz; Wojtas, Jacek; Swiderski, Jacek

    2016-12-01

    Broadband, mid-infrared supercontinuum generation in a step-index fluoroindate fibre is reported. By using ~70-picosecond laser pulses at 2.02 μm, provided by an optical parametric generator, a wide spectrum with a cut-off wavelength at 5.25 μm and a 5-dB bandwidth covering the entire 2–5 μm spectral interval has been demonstrated for the first time. The behaviour of the supercontinuum was investigated by changing the peak power and the wavelength of the pump pulses. This allowed the optimal pumping conditions to be determined for the nonlinear medium that was used. The optical damage threshold for the fluoroindate fibre was experimentally found to be ~200 GW/cm2.

  19. Tracking Jupiter's Quasi-Quadrennial Oscillation and Mid-Latitude Zonal Waves with High Spectral Resolution Mid-Infrared Observations

    Science.gov (United States)

    Greathouse, Thomas K.; Orton, Glenn S.; Cosentino, Rick; Morales-Juberias, Raul; Fletcher, Leigh N.; Giles, Rohini Sara; Melin, Henrik; Encrenaz, Therese A.; Fouchet, Thierry; DeWitt, Curtis N.

    2016-10-01

    We report on early results of a long term observational study to track the temporal and 3-dimensional evolution of the Quasi-Quadrennial Oscillation (QQO) and the propagation and evolution of mid-latitude zonal waves in Jupiter's stratosphere. These wave-driven phenomena affect variations in Jupiter's vertical and horizontal temperature field, which can be inferred by measuring methane emission in the thermal infrared near 1245 cm-1. Using TEXES, the Texas Echelon cross-dispersed Echelle Spectrograph, mounted on the NASA Infrared Telescope Facility (IRTF) we observed high-spectral resolution (R=75,000) scan maps of Jupiter's equator to mid-latitudes from January 2012 through to the present. We will present the zonally averaged inferred thermal structure within ±30° latitude of the equator and between 10 and 0.01 mbar, showing the QQO's downward progression along with inferred 3-dimensional thermal maps (latitude, longitude, pressure) displaying a multitude of independent waves and eddies at various latitudes and pressures. These results reveal a vast array of wave activity on Jupiter and will serve to: 1) significantly improve the determination of the period and vertical descent velocity of Jupiter's QQO; 2) measure the zonal wavenumbers, vertical wavelengths, zonal group velocities and lifetimes of transient mid-latitude waves; and 3) record the thermal state of Jupiter's stratosphere in detail prior to, during, and after Juno's prime mission.

  20. Design and implementation of film coating for tunable liquid crystal Fabry-Perot filter working in mid-infrared spectral region

    Science.gov (United States)

    Zhang, Huaidong; Fu, Anbang; Zhang, Xinyu; Sang, Hongshi; Xie, Changsheng

    2013-10-01

    In this paper, we design and implementation anti-reflection and high reflection film for tunable LC-FP filter working in typical medium wave infrared (MWIR) spectral region. As to reflection mirror, we complete it by depositing gold film on the silicon substrate. By using the analytical method of dividing amplitude multiple beam interference to simulate the reflectance, the reflectivity result of the gold film is around 98% at the average in the MWIR spectral region. When take the absorption of the gold film into consideration, the gold film should be thin under the condition that it is conductive well. The anti-reflection film is introduced to reduce the reflection of the other side of the wafer. In anti-reflection structure, we simulate the reflection of the films with the algorithm of the equivalent membrane and fulfill our design with the technology of vapor deposition. Finally, we test the total transmittance of the wafer deposited gold films and anti-reflection films, which is about 0.2% of single chip. By making use of the wafer designed by us, we fabricate the LC-FP filter by placing two wafers side by side with the anti-reflection structure face to the direction of wavelength incident. Simultaneously, the LC layer with fixed thickness is sealed between the two high reflection mirrors formed by gold film. Compared with other method to fabricate mid-infrared FP filter, deposition of reflection and anti-reflection films on wafer have the advantage of low cost, simple technology.

  1. Terahertz and Mid Infrared

    CERN Document Server

    Shulika, Oleksiy; Detection of Explosives and CBRN (Using Terahertz)

    2014-01-01

    The reader will find here a timely update on new THz sources and detection schemes as well as concrete applications to the detection of Explosives and CBRN. Included is a method to identify hidden RDX-based explosives (pure and plastic ones) in the frequency domain study by Fourier Transformation, which has been complemented by the demonstration of improvement of the quality of the images captured commercially available THz passive cameras. The presented examples show large potential for the detection of small hidden objects at long distances (6-10 m).  Complementing the results in the short-wavelength range, laser spectroscopy with a mid-infrared, room temperature, continuous wave, DFB laser diode and high performance DFB QCL have been demonstrated to offer excellent enabling sensor technologies for environmental monitoring, medical diagnostics, industrial and security applications.  From the new source point of view a number of systems have been presented - From superconductors to semiconductors, e.g. Det...

  2. Nonlinear photothermal mid-infrared spectroscopy

    Science.gov (United States)

    Totachawattana, Atcha; Erramilli, Shyamsunder; Sander, Michelle Y.

    2016-10-01

    Mid-infrared photothermal spectroscopy is a pump-probe technique for label-free and non-destructive sample characterization by targeting intrinsic vibrational modes. In this method, the mid-infrared pump beam excites a temperature-induced change in the refractive index of the sample. This laser-induced change in the refractive index is measured by a near-infrared probe laser using lock-in detection. At increased pump powers, emerging nonlinear phenomena not previously demonstrated in other mid-infrared techniques are observed. Nonlinear study of a 6 μm-thick 4-Octyl-4'-Cyanobiphenyl (8CB) liquid crystal sample is conducted by targeting the C=C stretching band at 1606 cm-1. At high pump powers, nonlinear signal enhancement and multiple pitchfork bifurcations of the spectral features are observed. An explanation of the nonlinear peak splitting is provided by the formation of bubbles in the sample at high pump powers. The discontinuous refractive index across the bubble interface results in a decrease in the forward scatter of the probe beam. This effect can be recorded as a bifurcation of the absorption peak in the photothermal spectrum. These nonlinear effects are not present in direct measurements of the mid-infrared beam. Evolution of the nonlinear photothermal spectrum of 8CB liquid crystal with increasing pump power shows enhancement of the absorption peak at 1606 cm-1. Multiple pitchfork bifurcations and spectral narrowing of the photothermal spectrum are demonstrated. This novel nonlinear regime presents potential for improved spectral resolution as well as a new regime for sample characterization in mid-infrared photothermal spectroscopy.

  3. Mid infrared upconversion spectroscopy using diffuse reflectance

    DEFF Research Database (Denmark)

    Sanders, Nicolai Højer; Kehlet, Louis M.; Dam, Jeppe Seidelin

    2014-01-01

    We present a novel approach for mid infrared (mid-IR) spectral analysis using upconversion technology applied in a diffuse reflectance setup. We demonstrate experimentally that mid-IR spectral features in the 2.6-4 μm range using different test samples (e.g. zeolites) can be obtained. The results...... are in good agreement with published data. We believe that the benefit of low noise upconversion methods combined with spectral analysis will provide an alternative approach to e.g. mid-IR Fourier Transform microscopy. We discuss in detail the experimental aspects of the proposed method. The upconversion unit...... located in the near infrared (NIR) wavelength region easily accessible for low noise Silicon CCD camera technology. Thus the room temperature upconversion unit and the Silicon CCD camera replaces noisy mid infrared detectors used in existing Fourier Transform Infrared Spectroscopy. We demonstrate...

  4. Mid-infrared supercontinuum generation in the fingerprint region

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Petersen, Christian Rosenberg; Kubat, Irnis

    The mid-infrared spectral region is of great technical and scientific interest because most molecules display fundamental vibrational absorptions in this region, leaving distinctive spectral fingerprints. Here, we demonstrate experimentally that launching intense ultra-short pulses with a central...... the potential of fibres to emit across the mid-infrared molecular fingerprint region, which is of key importance for applications such as early cancer diagnostics, gas sensing and food quality control....

  5. Mid-infrared tunable metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Brener, Igal; Miao, Xiaoyu; Shaner, Eric A.; Passmore, Brandon Scott

    2017-07-11

    A mid-infrared tunable metamaterial comprises an array of resonators on a semiconductor substrate having a large dependence of dielectric function on carrier concentration and a semiconductor plasma resonance that lies below the operating range, such as indium antimonide. Voltage biasing of the substrate generates a resonance shift in the metamaterial response that is tunable over a broad operating range. The mid-infrared tunable metamaterials have the potential to become the building blocks of chip based active optical devices in mid-infrared ranges, which can be used for many applications, such as thermal imaging, remote sensing, and environmental monitoring.

  6. Mid-infrared tunable metamaterials

    Science.gov (United States)

    Brener, Igal; Miao, Xiaoyu; Shaner, Eric A; Passmore, Brandon Scott; Jun, Young Chul

    2015-04-28

    A mid-infrared tunable metamaterial comprises an array of resonators on a semiconductor substrate having a large dependence of dielectric function on carrier concentration and a semiconductor plasma resonance that lies below the operating range, such as indium antimonide. Voltage biasing of the substrate generates a resonance shift in the metamaterial response that is tunable over a broad operating range. The mid-infrared tunable metamaterials have the potential to become the building blocks of chip based active optical devices in mid-infrared ranges, which can be used for many applications, such as thermal imaging, remote sensing, and environmental monitoring.

  7. Mid infrared MEMS FTIR spectrometer

    Science.gov (United States)

    Erfan, Mazen; Sabry, Yasser M.; Mortada, Bassem; Sharaf, Khaled; Khalil, Diaa

    2016-03-01

    In this work we report, for the first time to the best of our knowledge, a bulk-micromachined wideband MEMS-based spectrometer covering both the NIR and the MIR ranges and working from 1200 nm to 4800 nm. The core engine of the spectrometer is a scanning Michelson interferometer micro-fabricated using deep reactive ion etching (DRIE) technology. The spectrum is obtained using the Fourier Transform techniques that allows covering a very wide spectral range limited by the detector responsivity. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator. Zirconium fluoride (ZrF4) multimode optical fibers are used to connect light between the white light source and the interferometer input, as well as the interferometer output to a PbSe photoconductive detector. The recorded signal-to-noise ratio is 25 dB at the wavelength of 3350 nm. The spectrometer is successfully used in measuring the absorption spectra of methylene chloride, quartz glass and polystyrene film. The presented solution provides a low cost method for producing miniaturized spectrometers in the near-/mid-infrared.

  8. A Spitzer Survey of Mid-Infrared Molecular Emission from Protoplanetary Disks II: Correlations and LTE Models

    CERN Document Server

    Salyk, C; Blake, G A; Najita, J R; Carr, J S; 10.1088/0004-637X/731/2/130

    2011-01-01

    We present an analysis of Spitzer-IRS observations of H2O, OH, HCN, C2H2, and CO2 emission, and Keck-NIRSPEC observations of CO emission, from a diverse sample of T Tauri and Herbig Ae/Be circumstellar disks. We find that detections and strengths of most mid-IR molecular emission features are correlated with each other, suggesting a common origin and similar excitation conditions. We note that the line detection efficiency is anti-correlated with the 13/30 um SED spectral slope, which is a measure of the degree of grain settling in the disk atmosphere. We also note a correlation between detection efficiency and H-alpha equivalent width, and tentatively with accretion rate, suggesting that accretional heating contributes to line excitation. If detected, H2O line fluxes are correlated with the mid-IR continuum flux, and other co-varying system parameters, such as L_star. However, significant sample variation, especially in molecular line ratios, remains. LTE models of the H2O emission show that line strength is...

  9. Mid infrared upconversion spectroscopy using diffuse reflectance

    Science.gov (United States)

    Sanders, Nicolai; Kehlet, Louis; Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Beato, Pablo; Pedersen, Christian

    2014-02-01

    We present a novel approach for mid infrared (mid-IR) spectral analysis using upconversion technology applied in a diffuse reflectance setup. We demonstrate experimentally that mid-IR spectral features in the 2.6-4 μm range using different test samples (e.g. zeolites) can be obtained. The results are in good agreement with published data. We believe that the benefit of low noise upconversion methods combined with spectral analysis will provide an alternative approach to e.g. mid-IR Fourier Transform microscopy. We discuss in detail the experimental aspects of the proposed method. The upconversion unit consists of a PP:LN crystal situated as an intracavity component in a Nd:YVO4 laser. Mixing incoming spectrally and spatially incoherent light from the test sample with the high power intracavity beam of the Nd:YVO4 laser results in enhanced conversion efficiency. The upconverted light is spectrally located in the near infrared (NIR) wavelength region easily accessible for low noise Silicon CCD camera technology. Thus the room temperature upconversion unit and the Silicon CCD camera replaces noisy mid infrared detectors used in existing Fourier Transform Infrared Spectroscopy. We demonstrate specifically that upconversion methods can be deployed using a diffuse reflectance setup where the test sample is irradiated by a thermal light source, i.e. a globar. The diffuse reflectance geometry is particularly well suited when a transmission setup cannot be used. This situation may happen for highly scattering or absorbing samples.

  10. TYPE 1 AND TYPE 2 QUASARS IN THE MID-INFRARED

    Directory of Open Access Journals (Sweden)

    S. E. Ridgway

    2009-01-01

    Full Text Available Type 2 or \\obscured" AGN have long been identi ed at low AGN luminosities (e.g. Seyfert 2s or through their radio luminosities (e.g. radio galaxies. But radio-quiet quasars (RQQs are many times more common than radio-loud quasars, and it's therefore unsurprising that recent searches have revealed that radio-quiet quasar 2s also form a signi cant population. Finding the numbers, properties, and redshift distribution of quasar 2s will be very important to resolving questions about the formation and co-evolution of black holes and galaxies. We have selected a sample of Type 2 and Type 1 quasars matched in their mid-infrared luminosity from the Spitzer First Look Survey by selecting on their mid-infrared dust emission properties (as measured by Spitzer IRAC photometry. This emission provides a distinctive signature of AGN activity but should not be a cted by orientation or torus opening angle. We have obtained mid-infrared IRS spectroscopy of these samples to study star formation activity in the host galaxies and the dust environments of the AGN, using measurements of the PAH features, the shape of the mid-infrared SED, and the equivalent width of the silicate features at 10 microns. We nd that the quasar 2s have more diverse mid-IR spectral properties, and that obscuration of the AGN is linked to star formation activity in the host.

  11. Mid-infrared upconversion spectroscopy

    DEFF Research Database (Denmark)

    Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin; Andersen, H. V.

    2016-01-01

    Mid-infrared (MIR) spectroscopy is emerging as an attractive alternative to near-infrared or visible spectroscopy. MIR spectroscopy offers a unique possibility to probe the fundamental absorption bands of a large number of gases as well as the vibrational spectra of complex molecules. In this paper...

  12. Mid-Infrared Optical Frequency Combs based on Crystalline Microresonators

    CERN Document Server

    Wang, C Y; Del'Haye, P; Schliesser, A; Hofer, J; Holzwarth, R; Hänsch, T W; Picqué, N; Kippenberg, T J

    2011-01-01

    The mid-infrared spectral range (\\lambda ~ 2 \\mu m to 20 \\mu m) is known as the "molecular fingerprint" region as many molecules have their highly characteristic, fundamental ro-vibrational bands in this part of the electromagnetic spectrum. Broadband mid-infrared spectroscopy therefore constitutes a powerful and ubiquitous tool for optical analysis of chemical components that is used in biochemistry, astronomy, pharmaceutical monitoring and material science. Optical frequency combs, i.e. broad spectral bandwidth coherent light sources consisting of equally spaced sharp lines, have revolutionized optical frequency metrology one decade ago. They now demonstrate dramatically improved acquisition rates, resolution and sensitivity for molecular spectroscopy mostly in the visible and near-infrared ranges. Mid-infrared frequency combs have therefore become highly desirable and recent progress in generating such combs by nonlinear frequency conversion has opened access to this spectral region. Here we report on a pr...

  13. Mid infrared emission spectroscopy of carbon plasma

    Science.gov (United States)

    Nemes, Laszlo; Brown, Ei Ei; Yang, Clayton S.-C.; Hommerich, Uwe

    2017-01-01

    Mid infrared time-resolved emission spectra were recorded from laser-induced carbon plasma. These spectra constitute the first study of carbon materials LIB spectroscopy in the mid infrared range. The carbon plasma was induced using a Q-switched Nd: YAG laser. The laser beam was focused to high purity graphite pellets mounted on a translation stage. Mid infrared emission from the plasma in an atmospheric pressure background gas was detected by a cooled HgCdTe detector in the range 4.4-11.6 μm, using long-pass filters. LIB spectra were taken in argon, helium and also in air. Despite a gate delay of 10 μs was used there were strong backgrounds in the spectra. Superimposed on this background broad and noisy emission bands were observed, the form and position of which depended somewhat on the ambient gas. The spectra were digitally smoothed and background corrected. In argon, for instance, strong bands were observed around 4.8, 6.0 and 7.5 μm. Using atomic spectral data by NIST it could be concluded that carbon, argon, helium and nitrogen lines from neutral and ionized atoms are very weak in this spectral region. The width of the infrared bands supports molecular origin. The infrared emission bands were thus compared to vibrational features of carbon molecules (excluding C2) of various sizes on the basis of previous carbon cluster infrared absorption and emission spectroscopic analyses in the literature and quantum chemical calculations. Some general considerations are given about the present results.

  14. Mid infrared emission spectroscopy of carbon plasma.

    Science.gov (United States)

    Nemes, Laszlo; Brown, Ei Ei; S-C Yang, Clayton; Hommerich, Uwe

    2017-01-05

    Mid infrared time-resolved emission spectra were recorded from laser-induced carbon plasma. These spectra constitute the first study of carbon materials LIB spectroscopy in the mid infrared range. The carbon plasma was induced using a Q-switched Nd: YAG laser. The laser beam was focused to high purity graphite pellets mounted on a translation stage. Mid infrared emission from the plasma in an atmospheric pressure background gas was detected by a cooled HgCdTe detector in the range 4.4-11.6μm, using long-pass filters. LIB spectra were taken in argon, helium and also in air. Despite a gate delay of 10μs was used there were strong backgrounds in the spectra. Superimposed on this background broad and noisy emission bands were observed, the form and position of which depended somewhat on the ambient gas. The spectra were digitally smoothed and background corrected. In argon, for instance, strong bands were observed around 4.8, 6.0 and 7.5μm. Using atomic spectral data by NIST it could be concluded that carbon, argon, helium and nitrogen lines from neutral and ionized atoms are very weak in this spectral region. The width of the infrared bands supports molecular origin. The infrared emission bands were thus compared to vibrational features of carbon molecules (excluding C2) of various sizes on the basis of previous carbon cluster infrared absorption and emission spectroscopic analyses in the literature and quantum chemical calculations. Some general considerations are given about the present results.

  15. Mid infrared supercontinuum generation from chalcogenide glass waveguides and fibers

    DEFF Research Database (Denmark)

    Luther-Davies, Barry; Yu, Yi; Zhang, Bin;

    2015-01-01

    I report work on mid-infrared super-continuum generation in chalcogenide fibers and waveguides pumped by 320fsec pulses at 21MHz in the 3-4.6µm range. Average powers of ≈20mW were produced with spectral coverage from <2µm to >11µm.......I report work on mid-infrared super-continuum generation in chalcogenide fibers and waveguides pumped by 320fsec pulses at 21MHz in the 3-4.6µm range. Average powers of ≈20mW were produced with spectral coverage from 11µm....

  16. Mid-infrared Semiconductor Optoelectronics

    CERN Document Server

    Krier, Anthony

    2006-01-01

    The practical realisation of optoelectronic devices operating in the 2–10 µm (mid-infrared) wavelength range offers potential applications in a variety of areas from environmental gas monitoring around oil rigs and landfill sites to the detection of pharmaceuticals, particularly narcotics. In addition, an atmospheric transmission window exists between 3 µm and 5 µm that enables free-space optical communications, thermal imaging applications and the development of infrared measures for "homeland security". Consequently, the mid-infrared is very attractive for the development of sensitive optical sensor instrumentation. Unfortunately, the nature of the likely applications dictates stringent requirements in terms of laser operation, miniaturisation and cost that are difficult to meet. Many of the necessary improvements are linked to a better ability to fabricate and to understand the optoelectronic properties of suitable high-quality epitaxial materials and device structures. Substantial progress in these m...

  17. Absorber Coatings for Mid-Infrared Astrophysics

    Science.gov (United States)

    Baker, Dahlia Anne; Wollack, Edward; Rostem, Karwan

    2017-01-01

    Control over optical response is an important aspect of instrument design for astrophysical imaging. Here we consider a mid-infrared absorber coating proposed for use on HIRMES (High Resolution Mid-Infrared Spectrometer), a cryogenic spectrometer which will fly on the SOFIA (Stratospheric Observatory for Infrared Astronomy) aircraft. The aim of this effort is to develop an absorptive coating for the 20-200 microns spectral range based on a graphene loaded epoxy binder (Epotek 377H) and glass microsphere scatterers (3M K1). The coatings electromagnetic response was modeled using a Matlab script and the glass microspheres were characterized by the measured size distribution, the dielectric constant, and the filling fraction. Images of the microspheres taken by a microscope were used to determine the size distribution with an ImageJ particle analysis program. Representative test samples for optical evaluation were fabricated for characterization via infrared Fourier transform spectroscopy. The optical tests will determine the material’s absorptance and reflectance. These test results will be compared to the modeled response.

  18. Nonlinear photothermal Mid-Infrared Microspectroscopy with Superresolution

    Science.gov (United States)

    Erramilli, Shyamsunder; Mertiri, Alket; Liu, Hui; Totachawattana, Atcha; Hong, Mi; Sander, Michelle

    2015-03-01

    We describe a nonlinear method for breaking the diffraction limit in mid-infrared microscopy using nonlinear photothermal microspectroscopy. A Quantum Cascade Laser (QCL) tuned to an infrared active vibrational molecular normal mode is used as the pump laser. A low-phase noise Erbium-doped fiber (EDFL) laser is used as the probe. When the incident intensity of the mid-infrared pump laser is increased past a critical threshold, a nanobubble is nucleated, strongly modulating the scatter of the probe beam, in agreement with prior work. Remarkably, we have also found that the photothermal spectral signature of the mid-infrared absorption bifurcates and is strongly narrowed, consistent with an effective ``mean-field'' theory of the observed pitchfork bifurcation. This ultrasharp narrowing can be exploited to obtain mid-infrared images with a resolution that breaks the diffraction limit, without the need of mechanical scanning near-field probes. The method provides a powerful new tool for hyperspectral label-free mid-infrared imaging and characterization of biological tissues and materials science and engineering. We thank our collaborators H. Altug, L. D. Ziegler, J. Mertz, for their advice and generous loan of equipment.

  19. Far and mid infrared observations of two ultracompact H II regions and one compact CO clump

    CERN Document Server

    Verma, R P; Mookerjea, B; Rengarajan, T N

    2003-01-01

    Two ultracompact H II regions (IRAS 19181+1349 and 20178+4046) and one compact molecular clump (20286+4105) have been observed at far infrared wavelengths using the TIFR 1 m balloon-borne telescope and at mid infrared wavelengths using ISO. Far infrared observations have been made simultaneously in two bands with effective wavelengths of ~ 150 and ~ 210 micron, using liquid 3He cooled bolometer arrays. ISO observations have been made in seven spectral bands using the ISOCAM instrument; four of these bands cover the emission from Polycyclic Aromatic Hydrocarbon (PAH) molecules. In addition, IRAS survey data for these sources in the four IRAS bands have been processed using the HIRES routine. In the high resolution mid infrared maps as well as far infrared maps multiple embedded energy sources have been resolved. There are structural similarities between the images in the mid infrared and the large scale maps in the far infrared bands, despite very different angular resolutions of the two. Dust temperature and ...

  20. Sub-Doppler resolution mid-infrared spectroscopy using a difference-frequency-generation source spectrally narrowed by laser linewidth transfer.

    Science.gov (United States)

    Sera, Hideyuki; Abe, Masashi; Iwakuni, Kana; Okubo, Sho; Inaba, Hajime; Hong, Feng-Lei; Sasada, Hiroyuki

    2015-12-01

    The spectral linewidth of a 3.28 μm difference-frequency-generation source has been reduced to 3.5 kHz using a laser linewidth transfer technique [Opt. Express21, 7891 (2013)]. We use an optical frequency comb with a broad servo bandwidth to transfer a narrow linewidth of a pump laser, a 1.06 μm Nd:YAG laser, to a signal laser, a 1.57 μm external-cavity laser diode. This source enables us to record the Lamb dip of the ν3 band R(2) E transition of methane with a molecular spectral linewidth of 21 kHz while the frequency axis is absolutely calibrated.

  1. Analysis of the Intrinsic Mid-Infrared L-band to Visible--Near-Infrared Flux Ratios in Spectral Synthesis Models of Composite Stellar Populations

    CERN Document Server

    Kim, Duho; Windhorst, Rogier A

    2016-01-01

    We analyze the intrinsic flux ratios of various visible--near-infrared filters with respect to 3.5micron for simple and composite stellar populations, and their dependence on age, metallicity and star formation history. UV/optical light from stars is reddened and attenuated by dust, where different sightlines across a galaxy suffer varying amounts of extinction. Tamura et al. (2009) developed an approximate method to correct for dust extinction on a pixel-by-pixel basis, dubbed the "beta_V" method, by comparing the observed flux ratio to an empirical estimate of the intrinsic ratio of visible and ~3.5micron data. Through extensive modeling, we aim to validate the "beta_V" method for various filters spanning the visible through near-infrared wavelength range, for a wide variety of simple and composite stellar populations. Combining Starburst99 and BC03 models, we built spectral energy distributions (SEDs) of simple (SSP) and composite (CSP) stellar populations for various realistic star formation histories (SF...

  2. Mid-infrared guided optics: a perspective for astronomical instruments

    CERN Document Server

    Labadie, L; 10.1364/OE.17.001947

    2009-01-01

    Research activities during the last decade have shown the strong potential of photonic devices to greatly simplify ground based and space borne astronomical instruments and to improve their performance. We focus specifically on the mid-infrared wavelength regime (about 5-20 microns), a spectral range offering access to warm objects (about 300 K) and to spectral features that can be interpreted as signatures for biological activity (e.g. water, ozone, carbon dioxide). We review the relevant research activities aiming at the development of single-mode guided optics and the corresponding manufacturing technologies. We evaluate the experimentally achieved performance and compare it with the performance requirements for applications in various fields of astronomy. Our goal is to show a perspective for future astronomical instruments based on mid-infrared photonic devices.

  3. Mid-Infrared Frequency Comb Fourier Transform Spectrometer

    CERN Document Server

    Adler, Florian; Foltynowicz, Aleksandra; Cossel, Kevin C; Briles, Travis C; Hartl, Ingmar; Ye, Jun

    2010-01-01

    Optical frequency-comb-based-high-resolution spectrometers offer enormous potential for spectroscopic applications. Although various implementations have been demonstrated, the lack of suitable mid-infrared comb sources has impeded explorations of molecular fingerprinting. Here we present for the first time a frequency-comb Fourier transform spectrometer operating in the 2100-to-3700-cm-1 spectral region that allows fast and simultaneous acquisitions of broadband absorption spectra with up to 0.0056 cm-1 resolution. We demonstrate part-per-billion detection limits in 30 seconds of integration time for various important molecules including methane, ethane, isoprene, and nitrous oxide. Our system enables precise concentration measurements even in gas mixtures that exhibit continuous absorption bands, and it allows detection of molecules at levels below the noise floor via simultaneous analysis of multiple spectral features. This system represents a near real-time, high-resolution, high-bandwidth mid-infrared sp...

  4. Mid-infrared guided optics: a perspective for astronomical instruments.

    Science.gov (United States)

    Labadie, Lucas; Wallner, Oswald

    2009-02-02

    Research activities during the last decade have shown the strong potential of photonic devices to greatly simplify ground based and space borne astronomical instruments and to improve their performance. We focus specifically on the mid-infrared wavelength regime (about 5-20 microm), a spectral range offering access to warm objects (about 300 K) and to spectral features that can be interpreted as signatures for biological activity (e.g. water, ozone, carbon dioxide). We review the relevant research activities aiming at the development of single-mode guided optics and the corresponding manufacturing technologies. We evaluate the experimentally achieved performance and compare it with the performance requirements for applications in various fields of astronomy. Our goal is to show a perspective for future astronomical instruments based on mid-infrared photonic devices.

  5. Mid-infrared spectra of comet nuclei

    Science.gov (United States)

    Kelley, Michael S. P.; Woodward, Charles E.; Gehrz, Robert D.; Reach, William T.; Harker, David E.

    2017-03-01

    Comet nuclei and D-type asteroids have several similarities at optical and near-IR wavelengths, including near-featureless red reflectance spectra, and low albedos. Mineral identifications based on these characteristics are fraught with degeneracies, although some general trends can be identified. In contrast, spectral emissivity features in the mid-infrared provide important compositional information that might not otherwise be achievable. Jovian Trojan D-type asteroids have emissivity features strikingly similar to comet comae, suggesting that they have the same compositions and that the surfaces of the Trojans are highly porous. However, a direct comparison between a comet and asteroid surface has not been possible due to the paucity of spectra of comet nuclei at mid-infrared wavelengths. We present 5-35 μm thermal emission spectra of comets 10P/Tempel 2, and 49P/Arend-Rigaux observed with the Infrared Spectrograph on the Spitzer Space Telescope. Our analysis reveals no evidence for a coma or tail at the time of observation, suggesting the spectra are dominated by the comet nucleus. We fit each spectrum with the near-Earth asteroid thermal model (NEATM) and find sizes in agreement with previous values. However, the NEATM beaming parameters of the nuclei, 0.74-0.83, are systematically lower than the Jupiter-family comet population mean of 1.03 ± 0.11, derived from 16- and 22-μm photometry. We suggest this may be either an artifact of the spectral reduction, or the consequence of an emissivity low near 16 μm. When the spectra are normalized by the NEATM model, a weak 10-μm silicate plateau is evident, with a shape similar to those seen in mid-infrared spectra of D-type asteroids. A silicate plateau is also evident in previously published Spitzer spectra of the nucleus of comet 9P/Tempel 1. We compare, in detail, these comet nucleus emission features to those seen in spectra of the Jovian Trojan D-types (624) Hektor, (911) Agamemnon, and (1172) Aneas, as well

  6. Mid-infrared dual-comb spectroscopy with an optical parametric oscillator.

    Science.gov (United States)

    Zhang, Zhaowei; Gardiner, Tom; Reid, Derryck T

    2013-08-15

    We present the first implementation of mid-infrared dual-comb spectroscopy with an optical parametric oscillator. Methane absorption spectroscopy was demonstrated with a resolution of 0.2 cm(-1) (5 GHz) at an acquisition time of ~10.4 ms over a spectral coverage at 2900-3050 cm(-1). The average power from each individual mid-infrared comb line was ~1 μW, representing a power level much greater than typical difference-frequency-generation sources. Mid-infrared dual-comb spectroscopy opens up unique opportunities to perform broadband spectroscopic measurements with high resolution, high requisition rate, and high detection sensitivity.

  7. A Mid-infrared QEPAS sensor device for TATP detection

    Science.gov (United States)

    Bauer, C.; Willer, U.; Lewicki, R.; Pohlkötter, A.; Kosterev, A.; Kosynkin, D.; Tittel, F. K.; Schade, W.

    2009-03-01

    Recent developments of external cavity quantum cascade lasers (EC-QC lasers) enable new applications in laser spectroscopy of trace gas species in the mid-infrared spectral region. We report the application of quartz enhanced photo acoustic spectroscopy (QEPAS) with widely tuneable EC-QC lasers as excitation sources for chemical sensing of different species such as triacetone triperoxide (TATP). A pulsed EC-QC laser operating at v~1120cm-1 and a cw EC-QC laser operating at v~950cm-1 are used for the detection of the explosive TATP which is a mid infrared broad band absorber. The detection limit of our present setup is ~1ppm TATP at atmospheric pressure.

  8. Near-infrared and Mid-infrared Spectroscopy with the Infrared Camera (IRC) for AKARI

    CERN Document Server

    Ohyama, Youichi; Matsuhara, Hideo; Wada, Takehiko; Kim, Woojung; Fujishiro, Naofumi; Uemizu, Kazunori; Sakon, Itsuki; Cohen, Martin; Ishigaki, Miho; Ishihara, Daisuke; Ita, Yoshifusa; Kataza, Hirokazu; Matsumoto, Toshio; Murakami, Hiroshi; Oyabu, Shinki; Tanabe, Toshihiko; Takagi, Toshinobu; Ueno, Munetaka; Usui, Fumio; Watarai, Hidenori; Pearson, Chris P; Takeyama, Norihide; Yamamuro, Tomoyasu; Ikeda, Yuji

    2007-01-01

    The Infrared Camera (IRC) is one of the two instruments on board the AKARI satellite. In addition to deep imaging from 1.8-26.5um for the pointed observation mode of the AKARI, it has a spectroscopic capability in its spectral range. By replacing the imaging filters by transmission-type dispersers on the filter wheels, it provides low-resolution (lambda/d_lambda ~ 20-120) spectroscopy with slits or in a wide imaging field-of-view (approximately 10'X10'). The IRC spectroscopic mode is unique in space infrared missions in that it has the capability to perform sensitive wide-field spectroscopic surveys in the near- and mid-infrared wavelength ranges. This paper describes specifications of the IRC spectrograph and its in-orbit performance.

  9. Mid-Infrared Frequency-Agile Dual-Comb Spectroscopy

    Science.gov (United States)

    Luo, Pei-Ling; Yan, Ming; Iwakuni, Kana; Millot, Guy; Hänsch, Theodor W.; Picqué, Nathalie

    2016-06-01

    We demonstrate a new approach to mid-infrared dual-comb spectroscopy. It opens up new opportunities for accurate real-time spectroscopic diagnostics and it significantly simplifies the technique of dual-comb spectroscopy. Two mid-infrared frequency combs of slightly different repetition frequencies and moderate, but rapidly tunable, spectral span are generated in the 2800-3200 cm-1 region. The generators rely on electro-optic modulators, nonlinear fibers for spectral broadening and difference frequency generation and do not involve mode-locked lasers. Flat-top frequency combs span up to 10 cm-1 with a comb line spacing of 100 MHz (3×10-3 cm-1). The performance of the spectrometer without any phase-lock electronics or correction scheme is illustrated with spectra showing resolved comb lines and Doppler-limited spectra of methane. High precision on the spectroscopic parameter (line positions and intensities) determination is demonstrated for spectra measured on a millisecond time scale and it is validated with comparison with literature data. G. Millot, S. Pitois, M. Yan, T. Hovannysyan, A. Bendahmane, T.W. Hänsch, N. Picqué, Frequency-agile dual-comb spectroscopy, Nature Photonics 10, 27-30 (2016).

  10. Group IV mid-infrared photonics

    Science.gov (United States)

    Mashanovich, G. Z.; Nedeljkovic, M.; Soler Penades, J.; Mitchell, C. J.; Khokhar, A. Z.; Littlejohns, C. J.; Stankovic, S.; Troia, B.; Wang, Y.; Reynolds, S.; Passaro, V. M. N.; Shen, L.; Healy, N.; Peacock, A. C.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Rowe, D. J.; Wilkinson, J. S.; Cheben, P.; Ackert, J. J.; Knights, A. P.; Thomson, D. J.; Gardes, F. Y.

    2015-02-01

    In this paper we present SOI, suspended Si, and Ge-on-Si photonic platforms and devices for the mid-infrared. We demonstrate low loss strip and slot waveguides in SOI and show efficient strip-slot couplers. A Vernier configuration based on racetrack resonators in SOI has been also investigated. Mid-infrared detection using defect engineered silicon waveguides is reported at the wavelength of 2-2.5 μm. In order to extend transparency of Si waveguides, the bottom oxide cladding needs to be removed. We report a novel suspended Si design based on subwavelength structures that is more robust than previously reported suspended designs. We have fabricated record low loss Ge-on-Si waveguides, as well as several other passive devices in this platform. All optical modulation in Ge is also analyzed.

  11. Selection of a Sample of Suitable Potential Mid-Infrared Calibration Stars from the Hipparcos/Tycho Catalogue

    Science.gov (United States)

    Martín-Luis, F.; Kidger, M.; Cohen, M.

    With the increasing availability of sensitive mid-IR area detectors on large telescopes there is a pressing need to increase the number and faintness of mid-infrared flux standards that are available. It is necessary to go as much as 4 orders of magnitude fainter in flux than the faintest ISO calibrators, although building on the foundations of the ISO calibration legacy. In an attempt to resolve this problem we have searched the Hipparcos/Tycho catalogue for stars of type KIII and AV that are suitable potential standard stars for the mid-infrared. Colour, variability, and astrometric criteria have been used. We discuss the progress that has already been made towards the resolution of the problem of calibration, particularly the studies aimed at obtaining an initial list of normal stars with reliable spectral type and good visible photometry, and which have a high density on the sky. We discuss a method for templating highly accurate fluxes from 1 to 30 μm from the visible colours and spectral type of a star of type AV or KIII that will allow us to predict fluxes with great accuracy, with a resolution Δ λ/λ ˜ 3000. This resolution is well adapted to proposed infrared instruments on the Spanish 10m Gran Telescopio Canarias. Our aim is to produce a list of 1000 standard stars with highly accurate calibration from 1 to 30 μm for Day 1 of the GTC. Work in progress has produced an initial list of ˜7000 candidate stars north of declination -44o. MSX infrared photometry has been found for 881 of the stars included in our all-sky survey, allowing us to extend the spectral coverage of a significant fraction of these stars into the mid-infrared.

  12. A variable mid-infrared synchrotron break associated with the compact jet in GX 339-4

    CERN Document Server

    Gandhi, P; Russell, D M; Casella, P; Malzac, J; Corbel, S; D'Avanzo, P; Lewis, F W; Markoff, S; Bel, M Cadolle; Goldoni, P; Wachter, S; Khangulyan, D; Mainzer, A

    2011-01-01

    Many X-ray binaries remain undetected in the mid-infrared, a regime where emission from their compact jets is likely to dominate. Here, we report the detection of the black hole binary GX 339-4 with the Wide-field Infrared Survey Explorer (WISE) during a very bright, hard accretion state in 2010. Combined with a rich contemporaneous multiwavelength dataset, clear spectral curvature is found in the infrared, associated with the peak flux density expected from the compact jet. An optically-thin slope of ~-0.7 and a jet radiative power of >6x10^{35} erg/s (d/8 kpc)^2 are measured. A ~24 h WISE light curve shows dramatic variations in mid-infrared spectral slope on timescales at least as short as the satellite orbital period ~95 mins. There is also significant change during one pair of observations spaced by only 11 s. These variations imply that the spectral break associated with the transition from self-absorbed to optically-thin jet synchrotron radiation must be varying across the full wavelength range of ~3-2...

  13. Advances in Mid-Infrared Spectroscopy for Chemical Analysis

    Science.gov (United States)

    Haas, Julian; Mizaikoff, Boris

    2016-06-01

    Infrared spectroscopy in the 3-20 μm spectral window has evolved from a routine laboratory technique into a state-of-the-art spectroscopy and sensing tool by benefitting from recent progress in increasingly sophisticated spectra acquisition techniques and advanced materials for generating, guiding, and detecting mid-infrared (MIR) radiation. Today, MIR spectroscopy provides molecular information with trace to ultratrace sensitivity, fast data acquisition rates, and high spectral resolution catering to demanding applications in bioanalytics, for example, and to improved routine analysis. In addition to advances in miniaturized device technology without sacrificing analytical performance, selected innovative applications for MIR spectroscopy ranging from process analysis to biotechnology and medical diagnostics are highlighted in this review.

  14. NATO Advanced Research Workshop on Terahertz and Mid Infrared Radiation

    CERN Document Server

    Pereira, Mauro F; Terahertz and Mid Infrared Radiation

    2011-01-01

    Terahertz (THz) and Mid-Infrared (MIR) radiation  (TERA-MIR) can be transmitted through nearly any material without causing biological harm. Novel and rapid methods of detection can be created with devices operation in these spectral ranges allowing scanning for weapons, detecting hidden explosives (including plastic landmines), controlling the quality of food and a host of other exciting applications.  This book focuses on mathematical and physical aspects of the field, on unifying these two spectral domains (THz and MIR) with regard to common sources, detectors, materials and applications, and on key interdisciplinary topics. The main THz and MIR source is the quantum cascade laser (QCL). Thus significant attention is paid to the challenge of turning this advanced technology into affordable commercial devices so as to exploit its enormous potential. However other alternatives to THz QCLs are also presented, e.g.  sub-terahertz imaging from avalanching GaAs bipolar transistors, Josephson junctions as THz ...

  15. Mid-Infrared Tunable Resonant Cavity Enhanced Detectors

    Directory of Open Access Journals (Sweden)

    Hans Zogg

    2008-09-01

    Full Text Available Mid-infrared detectors that are sensitive only in a tunable narrow spectral band are presented. They are based on the Resonant Cavity Enhanced Detector (RCED principle and employing a thin active region using IV-VI narrow gap semiconductor layers. A Fabry-Pérot cavity is formed by two mirrors. The active layer is grown onto one mirror, while the second mirror can be displaced. This changes the cavity length thus shifting the resonances where the detector is sensitive. Using electrostatically actuated MEMS micromirrors, a very compact tunable detector system has been fabricated. Mirror movements of more than 3 μm at 30V are obtained. With these mirrors, detectors with a wavelength tuning range of about 0.7 μm have been realized. Single detectors can be used in mid-infrared micro spectrometers, while a detector arrangement in an array makes it possible to realize Adaptive Focal Plane Arrays (AFPA.

  16. Time-domain spectroscopy in the mid-infrared

    Science.gov (United States)

    Lanin, A. A.; Voronin, A. A.; Fedotov, A. B.; Zheltikov, A. M.

    2014-10-01

    When coupled to characteristic, fingerprint vibrational and rotational motions of molecules, an electromagnetic field with an appropriate frequency and waveform offers a highly sensitive, highly informative probe, enabling chemically specific studies on a broad class of systems in physics, chemistry, biology, geosciences, and medicine. The frequencies of these signature molecular modes, however, lie in a region where accurate spectroscopic measurements are extremely difficult because of the lack of efficient detectors and spectrometers. Here, we show that, with a combination of advanced ultrafast technologies and nonlinear-optical waveform characterization, time-domain techniques can be advantageously extended to the metrology of fundamental molecular motions in the mid-infrared. In our scheme, the spectral modulation of ultrashort mid-infrared pulses, induced by rovibrational motions of molecules, gives rise to interfering coherent dark waveforms in the time domain. These high-visibility interference patterns can be read out by cross-correlation frequency-resolved gating of the field in the visible generated through ultrabroadband four-wave mixing in a gas phase.

  17. Discovery of planetary nebulae using predictive mid-infrared diagnostics

    CERN Document Server

    Parker, Quentin A; Stupar, Milorad; Frew, David J; Green, Anne J; Bojicic, Ivan; Guzman-Ramirez, Lizette; Sabin, Laurence; Vogt, Frederic

    2012-01-01

    We demonstrate a newly developed mid-infrared planetary nebula (PN) selection technique. It is designed to enable efficient searches for obscured, previously unknown, PN candidates present in the photometric source catalogues of Galactic plane MIR sky surveys. Such selection is now possible via new, sensitive, high-to-medium resolution, MIR satellite surveys such as those from the Spitzer Space Telescope and the all-sky Wide-Field Infrared Survey Explorer (WISE) satellite missions. MIR selection is based on how different colour-colour planes isolate zones (sometimes overlapping) that are predominately occupied by different astrophysical object types. These techniques depend on the reliability of the available MIR source photometry. In this pilot study we concentrate on MIR point source detections and show that it is dangerous to take the MIR GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) photometry from Spitzer for each candidate at face value without examining the actual MIR image data. A...

  18. Angle-resolved multioctave supercontinua from mid-infrared laser filaments.

    Science.gov (United States)

    Mitrofanov, A V; Voronin, A A; Sidorov-Biryukov, D A; Mitryukovsky, S I; Rozhko, M V; Pugžlys, A; Fedotov, A B; Panchenko, V Ya; Baltuška, A; Zheltikov, A M

    2016-08-01

    Angle-resolved spectral analysis of a multioctave high-energy supercontinuum output of mid-infrared laser filaments is shown to provide a powerful tool for understanding intricate physical scenarios behind laser-induced filamentation in the mid-infrared. The ellipticity of the mid-infrared driver beam breaks the axial symmetry of filamentation dynamics, offering a probe for a truly (3+1)-dimensional spatiotemporal evolution of mid-IR pulses in the filamentation regime. With optical harmonics up to the 15th order contributing to supercontinuum generation in such filaments alongside Kerr-type and ionization-induced nonlinearities, the output supercontinuum spectra span over five octaves from the mid-ultraviolet deep into the mid-infrared. Full (3+1)-dimensional field evolution analysis is needed for an adequate understanding of this regime of laser filamentation. Supercomputer simulations implementing such analysis articulate the critical importance of angle-resolved measurements for both descriptive and predictive power of filamentation modeling. Strong enhancement of ionization-induced blueshift is shown to offer new approaches in filamentation-assisted pulse compression, enabling the generation of high-power few- and single-cycle pulses in the mid-infrared.

  19. Towards supercontinuum-driven hyperspectral microscopy in the mid-infrared

    DEFF Research Database (Denmark)

    Lindsay, I. D.; Valle, S.; Ward, J.;

    2016-01-01

    The extension of supercontinuum (SC) sources into the mid-infrared, via the use of fluoride and chalcogenide optical fibers, potentially offers the high radiance of a laser combined with spectral coverage far exceeding that of typical tunable lasers and comparable to traditional black-body emitters...

  20. Unstable Resonator Mid-Infrared Laser Sources

    Science.gov (United States)

    2016-02-26

    AFRL-AFOSR-VA-TR-2016-0110 Unstable Resonator Mid-Infrared Laser Sources Steven Brueck UNIVERSITY OF NEW MEXICO Final Report 02/26/2016 DISTRIBUTION...5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) The Regents of the University of New Mexico 8...Transistors: State-of-the- Art ," IEEE J. Electron Device Soc. 2, 44 (2014). 43 A. M. Ionescu1 & H. Riel, "Tunnel field-effect transistors as energy

  1. Mid-infrared spectra of comet nuclei

    CERN Document Server

    Kelley, Michael S P; Gehrz, Robert D; Reach, William T; Harker, David E

    2016-01-01

    Jovian Trojan D-type asteroids have mid-infrared emissivity features strikingly similar to comet comae, suggesting that they have the same compositions and that the surfaces of the Trojans are highly porous. However, a direct comparison between a comet and asteroid surface has not been possible due to the paucity of spectra of comet nuclei at mid-infrared wavelengths. We present 5-35 {\\mu}m thermal emission spectra of comets 10P/Tempel 2, and 49P/Arend-Rigaux observed with the Infrared Spectrograph on the Spitzer Space Telescope. Our analysis suggests the spectra are dominated by the comet nucleus. We fit each spectrum with the near-Earth asteroid thermal model (NEATM) and find sizes in agreement with previous values. However, the NEATM beaming parameters of the nuclei, 0.74 to 0.83, are systematically lower than the Jupiter-family comet population mean of 1.03+/-0.11, derived from 16- and 22-{\\mu}m photometry. When the spectra are normalized by the NEATM model, a weak 10-{\\mu}m silicate plateau is evident, w...

  2. New Opportunities in Mid-Infrared Emission Control

    Directory of Open Access Journals (Sweden)

    Peter Geiser

    2015-09-01

    Full Text Available Tunable laser absorption spectroscopy (TLAS has been well accepted as a preferred measurement technique for many industrial applications in recent years, especially for in situ applications. Previously, mainly near-infrared lasers have been used in TLAS sensors. The advent of compact mid-infrared light sources, like quantum cascade lasers and interband cascade lasers, has made it possible to detect gases with better sensitivity by utilizing fundamental absorption bands and to measure species that do not have any absorption lines in the near-infrared spectral region. This technological advancement has allowed developing new sensors for gases, such as nitric oxide and sulfur dioxide, for industrial applications. Detection limits of better than 1 ppm·m for nitric oxide and better than 10 ppm·m for sulfur dioxide are demonstrated in field experiments.

  3. Mid-infrared Plasmonic Circular Dichroism Generated by Graphene Nanodisk Assemblies.

    Science.gov (United States)

    Kong, Xiang-Tian; Zhao, Runbo; Wang, Zhiming; Govorov, Alexander O

    2017-08-09

    It is very interesting to bring plasmonic circular dichroism spectroscopy to the mid-infrared spectral interval, and there are two reasons for this. This spectral interval is very important for thermal bioimaging, and simultaneously, this spectral range includes vibrational lines of many chiral biomolecules. Here we demonstrate that graphene plasmons indeed offer such opportunity. In particular, we show that chiral graphene assemblies consisting of a few graphene nanodisks can generate strong circular dichroism (CD) in the mid-infrared interval. The CD signal is generated due to the plasmon-plasmon coupling between adjacent nanodisks in the specially designed chiral graphene assemblies. Because of the large dimension mismatch between the thickness of a graphene layer and the incoming light's wavelength, three-dimensional configurations with a total height of a few hundred nanometers are necessary to obtain a strong CD signal in the mid-infrared range. The mid-infrared CD strength is mainly governed by the total dimensions (total height and helix scaffold radius) of the graphene nanodisk assembly and by the plasmon-plasmon interaction strength between its constitutive nanodisks. Both positive and negative CD bands can be observed in the graphene assembly array. The frequency interval of the plasmonic CD spectra overlaps with the vibrational modes of some important biomolecules, such as DNA and many different peptides, giving rise to the possibility of enhancing the vibrational optical activity of these molecular species by attaching them to the graphene assemblies. Simultaneously the spectral range of chiral mid-infrared plasmons in our structures appears near the typical wavelength of the human-body thermal radiation, and therefore, our chiral metastructures can be potentially utilized as optical components in thermal imaging devices.

  4. Mid-infrared Plasmonic Circular Dichroism Generated by Graphene Nanodisk Assemblies

    Science.gov (United States)

    Kong, Xiang-Tian; Zhao, Runbo; Wang, Zhiming; Govorov, Alexander O.

    2017-08-01

    It is very interesting to bring plasmonic circular dichroism spectroscopy to the mid-infrared spectral interval, and there are two reasons for this. This spectral interval is very important for thermal bio-imaging and, simultaneously, this spectral range includes vibrational lines of many chiral biomolecules. Here we demonstrate that graphene plasmons indeed offer such opportunity. In particular, we show that chiral graphene assemblies consisting of a few graphene nanodisks can generate strong circular dichroism (CD) in the mid-infrared interval. The CD signal is generated due to the plasmon-plasmon coupling between adjacent nanodisks in the specially designed chiral graphene assemblies. Because of the large dimension mismatch between the thickness of a graphene layer and the incoming light's wavelength, three-dimensional configurations with a total height of a few hundred nanometers are necessary to obtain a strong CD signal in the mid-infrared range. The mid-infrared CD strength is mainly governed by the total dimensions (total height and helix scaffold radius) of the graphene nanodisk assembly, and by the plasmon-plasmon interaction strength between its constitutive nanodisks. Both positive and negative CD bands can be observed in the graphene assembly array. The frequency interval of the plasmonic CD spectra overlaps with the vibrational modes of some important biomolecules, such as DNA and many different peptides, giving rise to the possibility of enhancing the vibrational optical activity of these molecular species by attaching them to the graphene assemblies. Simultaneously the spectral range of chiral mid-infrared plasmons in our structures appears near the typical wavelength of the human-body thermal radiation and, therefore, our chiral metastructures can be potentially utilized as optical components in thermal imaging devices.

  5. Mid-infrared supercontinuum covering the 1.4–13.3 μm molecular fingerprint region using ultra-high NA chalcogenide step-index fibre

    DEFF Research Database (Denmark)

    Petersen, Christian Rosenberg; Møller, Uffe Visbech; Kubat, Irnis

    2014-01-01

    The mid-infrared spectral region is of great technical and scientific interest because most molecules display fundamental vibrational absorptions in this region, leaving distinctive spectral fingerprints. To date, the limitations of mid-infrared light sources such as thermal emitters, low...... the potential of fibres to emit across the mid-infrared molecular ‘fingerprint region’, which is of key importance for applications such as early cancer diagnostics3, gas sensing and food quality control....

  6. Mid-infrared photonics devices in SOI

    Science.gov (United States)

    Mashanovich, G. Z.; Nedeljkovic, M.; Milošević, M. M.; Hu, Y.; Ben Masaud, T. M.; Jaberansary, E.; Chen, X.; Strain, M.; Sorel, M.; Peacock, A. C.; Chong, H. M. H.; Reed, G. T.

    2013-02-01

    In this paper we present silicon photonics devices designed for the 3-4μm wavelength region including waveguides, MMIs, ring resonators and Mach-Zehnder interferometers. The devices are based on silicon on insulator (SOI) platform. We show that 400-500 nm high silicon waveguides can have propagation losses as low as ~ 4 dB/cm at 3.8μm. We also demonstrate MMIs with insertion loss of 0.25 dB, high extinction ratio asymmetric Mach-Zehnder interferometers, and SOI ring resonators. This combined with our previous results reported at 3.4μm confirm that SOI is a viable platform for the 3-4 μm region and that low loss mid-infrared passive devices can be realized on it.

  7. High spatial resolution mid-infrared studies of planetary systems

    Science.gov (United States)

    Skemer, Andrew

    I present the results of six papers related the formation and evolution of planets and planetary systems, all of which are based on high-resolution, ground-based, mid-infrared observations. The first three chapters are studies of T Tauri binaries. T Tauri stars are young, low mass stars, whose disks form the building blocks of extrasolar planets. The first chapter is a study of the 0.68"/0.12" triple system, T Tauri. Our spatially resolved N-band photometry reveals silicate absorption towards one component, T Tau Sa, indicating the presence of an edge-on disk, which is in contrast to the other components. The second chapter is an adaptive optics fed N-band spectroscopy study of the 0.88" binary, UY Aur. We find that the dust grains around UY Aur A are ISM-like, while the mineralogy of the dust around UY Aur B is more uncertain, due to self-extinction. The third chapter presents a survey of spatially resolved silicate spectroscopy for nine T Tauri binaries. We find with 90%-95% confidence that the silicate features of the binaries are more similar than those of randomly paired single stars. This implies that a shared binary property, such as age or composition, is an important parameter in dust grain evolution. The fourth chapter is a study of the planetary system, 2MASS 1207. We explore the source of 2MASS 1207 b's under-luminosity, which has typically been explained as the result of an edge-on disk of large, grey-extincting dust grains. We find that the edge-on disk theory is incompatible with several lines of evidence, and suggest that 2MASS 1207 b's appearance can be explained by a thick cloudy atmosphere, which might be typical among young, planetary systems. The fifth chapter is a study of the white dwarf, Sirius B, which in the context of this thesis is being studied as a post-planetary system. Our N-band imaging demonstrates that Sirius B does not have an infrared excess, in contrast to previous results. The sixth chapter is a study of mid-infrared

  8. The Mid-Infrared Luminosity Evolution and Luminosity Function of Quasars with SDSS and WISE

    CERN Document Server

    Singal, J; Gerber, A

    2016-01-01

    We determine the 22$\\mu$m luminosity evolution and luminosity function for quasars from a data set of over 20,000 objects obtained by combining flux-limited Sloan Digital Sky Survey optical and Wide field Infrared Survey Explorer mid-infrared data. We apply methods developed in previous works to access the intrinsic population distributions non-parametrically, taking into account the truncations and correlations inherent in the data. We find that the population of quasars exhibits positive luminosity evolution with redshift in the mid-infrared, but with considerably less mid-infrared evolution than in the optical or radio bands. With the luminosity evolutions accounted for, we determine the density evolution and local mid-infrared luminosity function. The latter displays a sharp flattening at local luminosities below $\\sim 10^{31}$ erg sec$^{-1}$ Hz$^{-1}$, which has been reported previously at 15 $\\mu$m for AGN classified as both type-1 and type-2. We calculate the integrated total emission from quasars at 2...

  9. Herbig-Haro objects and mid-infrared outflows in the Vela C molecular cloud

    CERN Document Server

    Zhang, Miaomiao; Henning, Thomas

    2014-01-01

    We have performed a deep [SII]6717/6731 wide field Herbig-Haro (HH) object survey toward the Vela C molecular cloud with a sky coverage of about 2 deg2. In total, 18 new HH objects, HH 1090-1107, are discovered and the two previously known HH objects, HH 73-74, are also detected in our [SII] images. We also present an investigation of mid-infrared outflows in the Vela C molecular cloud using the Wide-field Infrared Survey Explorer images taken from AllWISE data release. Using the method suggested by Zhang & Wang, eleven extended green objects (EGOs) are identified to be the mid-infrared outflows, including 6 new mid-infrared outflows that have not been detected previously at other wavelengths and 5 mid-infrared counterparts of the HH objects detected in this work. Using the AllWISE Source Catalog and the source classification scheme suggested by Koenig et al., we have identified 56 young stellar object (YSO) candidates in the Vela C molecular cloud. The possible driving sources of the HH objects and EGOs ...

  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. Sub-kHz linewidth narrowing of a mid-infrared OPO idler frequency by direct cavity stabilization

    CERN Document Server

    Ricciardi, I; Parisi, M; Maddaloni, P; Santamaria, L; De Natale, P; De Rosa, M

    2015-01-01

    We stabilize the idler frequency of a singly-resonant optical parametric oscillator directly to the resonance of a mid-infrared Fabry-P\\'erot reference cavity. This is accomplished by the Pound-Drever-Hall locking scheme, controlling either the pump laser or the resonant signal frequency. A residual relative frequency noise power spectral density below 10$^3$ Hz$^2$/Hz is reached, with a Gaussian linewidth of 920 Hz over 100 ms, which demonstrates the potential for reaching spectral purity down to the Hz level by locking the optical parametric oscillator against a mid-infrared cavity with state-of-the-art superior performance.

  12. Split-cross antenna based narrowband mid-infrared absorber for sensing applications

    Science.gov (United States)

    Yang, Ao; Yang, Kecheng; Zhou, Lun; Li, Junyu; Tan, Xiaochao; Liu, Huan; Song, Haisheng; Tang, Jiang; Liu, Feng; Yi, Fei

    2017-03-01

    We have investigated numerically a narrowband near unity mid-infrared absorber based on a periodic array of gold split cross antenna backed by a dielectric spacer and a gold backmirror. We systematically studied the spectral dependence on the antenna parameters and explored the optimized parameters for nanofabrication. The optimized structure has a linewidth of 39 nm at 3.17 μm and the peak absorption is 96.5%. This can be explained in terms of surface lattice resonance of the periodic structure. The investigated structure can be devised as a mid-infrared refractive index sensor. Due to the strong near field enhancement and spectral dependence on the surface dielectric conditions, the narrow linewidth arises from the coupled plasmonic-photonic modes in the structure and has potential applications in plasmonic biosensing.

  13. SIBI: A compact hyperspectral camera in the mid-infrared

    Science.gov (United States)

    Pola Fossi, Armande; Ferrec, Yann; Domel, Roland; Coudrain, Christophe; Guerineau, Nicolas; Roux, Nicolas; D'Almeida, Oscar; Bousquet, Marc; Kling, Emmanuel; Sauer, Hervé

    2015-10-01

    Recent developments in unmanned aerial vehicles have increased the demand for more and more compact optical systems. In order to bring solutions to this demand, several infrared systems are being developed at ONERA such as spectrometers, imaging devices, multispectral and hyperspectral imaging systems. In the field of compact infrared hyperspectral imaging devices, ONERA and Sagem Défense et Sécurité have collaborated to develop a prototype called SIBI, which stands for "Spectro-Imageur Birefringent Infrarouge". It is a static Fourier transform imaging spectrometer which operates in the mid-wavelength infrared spectral range and uses a birefringent lateral shearing interferometer. Up to now, birefringent interferometers have not been often used for hyperspectral imaging in the mid-infrared because of the lack of crystal manufacturers, contrary to the visible spectral domain where the production of uniaxial crystals like calcite are mastered for various optical applications. In the following, we will present the design and the realization of SIBI as well as the first experimental results.

  14. Mid-infrared spectropolarimetry as a remote sensing tool

    Science.gov (United States)

    Johnson, Paul E.; Watne, Bruce; Shipman, Russell; Cleavlin, Chris

    1994-01-01

    A preliminary investigation of mid-infrared spectropolarimetry as a new technique to accurately measure features in the thermal spectra of planetary regoliths is described. The 5- to 12-micron polarization of igneous rocks and powders commonly found on planetary surfaces is measured to explore the viability of this technique for future groundbased and space-based experiments. Mid-infrared polarization is found to be diagnostic of composition for both whole rock and sand samples, while exhibiting less interference from surface roughness effects than with mid-infrared spectrophotometry.

  15. Multi-octave supercontinuum generation from mid-infrared filamentation in a bulk crystal

    Directory of Open Access Journals (Sweden)

    Faccio D.

    2013-03-01

    Full Text Available We present supercontinuum generation pumped by femtosecond mid-infrared pulses in a bulk homogeneous material. The spectrum extends from 450 nm into the midinfrared, and carries high spectral energy density (3 pJ/nm–10 nJ/nm. The supercontinuum has high shot-to-shot reproducibility and preserves the carrier-to-envelope phase. Our result paves the way for compact supercontinuum sources with unprecedented bandwidth.

  16. Mid-infrared nonlinear silicon photonics

    Science.gov (United States)

    Liu, Xiaoping; Kuyken, Bart; Green, William M. J.; Osgood, Richard M.; Baets, Roel; Roelkens, Gunther

    2014-03-01

    Recently there has been a growing interest in mid-infrared (mid-IR) photonic technology with a wavelength of operation approximately from 2-14 μm. Among several established mid-IR photonic platforms, silicon nanophotonic platform could potentially offer ultra-compact, and monolithically integrated mid-IR photonic devices and device arrays, which could have board impact in the mid-IR technology, such as molecular spectroscopy, and imaging. At room temperature, silicon has a bandgap ~ 1.12 eV resulting in vanishing two-photon absorption (TPA) for mid-IR wavelengths beyond 2.2 μm, which, coupled with silicon's large nonlinear index of refraction and its strong waveguide optical confinement, enables efficient nonlinear processes in the mid-IR. By taking advantage of these nonlinear processes and judicious dispersion engineering in silicon waveguides, we have recently demonstrated a handful of silicon mid-IR nonlinear components, including optical parametric amplifiers (OPA), broadband sources, and a wavelength translator. Silicon nanophotonic waveguide's anomalous dispersion design, providing four-wave-mixing (FWM) phase-matching, has enabled the first demonstration of silicon mid-IR optical parametric amplifier (OPA) with a net off-chip gain exceeding 13 dB. In addition, reduction of propagation losses and balanced second and fourth order waveguide dispersion design led to an OPA with an extremely broadband gain spectrum from 1.9-2.5 μm and >50 dB parametric gain, upon which several novel silicon mid-IR light sources were built, including a mid-IR optical parametric oscillator, and a supercontinuum source. Finally, a mid-IR wavelength translation device, capable of translating signals near 2.4 μm to the telecom-band near 1.6 μm with simultaneous 19 dB gain, was demonstrated.

  17. Miniaturized Mid-Infrared Sensor Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S; Young, C; Mizaikoff, B

    2007-08-16

    Fundamental vibrational and rotational modes associated with most inorganic and organic molecules are spectroscopically accessible within the mid-infrared (MIR; 3-20 {micro}m) regime of the electromagnetic spectrum. The interaction between MIR photons and organic molecules provides particularly sharp transitions, which - despite the wide variety of organic molecules - provide unique MIR absorption spectra reflecting the molecularly characteristic arrangement of chemical bonds within the probed molecules via the frequency position of the associated vibrational and rotational transitions. Given the inherent molecular selectivity and achievable sensitivity, MIR spectroscopy provides an ideal platform for optical sensing applications. Despite this potential, early MIR sensing applications were limited to localized applications due to the size of the involved instrumentation, and limited availability of appropriately compact MIR optical components including light sources, detectors, waveguides, and spectrometers. During the last decades, engineering advances in photonics and optical engineering have facilitated the translation of benchtop-style MIR spectroscopy into miniaturized optical sensing schemes providing a footprint compatible with portable instrumentation requirements for field deployable analytical tools. In this trend article, we will discuss recent advances and future strategies for miniaturizing MIR sensor technology. The Beer-Lambert law implies that achievable limit of detection (LOD) for any optical sensor system improves by increasing the interaction length between photons and target analyte species such as e.g., folding the optical path multiple times as in multi-pass gas phase sensing; however, this governing paradigm naturally leads to an increase in system dimensions. Hence, miniaturization of optical sensing system requires scaling down of each optical component, yet improving the performance of each optical element within a smaller form factor for

  18. A Mid-Infrared View of the High Mass Star Formation Region W51A

    Science.gov (United States)

    Barbosa, C. L.; Blum, R. D.; Damineli, A.; Conti, P. S.; Gusmão, D. M.

    2016-07-01

    In this paper we present the results of a mid-infrared study of G49.5-0.4, or W51A, part of the massive starbirth complex W51. Combining public data from the Spitzer IRAC camera, and Gemini mid-infrared camera T-ReCS at 7.73, 9.69, 12.33, and 24.56 μm, with a spatial resolution of ˜0.″5, we have identified the mid-infrared counterparts of eight ultracompact H ii regions, showing that two radio sources are deeply embedded in molecular clouds and another is a cloud of ionized gas. From the T-ReCS data we have unveiled the central core of the W51 region, revealing massive young stellar candidates. We modeled the spectral energy distribution of the detected sources. The results suggest that the embedded objects are sources with spectral types ranging from B3 to O5, but the majority of the fits indicate stellar objects with B1 spectral types. We also present an extinction map of IRS 2, showing that a region with lower extinction corresponds to the region where a proposed jet of gas has impacted the foreground cloud. From this map, we also derived the total extinction toward the enigmatic source IRS 2E, which amounts to ˜60 mag in the V band. We calculated the color temperature due to thermal emission of the circumstellar dust of the detected sources; the temperatures are in the interval of ˜100-150 K, which corresponds to the emission of dust located at 0.1 pc from the central source. Finally, we show a possible mid-infrared counterpart of a detected source at millimeter wavelengths that was found by Zapata et al. to be a massive young stellar object undergoing a high accretion rate.

  19. Mid-infrared spectroscopy combined with chemometrics to detect Sclerotinia stem rot on oilseed rape (Brassica napus L.) leaves.

    Science.gov (United States)

    Zhang, Chu; Feng, Xuping; Wang, Jian; Liu, Fei; He, Yong; Zhou, Weijun

    2017-01-01

    Detection of plant diseases in a fast and simple way is crucial for timely disease control. Conventionally, plant diseases are accurately identified by DNA, RNA or serology based methods which are time consuming, complex and expensive. Mid-infrared spectroscopy is a promising technique that simplifies the detection procedure for the disease. Mid-infrared spectroscopy was used to identify the spectral differences between healthy and infected oilseed rape leaves. Two different sample sets from two experiments were used to explore and validate the feasibility of using mid-infrared spectroscopy in detecting Sclerotinia stem rot (SSR) on oilseed rape leaves. The average mid-infrared spectra showed differences between healthy and infected leaves, and the differences varied among different sample sets. Optimal wavenumbers for the 2 sample sets selected by the second derivative spectra were similar, indicating the efficacy of selecting optimal wavenumbers. Chemometric methods were further used to quantitatively detect the oilseed rape leaves infected by SSR, including the partial least squares-discriminant analysis, support vector machine and extreme learning machine. The discriminant models using the full spectra and the optimal wavenumbers of the 2 sample sets were effective for classification accuracies over 80%. The discriminant results for the 2 sample sets varied due to variations in the samples. The use of two sample sets proved and validated the feasibility of using mid-infrared spectroscopy and chemometric methods for detecting SSR on oilseed rape leaves. The similarities among the selected optimal wavenumbers in different sample sets made it feasible to simplify the models and build practical models. Mid-infrared spectroscopy is a reliable and promising technique for SSR control. This study helps in developing practical application of using mid-infrared spectroscopy combined with chemometrics to detect plant disease.

  20. in the mid-infrared with large aperture telescopes

    Directory of Open Access Journals (Sweden)

    James M. De Buizer

    2007-01-01

    Full Text Available Thanks to the high spatial resolution af- forded by 8-10-m class telescopes, we are be- ginning to learn that some sources are ex- tended in their mid-infrared emission because of dusty outows or heated outow cavity walls. Therefore one must be extremely care- ful in interpreting the nature of extended mid-infrared sources (i.e. just because it is extended does not automatically mean it is a disk!.

  1. Mid-infrared interferometric variability of DG Tauri: Implications for the inner-disk structure

    Science.gov (United States)

    Varga, J.; Gabányi, K. É.; Ábrahám, P.; Chen, L.; Kóspál, Á.; Menu, J.; Ratzka, Th.; van Boekel, R.; Dullemond, C. P.; Henning, Th.; Jaffe, W.; Juhász, A.; Moór, A.; Mosoni, L.; Sipos, N.

    2017-08-01

    Context. DG Tau is a low-mass pre-main sequence star, whose strongly accreting protoplanetary disk exhibits a so-far enigmatic behavior: its mid-infrared thermal emission is strongly time-variable, even turning the 10 μm silicate feature from emission to absorption temporarily. Aims: We look for the reason for the spectral variability at high spatial resolution and at multiple epochs. Methods: Infrared interferometry can spatially resolve the thermal emission of the circumstellar disk, also giving information about dust processing. We study the temporal variability of the mid-infrared interferometric signal, observed with the VLTI/MIDI instrument at six epochs between 2011 and 2014. We fit a geometric disk model to the observed interferometric signal to obtain spatial information about the disk. We also model the mid-infrared spectra by template fitting to characterize the profile and time dependence of the silicate emission. We use physically motivated radiative transfer modeling to interpret the mid-infrared interferometric spectra. Results: The inner disk (r 1-3 au) spectra show a crystalline silicate feature in emission, similar to the spectra of comet Hale-Bopp. The striking difference between the inner and outer disk spectral feature is highly unusual among T Tauri stars. The mid-infrared variability is dominated by the outer disk. The strength of the silicate feature changed by more than a factor of two. Between 2011 and 2014 the half-light radius of the mid-infrared-emitting region decreased from 1.15 to 0.7 au. Conclusions: For the origin of the absorption we discuss four possible explanations: a cold obscuring envelope, an accretion heated inner disk, a temperature inversion on the disk surface and a misaligned inner geometry. The silicate emission in the outer disk can be explained by dusty material high above the disk plane, whose mass can change with time, possibly due to turbulence in the disk. Based on observations made with the ESO Very Large

  2. Rapid Mid-Infrared Variability in Protostellar Disks

    CERN Document Server

    Ke, Te T; Lin, Douglas N C

    2011-01-01

    Spectral energy distribution (SED) in protostellar disks is determined by the disks'internal dissipation and reprocessing of irradiation from their host stars. Around T Tauri stars, most mid-infrared (MIR) radiation (in a few to a few ten {\\mu}m wavelength range) emerge from regions around a fraction to a few AU's. This region is interesting because it contains both the habitable zone and the snow line. Recent observations reveal that SED variations, in the MIR wavelength range. These variations are puzzling because they occur on time scale (a few days) which is much shorter than the dynamical (months to years) time scale at 1AU to a few AU's. They are probably caused by shadows casted by inner onto outer disk regions. Interaction between disks and their misaligned magnetized host stars can lead to warped structure and periodic SED modulations. Rapid aperiodic SED variations may also be induced by observed X-ray flares from T Tauri stars. These flares can significantly modulate the ionization fraction of the ...

  3. Mid-Infrared Sensing of Organic Pollutants in Aqueous Environments

    Directory of Open Access Journals (Sweden)

    Andrew Ross

    2009-08-01

    Full Text Available The development of chemical sensors for monitoring the levels of organic pollutants in the aquatic environment has received a great deal of attention in recent decades. In particular, the mid-infrared (MIR sensor based on attenuated total reflectance (ATR is a promising analytical tool that has been used to detect a variety of hydrocarbon compounds (i.e., aromatics, alkyl halides, phenols, etc. dissolved in water. It has been shown that under certain conditions the MIR-ATR sensor is capable of achieving detection limits in the 10-100 ppb concentration range. Since the infrared spectral features of every single organic molecule are unique, the sensor is highly selective, making it possible to distinguish between many different analytes simultaneously. This review paper discusses some of the parameters (i.e., membrane type, film thickness, conditioning that dictate MIR ATR sensor response. The performance of various chemoselective membranes which are used in the fabrication of the sensor will be evaluated. Some of the challenges associated with long-term environmental monitoring are also discussed.

  4. The First Mid-Infrared Spectra of Cool White Dwarfs

    CERN Document Server

    Kilic, Mukremin; Mullally, Fergal; Reach, William T; von Hippel, Ted

    2007-01-01

    We present the first mid-infrared spectra of two cool white dwarfs obtained with the Spitzer Space Telescope. We also present 3.5-8 micron photometry for 19 cool white dwarfs with 5000K < Teff < 9000K. We perform a detailed model atmosphere analysis of these white dwarfs by fitting their UBVRIJHK and Spitzer photometry with state-of-the-art model atmospheres, and demonstrate that the optical and infrared spectral energy distributions of cool white dwarfs are well reproduced by our grid of models. Our mid-IR photometry and 7.5-14.5 micron spectrum of WD0018-267 are consistent with a Teff = 5720K, pure hydrogen white dwarf model atmosphere. On the other hand, LHS 1126 remains peculiar with significant mid-IR flux deficits in all IRAC bands and a featureless spectrum in the 5.2-7.5 micron range. Even though this deficit is attributed to collision induced absorption (CIA) due to molecular hydrogen, the shape of the deficit cannot be explained with current CIA opacity calculations. The infrared portion of th...

  5. Resolving the mid-infrared cores of local Seyferts

    CERN Document Server

    Gandhi, P; Smette, A; Hoenig, S; Comastri, A; Gilli, R; Vignali, C; Duschl, W

    2009-01-01

    We present new photometry of 16 local Seyferts including 6 Compton-thick sources in N-band filters around 12-microns, obtained with the VISIR instrument on the 8-m Very Large Telescope. The near-diffraction-limited imaging provides the least-contaminated core fluxes for these sources to date. Augmenting these with our previous observations and with published intrinsic X-ray fluxes, we form a total sample of 42 sources for which we find a strong mid-infrared:X-ray (12.3 micron:2-10 keV) luminosity correlation. Performing a physically-motivated sub-selection of sources in which the Seyfert torus is likely to be best-resolved results in the correlation L_{MIR} ~ L_X^{1.11+/-0.07}, with a reduction of the scatter in luminosities as compared to the full sample. Consideration of systematics suggests a range of 1.02-1.21 for the correlation slope. The mean 2 keV:12.3 micron spectral index (alpha_IX) is found to be -1.10+/-0.01, largely independent of luminosity. Observed 12-micron bolometric corrections range over ~...

  6. Spitzer mid-infrared spectroscopic observations of planetary nebulae

    CERN Document Server

    Mata, Héctor; Guerrero, Martin A; Nigoche-Netro, Alberto; Toalá, Jesús A; Fang, Xuan; Rubio, Gabriel M; Kemp, Simon N; Navarro, Silvana G; Corral, Luis J

    2016-01-01

    We present Spitzer Space Telescope archival mid-infrared (mid-IR) spectroscopy of a sample of eleven planetary nebulae (PNe). The observations, acquired with the Spitzer Infrared Spectrograph (IRS), cover the spectral range 5.2-14.5 {\\mu}m that includes the H2 0-0 S(2) to S(7) rotational emission lines. This wavelength coverage has allowed us to derive the Boltzmann distribution and calculate the H2 rotational excitation temperature (Tex). The derived excitation temperatures have consistent values ~900+/-70 K for different sources despite their different structural components. We also report the detection of mid-IR ionic lines of [Ar III], [S IV], and [Ne II] in most objects, and polycyclic aromatic hydrocarbon (PAH) features in a few cases. The decline of the [Ar III]/[Ne II] line ratio with the stellar effective temperature can be explained either by a true neon enrichment or by high density circumstellar regions of PNe that presumably descend from higher mass progenitor stars.

  7. The JCMT Spectral Legacy Survey

    CERN Document Server

    Plume, R; Helmich, F; Van der Tak, F F S; Roberts, H; Bowey, J; Buckle, J; Butner, H; Caux, E; Ceccarelli, C; Van Dishoeck, E F; Friberg, P; Gibb, A G; Hatchell, J; Hogerheijde, M R; Matthews, H; Millar, T; Mitchell, G; Moore, T J T; Ossenkopf, V; Rawlings, J; Richer, J; Roellig, M; Schilke, P; Spaans, M; Tielens, A G G M; Thompson, M A; Viti, S; Weferling, B; White, G J; Wouterloot, J; Yates, J; Zhu, M; White, Glenn J.

    2006-01-01

    Stars form in the densest, coldest, most quiescent regions of molecular clouds. Molecules provide the only probes which can reveal the dynamics, physics, chemistry and evolution of these regions, but our understanding of the molecular inventory of sources and how this is related to their physical state and evolution is rudimentary and incomplete. The Spectral Legacy Survey (SLS) is one of seven surveys recently approved by the JCMT Board. Starting in 2007, the SLS will produce a spectral imaging survey of the content and distribution of all the molecules detected in the 345 GHz atmospheric window (between 332 GHz and 373 GHz) towards a sample of 5 sources. Our intended targets are: a low mass core (NGC1333 IRAS4), 3 high mass cores spanning a range of star forming environments and evolutionary states (W49, AFGL2591, and IRAS20126), and a PDR (the Orion Bar). The SLS will use the unique spectral imaging capabilities of HARP-B/ACSIS to study the molecular inventory and the physical structure of these objects, w...

  8. Low-luminosity Blazars in Wise: A Mid-infrared View of Unification

    Science.gov (United States)

    Plotkin, Richard M.; Anderson, S. F.; Brandt, W. N.; Markoff, S.; Shemmer, O.; Wu, J.

    2012-01-01

    We use the preliminary data release from the Wide-Field Infrared Survey Explorer (WISE) to perform the first statistical study on the mid-infrared (IR) properties of a large number ( 102) of BL Lac objects -- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions (SEDs), and the shape of their SEDs in the IR correlates well with SED peak frequency. In other BL Lac objects, the jet is not strong enough to completely dilute the rest of the AGN, and we do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. While at odds with simple unification, the missing torus is consistent with recent suggestions that BL Lac objects are fed by radiatively inefficient accretion flows. We discuss implications on the ``nature vs. nurture" debate for FR I and FR II galaxies, and also on the standard orientation-based AGN unification model.

  9. The (new) Mid-Infrared Spectrometer and Imager (MIRSI) for the NASA Infrared Telescope Facility

    Science.gov (United States)

    Hora, Joseph L.; Trilling, David; Mommert, Michael; Smith, Howard A.; Moskovitz, Nicholas; Marscher, Alan P.; Tokunaga, Alan; Bergknut, Lars; Bonnet, Morgan; Bus, Schelte J.; Connelly, Michael; Rayner, John; Watanabe, Darryl

    2015-11-01

    The Mid-Infrared Spectrometer and Imager (MIRSI) was developed at Boston University and has been in use since 2002 on the Infrared Telescope Facility (IRTF), making observations of asteroids, planets, and comets in the 2 - 25 μm wavelength range. Recently the instrument has been unavailable due to electronics issues and the high cost of supplying liquid helium on Maunakea. We have begun a project to upgrade MIRSI to a cryocooler-based system with new array readout electronics and a dichroic and optical camera to simultaneously image the science field for image acquisition and optical photometry. The mechanical cryocooler will enable MIRSI to be continuously mounted on the IRTF multiple instrument mount (MIM) along with the other facility instruments, making it available to the entire community for multi-wavelength imaging and spectral observations. We will propose to use the refurbished MIRSI to measure the 10 μm flux from Near Earth Objects (NEOs) and determine their diameters and albedos through the use of a thermal model. We plan to observe up to 750 NEOs over the course of a three year survey, most of whose diameters will be under 300 meters. Here we present an overview of the MIRSI upgrade and give the current status of the project.This work is funded by the NASA Solar System Observations/NEOO program.

  10. Welcome to the Twilight Zone: The Mid-Infrared Properties of Poststarburst Galaxies

    CERN Document Server

    Alatalo, K; Bitsakis, T; Brown, M J I; Ciesla, L; Appleton, P N; Beaton, R L; Cales, S L; Crossett, J; Falcon-Barroso, J; French, K D; Kewley, L J; Kelson, D D; Kriek, M; Lanz, L; Medling, A M; Mulchaey, J S; Nyland, K; Rich, J A; Urry, C M

    2016-01-01

    We investigate the optical and Wide-field Survey Explorer (WISE) colors of "E+A" identified poststarburst galaxies, including a deep analysis on 190 poststarbursts detected in the 2MASS Extended Source Catalog. The poststarburst galaxies appear in both the optical green valley and the WISE Infrared Transition Zone (IRTZ). Furthermore, we find that poststarbursts occupy a distinct region [3.4]-[4.6] vs. [4.6]-[12] WISE colors, enabling the identification of this class of transitioning galaxies through the use of broad band photometric criteria alone. We have investigated possible causes for the WISE colors of poststarbursts by constructing a composite spectral energy distribution (SED), finding that mid-infrared (4--12\\micron) properties of poststarbursts are consistent with either 11.3um polycyclic aromatic hydrocarbon emission, or Thermally Pulsating Asymptotic Giant Branch (TP-AGB) and post-AGB stars. The composite SED of extended poststarburst galaxies with 22um emission detected with signal to noise >3 re...

  11. YSOVAR: Mid-infrared variability in the star-forming region Lynds 1688

    Energy Technology Data Exchange (ETDEWEB)

    Günther, H. M.; Poppenhaeger, K.; Wolk, S. J.; Hora, J. L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Cody, A. M. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Covey, K. R. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Plavchan, P. [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Rebull, L. M.; Stauffer, J. R. [Spitzer Science Center/Caltech, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Allen, L. [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Bayo, A. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Meng, H. Y. A. [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Morales-Calderón, M. [Centro de Astrobiología (INTA-CSIC), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Canada (Spain); Parks, J. R. [Department of Physics and Astronomy, Georgia State University, 25 Park Place South, Atlanta, GA 30303 (United States); Song, Inseok, E-mail: hguenther@cfa.harvard.edu [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States)

    2014-12-01

    The emission from young stellar objects (YSOs) in the mid-infrared (mid-IR) is dominated by the inner rim of their circumstellar disks. We present IR data from the Young Stellar Object VARiability (YSOVAR) survey of ∼800 objects in the direction of the Lynds 1688 (L1688) star-forming region over four visibility windows spanning 1.6 yr using the Spitzer Space Telescope in its warm mission phase. Among all light curves, 57 sources are cluster members identified based on their spectral energy distribution and X-ray emission. Almost all cluster members show significant variability. The amplitude of the variability is larger in more embedded YSOs. Ten out of 57 cluster members have periodic variations in the light curves with periods typically between three and seven days, but even for those sources, significant variability in addition to the periodic signal can be seen. No period is stable over 1.6 yr. Nonperiodic light curves often still show a preferred timescale of variability that is longer for more embedded sources. About half of all sources exhibit redder colors in a fainter state. This is compatible with time-variable absorption toward the YSO. The other half becomes bluer when fainter. These colors can only be explained with significant changes in the structure of the inner disk. No relation between mid-IR variability and stellar effective temperature or X-ray spectrum is found.

  12. Emission Features and Source Counts of Galaxies in Mid-Infrared

    CERN Document Server

    Xu, C; Fang, F; Shupe, D L; Lonsdale, C J; Lu, N Y; Helou, G; Stacey, G J; Ashby, M L N; Xu, Cong; Hacking, Perry B.; Fang, Fan; Shupe, David L.; Lonsdale, Carol J.; Lu, Nanyao Y.; Helou, George; Stacey, Gordon J.; Ashby, Matthew L.N.

    1998-01-01

    In this work we incorporate the newest ISO results on the mid-infrared spectral-energy-distributions (MIR SEDs) of galaxies into models for the number counts and redshift distributions of MIR surveys. A three-component model, with empirically determined MIR SED templates of (1) a cirrus/PDR component (2) a starburst component and (3) an AGN component, is developed for infrared (3--120\\micron) SEDs of galaxies. The model includes a complete IRAS 25\\micron selected sample of 1406 local galaxies ($z \\leq 0.1$; Shupe et al. 1998a). Results based on these 1406 spectra show that the MIR emission features cause significant effects on the redshift dependence of the K-corrections for fluxes in the WIRE 25\\micron band and ISOCAM 15\\micron band. This in turn will affect deep counts and redshift distributions in these two bands, as shown by the predictions of two evolution models (a luminosity evolution model with $L\\propto (1+z)^3$ and a density evolution model with $\\rho\\propto (1+z)^4$). The dips-and-bumps on curves o...

  13. Mid-infrared supercontinuum generation in a suspended core chalcogenide fiber

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Yu, Yi; Gai, Xin;

    The mid-infrared spectral region is of great interest because virtually all organic compounds display distinctive spectral fingerprints herein that reveal chemical information about them [1], and the mid-infrared region is therefore of key importance to many applications, including food quality...... control [2], gas sensing [3] and medical diagnostics [4] . We have used a low-loss suspended core As 38 Se 62 fiber with core diameter of 4.5 μ m and a zero - dispersion wavelength of 3.5 μ m to generate mid-infrared supercontinuum by pumping with an optical parametric amplifier delivering 320 fs pulses...... with a peak power of ~5.5 kW at a repetition rate of 21 MHz at different wavelengths from 3.3 to 4.7 μ m . By pumping at 4.4 μ m with a peak power of 5.2 kW coupled to the fiber a supercontinuum spanning from 1.7 to 7.5 μ m with an average output power of 15.6 mW was obtained. Figure 1 shows the results...

  14. Gate-controlled mid-infrared light bending with aperiodic graphene nanoribbons array

    CERN Document Server

    Carrasco, Eduardo; Mosig, Juan R; Low, Tony; Perruisseau-Carrier, Julien

    2014-01-01

    Graphene plasmonic nanostructures enable subwavelength confinement of electromagnetic energy from the mid-infrared down to the terahertz frequencies. By exploiting the spectrally varying light scattering phase at vicinity of the resonant frequency of the plasmonic nanostructure, it is possible to control the angle of reflection of an incoming light beam. We demonstrate, through full-wave electromagnetic simulations based on Maxwell equations, the electrical control of the angle of reflection of a mid-infrared light beam by using an aperiodic array of graphene nanoribbons, whose widths are engineered to produce a spatially varying reflection phase profile that allows for the construction of a far-field collimated beam towards a predefined direction.

  15. Nanowires-assisted excitation and propagation of mid-infrared surface plasmon polaritons in graphene

    Science.gov (United States)

    Lu, Hua; Zhao, Jianlin; Gu, Min

    2016-10-01

    We investigate the excitation and propagation of surface plasmon polaritons in a novel graphene hybrid photonic nanostructure, which consists of a graphene sheet and a dielectric layer with partly etched nanowires coated on the silicon substrate. The simulation and analytical results show that the mid-infrared plasmonic wave can be generated in the graphene sheet by normally incident light due to the satisfaction of the wavevector matching condition. Especially, we find that the plasmonic wavelength and spectral width are determined by the width, pitch, and refractive index of the dielectric nanowires, as well as the layer number and the Fermi level of graphene sheet. The analytical calculations agree well with the finite-difference time-domain simulations. These results would provide an new avenue toward the excitation of graphene plasmonics for the manipulation of mid-infrared light at nanoscale.

  16. Mid-Infrared Properties of Disk Averaged Observations of Earth with AIRS

    CERN Document Server

    Hearty, Thomas; Kim, Sam; Tinetti, Giovanna

    2008-01-01

    We have investigated mid-infrared spectra of Earth obtained by the Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to explore the characteristics that may someday be observed in extrasolar terrestrial planets. We have used the AIRS infrared (R ~ 1200; 3.75-15.4 microns) spectra to construct directly-observed high-resolution spectra of the only known life bearing planet, Earth. The AIRS spectra are the first such spectra that span the seasons. We investigate the rotational and seasonal spectral variations that would arise due to varying cloud amount and viewing geometry and we explore what signatures may be observable in the mid-infrared by the next generation of telescopes capable of observing extrasolar terrestrial planets.

  17. Confronting Standard Models of Proto--Planetary Disks With New Mid--Infrared Sizes from the Keck Interferometer

    CERN Document Server

    Millan-Gabet, Rafael; Monnier, John D; Sitko, Michael L; Russell, Ray W; Grady, Carol A; Day, Amanda N; Perry, R B; Harries, Tim J; Aarnio, Alicia N; Colavita, Mark M; Wizinowich, Peter L; Ragland, Sam; Woillez, Julien

    2016-01-01

    We present near and mid-infrared interferometric observations made with the Keck Interferometer Nuller and near-contemporaneous spectro-photometry from the IRTF of 11 well known young stellar objects, several observed for the first time in these spectral and spatial resolution regimes. With AU-level spatial resolution, we first establish characteristic sizes of the infrared emission using a simple geometrical model consisting of a hot inner rim and mid-infrared disk emission. We find a high degree of correlation between the stellar luminosity and the mid-infrared disk sizes after using near-infrared data to remove the contribution from the inner rim. We then use a semi-analytical physical model to also find that the very widely used "star + inner dust rim + flared disk" class of models strongly fails to reproduce the SED and spatially-resolved mid-infrared data simultaneously; specifically a more compact source of mid-infrared emission is required than results from the standard flared disk model. We explore t...

  18. Standardization of milk mid-infrared spectra from a European dairy network.

    Science.gov (United States)

    Grelet, C; Fernández Pierna, J A; Dardenne, P; Baeten, V; Dehareng, F

    2015-04-01

    The goal of this study was to find a procedure to standardize dairy milk mid-infrared spectra from different Fourier transform mid-infrared spectrophotometers (different brands or models) inside a European dairy network to create new farm-management indicators (e.g., fertility, health, feed, environmental impact) based on milk infrared spectra. This step is necessary to create common spectral databases, allowing the building of statistical tools, to be used by all instruments of the network. The method used was piecewise direct standardization (PDS), which matches slave-instrument spectra on master-instrument spectra. To evaluate the possibility of using common equations on different instruments, the PDS method was tested on a set of milk samples measured on each machine, and an equation predicting fat content of milk is applied on all. Regressions were performed between master and slaves fat predictions, before and after PDS. Bias and root mean square error between predictions were decreased after PDS, respectively, from 0.3781 to 0.0000 and from 0.4609 to 0.0156 (g of fat/100mL of milk). The stability over time of these results was confirmed by an application of the coefficients created by PDS 1 mo later on the slave spectra. These preliminary results showed that the PDS method permits a reduction of the inherent spectral variability between instruments, allowing the merging of Fourier transform mid-infrared milk spectra from different instruments into a common database, the creation of new types of dairy farm management indicators, and the use of these common calibrations for all Fourier transform mid-infrared instruments of the European dairy network.

  19. Increased mid-infrared supercontinuum bandwidth and average power by tapering large-mode-area chalcogenide photonic crystal fibers

    DEFF Research Database (Denmark)

    Petersen, Christian Rosenberg; Engelsholm, Rasmus Dybbro; Markos, Christos

    2017-01-01

    The trade-off between the spectral bandwidth and average output power from chalcogenide fiber-based mid-infrared supercontinuum sources is one of the major challenges towards practical application of the technology. In this paper we address this challenge through tapering of large-mode-area chalc...... m. (C) 2017 Optical Society of America...

  20. Diffuse-reflectance fourier-transform mid-infrared spectroscopy as a method of characterizing changes in soil organic matter

    Science.gov (United States)

    Diffuse-Reflectance Fourier-Transform Mid-Infrared Spectroscopy (MidIR) can identify the presence of important organic functional groups in soil organic matter (SOM). Soils contain myriad organic and inorganic components that absorb in the MidIR so spectral interpretation needs to be validated in or...

  1. Jupiter's Mid-Infrared Aurora: Solar Connection and Minor Constituents

    Science.gov (United States)

    Kostiuk, Theodore; Livengood, T.A.; Fast, K.E.; Hewagama, T.; Schmilling, F.; Sonnabend, G.; Delgado, J.

    2009-01-01

    High spectral resolution in the 12 pin region of the polar regions of Jupiter reveal unique information on auroral phenomena and upper stratospheric composition. Polar aurorae in Jupiter's atmosphere radiate; throughout the electromagnetic spectrum from X-ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based. spectroscopic measurements of Jupiter's northern mid-IR aurora acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane, emission brightness and solar 10.7-cm radar flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high scalar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. The spectra measured contain features that cannot be attributed to ethane and are most likely spectra of minor constituents whose molecular bands overlap the v9 band of ethane. Possible candidates are allene, propane, and other higher order hydrocarbons. These features appear to be enhanced in the active polar regions. Laboratory measurements at comparable spectral resolution of spectra of candidate molecules will be used to identify the constituents. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the NASA/ESA Europa Jupiter System Mission.

  2. ISO Mid-Infrared spectroscopy of Galactic Bulge AGB stars

    CERN Document Server

    Blommaert, J A D L; Okumura, K; Ganesh, S; Omont, A; Cami, J; Glass, I S; Habing, H J; Schultheis, M; Simon, G; Van Loon, J T; Blommaert, Joris A.D.L.; Groenewegen, Martin A.T.; Okumura, Koryo; Ganesh, Shashikiran; Omont, Alain; Cami, Jan; Glass, Ian S.; Habing, Harm J.; Schultheis, Mathias; Simon, Guy; Loon, Jacco Th. van

    2006-01-01

    To study the nature of Bulge AGB stars and in particular their circumstellar dust, we have analysed mid-infrared spectra obtained with the ISOCAM CVF spectrometer in three Bulge fields. The ISOCAM 5-16.5 micron CVF spectra were obtained as part of the ISOGAL infrared survey of the inner Galaxy. A classification of the shape of the 10 micron dust feature was made for each case. The spectra of the individual sources were modelled using a radiative transfer model. Different combinations of amorphous silicates and aluminium-oxide dust were used in the modelling. Spectra were obtained for 29 sources of which 26 are likely to be Bulge AGB stars. Our modelling shows that the stars suffer mass loss rates in the range of 10^{-8} - 5 x 10^{-7} Msun / yr, which is at the low end of the mass-loss rates experienced on the Thermally Pulsing AGB. The luminosities range from 1,700 to 7,700 Lsun as expected for a population of AGB stars with Minit of 1.5 - 2Msun. In agreement with the condensation sequence scenario, we find t...

  3. Stellar populations in the outskirts of M31: the mid-infrared view

    CERN Document Server

    Barmby, P

    2016-01-01

    The mid-infrared provides a unique view of galaxy stellar populations, sensitive to both the integrated light of old, low-mass stars and to individual dusty mass-losing stars. We present results from an extended Spitzer/IRAC survey of M31 with total lengths of 6.6 and 4.4 degrees along the major and minor axes, respectively. The integrated surface brightness profile proves to be surprisingly diffcult to trace in the outskirts of the galaxy, but we can also investigate the disk/halo transition via a star count profile, with careful correction for foreground and background contamination. Our point-source catalog allows us to report on mid-infrared properties of individual objects in the outskirts of M31, via cross-correlation with PAndAS, WISE, and other catalogs.

  4. Fourier transform infrared spectroscopy approach for measurements of photoluminescence and electroluminescence in mid-infrared

    Science.gov (United States)

    Zhang, Y. G.; Gu, Y.; Wang, K.; Fang, X.; Li, A. Z.; Liu, K. H.

    2012-05-01

    An improved Fourier transform infrared spectroscopy approach adapting to photoluminescence and electroluminescence measurements in mid-infrared has been developed, in which diode-pumped solid-state excitation lasers were adopted for photoluminescence excitation. In this approach, three different Fourier transform infrared modes of rapid scan, double modulation, and step scan were software switchable without changing the hardware or connections. The advantages and limitations of each mode were analyzed in detail. Using this approach a group of III-V and II-VI samples from near-infrared extending to mid-infrared with photoluminescence intensities in a wider range have been characterized at room temperature to demonstrate the validity and overall performances of the system. The weaker electroluminescence of quantum cascade lasers in mid-infrared band was also surveyed at different resolutions. Results show that for samples with relatively strong photoluminescence or electroluminescence out off the background, rapid scan mode is the most preferable. For weaker photoluminescence or electroluminescence overlapped with background, double modulation is the most effective mode. To get a better signal noise ratio when weaker photoluminescence or electroluminescence signal has been observed in double modulation mode, switching to step scan mode should be an advisable option despite the long data acquiring time and limited resolution.

  5. Fourier transform infrared spectroscopy approach for measurements of photoluminescence and electroluminescence in mid-infrared.

    Science.gov (United States)

    Zhang, Y G; Gu, Y; Wang, K; Fang, X; Li, A Z; Liu, K H

    2012-05-01

    An improved Fourier transform infrared spectroscopy approach adapting to photoluminescence and electroluminescence measurements in mid-infrared has been developed, in which diode-pumped solid-state excitation lasers were adopted for photoluminescence excitation. In this approach, three different Fourier transform infrared modes of rapid scan, double modulation, and step scan were software switchable without changing the hardware or connections. The advantages and limitations of each mode were analyzed in detail. Using this approach a group of III-V and II-VI samples from near-infrared extending to mid-infrared with photoluminescence intensities in a wider range have been characterized at room temperature to demonstrate the validity and overall performances of the system. The weaker electroluminescence of quantum cascade lasers in mid-infrared band was also surveyed at different resolutions. Results show that for samples with relatively strong photoluminescence or electroluminescence out off the background, rapid scan mode is the most preferable. For weaker photoluminescence or electroluminescence overlapped with background, double modulation is the most effective mode. To get a better signal noise ratio when weaker photoluminescence or electroluminescence signal has been observed in double modulation mode, switching to step scan mode should be an advisable option despite the long data acquiring time and limited resolution.

  6. A variable mid-infrared synchrotron break associated with the compact jet in GX 339-4

    NARCIS (Netherlands)

    Gandhi, P.; Blain, A.W.; Russell, D.M.; Casella, P.; Malzac, J.; Corbel, S.; D'Avanzo, P.; Lewis, F.W.; Markoff, S.; Cadolle Bel, M.; Goldoni, P.; Wachter, S.; Khangulyan, D.; Mainzer, A.

    2011-01-01

    Many X-ray binaries remain undetected in the mid-infrared, a regime where emission from their compact jets is likely to dominate. Here, we report the detection of the black hole binary GX 339-4 with the Wide-field Infrared Survey Explorer (WISE) during a very bright, hard accretion state in 2010. Co

  7. Mid-infrared ISO spectroscopy of NGC 4945

    NARCIS (Netherlands)

    Spoon, HWW; Koornneef, J; Moorwood, AFM; Lutz, D; Tielens, AGGM

    2000-01-01

    We have observed the central region of the nearby starburst galaxy NGC 4945 with the mid-infrared spectrometers SWS and PHT-S aboard ISO. We do not find any evidence for the existence of the powerful AGN, inferred from hard X-ray observations. The upper limits on our AGN tracers [Nev]14.32 mu m&24.3

  8. Mid-infrared laser filaments in the atmosphere

    Science.gov (United States)

    Mitrofanov, A. V.; Voronin, A. A.; Sidorov-Biryukov, D. A.; Pugžlys, A.; Stepanov, E. A.; Andriukaitis, G.; Flöry, T.; Ališauskas, S.; Fedotov, A. B.; Baltuška, A.; Zheltikov, A. M.

    2015-01-01

    Filamentation of ultrashort laser pulses in the atmosphere offers unique opportunities for long-range transmission of high-power laser radiation and standoff detection. With the critical power of self-focusing scaling as the laser wavelength squared, the quest for longer-wavelength drivers, which would radically increase the peak power and, hence, the laser energy in a single filament, has been ongoing over two decades, during which time the available laser sources limited filamentation experiments in the atmosphere to the near-infrared and visible ranges. Here, we demonstrate filamentation of ultrashort mid-infrared pulses in the atmosphere for the first time. We show that, with the spectrum of a femtosecond laser driver centered at 3.9 μm, right at the edge of the atmospheric transmission window, radiation energies above 20 mJ and peak powers in excess of 200 GW can be transmitted through the atmosphere in a single filament. Our studies reveal unique properties of mid-infrared filaments, where the generation of powerful mid-infrared supercontinuum is accompanied by unusual scenarios of optical harmonic generation, giving rise to remarkably broad radiation spectra, stretching from the visible to the mid-infrared. PMID:25687621

  9. Raman and mid-infrared spectroscopic imaging: applications and advancements

    NARCIS (Netherlands)

    Gautam, R.; Samuel, A.; Sil, S.; Chaturvedi, D.; Dutta, A.; Ariese, F.; Umapathy, S.

    2015-01-01

    Using Raman and Mid-Infrared (MIR) spectroscopic imaging techniques one can examine the spatial distribution of various molecular constituents in a heterogeneous sample at a microscopic scale. Raman and MIR spectroscopy techniques provide bond-specific vibrational frequencies to characterize

  10. Group IV platforms for the mid-infrared

    Science.gov (United States)

    Mashanovich, G. Z.; Nedeljkovic, M.; Chen, X.; Ben Masaud, T. M.; Muneeb, M.; Strain, M.; Sorel, M.; Krauss, T. F.; Roelkens, G. C.; Peacock, A. C.; Chong, H. M. H.; Reed, G. T.

    2013-05-01

    We have investigated several material platforms for the mid-infrared including silicon on insulator (SOI), polycrystalline silicon, and suspended silicon structures. We review photonic devices based on these platforms including splitters, ring/racetrack resonators, Mach-Zehnder interferometers, and spectrometers.

  11. Group IV photonic devices for the mid-infrared

    Science.gov (United States)

    Mashanovich, G. Z.; Nedeljkovic, M.; Milosevic, M. M.; Hu, Y.; Gardes, F. Y.; Thomson, D. J.; Masaud, T.-B.; Jaberansary, E.; Chong, H. M. H.; Soref, R.; Reed, G. T.

    2012-06-01

    Group IV mid-infrared photonics is attracting more research interest lately. The main reason is a host of potential applications ranging from sensing, to medicine, to free space communications and infrared countermeasures. The field is, however, in its infancy and there are several serious challenges to be overcome before we see progress similar to that in the near-infrared silicon photonics. The first is to find suitable material platforms for the mid-infrared. In this paper we present experimental results for passive mid-infrared photonic devices realised in silicon-on-insulator, silicon-on-sapphire, and silicon on porous silicon. We also present relationships for the free-carrier induced electro-refraction and electro-absorption in silicon and germanium in the mid-infrared wavelength range. Electro-absorption modulation is calculated from impurity-doping spectra taken from the literature, and a Kramers-Kronig analysis of these spectra is used to predict electro-refraction modulation. We examine the wavelength dependence of electro-refraction and electro-absorption, finding that the predictions suggest longer-wave modulator designs will in many cases be different than those used in the telecom range.

  12. Mid-infrared followup of cold brown dwarfs: diversity in age, mass and metallicity

    Energy Technology Data Exchange (ETDEWEB)

    Saumon, Didier [Los Alamos National Laboratory; Leggett, Sandy K [GEMINI OBSERVATORY; Burningham, Ben [HERTFORDSHITE UNIV; Marley, Mark S [NASA AMES; Waren, S J [IMPERIAL COLLEGE LONDON; Jones, H R A [HERTFORDSHIRE U; Pinfield, D J [HERTFORDSHIRE U; Smart, R L [ASTRONOMICAL OBS

    2009-01-01

    We present new Spitzer IRAC [3.6], [4.5], [5.8] and [8.0] photometry of nine very late-type T dwarfs. Combining this with previously published photometry, we investigate trends with type and color that are useful for both the planning and interpretation of infrared surveys designed to discover the coldest T or Y dwarfs. Brown dwarfs with effective temperature (T{sub eff}) below 700 K emit more than half their flux at wavelengths longer than 3 {micro}m, and the ratio of the mid-infrared flux to the near-infrared flux becomes very sensitive to T{sub eff} at these low temperatures. We confirm that the color H (1.6 {micro}m) - [4.5] is a good indicator of T{sub eff} with a relatively weak dependence on metallicity and gravity. Conversely, the colors H - K (2.2 {micro}m) and [4.5] - [5.8] are sensitive to metallicity and gravity. Thus near- and mid-infrared photometry provide useful indicators of the fundamental properties of brown dwarfs, and if temperature and gravity are known, then mass and age can be reliably determined from evolutionary models. There are twelve dwarfs currently known with H - [4.5] > 3.0, and {approx} 500 < T{sub eff} K {approx}< 800, which we examine in detail. The ages of the dwarfs in the sample range from very young (0.1 - 1.0 Gyr) to relatively old (3 - 12 Gyr). The mass range is possibly as low as 5 Jupiter masses to up to 70 Jupiter masses, i.e. near the hydrogen burning limit. The metallicities also span a large range, from [m/H]= -0.3 to [m/H]= +0.2. The small number of T8 - T9 dwarfs found in the UKIRT Infrared Deep Sky Survey to date appear to be predominantly young low-mass dwarfs. Accurate mid-infrared photometry of cold brown dwarfs is essentially impossible from the ground, and extensions to the mid-infrared space missions warm-Spitzer and WISE are desirable in order to obtain the vital mid-infrared data for cold brown dwarfs, and to discover more of these rare objects.

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

    Science.gov (United States)

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

    2016-07-22

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

  14. Prediction of protein composition of individual cow milk using mid-infrared spectroscopy

    OpenAIRE

    Paolo Carnier; Guido Di Martino; Alessio Cecchinato; Valentina Bonfatti; Massimo De Marchi

    2010-01-01

    This study investigated the application of mid-infrared spectroscopy for the prediction of protein composition in individual milk samples (n=1,336) of Simmental cows. Protein fractions were quantified by RP-HPLC and MIR data were recorded over the spectral range from 4,000 to 900 cm-1. Models were developed by partial least squares regression using untreated spectra. The most successful predictions were for protein, casein, αS1-casein, whey protein, and β-lactoglobulin contents. Th...

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

    Science.gov (United States)

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

    2016-07-01

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

  16. Mid-Infrared Optical Frequency Combs based on Difference Frequency Generation for Molecular Spectroscopy

    CERN Document Server

    Cruz, Flavio C; Johnson, Todd; Ycas, Gabriel; Klose, Andrew; Giorgetta, Fabrizio R; Coddington, Ian; Diddams, Scott A

    2015-01-01

    Mid-infrared femtosecond optical frequency combs were produced by difference frequency generation of the spectral components of a near-infrared comb in a 3-mm-long MgO:PPLN crystal. We observe strong pump depletion and 9.3 dB parametric gain in the 1.5 \\mu m signal, which yields powers above 500 mW (3 \\mu W/mode) in the idler with spectra covering 2.8 \\mu m to 3.5 \\mu m. Potential for broadband, high-resolution molecular spectroscopy is demonstrated by absorption spectra and interferograms obtained by heterodyning two combs.

  17. Mid-Infrared Plasmonic Biosensing with Graphene

    CERN Document Server

    Rodrigo, Daniel; Janner, Davide; Etezadi, Dordaneh; de Abajo, F Javier García; Pruneri, Valerio; Altug, Hatice

    2015-01-01

    Infrared spectroscopy is the technique of choice for chemical identification of biomolecules through their vibrational fingerprints. However, infrared light interacts poorly with nanometric size molecules. Here, we exploit the unique electro-optical properties of graphene to demonstrate a high-sensitivity tunable plasmonic biosensor for chemically-specific label-free detection of protein monolayers. The plasmon resonance of nanostructured graphene is dynamically tuned to selectively probe the protein at different frequencies and extract its complex refractive index. Additionally, the extreme spatial light confinement in graphene, up to two orders of magnitude higher than in metals, produces an unprecedentedly high overlap with nanometric biomolecules, enabling superior sensitivity in the detection of their refractive index and vibrational fingerprints. The combination of tunable spectral selectivity and enhanced sensitivity of graphene opens exciting prospects for biosensing.

  18. Quasar Variability in the Mid-Infrared

    CERN Document Server

    Kozlowski, Szymon; Ashby, Matthew L N; Assef, Roberto J; Brodwin, Mark; Eisenhardt, Peter R; Jannuzi, Buell T; Stern, Daniel

    2015-01-01

    The Decadal IRAC Bootes Survey (DIBS) is a mid-IR variability survey of the ~9 sq. deg. of the NDWFS Bootes Field and extnds the time baseline of its predecessor, the Spitzer Deep, Wide-Field Survey (SDWFS), from 4 to 10 years. The Spitzer Space Telescope visited the field five times between 2004 and 2014 at 3.6 and 4.5 microns. We provide the difference image analysis photometry for a half a million mostly extragalactic sources. In the mid-IR color-color plane, sources with quasar colors constitute the largest variability class (75%), 16% of the variable objects have stellar colors and the remaining 9% have the colors of galaxies. Adding the fifth epoch doubles the number of variable AGNs for the same false positive rates as in SDWFS, or increases the number of sources by 20% while decreasing the false positive rates by factors of 2-3 for the same variability amplitude. We quantify the ensemble mid-IR variability of ~1500 spectroscopically confirmed AGNs using single power-law structure functions, which we f...

  19. YSOVAR: MID-INFRARED VARIABILITY AMONG YSOs IN THE STAR FORMATION REGION GGD12-15

    Energy Technology Data Exchange (ETDEWEB)

    Wolk, Scott J.; Günther, H. Moritz; Poppenhaeger, Katja; Forbrich, J. [Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Cody, A. M. [NASA Ames Research Center, M/S 244-5 Moffett Field, CA 94035 (United States); Rebull, L. M.; Stauffer, J. R. [Spitzer Science Center/Caltech, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Plavchan, P. [Department of Physics Astronomy and Materials Science, Missouri State University, Springfield, MO 65897 (United States); Covey, K. R. [Department of Physics and Astronomy, Western Washington Univ., Bellingham, WA 98225-9164 (United States); Song, Inseok, E-mail: swolk@cfa.harvard.edu [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States)

    2015-11-15

    We present an IR-monitoring survey with the Spitzer Space Telescope of the star-forming region GGD 12-15. More than 1000 objects were monitored, including about 350 objects within the central 5′, which is found to be especially dense in cluster members. The monitoring took place over 38 days and is part of the Young Stellar Object VARiability project. The region was also the subject of a contemporaneous 67 ks Chandra observation. The field includes 119 previously identified pre-main sequence star candidates. X-rays are detected from 164 objects, 90 of which are identified with cluster members. Overall, we find that about half the objects in the central 5′ are young stellar objects (YSOs) based on a combination of their spectral energy distribution, IR variability, and X-ray emission. Most of the stars with IR excess relative to a photosphere show large amplitude (>0.1 mag) mid-infrared (mid-IR) variability. There are 39 periodic sources, and all but one is found to be a cluster member. Almost half of the periodic sources do not show IR excesses. Overall, more than 85% of the Class I, flat spectrum, and Class II sources are found to vary. The amplitude of the variability is larger in more embedded YSOs. Most of the Class I/II objects exhibit redder colors in a fainter state, which is compatible with time-variable extinction. A few become bluer when fainter, which can be explained with significant changes in the structure of the inner disk. A search for changes in the IR due to X-ray events is carried out, but the low number of flares prevented an analysis of the direct impact of X-ray flares on the IR light curves. However, we find that X-ray detected Class II sources have longer timescales for change in the MIR than a similar set of non-X-ray detected Class IIs.

  20. Mid-infrared upconversion spectroscopy based on a Yb:fiber femtosecond laser

    CERN Document Server

    Johnson, Todd A

    2011-01-01

    We present a system for molecular spectroscopy using a broadband mid-infrared laser with near infrared detection. Difference frequency generation of a Yb:fiber femtosecond laser produced a mid-infrared (MIR) source tunable from 2100-3700 cm^-1 (2.7-4.7 microns) with average power up to 40 mW. The MIR spectrum was upconverted to near-infrared wavelengths for broadband detection using a two-dimensional dispersion imaging technique. Absorption measurements were performed over bandwidths of 240 cm^-1 (7.2 THz) with 0.048 cm^-1 (1.4 GHz) resolution, and absolute frequency scale uncertainty was better than 0.005 cm^-1 (150 MHz). The minimum detectable absorption coefficient per spectral element was determined to be 4.4 x 10^-7 cm^-1 from measurements in low pressure CH_4, leading to a detection limit of 2 parts-per-billion. The spectral range, resolution, and frequency accuracy of this system show promise for determination of trace concentrations in gas mixtures containing both narrow and broad overlapping spectral...

  1. Observations of V592 Cassiopeiae with the Spitzer Space Telescope - Dust in the Mid-Infrared

    CERN Document Server

    Hoard, D W; Wachter, Stefanie; Howell, Steve B; Brinkworth, Carolyn S; Ciardi, David R; Szkody, Paula; Belle, Kunegunda; Froning, Cynthia; van Belle, Gerard

    2008-01-01

    We present the ultraviolet-optical-infrared spectral energy distribution of the low inclination novalike cataclysmic variable V592 Cassiopeiae, including new mid-infrared observations from 3.5-24 microns obtained with the Spitzer Space Telescope. At wavelengths shortward of 8 microns, the spectral energy distribution of V592 Cas is dominated by the steady state accretion disk, but there is flux density in excess of the summed stellar components and accretion disk at longer wavelengths. Reproducing the observed spectral energy distribution from ultraviolet to mid-infrared wavelengths can be accomplished by including a circumbinary disk composed of cool dust, with a maximum inner edge temperature of ~500 K. The total mass of circumbinary dust in V592 Cas (~10^21 g) is similar to that found from recent studies of infrared excess in magnetic CVs, and is too small to have a significant effect on the long-term secular evolution of the cataclysmic variable. The existence of circumbinary dust in V592 Cas is possibly ...

  2. A multiwavelength study of Cygnus X-1: the first mid-infrared spectroscopic detection of compact jets

    CERN Document Server

    Rahoui, Farid; Heinz, Sebastian; Hynes, Dean C; Pottschmidt, Katja; Wilms, Jörn; Grinberg, Victoria

    2011-01-01

    We report on a Spitzer/IRS (mid-infrared), RXTE/PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multiwavelength study of the microquasar Cygnus X-1, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break - where the transition from the optically thick to the optically thin regime takes place - at about 2.9e13 Hz. We then show that the jet's optically thin synchrotron emission accounts for the Cygnus X-1's emission beyond 400 keV, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 micron mid-infrared continuum of Cygnus X-1 stems from the blue supergiant com...

  3. 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.

  4. Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings

    Science.gov (United States)

    Edlridge, Jeffrey I.; Martin, Richard E.

    2009-01-01

    An apparatus for mid-infrared reflectance imaging has been developed as means of inspecting for subsurface damage in thermal-barrier coatings (TBCs). The apparatus is designed, more specifically, for imaging the progression of buried delamination cracks in plasma-sprayed yttria-stabilized zirconia coatings on turbine-engine components. Progression of TBC delamination occurs by the formation of buried cracks that grow and then link together to produce eventual TBC spallation. The mid-infrared reflectance imaging system described here makes it possible to see delamination progression that is invisible to the unaided eye, and therefore give sufficiently advanced warning before delamination progression adversely affects engine performance and safety. The apparatus (see figure) includes a commercial mid-infrared camera that contains a liquid-nitrogen-cooled focal plane indium antimonide photodetector array, and imaging is restricted by a narrow bandpass centered at wavelength of 4 microns. This narrow wavelength range centered at 4 microns was chosen because (1) it enables avoidance of interfering absorptions by atmospheric OH and CO2 at 3 and 4.25 microns, respectively; and (2) the coating material exhibits maximum transparency in this wavelength range. Delamination contrast is produced in the midinfrared reflectance images because the introduction of cracks into the TBC creates an internal TBC/air-gap interface with a high diffuse reflectivity of 0.81, resulting in substantially higher reflectance of mid-infrared radiation in regions that contain buried delamination cracks. The camera is positioned a short distance (.12 cm) from the specimen. The mid-infrared illumination is generated by a 50-watt silicon carbide source positioned to the side of the mid-infrared camera, and the illumination is collimated and reflected onto the specimen by a 6.35-cm-diameter off-axis paraboloidal mirror. Because the collected images are of a steady-state reflected intensity (in

  5. YSOVAR: MID-INFRARED VARIABILITY IN NGC 1333

    Energy Technology Data Exchange (ETDEWEB)

    Rebull, L. M. [Infrared Science Archive (IRSA), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Stauffer, J. R.; Cody, A. M. [Spitzer Science Center (SSC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Günther, H. M.; Poppenhaeger, K.; Wolk, S. J.; Hora, J.; Forbrich, J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Hernandez, J. [Centro de Investigaciones de Astronomía, Apdo. Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Bayo, A. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Covey, K. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Gutermuth, R. [Dept. of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Morales-Calderón, M.; Bouy, H. [Depto. Astrofísica, Centro de Astrobiología (INTA-CSIC), ESAC campus, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Plavchan, P. [NASA Exoplanet Science Institute (NExScI), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Song, I. [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States); Terebey, S., E-mail: rebull@ipac.caltech.edu [Department of Physics and Astronomy, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States); and others

    2015-12-15

    As part of the Young Stellar Object VARiability (YSOVAR) program, we monitored NGC 1333 for ∼35 days at 3.6 and 4.5 μm using the Spitzer Space Telescope. We report here on the mid-infrared variability of the point sources in the ∼10′ × ∼20′ area centered on 03:29:06, +31:19:30 (J2000). Out of 701 light curves in either channel, we find 78 variables over the YSOVAR campaign. About half of the members are variable. The variable fraction for the most embedded spectral energy distributions (SEDs) (Class I, flat) is higher than that for less embedded SEDs (Class II), which is in turn higher than the star-like SEDs (Class III). A few objects have amplitudes (10–90th percentile brightness) in [3.6] or [4.5] > 0.2 mag; a more typical amplitude is 0.1–0.15 mag. The largest color change is >0.2 mag. There are 24 periodic objects, with 40% of them being flat SED class. This may mean that the periodic signal is primarily from the disk, not the photosphere, in those cases. We find 9 variables likely to be “dippers,” where texture in the disk occults the central star, and 11 likely to be “bursters,” where accretion instabilities create brightness bursts. There are 39 objects that have significant trends in [3.6]–[4.5] color over the campaign, about evenly divided between redder-when-fainter (consistent with extinction variations) and bluer-when-fainter. About a third of the 17 Class 0 and/or jet-driving sources from the literature are variable over the YSOVAR campaign, and a larger fraction (∼half) are variable between the YSOVAR campaign and the cryogenic-era Spitzer observations (6–7 years), perhaps because it takes time for the envelope to respond to changes in the central source. The NGC 1333 brown dwarfs do not stand out from the stellar light curves in any way except there is a much larger fraction of periodic objects (∼60% of variable brown dwarfs are periodic, compared to ∼30% of the variables overall)

  6. Inductive tuning of Fano-resonant metasurfaces using plasmonic response of graphene in the mid-infrared.

    Science.gov (United States)

    Mousavi, S Hossein; Kholmanov, Iskandar; Alici, Kamil B; Purtseladze, David; Arju, Nihal; Tatar, Kaya; Fozdar, David Y; Suk, Ji Won; Hao, Yufeng; Khanikaev, Alexander B; Ruoff, Rodney S; Shvets, Gennady

    2013-03-13

    Graphene is widely known for its anomalously strong broadband optical absorptivity of 2.3% that enables seeing its single-atom layer with the naked eye. However, in the mid-infrared part of the spectrum graphene represents a quintessential lossless zero-volume plasmonic material. We experimentally demonstrate that, when integrated with Fano-resonant plasmonic metasurfaces, single-layer graphene (SLG) can be used to tune their mid-infrared optical response. SLG's plasmonic response is shown to induce large blue shifts of the metasurface's resonance without reducing its spectral sharpness. This effect is explained by a generalized perturbation theory of SLG-metamaterial interaction that accounts for two unique properties of the SLG that set it apart from all other plasmonic materials: its anisotropic response and zero volume. These results pave the way to using gated SLG as a platform for dynamical spectral tuning of infrared metamaterials and metasurfaces.

  7. Deep-ultraviolet to mid-infrared supercontinuum generated in solid-core ZBLAN photonic crystal fibre

    Science.gov (United States)

    Jiang, Xin; Joly, Nicolas Y.; Finger, Martin A.; Babic, Fehim; Wong, Gordon K. L.; Travers, John C.; Russell, Philip St. J.

    2015-02-01

    Silica-based photonic crystal fibre has proven highly successful for supercontinuum generation, with smooth and flat spectral power densities. However, fused silica glass suffers from strong material absorption in the mid-infrared (>2,500 nm), as well as ultraviolet-related optical damage (solarization), which limits performance and lifetime in the ultraviolet (glasses have been used to extend the mid-infrared performance, including chalcogenides, fluorides and heavy-metal oxides, but none has extended the ultraviolet performance. Here, we describe the successful fabrication (using the stack-and-draw technique) of a ZBLAN photonic crystal fibre with a high air-filling fraction, a small solid core, nanoscale features and near-perfect structure. We also report its use in the generation of ultrabroadband, long-term stable, supercontinua spanning more than three octaves in the spectral range 200-2,500 nm.

  8. Mid-Infrared Spectroscopy of Lensed Galaxies at 1

    CERN Document Server

    Rigby, J R; Egami, E; Rieke, G H; Richard, J; Kneib, J -P; Fadda, D; Willmer, C N A; Borys, C; Van der Werf, P P; Pérez-González, P G; Knudsen, K K; Papovich, C

    2007-01-01

    We present Spitzer/IRS mid-infrared spectra for 15 gravitationally lensed, 24 micron--selected galaxies, and combine the results with 4 additional very faint galaxies with IRS spectra in the literature. The median intrinsic 24 micron flux density of the sample is 130 microJy, enabling a systematic survey of the spectral properties of the very faint 24 micron sources that dominate the number counts of Spitzer cosmological surveys. Six of the 19 galaxy spectra (32%) show the strong mid-IR continuua expected of AGN; X-ray detections confirm the presence of AGN in three of these cases, and reveal AGNs in two other galaxies. These results suggest that nuclear accretion may contribute more flux to faint 24 micron--selected samples than previously assumed. Almost all the spectra show some aromatic (PAH) emission features; the measured aromatic flux ratios do not show evolution from z=0. In particular, the high S/N mid-IR spectrum of SMM J163554.2+661225 agrees remarkably well with low--redshift, lower--luminosity te...

  9. An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status

    CERN Document Server

    Matter, A; Antonelli, P; Lehmitz, M; Bettonvil, F; Beckmann, U; Lagarde, S; Jaffe, W; Petrov, R G; Berio, P; Millour, F; Robbe-Dubois, S; Glindemann, A; Bristow, P; Schoeller, M; Lanz, T; Henning, T; Weigelt, G; Heininger, M; Morel, S; Cruzalebes, P; Meisenheimer, K; Hofferbert, R; Wolf, S; Bresson, Y; Agocs, T; Allouche, F; Augereau, J -C; Avila, G; Bailet, C; Behrend, J; Van Belle, G; Berger, J -P; van Boekel, R; Bourget, P; Brast, R; Clausse, J -M; Connot, C; Conzelmann, R; Csepany, G; Danchi, W C; Delbo, M; Dominik, C; van Duin, A; Elswijk, E; Fantei, Y; Finger, G; Gabasch, A; Gonté, F; Graser, U; Guitton, F; Guniat, S; De Haan, M; Haguenauer, P; Hanenburg, H; Hofmann, K -H; Hogerheijde, M; ter Horst, R; Hron, J; Hummel, C; Isderda, J; Ives, D; Jakob, G; Jasko, A; Jolley, P; Kiraly, S; Kragt, J; Kroener, T; Kroes, G; Kuindersma, S; Labadie, L; Laun, W; Leinert, C; Lizon, J -L; Lucuix, C; Marcotto, A; Martinache, F; Martinot-Lagarde, G; Mauclert, N; Mehrgan, L; Meilland, A; Mellein, M; Menardi, S; Merand, A; Neumann, U; Nussbaum, E; Ottogalli, S; Palsa, R; Panduro, J; Pantin, E; Percheron, I; Duc, T Phan; Pott, J -U; Pozna, E; Roelfsema, R; Rupprecht, G; Schertl, D; Schmidt, C; Schuil, M; Spang, A; stegmeier, J; Tromp, N; Vakili, F; Vannier, M; Wagner, K; Venema, L; Woillez, J

    2016-01-01

    MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances by opening new avenues in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments of black holes in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the spectral domain of current optical interferometers by offering the L and M bands in addition to the N band. This will open a wide wavelength domain, ranging from 2.8 to 13 um, exploring angular scales as small as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared imaging - closure-phase aperture-synthesis imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE will offer a spectral re...

  10. Low loss mid-infrared ZBLAN waveguides for future astronomical applications.

    Science.gov (United States)

    Gross, Simon; Jovanovic, Nemanja; Sharp, Adam; Ireland, Michael; Lawrence, Jon; Withford, Michael J

    2015-03-23

    Photonic technologies will be at the heart of future terrestrial planet hunting interferometers. In particular the mid-infrared spectral region between 3.5 - 4.2 μm is the ideal window for hunting for young extra-solar planets, since the planet is still hot from its formation and thus offers a favorable contrast with respect to the parent star compared to other spectral regions. This paper demonstrates two basic photonic building blocks of such an instrument, namely single-mode waveguides with propagation losses as low as 0.29±0.03 dB/cm at a wavelength of 4 μm as well as directional couplers with a constant splitting ratio across a broad wavelength band of 500 nm. The devices are based on depressed cladding waveguides inscribed into ZBLAN glass using the femtosecond laser direct-write technique. This demonstration is the first stepping stone towards the realization of a high transmission mid-infrared nulling interferometer.

  11. A Multiwavelength Study of Cygnus X-1: The First Mid-infrared Spectroscopic Detection of Compact Jets

    Science.gov (United States)

    Rahoui, Farid; Lee, Julia C.; Heinz, Sebastian; Hines, Dean C.; Pottschmidt, Katja; Wilms, Jörn; Grinberg, Victoria

    2011-07-01

    We report on a Spitzer/InfraRed Spectrograph (mid-infrared), RXTE/PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multiwavelength study of the microquasar Cygnus X-1, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break—where the transition from the optically thick to the optically thin regime takes place—at about 2.9 × 1013 Hz. We then show that the jet's optically thin synchrotron emission accounts for Cygnus X-1's emission beyond 400 keV, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 μm mid-infrared continuum of Cygnus X-1 stems from the blue supergiant companion star HD 226868. Indeed, the emission can then be understood as the combination of the photospheric Rayleigh-Jeans tail and the bremsstrahlung from the expanding stellar wind. Moreover, the stellar wind is found to be clumpy, with a filling factor f ∞ ≈ 0.09-0.10. Its bremsstrahlung emission is likely anti-correlated to the soft X-ray emission, suggesting an anti-correlation between the mass-loss and mass-accretion rates. Nevertheless, we do not detect any mid-infrared spectroscopic evidence of interaction between the jets and Cygnus X-1's environment and/or the companion star's stellar wind.

  12. Flexible chalcogenide glass microring resonator for mid-infrared emission

    Science.gov (United States)

    Wang, Liangliang; Li, Lijing; Sun, Mingjie

    2016-10-01

    Emerging applications in communication, sensing, medical, and many other fields call for on-chip microring laser, however, the method to make it work at mid-infrared still need to be explored. In this paper, a microring resonator integrated in flexible substrate is designed and evaluated, with high Q-factor ( 105) at pump and signal wavelengths, achieving emission in mid-infrared (3.6μm) using rare earth doped chalcogenide glass. Furthermore, the strain-optical coupling in multilayer flexible materials is numerically verified, and a 0.3 nm/μɛ resonance wavelength shift is achieved by local neutral axis theory, without significant loss of flexible device performance.

  13. Mid-infrared predictions of cheese yield from bovine milk

    OpenAIRE

    Vanlierde, Amélie; Soyeurt, Hélène; Anceau, Christine; Vanden Bossche, sandrine; Dehareng, Frédéric; Pierre DARDENNE; Gengler, Nicolas; Sindic, Marianne; Colinet, Frédéric

    2011-01-01

    Economically, cheese yield (CY) is very important. Todate, empirical or theoretical formulae allow estimating the theoretical CY from milk fat and casein or protein content of milk. It would be interesting to predict CY during milk recording directly without the need to estimate milk components. Through the BlueSel project, 157 milk samples were collected in Wallonia from individual cows and analyzed using a mid-infrared (MIR) MilkoScanFT6000 spectrometer. Individual laboratory cheese yields ...

  14. Compact, High-Power, Fiber-Laser-Based Coherent Sources Tunable in the Mid-Infrared and THz Spectrum

    Science.gov (United States)

    2015-02-20

    conversion sources and optical parametric oscillators (OPOs) for the deep mid-infrared (mid-IR) spectral regions >5 μm. We have successfully developed...tunable deep mid-IR systems in both continuous-wave (cw) and ultrafast femtosecond time- scales using compact fiber lasers and Kerr-lens modelocked...Ti:sapphire laser as pump source. In cw operation, we have achieved world-record output powers, while in the ultrafast femtosecond time- scale we have

  15. Mid-to-Far Infrared Spectral Energy Distribution of Galaxies in the Spitzer First Look Survey Field

    Institute of Scientific and Technical Information of China (English)

    Xiao-Qing Wen; Hong Wu; Chen Cao; Xiao-Yang Xia

    2007-01-01

    We made model fitting to the mid-to-far infrared spectral energy distributions (SEDs) for different categories of galaxies in the main extragalactic field of the Spitzer First Look Survey with the aid of spectroscopic information from the Sloan Digital Sky Survey.We find that the mid-to-far infrared SEDs of HII galaxies, mixture type galaxies and LINERs can be well fitted by the one-parameter (α) dust model of Dale et al. plus the 13 Gyr dust-free elliptical galaxy model. The statistics of α values indicates that all these galaxies tend to be quiescent, although the HII galaxies are relatively more active than the LINERs. The midinfrared SEDs of absorption galaxies are well fitted simply by the 13 Gyr dust-free elliptical galaxy template, and the near-to-mid infrared SEDs of QSOs can be represented by AGN NGC 5506.

  16. Authentication of Whey Protein Powders by Portable Mid-Infrared Spectrometers Combined with Pattern Recognition Analysis.

    Science.gov (United States)

    Wang, Ting; Tan, Siow Ying; Mutilangi, William; Aykas, Didem P; Rodriguez-Saona, Luis E

    2015-10-01

    The objective of this study was to develop a simple and rapid method to differentiate whey protein types (WPC, WPI, and WPH) used for beverage manufacturing by combining the spectral signature collected from portable mid-infrared spectrometers and pattern recognition analysis. Whey protein powders from different suppliers are produced using a large number of processing and compositional variables, resulting in variation in composition, concentration, protein structure, and thus functionality. Whey protein powders including whey protein isolates, whey protein concentrates and whey protein hydrolysates were obtained from different suppliers and their spectra collected using portable mid-infrared spectrometers (single and triple reflection) by pressing the powder onto an Attenuated Total Reflectance (ATR) diamond crystal with a pressure clamp. Spectra were analyzed by soft independent modeling of class analogy (SIMCA) generating a classification model showing the ability to differentiate whey protein types by forming tight clusters with interclass distance values of >3, considered to be significantly different from each other. The major bands centered at 1640 and 1580 cm(-1) were responsible for separation and were associated with differences in amide I and amide II vibrations of proteins, respectively. Another important band in whey protein clustering was associated with carboxylate vibrations of acidic amino acids (∼1570 cm(-1)). The use of a portable mid-IR spectrometer combined with pattern recognition analysis showed potential for discriminating whey protein ingredients that can help to streamline the analytical procedure so that it is more applicable for field-based screening of ingredients. A rapid, simple and accurate method was developed to authenticate commercial whey protein products by using portable mid-infrared spectrometers combined with chemometrics, which could help ensure the functionality of whey protein ingredients in food applications. © 2015

  17. Migrating the Mach-Zehnder chemical and bio-sensor to the mid-infrared region

    Science.gov (United States)

    Leidner, L.; Ewald, M.; Sieger, M.; Mizaikoff, B.; Gauglitz, G.

    2013-05-01

    The properties of integrated optical phase-modulated Mach-Zehnder interferometers (IO-MZI) are used to set up a new generation of chemical and biochemical sensors working in the mid-infrared. First applications of the MZI principle were introduced in the beginning 1990s. They range from a gas sensor to monitor organic solvent concentrations1 to setting up an immunoassay for the detection of the herbicide simazine2. Most if not all sensors of MZI type operate at wavelengths of the visible or near infrared spectrum. There are several reasons to change this strategy and move into the mid-infrared spectral range (MIR): higher manufacturing tolerances, increased evanescent field penetration depth, signal amplification by surface enhanced infrared absorption effect (SEIRA), species identification by MIR fingerprints. The basis of the planned MIR-MZI is a GaAs waveguide pattern epitaxially grown on a substrate3. As a first step towards nanostructuring the waveguide surface, chemical deposition of Au nanoparticles on GaAs transducers was established. For the use of MIR-MZI sensors in bioanalytical assay development, chemical immobilization of molecular recognition elements on GaAs transducers was carried out. The modified surfaces were characterized by atomic force microscopy (AFM), dark field microscopy, contact angle measurements and ellipsometric data as well as by a modified version of Reflectometric Interference Spectroscopy (RIfS)4. It was possible to monitor both the immobilization of gold nanoparticles and time-resolved specific binding using a model antibody antigen assay. After successful setup of relevant assays with RIfS, e.g. the detection of bacteria or endocrine disruptors, the assays are designed to be transferred onto the mid-infrared Mach-Zehnder interferometer.

  18. Mid-infrared supercontinuum covering the 1.4-13.3 μm molecular fingerprint region using ultra-high NA chalcogenide step-index fibre

    Science.gov (United States)

    Petersen, Christian Rosenberg; Møller, Uffe; Kubat, Irnis; Zhou, Binbin; Dupont, Sune; Ramsay, Jacob; Benson, Trevor; Sujecki, Slawomir; Abdel-Moneim, Nabil; Tang, Zhuoqi; Furniss, David; Seddon, Angela; Bang, Ole

    2014-11-01

    The mid-infrared spectral region is of great technical and scientific interest because most molecules display fundamental vibrational absorptions in this region, leaving distinctive spectral fingerprints. To date, the limitations of mid-infrared light sources such as thermal emitters, low-power laser diodes, quantum cascade lasers and synchrotron radiation have precluded mid-infrared applications where the spatial coherence, broad bandwidth, high brightness and portability of a supercontinuum laser are all required. Here, we demonstrate experimentally that launching intense ultra-short pulses with a central wavelength of either 4.5 μm or 6.3 μm into short pieces of ultra-high numerical-aperture step-index chalcogenide glass optical fibre generates a mid-infrared supercontinuum spanning 1.5 μm to 11.7 μm and 1.4 μm to 13.3 μm, respectively. This is the first experimental demonstration to truly reveal the potential of fibres to emit across the mid-infrared molecular ‘fingerprint region’, which is of key importance for applications such as early cancer diagnostics, gas sensing and food quality control.

  19. THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

    CERN Document Server

    Groussin, O; Helbert, J; Reynaud, J -L; Levacher, P; García-Talavera, M Reyes; Alí-Lagoa, V; Blanc, P -E; Brageot, E; Davidsson, B; Delbó, M; Deleuze, M; Delsanti, A; Garcia, J J Diaz; Dohlen, K; Ferrand, D; Green, S; Jorda, L; Álvarez, E Joven; Knollenberg, J; Kührt, E; Lamy, P; Lellouch, E; Merrer, J Le; Marty, B; Mas, G; Rossin, C; Rozitis, B; Sunshine, J; Vernazza, P; Vives, S

    2015-01-01

    We present THERMAP, a mid-infrared (8-16 {\\mu}m) spectro-imager for space missions to small bodies in the inner solar system, developed in the framework of the MarcoPolo-R asteroid sample return mission. THERMAP is very well suited to characterize the surface thermal environment of a NEO and to map its surface composition. The instrument has two channels, one for imaging and one for spectroscopy: it is both a thermal camera with full 2D imaging capabilities and a slit spectrometer. THERMAP takes advantage of the recent technological developments of uncooled microbolometers detectors, sensitive in the mid-infrared spectral range. THERMAP can acquire thermal images (8-18 {\\mu}m) of the surface and perform absolute temperature measurements with a precision better than 3.5 K above 200 K. THERMAP can acquire mid-infrared spectra (8-16 {\\mu}m) of the surface with a spectral resolution {\\Delta}{\\lambda} of 0.3 {\\mu}m. For surface temperatures above 350 K, spectra have a signal-to-noise ratio >60 in the spectral rang...

  20. A "WISE BOSS": Finding The Cosmic Monsters in the Mid-Infrared Lochs

    Science.gov (United States)

    Ross, Nicholas; Hamann, F. W.; Alexandroff, R.; Brandt, W. N.; Strauss, M. A.; Dey, A.; Richards, G. T.; Worseck, G.; Zakamska, N. L.; Eisenstein, D.; Ge, J.; Glikman, E.; Greene, J. E.; Haggard, D.; Krolik, J. H.; Myers, A. D.; Petitjean, P.; Streblyanska, A.; Schawinski, K.; Shen, Y.; Villforth, C.; McMahon, R.

    2013-01-01

    Mid-infrared photometry of QSOs provide an important constraint on the presence of hot dust in the vicinity of the active nucleus. However, assembling large statistical MIR samples of quasars at the height of the ``quasar epoch'' ( 2.5) has, up until now, been challenging due to either wide but relatively shallow optical quasar surveys, or deep but narrow mid-IR data. The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) is the state-of-the-art in optical wide-field spectroscopy, and has over 150,000 quasars confirmed, with the majority of the quasar data at z=2.2-3.5. We combine these data with the all-sky mid-infrared coverage from the Wide-Field Infrared Survey Explorer (WISE), and initially concentrate on BOSS quasars with ``extreme'' colors, e.g. r-[22]>14, and those detected only in the redder WISE bands, a.k.a. "the W1W2drops". We find that these selections identify a heterogeneous sample within the BOSS quasar data, but also provide a key tool for finding interesting populations including the 2.5 Type II QSO population. We relate these very red BOSS quasars to the recent discoveries of the ``hyper-LIRG" and ``Hot Dust Obscured Galaxy'' (or Hot DOG) population.

  1. THE SPITZER SPACE TELESCOPE SURVEY OF THE ORION A AND B MOLECULAR CLOUDS. I. A CENSUS OF DUSTY YOUNG STELLAR OBJECTS AND A STUDY OF THEIR MID-INFRARED VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Megeath, S. T.; Kryukova, E. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43560 (United States); Gutermuth, R. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Muzerolle, J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Flaherty, K. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hora, J. L.; Myers, P. C.; Fazio, G. G. [Harvard Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Allen, L. E. [National Optical Astronomical Observatory, Tucson, AZ 85719 (United States); Hartmann, L. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Pipher, J. L. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Stauffer, J. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Young, E. T., E-mail: megeath@physics.utoledo.edu [SOFIA-Universities Space Research Association, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2012-12-01

    We present a survey of the Orion A and B molecular clouds undertaken with the IRAC and MIPS instruments on board Spitzer. In total, five distinct fields were mapped, covering 9 deg{sup 2} in five mid-IR bands spanning 3-24 {mu}m. The survey includes the Orion Nebula Cluster, the Lynds 1641, 1630, and 1622 dark clouds, and the NGC 2023, 2024, 2068, and 2071 nebulae. These data are merged with the Two Micron All Sky Survey point source catalog to generate a catalog of eight-band photometry. We identify 3479 dusty young stellar objects (YSOs) in the Orion molecular clouds by searching for point sources with mid-IR colors indicative of reprocessed light from dusty disks or infalling envelopes. The YSOs are subsequently classified on the basis of their mid-IR colors and their spatial distributions are presented. We classify 2991 of the YSOs as pre-main-sequence stars with disks and 488 as likely protostars. Most of the sources were observed with IRAC in two to three epochs over six months; we search for variability between the epochs by looking for correlated variability in the 3.6 and 4.5 {mu}m bands. We find that 50% of the dusty YSOs show variability. The variations are typically small ({approx}0.2 mag) with the protostars showing a higher incidence of variability and larger variations. The observed correlations between the 3.6, 4.5, 5.8, and 8 {mu}m variability suggests that we are observing variations in the heating of the inner disk due to changes in the accretion luminosity or rotating accretion hot spots.

  2. The Spitzer Space Telescope Survey of the Orion A and B Molecular Clouds. I. A Census of Dusty Young Stellar Objects and a Study of Their Mid-infrared Variability

    Science.gov (United States)

    Megeath, S. T.; Gutermuth, R.; Muzerolle, J.; Kryukova, E.; Flaherty, K.; Hora, J. L.; Allen, L. E.; Hartmann, L.; Myers, P. C.; Pipher, J. L.; Stauffer, J.; Young, E. T.; Fazio, G. G.

    2012-12-01

    We present a survey of the Orion A and B molecular clouds undertaken with the IRAC and MIPS instruments on board Spitzer. In total, five distinct fields were mapped, covering 9 deg2 in five mid-IR bands spanning 3-24 μm. The survey includes the Orion Nebula Cluster, the Lynds 1641, 1630, and 1622 dark clouds, and the NGC 2023, 2024, 2068, and 2071 nebulae. These data are merged with the Two Micron All Sky Survey point source catalog to generate a catalog of eight-band photometry. We identify 3479 dusty young stellar objects (YSOs) in the Orion molecular clouds by searching for point sources with mid-IR colors indicative of reprocessed light from dusty disks or infalling envelopes. The YSOs are subsequently classified on the basis of their mid-IR colors and their spatial distributions are presented. We classify 2991 of the YSOs as pre-main-sequence stars with disks and 488 as likely protostars. Most of the sources were observed with IRAC in two to three epochs over six months; we search for variability between the epochs by looking for correlated variability in the 3.6 and 4.5 μm bands. We find that 50% of the dusty YSOs show variability. The variations are typically small (~0.2 mag) with the protostars showing a higher incidence of variability and larger variations. The observed correlations between the 3.6, 4.5, 5.8, and 8 μm variability suggests that we are observing variations in the heating of the inner disk due to changes in the accretion luminosity or rotating accretion hot spots.

  3. Mid-Infrared Galaxy Morphology from the Spitzer Survey of Stellar Structure in Galaxies (S^4G): The Imprint of the de Vaucouleurs Revised Hubble-Sandage Classification System at 3.6 microns

    CERN Document Server

    Buta, R; Regan, M; Hinz, J; de Paz, A Gil; Menendez-Delmestre, K; Munoz-Mateos, J; Seibert, M; Laurikainen, E; Salo, H; Gadotti, D; Athanassoula, E; Bosma, A; Knapen, J; Ho, L; Madore, B; Elmegreen, D; Masters, K; Comeron, S; Aravena, M

    2010-01-01

    Spitzer Space Telescope Infrared Array Camera (IRAC) imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6 micron band, which is the best Spitzer waveband for galactic stellar mass morphology owing to its depth and its reddening-free sensitivity mainly to older stars. For this purpose, we have prepared classification images for 207 galaxies from the Spitzer archive, most of which are formally part of the Spitzer Survey of Stellar Structure in Galaxies (S^4G), a Spitzer post-cryogenic ("warm") mission Exploration Science Legacy Program survey of 2,331 galaxies closer than 40 Mpc. For the purposes of morphology, the galaxies are interpreted as if the images are {\\it blue light}, the historical waveband for classical galaxy classification studies. We find that 3.6 micron classification...

  4. Mid-infrared surface plasmon coupled emitters utilizing intersublevel transitions in InAs quantum dots.

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, Stephen A. (Princeton University, Princeton, NJ); Chow, Weng Wah; Passmore, Brandon Scott; Ribaudo, Troy (University of Massachusetts Lowell, Lowell, MA); Adams, David (University of Massachusetts Lowell, Lowell, MA); Wasserman, Daniel (University of Massachusetts Lowell, Lowell, MA); Shaner, Eric Arthur

    2010-08-01

    We demonstrate mid-infrared electroluminescence from intersublevel transitions in self-assembled InAs quantum dots coupled to surface plasmon modes on metal hole arrays. Subwavelength metal hole arrays with different periodicity are patterned into the top contact of the broadband (9-15 {micro}m) quantum dot material and the measured electroluminescence is compared to devices without a metal hole array. The resulting normally directed emission is narrowed and a splitting in the spectral structure is observed. By applying a coupled quantum electrodynamic model and using reasonable values for quantum dot distributions and plasmon linewidths we are able to reproduce the experimentally measured spectral characteristics of device emission when using strong coupling parameters.

  5. Mid-Infrared Mapping of Jupiter's Temperatures, Aerosol Opacity and Chemical Distributions with IRTF/TEXES

    CERN Document Server

    Fletcher, L N; Orton, G S; Sinclair, J A; Giles, R S; Irwin, P G J; Encrenaz, T

    2016-01-01

    Global maps of Jupiter's atmospheric temperatures, gaseous composition and aerosol opacity are derived from a programme of 5-20 $\\mu$m mid-infrared spectroscopic observations using the Texas Echelon Cross Echelle Spectrograph (TEXES) on NASA's Infrared Telescope Facility (IRTF). Image cubes from December 2014 in eight spectral channels, with spectral resolutions of $R\\sim2000-12000$ and spatial resolutions of $2-4^\\circ$ latitude, are inverted to generate 3D maps of tropospheric and stratospheric temperatures, 2D maps of upper tropospheric aerosols, phosphine and ammonia, and 2D maps of stratospheric ethane and acetylene. The results are compared to a re-analysis of Cassini Composite Infrared Spectrometer (CIRS) observations acquired during Cassini's closest approach to Jupiter in December 2000, demonstrating that this new archive of ground-based mapping spectroscopy can match and surpass the quality of previous investigations, and will permit future studies of Jupiter's evolving atmosphere. We identify mid-i...

  6. MID-INFRARED IMAGING OF THE TRANSITIONAL DISK OF HD 169142: MEASURING THE SIZE OF THE GAP

    Energy Technology Data Exchange (ETDEWEB)

    Honda, M. [Department of Mathematics and Physics, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka, Kanagawa 259-1293 (Japan); Maaskant, Koen; Waters, L. B. F. M.; Dominik, C.; Mulders, G. D. [Astronomical Institute Anton Pannekoek, University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands); Okamoto, Y. K. [Institute of Astrophysics and Planetary Sciences, Faculty of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan); Kataza, H. [Department of Infrared Astrophysics, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Fukagawa, M. [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Tielens, A. G. G. M. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Min, M. [Astronomical Institute Utrecht, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands); Yamashita, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Fujiyoshi, T.; Fujiwara, H. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Miyata, T.; Sako, S. [Institute of Astronomy, School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Sakon, I.; Onaka, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-06-20

    The disk around the Herbig Ae star HD 169142 was imaged and resolved at 18.8 and 24.5 {mu}m using Subaru/COMICS. We interpret the observations using a two-dimensional radiative transfer model and find evidence for the presence of a large gap. The mid-infrared images trace dust that is emitted at the onset of a strong rise in the spectral energy distribution (SED) at 20 {mu}m, and are therefore very sensitive to the location and characteristics of the inner wall of the outer disk and its dust. We determine the location of the wall to be 23{sup +3}{sub -5} AU from the star. An extra component of hot dust must exist close to the star. We find that a hydrostatic optically thick inner disk does not produce enough flux in the near-infrared, and an optically thin, geometrically thick component is our solution to fit the SED. Considering the recent findings of gaps and holes in a number of Herbig Ae/Be group I disks, we suggest that such disk structures may be common in group I sources. Classification as group I should be considered a strong case for classification as a transitional disk, though improved imaging surveys are needed to support this speculation.

  7. Towards mid-infrared supercontinuum generation: Ge-Sb-Se mid-infrared step-index small-core optical fiber

    Science.gov (United States)

    Butterworth, J. H.; Jayasuriya, D.; Li, Q. Q.; Furniss, D.; Moneim, N. A.; Barney, E.; Sujecki, S.; Benson, T. M.; Sanghera, J. S.; Seddon, A. B.

    2014-02-01

    In the 21st century, cancer has become a common and feared illness. Early detection is crucial for delivering the most effective treatment of patients, yet current diagnostic tests depend upon the skill of a consultant clinician and histologist for recognition of the cancerous cells. Therefore it is necessary to develop a medical diagnostic system which can analyze and image tissue instantly, removing the margin of human error and with the additional benefit of being minimally invasive. The molecular fingerprint of biological tissue lies within the mid-infrared (IR) region of the electromagnetic spectrum, 3-25μm wavelength. This can be used to determine a tissue spectral map and provide information about the absence or existence of disease, potentially in real-time and in vivo. However, current mid-IR broadband sources are not bright enough to achieve this. One alternative is to develop broadband, mid-IR, supercontinuum generation (SCG). Chalcogenide glass optical fibers have the potential to provide such mid-IR SC light. A popular chalcogenide glass fiber type is based on Ge-As-Se. For biomedical applications it is prudent to avoid the use of arsenic, on account of its toxicity. This paper investigates replacing arsenic with antimony, towards Ge-Sb-Se smallcore optical fibers for SCG. Physical properties of candidate glass pairs are investigated for glass stability via differential thermal analysis etc. and fiber optical loss measurements of associated fibers are assessed. These results are compared to analogous arsenic-containing chalcogenide glasses and optical fibers, and conclusions are drawn focusing on whether there is potential for antimony chalcogenide glass to be used for SCG for mid-infrared medical diagnostics.

  8. Terahertz and mid-infrared plasmons in three-dimensional nanoporous graphene

    Science.gov (United States)

    D'Apuzzo, Fausto; Piacenti, Alba R.; Giorgianni, Flavio; Autore, Marta; Guidi, Mariangela Cestelli; Marcelli, Augusto; Schade, Ulrich; Ito, Yoshikazu; Chen, Mingwei; Lupi, Stefano

    2017-01-01

    Two-dimensional (2D) graphene emerged as an outstanding material for plasmonic and photonic applications due to its charge-density tunability, high electron mobility, optical transparency and mechanical flexibility. Recently, novel fabrication processes have realised a three-dimensional (3D) nanoporous configuration of high-quality monolayer graphene which provides a third dimension to this material. In this work, we investigate the optical behaviour of nanoporous graphene by means of terahertz and infrared spectroscopy. We reveal the presence of intrinsic 2D Dirac plasmons in 3D nanoporous graphene disclosing strong plasmonic absorptions tunable from terahertz to mid-infrared via controllable doping level and porosity. In the far-field the spectral width of these absorptions is large enough to cover most of the mid-Infrared fingerprint region with a single plasmon excitation. The enhanced surface area of nanoporous structures combined with their broad band plasmon absorption could pave the way for novel and competitive nanoporous-graphene based plasmonic-sensors. PMID:28345584

  9. Reduced graphene oxide mid-infrared photodetector at 300 K

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Gustavo E.; Kim, Jin Ho; Oller, Declan; Xu, Jimmy [School of Engineering, Brown University, Box D, Providence, Rhode Island 02912 (United States)

    2015-09-14

    We report on uncooled mid-infrared photovoltaic responses at 300 K arising in heterojunctions of reduced graphene oxide with p-Si. Two major photoresponse spectral peaks are observed, one in the near infrared starting at 1.1 μm corresponding to electron-hole pair generation in the Si substrate, and another at wavelengths below 2.5 μm, arising from properties of the reduced graphene oxide-Si heterojunction. Our analysis of the current-voltage characteristics at various temperatures suggests that the two materials form a type-II (broken-gap) heterojunction, with a characteristic transition between direct tunneling to field emission, to over-the-barrier excitation with increasing reverse voltage. Illumination was found to affect the onset of the transition between direct tunneling and field-emission, suggesting that the mid infrared response results from the excitation of minority carriers (electrons) from the Si and their collection in the reduced graphene oxide contact. The photoresponse near 1.1 μm showed a time constant at least five times faster than the one at 2.5 μm, which points to surface defects as well as high series resistance and capacitance as potentially limiting factors in this mode of operation. With proper device engineering considerations, these devices could be promising as a graphene-based platform for infrared sensing.

  10. Tunable graphene-based mid-infrared plasmonic wide-angle narrowband perfect absorber

    Science.gov (United States)

    Li, Hongju; Wang, Lingling; Zhai, Xiang

    2016-11-01

    In this paper, the periodic double-layer graphene ribbon arrays placed near a metallic ground plate coated by a dielectric layer are proposed and analyzed by the coupled-mode theory (CMT) to predict the perfect absorption response in the mid-infrared region. Numerical simulations of the finite-difference time-domain (FDTD) method confirm this effect and give the underlying physical origin. The anti-symmetric dipole-dipole coupling mode is supported by the double-layer graphene ribbons and acts as the electrical resonance to suppress the reflection, because of the impedance matching. The transmission from this system is restricted by the ultra-thick metallic ground plate. All incident electromagnetic energy is efficiently confined in the interlayer between graphene ribbons and the metallic plate, and the dramatic narrowband perfect absorption peak with the FWHM (full width at half maximums) of 300 nm hence is achieved. The spectral position of the absorption peak can be dynamically tuned by a small change in the chemical potential of graphene, in addition to varying geometrical parameters of the absorber. Meanwhile, this device exhibits good absorption stability over a wide angle range of incidence around ± 60° at least. Such absorber will benefit the fabrication of mid-infrared nano-photonic devices for optical filtering and storage.

  11. Mid-infrared spectroscopy for detection of Huanglongbing (greening) in citrus leaves.

    Science.gov (United States)

    Sankaran, Sindhuja; Ehsani, Reza; Etxeberria, Edgardo

    2010-12-15

    In recent years, Huanglongbing (HLB) also known as citrus greening has greatly affected citrus orchards in Florida. This disease has caused significant economic and production losses costing about $750/acre for HLB management. Early and accurate detection of HLB is a critical management step to control the spread of this disease. This work focuses on the application of mid-infrared spectroscopy for the detection of HLB in citrus leaves. Leaf samples of healthy, nutrient-deficient, and HLB-infected trees were processed in two ways (process-1 and process-2) and analyzed using a rugged, portable mid-infrared spectrometer. Spectral absorbance data from the range of 5.15-10.72 μm (1942-933 cm(-1)) were preprocessed (baseline correction, negative offset correction, and removal of water absorbance band) and used for data analysis. The first and second derivatives were calculated using the Savitzky-Golay method. The preprocessed raw dataset, first derivatives dataset, and second derivatives dataset were first analyzed by principal component analysis. Then, the selected principal component scores were classified using two classification algorithms, quadratic discriminant analysis (QDA) and k-nearest neighbor (kNN). When the spectral data from leaf samples processed using process-1 were used for data analysis, the kNN-based algorithm yielded higher classification accuracies (especially nutrient-deficient leaf class) than that of the other spectral data (process-2). The performance of the kNN-based algorithm (higher than 95%) was better than the QDA-based algorithm. Moreover, among different types of datasets, preprocessed raw dataset resulted in higher classification accuracies than first and second derivatives datasets. The spectral peak in the region of 9.0-10.5 μm (952-1112 cm(-1)) was found to be distinctly different between the healthy and HLB-infected leaf samples. This carbohydrate peak could be attributed to the starch accumulation in the HLB-infected citrus leaves

  12. Surface-enhanced molecular spectroscopy (SEMS) based on perfect-absorber metamaterials in the mid-infrared

    Science.gov (United States)

    Li, Yongqian; Su, Lei; Shou, Chen; Yu, Chunmeng; Deng, Jinjun; Fang, Yu

    2013-10-01

    Surface-enhanced infrared absorption spectroscopy has attracted increased attention for direct access to molecular vibrational fingerprints in the mid-infrared. Perfect-absorber metamaterials (PAMs) with multi-band spectral responses and significant enhancement of the local near-field intensity were developed to improve the intrinsic absorption cross sections of absorption spectrum to identify the vibrational spectra of biomolecules. To verify its performance, the proposed infrared PAM array was used to identify the molecular stretches of a Parylene C film. The resonant responses of the infrared PAMs were accurately tuned to the vibrational modes of the C = C target bonds. The vibrational stretches of the C = C moiety were observed and the auto-fluorescence mechanisms of the Parylene C film were monitored. The unique properties of the PAMs indicate that this approach is a promising strategy for surface-enhanced molecular absorption spectroscopy (SEMS) in the mid-infrared region and for the tracking of characteristic molecular vibrational modes.

  13. Nonlinearly enhanced linear absorption under filamentation in mid-infrared (Conference Presentation)

    Science.gov (United States)

    Shipilo, Daniil; Panov, Nicolay; Andreeva, Vera; Kosareva, Olga G.; Saletski, Alexander M.; Xu, Huai-Liang; Polynkin, Pavel

    2017-05-01

    The mid-infrared OPCPA-based laser facilities have recently reached the critical power for self-focusing in air [1]. This ensures the demonstration of the major difference between the mid- and near-infrared filamentation in air: the odd optical harmonics, harshly suppressed by the material dispersion and phase-mismatch in the near-infrared (800 nm), gain reliable energies in the mid-infrared (3.9 µm) filament [1,2]. Another issue that makes mid-infrared filamentation different from the near-infrared one is a lot of molecular vibrational lines belonging to atmospheric constituents and located in the mid-infrared range [3]. As the result the mid-infrared region of interest becomes subdivided into the bands of normal and anomalous dispersion, the former of which leads to the pulse splitting in temporal domain, while the latter produces the confined light bullet. We simulate the 3.9-µm filamentation using Forward Maxwell equation. We include the tunnel ionization and transient photocurrent as the collapse arresting mechanism, which balances dynamically the instantaneous third-order medium response (similarly to 800-nm filamentation). The key feature that allows us to quantify the losses due to absorption bands is the accurate account of the complex linear absorption index. The absorption index obtained from Mathar model [3] is interpolated to the fine frequency grid (step of about 0.1 THz), and the refractive index is matched according to Kramers-Krönig relations [4]. If the initial Gaussian pulse has a center wavelength of 3.9 µm and a duration of 80 fs FWHM, the energy loss in the carbon dioxide (CO_2) absorption band at 4.3 µm is about 1% in the linear propagation regime. But when we take the 80-mJ pulse (about 3 critical powers for self-focusing), the Kerr-induced spectral broadening develops significantly before the clamping level of intensity is reached. In the collimated beam geometry about 2% of the initial pulse energy is absorbed on the CO_2 band before

  14. Demonstration of mid-infrared waveguide photonic crystal cavities

    CERN Document Server

    Lin, Hongtao; Deng, Fei; Ni, Chaoying; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Hu, Juejun

    2013-01-01

    We have demonstrated what we believe to be the first waveguide photonic crystal cavity operating in the mid-infrared. The devices were fabricated from Ge23Sb7S70 chalcogenide glass on CaF2 substrates by combing photolithographic patterning and focus ion beam milling. The waveguide-coupled cavities were characterized using a fiber end fire coupling method at 5.2 {\\mu}m wavelength, and a loaded quality factor of ~ 2,000 was measured near the critical coupling regime.

  15. Demonstration of mid-infrared waveguide photonic crystal cavities.

    Science.gov (United States)

    Lin, Hongtao; Li, Lan; Deng, Fei; Ni, Chaoying; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Hu, Juejun

    2013-08-01

    We have demonstrated what we believe to be the first waveguide photonic crystal cavity operating in the mid-infrared. The devices were fabricated from Ge23Sb7S70 chalcogenide glass (ChG) on CaF2 substrates by combing photolithographic patterning and focused ion beam milling. The waveguide-coupled cavities were characterized using a fiber end fire coupling method at 5.2 μm wavelength, and a loaded quality factor of ~2000 was measured near the critical coupling regime.

  16. Research and evolution of mid-infrared optical source

    Science.gov (United States)

    Chen, Changshui; Hu, Hui; Xu, Lei

    2016-10-01

    3-5 μm mid-infrared wave band is in the atmosphere window, it has lots of promising applications on the spectroscopy, remote sensing, medical treatment, environmental protection and military affairs. So, it has been a hot topic around the world to research the lasers at this wave band. In recent years, adiabatic passage technology has been applied in frequency conversion area, which borrowed from atomic physics. In this paper we will introduce efficient nonlinear optics frequency conversion by suing this technology.

  17. Emerging techniques for soil analysis via mid-infrared spectroscopy

    Science.gov (United States)

    Linker, R.; Shaviv, A.

    2009-04-01

    Transmittance and diffuse reflectance (DRIFT) spectroscopy in the mid-IR range are well-established methods for soil analysis. Over the last five years, additional mid-IR techniques have been investigated, and in particular: 1. Attenuated total reflectance (ATR) Attenuated total reflectance is commonly used for analysis of liquids and powders for which simple transmittance measurements are not possible. The method relies on a crystal with a high refractive index, which is in contact with the sample and serves as a waveguide for the IR radiation. The radiation beam is directed in such a way that it hits the crystal/sample interface several times, each time penetrating a few microns into the sample. Since the penetration depth is limited to a few microns, very good contact between the sample and the crystal must be ensured, which can be achieved by working with samples close to water saturation. However, the strong absorbance of water in the mid-infrared range as well as the absorbance of some soil constituents (e.g., calcium carbonate) interfere with some of the absorbance bands of interest. This has led to the development of several post-processing methods for analysis of the spectra. The FTIR-ATR technique has been successfully applied to soil classification as well as to determination of nitrate concentration [1, 6-8, 10]. Furthermore, Shaviv et al. [12] demonstrated the possibility of using fiber optics as an ATR devise for direct determination of nitrate concentration in soil extracts. Recently, Du et al. [5] showed that it is possible to differentiate between 14N and 15N in such spectra, which opens very promising opportunities for developing FTIR-ATR based methods for investigating nitrogen transformation in soils by tracing changes in N-isotopic species. 2. Photo-acoustic spectroscopy Photoacoustic spectroscopy (PAS) is based on absorption-induced heating of the sample, which produces pressure fluctuations in a surrounding gas. These fluctuations are

  18. Plasmonic lens enhanced mid-infrared quantum cascade detector

    Energy Technology Data Exchange (ETDEWEB)

    Harrer, Andreas, E-mail: andreas.harrer@tuwien.ac.at; Schwarz, Benedikt; Gansch, Roman; Reininger, Peter; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, 1040 Vienna (Austria)

    2014-10-27

    We demonstrate monolithic integrated quantum cascade detectors enhanced by plasmonic lenses. Surface normal incident mid-infrared radiation is coupled to surface plasmon polaritons guided to and detected by the active region of the detector. The lens extends the optical effective active area of the device up to a 5 times larger area than for standard mesa detectors or pixel devices while the electrical active region stays the same. The extended optical area increases the absorption efficiency of the presented device as well as the room temperature performance while it offers a flexible platform for various detector geometries. A photocurrent response increase at room temperature up to a factor of 6 was observed.

  19. Dilute bismides for near and mid-infrared applications

    DEFF Research Database (Denmark)

    Song, Yuxin; Gu, Yi; Ye, Hong

    2013-01-01

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

  20. High resolution mid-infrared cross-sections for peroxyacetyl nitrate (PAN vapour

    Directory of Open Access Journals (Sweden)

    G. Allen

    2004-09-01

    Full Text Available Absorption spectra of peroxyacetyl nitrate (PAN, CH3C(OOONO2 vapour at room temperature (295 K have been measured in the mid-infrared range, 550–2200 cm−1 (18.2–3.33 µm, using a Fourier transform infrared spectrometer at instrument resolutions of 0.25 and 0.03 cm−1 (unapodised. Both cross-section data and integrated absorption intensities for the five principal bands in the PAN spectra in this spectral range have been derived from fourteen separate PAN transmission spectra measurements. Band intensities and band centre absorptivities are also reported for four weaker PAN absorption bands in the mid infrared for the first time. These observations are the highest spectral resolution measurements of PAN bands recorded in the infrared to date. For three of the five strongest bands, the absolute integrated absorption intensities are in excellent agreement with previous studies. A 4.8% lower integrated intensity was found for the 1741 cm−1 νas (NO2 PAN absorption band, possibly as a result of the removal in this work of spectra affected by subtle acetone contamination, while a 10.6% higher intensity was determined for the 1163 cm−1 ν (C-O absorption band. No direct effects of spectral resolution were observed. The improved accuracy of these absorption cross-sections will allow more accurate investigations of PAN using infrared spectroscopy, particularly for remote sensing of PAN in the atmosphere.

  1. Spatiotemporal Characterization of Supercontinuum Extending from the Visible to the Mid-Infrared in Multimode Graded-Index Optical Fiber

    CERN Document Server

    Krupa, K; Couderc, V; Fabert, M; Guenard, R; Shalaby, B M; Tonello, A; Barthélémy, A; Pagnoux, D; Leproux, P; Bendahmane, A; Dupiol, R; Millot, G; Wabnitz, S

    2016-01-01

    We experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500\\,nm. We study the development of the supercontinuum along the multimode fiber by the cut-back method, which permits us to analyze the competition between the Kerr-induced geometric parametric instability and stimulated Raman scattering. We also performed a spectrally resolved temporal analysis of the supercontinuum emission.

  2. Realization of mid-infrared graphene hyperbolic metamaterials.

    Science.gov (United States)

    Chang, You-Chia; Liu, Che-Hung; Liu, Chang-Hua; Zhang, Siyuan; Marder, Seth R; Narimanov, Evgenii E; Zhong, Zhaohui; Norris, Theodore B

    2016-02-04

    While metal is the most common conducting constituent element in the fabrication of metamaterials, graphene provides another useful building block, that is, a truly two-dimensional conducting sheet whose conductivity can be controlled by doping. Here we report the experimental realization of a multilayer structure of alternating graphene and Al2O3 layers, a structure similar to the metal-dielectric multilayers commonly used in creating visible wavelength hyperbolic metamaterials. Chemical vapour deposited graphene rather than exfoliated or epitaxial graphene is used, because layer transfer methods are easily applied in fabrication. We employ a method of doping to increase the layer conductivity, and our analysis shows that the doped chemical vapour deposited graphene has good optical properties in the mid-infrared range. We therefore design the metamaterial for mid-infrared operation; our characterization with an infrared ellipsometer demonstrates that the metamaterial experiences an optical topological transition from elliptic to hyperbolic dispersion at a wavelength of 4.5 μm.

  3. Calibration of the Mid-Infrared Tully-Fisher Relation

    CERN Document Server

    Sorce, Jenny G; Tully, R Brent; Seibert, Mark; Scowcroft, Victoria; Freedman, Wendy L; Madore, Barry F; Persson, S Eric; Monson, Andy; Rigby, Jane

    2013-01-01

    Distance measures on a coherent scale around the sky are required to address the outstanding cosmological problems of the Hubble Constant and of departures from the mean cosmic flow. The correlation between galaxy luminosities and rotation rates can be used to determine distances to many thousands of galaxies in a wide range of environments potentially out to 200 Mpc. Mid-infrared (3.6 microns) photometry with the Spitzer Space Telescope is particularly valuable as the source of the luminosities because it provides products of uniform quality across the sky. From a perch above the atmosphere, essentially the total magnitude of targets can be registered in exposures of a few minutes. Extinction is minimal and the flux is dominated by the light from old stars which is expected to correlate with the mass of the targets. In spite of the superior photometry, the correlation between mid-infrared luminosities and rotation rates extracted from neutral hydrogen profiles is slightly degraded from the correlation found ...

  4. The Mid-infrared Evolution of the FU Orionis Disk

    Science.gov (United States)

    Green, Joel D.; Jones, Olivia C.; Keller, Luke D.; Poteet, Charles A.; Yang, Yao-Lun; Fischer, William J.; Evans, Neal J., II; Sargent, Benjamin A.; Rebull, Luisa M.

    2016-11-01

    We present new SOFIA-FORCAST observations obtained in 2016 February of the archetypal outbursting low-mass young stellar object FU Orionis, and we compare the continuum, solid-state, and gas properties with mid-infrared data obtained at the same wavelengths in 2004 with Spitzer-IRS. In this study, we conduct the first mid-infrared spectroscopic comparison of an FUor over a long time period. Over a 12-year period, UBVR monitoring indicates that FU Orionis has continued its steady decrease in overall brightness by ˜14%. We find that this decrease in luminosity occurs only at wavelengths ≲20 μm. In particular, the continuum shortward of the silicate emission complex at 10 μm exhibits a ˜12% (˜3σ) drop in flux density but no apparent change in slope; both the Spitzer and SOFIA spectra are consistent with a 7200 K blackbody. Additionally, the detection of water absorption is consistent with the Spitzer spectrum. The silicate emission feature at 10 μm continues to be consistent with unprocessed grains, unchanged over 12 years. We conclude that either the accretion rate in FU Orionis has decreased by ˜12-14% over this time baseline or the inner disk has cooled, but the accretion disk remains in a superheated state outside the innermost region.

  5. Realization of mid-infrared graphene hyperbolic metamaterials

    Science.gov (United States)

    Chang, You-Chia; Liu, Che-Hung; Liu, Chang-Hua; Zhang, Siyuan; Marder, Seth R.; Narimanov, Evgenii E.; Zhong, Zhaohui; Norris, Theodore B.

    2016-02-01

    While metal is the most common conducting constituent element in the fabrication of metamaterials, graphene provides another useful building block, that is, a truly two-dimensional conducting sheet whose conductivity can be controlled by doping. Here we report the experimental realization of a multilayer structure of alternating graphene and Al2O3 layers, a structure similar to the metal-dielectric multilayers commonly used in creating visible wavelength hyperbolic metamaterials. Chemical vapour deposited graphene rather than exfoliated or epitaxial graphene is used, because layer transfer methods are easily applied in fabrication. We employ a method of doping to increase the layer conductivity, and our analysis shows that the doped chemical vapour deposited graphene has good optical properties in the mid-infrared range. We therefore design the metamaterial for mid-infrared operation; our characterization with an infrared ellipsometer demonstrates that the metamaterial experiences an optical topological transition from elliptic to hyperbolic dispersion at a wavelength of 4.5 μm.

  6. Intracellular protein mass spectroscopy using mid-infrared laser ionization

    Science.gov (United States)

    Awazu, K.; Suzuki, S.

    2007-07-01

    Large-scale analysis of proteins, which can be regarded as functional biomolecule, assumes an important role in the life science. A MALDI using an ultraviolet laser (UV-MALDI) is one of ionization methods without fragmentation and has achieved conformation analysis of proteins. Recently, protein analysis has shifted from conformation analysis to functional and direct one that reserves posttranslational modifications such as the sugar chain addition and phosphorylation. We have proposed a MALDI using a mid-infrared tunable laser (IR-MALDI) as a new ionization method. IR-MALDI is promising because most biomolecules have a specific absorption in mid-infrared range, and IR-MALDI is expected to offer; (1) use of various matrices, (2) use of biomolecules such as water and lipid as the matrix, and (3) super-soft ionization. First, we evaluated the wavelength dependence of ionization of different matrices using a difference frequency generation (DFG) laser, which can tune the wavelength within a range from 5.5 to 10.0 μm. As results, ionization was specifically occurred at 5.8 μm which the C=O vibration stretching bond in matrix material and mass spectrum was observed. Next, protein mass spectrum was observed in the culture cells, MIN6, which secrete insulin, without the conventional cell-preparation processes. We demonstrate that the IR-MALDI has an advantage over the conventional method (UV-MALDI) in direct analysis of intracellular proteins.

  7. Broadband mid-infrared superlattice light-emitting diodes

    Science.gov (United States)

    Ricker, R. J.; Provence, S. R.; Norton, D. T.; Boggess, T. F.; Prineas, J. P.

    2017-05-01

    InAs/GaSb type-II superlattice light-emitting diodes were fabricated to form a device that provides emission over the entire 3-5 μm mid-infrared transmission window. Variable bandgap emission regions were coupled together using tunnel junctions to emit at peak wavelengths of 3.3 μm, 3.5 μm, 3.7 μm, 3.9 μm, 4.1 μm, 4.4 μm, 4.7 μm, and 5.0 μm. Cascading the structure recycles the electrons in each emission region to emit several wavelengths simultaneously. At high current densities, the light-emitting diode spectra broadened into a continuous, broadband spectrum that covered the entire mid-infrared band. When cooled to 77 K, radiances of over 1 W/cm2 sr were achieved, demonstrating apparent temperatures above 1000 K over the 3-5 μm band. InAs/GaSb type-II superlattices are capable of emitting from 3 μm to 30 μm, and the device design can be expanded to include longer emission wavelengths.

  8. AKARI Near- to Mid-Infrared Imaging and Spectroscopic Observations of the Small Magellanic Cloud. I. Bright Point Source List

    CERN Document Server

    Ita, Y; Tanabe, T; Matsunaga, N; Matsuura, M; Yamamura, I; Nakada, Y; Izumiura, H; Ueta, T; Mito, H; Fukushi, H; Kato, D

    2010-01-01

    We carried out a near- to mid-infrared imaging and spectroscopic observations of the patchy areas in the Small Magellanic Cloud using the Infrared Camera on board AKARI. Two 100 arcmin2 areas were imaged in 3.2, 4.1, 7, 11, 15, and 24 um and also spectroscopically observed in the wavelength range continuously from 2.5 to 13.4 um. The spectral resolving power (lambda/Delta lambda) is about 20, 50, and 50 at 3.5, 6.6 and 10.6 um, respectively. Other than the two 100 arcmin2 areas, some patchy areas were imaged and/or spectroscopically observed as well. In this paper, we overview the observations and present a list of near- to mid-infrared photometric results, which lists ~ 12,000 near-infrared and ~ 1,800 mid-infrared bright point sources detected in the observed areas. The 10 sigma limits are 16.50, 16.12, 13.28, 11.26, 9.62, and 8.76 in Vega magnitudes at 3.2, 4.1, 7, 11, 15, and 24 um bands, respectively.

  9. Discrimination of Cognacs and other distilled drinks by mid-infrared spectropscopy.

    Science.gov (United States)

    Picque, Daniel; Lieben, Pascale; Corrieu, Georges; Cantagrel, Roger; Lablanquie, Odile; Snakkers, Guillaume

    2006-07-26

    Mid-infrared spectroscopy was applied to the analysis and discrimination of Cognacs and other distilled drinks (Armagnacs, whiskies, brandies, bourbons, rums, and counterfeit products). Strong correlations were found between dry extract spectra, polyphenolic dry extract spectra, and the total polyphenol concentration of samples, notably of Cognacs. Principal component analysis applied to spectral data made it possible to emphasize the importance of dry extract data when a distinction is made between Cognacs and Armagnacs, whiskies, bourbons, and rums, and of polyphenol concentration when Cognacs, brandies, and counterfeit products are separated. Ninety-six percent of samples in the test set were correctly assigned to Cognacs and non-Cognacs by partial least-squares discriminant analysis.

  10. Identification of olive oil sensory defects by multivariate analysis of mid infrared spectra.

    Science.gov (United States)

    Borràs, Eva; Mestres, Montserrat; Aceña, Laura; Busto, Olga; Ferré, Joan; Boqué, Ricard; Calvo, Angels

    2015-11-15

    Mid-infrared (MIR) spectra (4000-600 cm(-1)) of olive oils were analyzed using chemometric methods to identify the four main sensorial defects, musty, winey, fusty and rancid, previously evaluated by an expert sensory panel. Classification models were developed using partial least squares discriminant analysis (PLS-DA) to distinguish between extra-virgin olive oils (defect absent) and lower quality olive oils (defect present). The most important spectral ranges responsible for the discrimination were identified. PLS-DA models were able to discriminate between defective and high quality oils with predictive abilities around 87% for the musty defect and around 77% for winey, fusty and rancid defects. This methodology advances instrumental determination of results previously only achievable with a human test panel.

  11. SPICA Mid-infrared Instrument (SMI): technical concepts and scientific capabilities

    Science.gov (United States)

    Kaneda, Hidehiro; Ishihara, Daisuke; Oyabu, Shinki; Yamagishi, Mitsuyoshi; Wada, Takehiko; Kawada, Mitsunobu; Isobe, Naoki; Asano, Kentaroh; Suzuki, Toyoaki; Nakagawa, Takao; Matsuhara, Hideo; Sakon, Itsuki; Tsumura, Kohji; Shibai, Hiroshi; Matsuo, Taro

    2016-07-01

    SMI (SPICA Mid-infrared Instrument) is one of the two focal-plane scientific instruments planned for new SPICA, and the Japanese instrument proposed and managed by a university consortium in Japan. SMI covers the wavelength range of 12 to 36 μm, using the following three spectroscopic channels with unprecedentedly high sensitivities: low-resolution spectroscopy (LRS; R = 50 - 120, 17 - 36 μm), mid-resolution spectroscopy (MRS; R = 1300 - 2300, 18 - 36 μm), and high-resolution spectroscopy (HRS; R = 28000, 12 - 18 μm). The key functions of these channels are high-speed dustband mapping with LRS, high-sensitivity multi-purpose spectral mapping with MRS, and high-resolution molecular-gas spectroscopy with HRS. This paper describes the technical concept and scientific capabilities of SMI.

  12. High-contrast GeTe4 waveguides for mid-infrared biomedical sensing applications

    Science.gov (United States)

    Mittal, Vinita; Wilkinson, James S.; Murugan, Ganapathy S.

    2014-03-01

    Realization of single-mode waveguides is essential for ultra-sensitive biosensing in the mid-infrared molecular "fingerprint" region for biomedical lab-on-chip applications. High contrast (Δn ≍ 1) germanium telluride (GeTe4) single mode rib waveguides were fabricated on zinc selenide (ZnSe) substrates for evanescent field based sensing to detect analytes at low concentration. Amorphous GeTe4 thin films were deposited by RF-sputtering and were found to transmit over the spectral range from 2μm - 20μm. Photolithography followed by reactive ion etching was carried out to etch the film, forming rib waveguide structures with minimum surface roughness and vertical sidewalls. It was found that films deposited at room temperature have average roughness of about 5nm. Optical constants were determined by IR-VASE ellipsometry.

  13. CdS/PbSe heterojunction for high temperature mid-infrared photovoltaic detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Binbin, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu; Qiu, Jijun; Zhao, Lihua; Chang, Caleb [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Shi, Zhisheng, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Nanolight, Inc., Norman, Oklahoma 73069 (United States)

    2014-03-24

    n-CdS/p-PbSe heterojunction is investigated. A thin CdS film is deposited by chemical bath deposition on top of epitaxial PbSe film by molecular beam epitaxy on Silicon. Current-voltage measurements demonstrate very good junction characteristics with rectifying ratio of ∼178 and ideality factor of 1.79 at 300 K. Detectors made with such structure exhibit mid-infrared spectral photoresponse at room temperature. The peak responsivity R{sub λ} and specific detectivity D{sup *} are 0.055 A/W and 5.482 × 10{sup 8} cm·Hz{sup 1/2}/W at λ = 4.7 μm under zero-bias photovoltaic mode. Temperature-dependent photoresponse measurements show abnormal intensity variation below ∼200 K. Possible reasons for this phenomenon are also discussed.

  14. The Mid-Infrared Instrument for the James Webb Space Telescope, X. Operations and Data Reduction

    CERN Document Server

    Gordon, Karl D; Anderson, Rachel E; Azzollini, Ruyman; Bergeron, L; Bouchet, Patrice; Bouwman, Jeroen; Cracraft, Misty; Fischer, Sebastian; Friedman, Scott D; Garcia-Marin, Macarena; Glasse, Alistair; Glauser, Adrian M; Goodson, G B; Greene, T P; Hines, Dean C; Khorrami, M A; Lahuis, Fred; Lajoie, C -P; Meixner, M E; Morrison, Jane E; O'Sullivan, Brian; Pontoppidan, K M; Regan, M W; Ressler, M E; Rieke, G H; Scheithauer, Silvia; Walker, Helen; Wright, G S

    2015-01-01

    We describe the operations concept and data reduction plan for the Mid- Infrared Instrument (MIRI) for the James Webb Space Telescope (JWST). The overall JWST operations concept is to use Observation Templates (OTs) to provide a straightforward and intuitive way for users to specify observations. MIRI has four OTs that correspond to the four observing modes: 1.) Imaging, 2.) Coronagraphy, 3.) Low Resolution Spectroscopy, and 4.) Medium Resolution Spectroscopy. We outline the user choices and expansion of these choices into detailed instrument operations. The data reduction plans for MIRI are split into three stages, where the specificity of the reduction steps to the observation type increases with stage. The reduction starts with integration ramps: stage 1 yields uncalibrated slope images; stage 2 calibrates the slope images; and then stage 3 combines multiple calibrated slope images into high level data products (e.g. mosaics, spectral cubes, and extracted source information). Finally, we give examples of t...

  15. Young massive stars and their environment in the mid-infrared at high angular resolution

    CERN Document Server

    De Wit, W J; Oudmaijer, R D; Fujiyoshi, T

    2008-01-01

    We present interferometric and single-dish mid-infrared observations of a sample of massive young stellar objects (BN-type objects), using VLTI-MIDI (10 micron) and Subaru-COMICS (24.5 micron). We discuss the regions S140, Mon R2, M8E-IR, and W33A. The observations probe the inner regions of the dusty envelope at scales of 50 milli arcsecond and 0.6 arcsec (100-1000 AU), respectively. Simultaneous model fits to spectral energy distributions and spatial data are achieved using self-consistent spherical envelope modelling. We conclude that those MYSO envelopes that are best described by a spherical geometry, the commensurate density distribution is a powerlaw with index -1.0. Such a powerlaw is predicted if the envelope is supported by turbulence on the 100-1000AU scales probed with MIDI and COMICS, but the role of rotation at these spatial scales need testing.

  16. Prospective for graphene based thermal mid-infrared light emitting devices

    Directory of Open Access Journals (Sweden)

    L. M. Lawton

    2014-08-01

    Full Text Available We have investigated the spatial and spectral characteristics of mid-infrared thermal emission from large area Chemical Vapor Deposition (CVD graphene, transferred onto SiO2/Si, and show that the emission is broadly that of a grey-body emitter, with emissivity values of approximately 2% and 6% for mono- and multilayer graphene. For the currents used, which could be sustained for over one hundred hours, the emission peaked at a wavelength of around 4 μm and covered the characteristic absorption of many important gases. A measurable modulation of thermal emission was obtained even when the drive current was modulated at frequencies up to 100 kHz.

  17. Evaluating mid-infrared spectroscopy as a new technique for predicting sensory texture attributes of processed cheese.

    Science.gov (United States)

    Fagan, C C; Everard, C; O'Donnell, C P; Downey, G; Sheehan, E M; Delahunty, C M; O'Callaghan, D J

    2007-03-01

    The objective of this study was to investigate the potential application of mid-infrared spectroscopy for determination of selected sensory attributes in a range of experimentally manufactured processed cheese samples. This study also evaluates mid-infrared spectroscopy against other recently proposed techniques for predicting sensory texture attributes. Processed cheeses (n = 32) of varying compositions were manufactured on a pilot scale. After 2 and 4 wk of storage at 4 degrees C, mid-infrared spectra (640 to 4,000 cm(-1)) were recorded and samples were scored on a scale of 0 to 100 for 9 attributes using descriptive sensory analysis. Models were developed by partial least squares regression using raw and pretreated spectra. The mouth-coating and mass-forming models were improved by using a reduced spectral range (930 to 1,767 cm(-1)). The remaining attributes were most successfully modeled using a combined range (930 to 1,767 cm(-1) and 2,839 to 4,000 cm(-1)). The root mean square errors of cross-validation for the models were 7.4 (firmness; range 65.3), 4.6 (rubbery; range 41.7), 7.1 (creamy; range 60.9), 5.1 (chewy; range 43.3), 5.2 (mouth-coating; range 37.4), 5.3 (fragmentable; range 51.0), 7.4 (melting; range 69.3), and 3.1 (mass-forming; range 23.6). These models had a good practical utility. Model accuracy ranged from approximate quantitative predictions to excellent predictions (range error ratio = 9.6). In general, the models compared favorably with previously reported instrumental texture models and near-infrared models, although the creamy, chewy, and melting models were slightly weaker than the previously reported near-infrared models. We concluded that mid-infrared spectroscopy could be successfully used for the nondestructive and objective assessment of processed cheese sensory quality.

  18. The Cepheid Period-Luminosity Relation at Mid-Infrared Wavelengths: I. First-Epoch LMC Data

    CERN Document Server

    Freedman, Wendy L; Rigby, Jane; Persson, S E; Sturch, Laura

    2008-01-01

    We present the first mid-infrared Period-Luminosity (PL) relations for Large Magellanic Cloud (LMC) Cepheids. Single-epoch observations of 70 Cepheids were extracted from Spitzer IRAC observations at 3.6, 4.5, 5.8 and 8.0 microns, serendipitously obtained during the SAGE (Surveying the Agents of a Galaxy's Evolution) imaging survey of the LMC. All four mid-infrared PL relations have nearly identical slopes over the period range 6 - 88 days, with a small scatter of only +/-0.16 mag independent of period for all four of these wavelengths. We emphasize that differential reddening is not contributing significantly to the observed scatter, given the nearly two orders of magnitude reduced sensitivity of the mid-IR to extinction compared to the optical. Future observations, filling in the light curves for these Cepheids, should noticeably reduce the residual scatter. These attributes alone suggest that mid-infrared PL relations will provide a practical means of significantly improving the accuracy of Cepheid distanc...

  19. High Efficiency, Room Temperature Mid-Infrared Semiconductor Laser Development for IR Countermeasures

    Science.gov (United States)

    2009-05-01

    CONTRACT NUMBER EFFICIENCY, ROOM TEMPERATURE MID-INFRARED SEMICONDUCTOR LASER DEVELOPMENT FOR IR COUNTERMEASURES Sb. GRANT NUMBER FA9550-04-1-0433...04-1-0433 Title: (DEPSCOR FY04) High Efficiency, Room Temperature Mid-Infrared Semiconductor Laser Development for IR Countermeasures Principal...AFOSR Final Performance Report, March 2008 Award No.: FA9550-04-1-0433 Title: High Efficiency, Room Temperature Mid-Infrared Semiconductor Laser

  20. An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status

    Science.gov (United States)

    Matter, A.; Lopez, B.; Antonelli, P.; Lehmitz, M.; Bettonvil, F.; Beckmann, U.; Lagarde, S.; Jaffe, W.; Petrov, R.; Berio, P.; Millour, F.; Robbe-Dubois, S.; Glindemann, A.; Bristow, P.; Schoeller, M.; Lanz, T.; Henning, T.; Weigelt, G.; Heininger, M.; Morel, S.; Cruzalebes, P.; Meisenheimer, K.; Hofferbert, R.; Wolf, S.; Bresson, Y.; Agocs, T.; Allouche, F.; Augereau, J.-C.; Avila, G.; Bailet, C.; Behrend, J.; van Belle, G.; Berger, J.-P.; van Boekel, R.; Bourget, P.; Brast, R.; Clausse, J.-M.; Connot, C.; Conzelmann, R.; Csepany, G.; Danchi, W. C.; Delbo, M.; Dominik, C.; van Duin, A.; Elswijk, E.; Fantei, Y.; Finger, G.; Gabasch, A.; Gonté, F.; Graser, U.; Guitton, F.; Guniat, S.; De Haan, M.; Haguenauer, P.; Hanenburg, H.; Hofmann, K.-H.; Hogerheijde, M.; ter Horst, R.; Hron, J.; Hummel, C.; Isderda, J.; Ives, D.; Jakob, G.; Jasko, A.; Jolley, P.; Kiraly, S.; Kragt, J.; Kroener, T.; Kroes, G.; Kuindersma, S.; Labadie, L.; Laun, W.; Leinert, C.; Lizon, J.-L.; Lucuix, C.; Marcotto, A.; Martinache, F.; Martinot-Lagarde, G.; Mauclert, N.; Mehrgan, L.; Meilland, A.; Mellein, M.; Menardi, S.; Merand, A.; Neumann, U.; Nussbaum, E.; Ottogalli, S.; Palsa, R.; Panduro, J.; Pantin, E.; Percheron, I.; Phan Duc, T.; Pott, J.-U.; Pozna, E.; Roelfsema, R.; Rupprecht, G.; Schertl, D.; Schmidt, C.; Schuil, M.; Spang, A.; Stegmeier, J.; Tromp, N.; Vakili, F.; Vannier, M.; Wagner, K.; Venema, L.; Woillez, J.

    2016-08-01

    MATISSE is the second-generation mid-infrared spectrograph and imager for the Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric instrument will allow significant advances by opening new avenues in various fundamental research fields: studying the planet-forming region of disks around young stellar objects, understanding the surface structures and mass loss phenomena affecting evolved stars, and probing the environments of black holes in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the spectral domain of current optical interferometers by offering the L and M bands in addition to the N band. This will open a wide wavelength domain, ranging from 2.8 to 13 μm, exploring angular scales as small as 3 mas (L band) / 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared imaging - closure-phase aperture-synthesis imaging - with up to four Unit Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE will offer a spectral resolution range from R ˜ 30 to R ˜ 5000. Here, we present one of the main science objectives, the study of protoplanetary disks, that has driven the instrument design and motivated several VLTI upgrades (GRA4MAT and NAOMI). We introduce the physical concept of MATISSE including a description of the signal on the detectors and an evaluation of the expected performances. We also discuss the current status of the MATISSE instrument, which is entering its testing phase, and the foreseen schedule for the next two years that will lead to the first light at Paranal.

  1. Time-dependent calculations in Potassium mid-infrared wavelengths

    CERN Document Server

    Maragakis, P; Lambropoulos, P

    1999-01-01

    We study the dynamics of the Potassium atom in the mid-infrared, high intensity, short laser pulse regime. We ascertain our numerical convergence by comparing the results of two different propagation methods of the time-dependent Schroedinger equation. We present ionization curves in the 12-, 13-, and 14-photon ionization range for Potassium. The ionization curve of a scaled system, namely Hydrogen starting from the 2s, is compared to the 12-photon results. In the 13-photon regime, a dynamic resonance is observed and analyzed in more detail. The results for all wavelengths and intensities, including the case of Hydrogen, display a clear plateau formation in the peak-heights of the low energy part of the Above Threshold Ionization (ATI) spectrum, which scales with the ponderomotive energy Up, and extends to (2.8 +- 0.5) Up.

  2. Mid-infrared plasmonic inductors: enhancing inductance with meandering lines.

    Science.gov (United States)

    Torres, Víctor; Ortuño, Rubén; Rodríguez-Ulibarri, Pablo; Griol, Amadeu; Martínez, Alejandro; Navarro-Cía, Miguel; Beruete, Miguel; Sorolla, Mario

    2014-01-07

    We present a mid-infrared inductor that when applied to an extraordinary transmission hole array produces a strong redshift of the resonant peak accompanied by an unprecedented enlargement of the operation bandwidth. The importance of the result is twofold: from a fundamental viewpoint, the direct applicability of equivalent circuit concepts borrowed from microwaves is demonstrated, in frequencies as high as 17 THz upholding unification of plasmonics and microwave concepts and allowing for a simplification of structure design and analysis; in practical terms, a broadband funnelling of infrared radiation with fractional bandwidth and efficiency as high as 97% and 48%, respectively, is achieved through an area less than one hundredth the squared wavelength, which leads to an impressive accessible strong field localization that may be of great interest in sensing applications.

  3. Nonsequential double ionization with mid-infrared laser fields

    Science.gov (United States)

    Li, Ying-Bin; Wang, Xu; Yu, Ben-Hai; Tang, Qing-Bin; Wang, Guang-Hou; Wan, Jian-Guo

    2016-11-01

    Using a full-dimensional Monte Carlo classical ensemble method, we present a theoretical study of atomic nonsequential double ionization (NSDI) with mid-infrared laser fields, and compare with results from near-infrared laser fields. Unlike single-electron strong-field processes, double ionization shows complex and unexpected interplays between the returning electron and its parent ion core. As a result of these interplays, NSDI for mid-IR fields is dominated by second-returning electron trajectories, instead of first-returning trajectories for near-IR fields. Some complex NSDI channels commonly happen with near-IR fields, such as the recollision-excitation-with-subsequent-ionization (RESI) channel, are virtually shut down by mid-IR fields. Besides, the final energies of the two electrons can be extremely unequal, leading to novel e-e momentum correlation spectra that can be measured experimentally.

  4. Atmospheric refractivity effects on mid-infrared ELT adaptive optics

    CERN Document Server

    Kendrew, S; Mathar, R J; Stuik, R; Hippler, S; Brandl, B

    2008-01-01

    We discuss the effect of atmospheric dispersion on the performance of a mid-infrared adaptive optics assisted instrument on an extremely large telescope (ELT). Dispersion and atmospheric chromaticity is generally considered to be negligible in this wavelength regime. It is shown here, however, that with the much-reduced diffraction limit size on an ELT and the need for diffraction-limited performance, refractivity phenomena should be carefully considered in the design and operation of such an instrument. We include an overview of the theory of refractivity, and the influence of infrared resonances caused by the presence of water vapour and other constituents in the atmosphere. `Traditional' atmospheric dispersion is likely to cause a loss of Strehl only at the shortest wavelengths (L-band). A more likely source of error is the difference in wavelengths at which the wavefront is sensed and corrected, leading to pointing offsets between wavefront sensor and science instrument that evolve with time over a long e...

  5. Chalcogenide optical fibers for mid-infrared sensing

    Science.gov (United States)

    Bureau, Bruno; Boussard, Catherine; Cui, Shuo; Chahal, Radwan; Anne, Marie Laure; Nazabal, Virginie; Sire, Olivier; Loréal, Olivier; Lucas, Pierre; Monbet, Valérie; Doualan, Jean-Louis; Camy, Patrice; Tariel, Hugues; Charpentier, Frédéric; Quetel, Lionel; Adam, Jean-Luc; Lucas, Jacques

    2014-02-01

    Chalcogenide glasses are a matchless material as far as mid-infrared (IR) applications are concerned. They transmit light typically from 2 to 12 μm and even as far as 20 μm depending on their composition, and numerous glass compositions can be designed for optical fibers. One of the most promising applications of these fibers consists in implementing fiber evanescent wave spectroscopy, which enables detection of the mid-IR signature of most biomolecules. The principles of fiber evanescent wave spectroscopy are recalled together with the benefit of using selenide glass to carry out this spectroscopy. Then, two large-scale studies in recent years in medicine and food safety are exposed. To conclude, the future strategy is presented. It focuses on the development of rare earth-doped fibers used as mid-IR sources on one hand and tellurium-based glasses to shift the limit of detection toward longer wavelength on the other hand.

  6. Modelocked mid-infrared frequency combs in a silicon microresonator

    CERN Document Server

    Yu, Mengjie; Griffith, Austin G; Lipson, Michal; Gaeta, Alexander L

    2016-01-01

    Mid-infrared (mid-IR) frequency combs have broad applications in molecular spectroscopy and chemical/biological sensing. Recently developed microresonator-based combs in this wavelength regime could enable portable and robust devices using a single-frequency pump field. Here, we report the first demonstration of a modelocked microresonator-based frequency comb in the mid-IR spanning 2.4 {\\mu}m to 4.3 {\\mu}m. We observe high pump-to-comb conversion efficiency, in which 40% of the pump power is converted to the output comb power. Utilizing an integrated PIN structure allows for tuning the silicon microresonator and controling modelocking and cavity soliton formation, simplifying the generation, monitoring and stabilization of mid-IR frequency combs via free-carrier detection and control. Our results significantly advance microresonator-based comb technology towards a portable and robust mid-IR spectroscopic device that operates at low pump powers.

  7. AMUSE-VIRGO. III. MID-INFRARED PHOTOMETRY OF EARLY-TYPE GALAXIES AND LIMITS ON OBSCURED NUCLEAR EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Leipski, Christian [Max-Planck Institut fuer Astronomie (MPIA), Koenigstuhl 17, D-69117 Heidelberg (Germany); Gallo, Elena; Miller, Brendan P. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Treu, Tommaso; Antonucci, Robert [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Woo, Jong-Hak, E-mail: leipski@mpia-hd.mpg.de [Department of Physics and Astronomy, Seoul National University, Seoul, 151-742 (Korea, Republic of)

    2012-01-10

    We complete our census of low-level nuclear activity in Virgo Cluster early-type galaxies by searching for obscured emission using Spitzer Space Telescope mid-infrared (MIR) imaging at 24 {mu}m. Of a total sample of 95 early-type galaxies, 53 objects are detected, including 16 showing kiloparsec-scale dust in optical images. One-dimensional and two-dimensional surface photometry of the 37 detections without extended dust features reveals that the MIR light is more centrally concentrated than the optical light as traced by Hubble Space Telescope F850LP-band images. No such modeling was performed for the sources with dust detected in the optical images. We explore several possible sources of the MIR excess emission, including obscured nuclear emission. We find that radial metallicity gradients in the stellar population appear to be a natural and most likely explanation for the observed behavior in a majority of the sources. Alternatively, if the concentrated MIR emission were due to nuclear activity, it would imply a MIR-to-X luminosity ratio {approx}5-10 for the low-luminosity active galactic nucleus (AGN) detected in X-rays by our survey. This ratio is an order of magnitude larger than that of typical low-luminosity AGNs and would imply an unusual spectral energy distribution. We conclude that the black holes found by our survey in quiescent early-type galaxies in Virgo have low bolometric Eddington ratios arising from low accretion rates and/or highly radiatively inefficient accretion.

  8. Mid-infrared supercontinuum laser system and its biomedical applications

    Science.gov (United States)

    Xia, Chenan

    A mid-infrared supercontinuum (SC) laser system is developed, which provides a continuous spectrum from ˜0.8 to ˜4.5 microm and is pumped by amplified nanosecond laser diode pulses. The SC laser uses ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) fluoride fibers. The SC light source is all-fiber-integrated with no moving parts, operates at room temperature, and eliminates the need of mode-locked lasers. The time-averaged power of the SC is scalable up to 10.5 W by amplifying the pump pulses using cladding-pumped erbium/ytterbium co-doped fiber power amplifiers. SC has also been generated in silica fibers with spectrum extending to ˜3 microm and an average power up to 5.3 W. The SC laser system comprises an all-fiber-spliced high power pump laser system followed by nonlinear optical generation fibers, i.e. ZBLAN and silica fibers. The SC generation is initiated by breaking up the nanosecond diode pulses into femtosecond pulses through modulation instability, and the spectrum is then broadened through the interplay of self-phase modulation, parametric four-wave mixing, and stimulated Raman scattering. Theoretical simulations have been carried out to study the SC generation mechanism by numerically solving the generalized nonlinear Schrodinger equation. The SC long wavelength edge is limited by the intrinsic fiber material absorption, i.e. ˜3 microm in silica fibers and ˜4.5 microm in ZBLAN fibers, respectively. Mid-infrared absorption spectroscopy of the constituents of normal artery, e.g. endothelial cells and smooth muscle cells, and atherosclerotic plaques, e.g. adipose tissue, macrophages and foam cells, and selective ablation of lipid-rich tissues have also been demonstrated using the SC laser system.

  9. Precalibration evaluation procedures for mid-infrared milk analyzers.

    Science.gov (United States)

    Lynch, J M; Barbano, D M; Schweisthal, M; Fleming, J R

    2006-07-01

    The purpose of this paper is to present a detailed account of the precalibration procedures developed and implemented by the USDA Federal Milk Market Administrators (FMMA) for evaluating mid-infrared (MIR) milk analyzers. Mid-infrared analyzers specifically designed for milk testing provide a rapid and cost-effective means for determining milk composition for payment and dairy herd improvement programs. These instruments determine the fat, protein, and lactose content of milk, and enable the calculation of total solids, solids-not-fat, and other solids. All MIR analyzers are secondary testing instruments that require calibration by chemical reference methods. Precalibration is the process of assuring that the instrument is in good working order (mechanically and electrically) and that the readings before calibration are stable and optimized. The main components of precalibration are evaluation of flow system integrity, homogenization efficiency, water repeatability, zero shift, linearity, primary slope, milk repeatability, purging efficiency, and establishment of intercorrection factors. These are described in detail and apply to both filter-based and Fourier transform infrared instruments operating using classical primary and reference wavelengths. Under the USDA FMMA Precalibration Evaluation Program, the precalibration procedures were applied longitudinally over time using a wide variety of instruments and instrument models. Instruments in this program were maintained to pass the criteria for all precalibration procedures. All instruments used similar primary wavelengths to measure fat, protein, and lactose but there were differences in reference wavelength selection. Intercorrection factors were consistent over time within all instruments and similar among groups of instruments using similar primary and reference wavelengths. However, the magnitude and sign of the intercorrection factors were significantly affected by the choice of reference wavelengths.

  10. The Mid-Infrared Extinction Law in the Large Magellanic Cloud

    OpenAIRE

    Gao, Jian; Jiang, B. W.; Li, Aigen; Xue, M. Y.

    2013-01-01

    Based on the photometric data from the Spitzer/SAGE survey and with red giants as the extinction tracers, the mid-infrared (MIR) extinction laws in the Large Magellanic Cloud (LMC) are derived for the first time in the form of A_\\lambda/A_Ks, the extinction in the four IRAC bands (i.e., [3.6], [4.5], [5.8] and [8.0]um) relative to the 2MASS Ks band at 2.16um. We obtain the near-infrared (NIR) extinction coefficient to be E(J-H)/E(H-Ks)=1.29\\pm0.04 and E(J-Ks)/E(H-Ks)=1.94\\pm0.04. The waveleng...

  11. Analysis of mid-infrared optical conductivity in electron-doped cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Varshney, Dinesh [School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road Campus, Indore-452017 (India); Patel, G S [School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road Campus, Indore-452017 (India); Singh, R K [M P Bhoj (Open) University, Shivaji Nagar, Bhopal-462016, Madhya Pradesh (India)

    2003-05-01

    Observed frequency dependent optical conductivity {sigma}({omega}) of electron-doped cuprate Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4-{delta}} ({delta} {approx} 0.02, T{sub c} {approx} 25 K) superconductors has been theoretically analysed. Starting from an effective two-dimensional (2D) interaction potential for superlattice of electron-doped cuprates treated as a layered electron gas, the spectral function is developed. Calculations of {sigma}({omega}) have been made within the two component scheme: one is the coherent Drude carriers responsible for superconductivity and the other is incoherent motion of carriers from one site to the other that leads to a pairing between Drude carriers. The approach accounts for the anomalies observed (frequency dependence of optical conductivity) in the optical measurements for the normal state. Estimating the effective mass from specific heat measurement and {epsilon}{sub {infinity}} from band structure calculations for the low-energy charge density waves, the model has only one free parameter, the relaxation rate. The frequency dependent relaxation rates are expressed in terms of memory functions, and the coherent Drude carriers from the effective interaction potential lead to a sharp peak at zero frequency and a long tail at higher frequencies, i.e. in the infrared region, while the hopping of carriers from one site to the other (incoherent motion of doped carriers) yields a peak value in the optical conductivity centred at mid-infrared region. We find that both the Drude and hopping carriers in the superlattice of electron-doped cuprates will contribute to the optical process of conduction in the CuO{sub 2} planes and show similar results on optical conductivity in the mid-infrared as well as infrared frequency regions as those revealed from experiments.

  12. Analysis of mid-infrared optical conductivity in electron-doped cuprates

    Science.gov (United States)

    Varshney, Dinesh; Patel, G. S.; Singh, R. K.

    2003-05-01

    Observed frequency dependent optical conductivity sigma(omega) of electron-doped cuprate Nd1.85Ce0.15CuO4-delta (delta approx 0.02, Tc approx 25 K) superconductors has been theoretically analysed. Starting from an effective two-dimensional (2D) interaction potential for superlattice of electron-doped cuprates treated as a layered electron gas, the spectral function is developed. Calculations of sigma(omega) have been made within the two component scheme: one is the coherent Drude carriers responsible for superconductivity and the other is incoherent motion of carriers from one site to the other that leads to a pairing between Drude carriers. The approach accounts for the anomalies observed (frequency dependence of optical conductivity) in the optical measurements for the normal state. Estimating the effective mass from specific heat measurement and varepsiloninfty from band structure calculations for the low-energy charge density waves, the model has only one free parameter, the relaxation rate. The frequency dependent relaxation rates are expressed in terms of memory functions, and the coherent Drude carriers from the effective interaction potential lead to a sharp peak at zero frequency and a long tail at higher frequencies, i.e. in the infrared region, while the hopping of carriers from one site to the other (incoherent motion of doped carriers) yields a peak value in the optical conductivity centred at mid-infrared region. We find that both the Drude and hopping carriers in the superlattice of electron-doped cuprates will contribute to the optical process of conduction in the CuO2 planes and show similar results on optical conductivity in the mid-infrared as well as infrared frequency regions as those revealed from experiments.

  13. DEVELOPMENT OF NEW MID-INFRARED ULTRAFAST LASER SOURCES FOR COMPACT COHERENT X-RAY SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Sterling Backus

    2012-05-14

    In this project, we proposed to develop laser based mid-infrared lasers as a potentially robust and reliable source of ultrafast pulses in the mid-infrared region of the spectrum, and to apply this light source to generating bright, coherent, femtosecond-to-attosecond x-ray beams.

  14. Mid infrared and fluorescence spectroscopies coupled with factorial discriminant analysis technique to identify sheep milk from different feeding systems

    OpenAIRE

    Karoui, Romdhane; Hammami, Moncef; Rouissi, Hamadi; Blecker, Christophe

    2011-01-01

    Mid infrared spectroscopy (MIR) combined with multivariate data analysis was used to discriminate between ewes milk samples according to their feeding systems (controls, ewes fed scotch bean and ewes fed soybean). The MIR spectra were scanned throughout the first 11 weeks of the lactation stage. When factorial discriminant analysis (FDA) with leave one-out cross-validation was applied, separately, to the three spectral regions in the MIR (i.e. 3000-2800, 1700-1500 and 1500-900 cm(-1)), the cl...

  15. Monolithic beam steering in a mid-infrared, surface-emitting, photonic integrated circuit.

    Science.gov (United States)

    Slivken, Steven; Wu, Donghai; Razeghi, Manijeh

    2017-08-16

    The mid-infrared (2.5 infrared optical systems, however, mid-infrared component technology is still rather crude, with isolated components exhibiting limited functionality. In this manuscript, we make a significant leap forward in mid-infrared technology by developing a platform which can combine functions of multiple mid-infrared optical elements, including an integrated light source. In a single device, we demonstrate wide wavelength tuning (240 nm) and beam steering (17.9 degrees) in the mid-infrared with a significantly reduced beam divergence (down to 0.5 degrees). The architecture is also set up to be manufacturable and testable on a wafer scale, requiring no cleaved facets or special mirror coating to function.

  16. The Mid-infrared Spectrum of the Transiting Exoplanet HD 209458b

    Science.gov (United States)

    Swain, M. R.; Bouwman, J.; Akeson, R. L.; Lawler, S.; Beichman, C. A.

    2008-01-01

    We report the spectroscopic detection of mid-infrared emission from the transiting exoplanet HD 209458b. Using archive data taken with the Spitzer IRS instrument, we have determined the spectrum of HD 209458b between 7.46 and 15.25 micrometers. We have used two independent methods to determine the planet spectrum, one differential in wavelength and one absolute, and find the results are in good agreement. Over much of this spectral range, the planet spectrum is consistent with featureless thermal emission. Between 7.5 and 8.5 m, we find evidence for an unidentified spectral feature. If this spectral modulation is due to absorption, it implies that the dayside vertical temperature profile of the planetary atmosphere is not entirely isothermal. Using the IRS data, we have determined the broadband eclipse depth to be 0:00315 +/- 0:000315, implying significant redistribution of heat from the dayside to the nightside. This work required the development of improved methods for Spitzer IRS data calibration that increase the achievable absolute calibration precision and dynamic range for observations of bright point sources.

  17. A mid-infrared statistical investigation of clumpy torus model predictions

    Science.gov (United States)

    García-González, J.; Alonso-Herrero, A.; Hönig, S. F.; Hernán-Caballero, A.; Ramos Almeida, C.; Levenson, N. A.; Roche, P. F.; González-Martín, O.; Packham, C.; Kishimoto, M.

    2017-09-01

    We present new calculations of the Clumpy AGN Tori in a 3D geometry (CAT3D) clumpy torus models, which now include a more physical dust sublimation model as well as active galactic nucleus (AGN) anisotropic emission. These new models allow graphite grains to persist at temperatures higher than the silicate dust sublimation temperature. This produces stronger near-infrared emission and bluer mid-infrared (MIR) spectral slopes. We make a statistical comparison of the CAT3D model MIR predictions with a compilation of sub-arcsecond resolution ground-based MIR spectroscopy of 52 nearby Seyfert galaxies (median distance of 36 Mpc) and 10 quasars. We focus on the AGN MIR spectral index αMIR and the strength of the 9.7 μm silicate feature SSil. As with other clumpy torus models, the new CAT3D models do not reproduce the Seyfert galaxies with deep silicate absorption (SSil low photon escape probabilities, while the quasars and the Seyfert 1-1.5 require generally models with higher photon escape probabilities. Quasars and Seyfert 1-1.5 tend to show steeper radial cloud distributions and fewer clouds along an equatorial line of sight than Seyfert 2. Introducing AGN anisotropic emission besides the more physical dust sublimation models alleviates the problem of requiring inverted radial cloud distributions (i.e. more clouds towards the outer parts of the torus) to explain the MIR spectral indices of type 2 Seyferts.

  18. Development of Mid-Infrared Lasers for the Measurement of Trace Atmospheric Gases

    Science.gov (United States)

    Hannun, R. A.; Witinski, M. F.; Forouhar, S.; Anderson, J.

    2012-12-01

    In order to thoroughly characterize atmospheric composition at all altitudes, an unprecedented scientific and technical effort is needed. Essential to the advancement of both satellite and in situ science are improvements in continuous wave (CW) and high-power pulsed laser systems in the infrared spectral region integrated with miniaturized electronic and optical components, allowing for the deployment of single mode light sources aboard satellite and UAV platforms. Sources in the the spectral region from 2.8 μm to 3.5 μm are crucial to the sensitive and precise quantification of several atmospherically relevant species, including: OH, H2O, H218O, HDO, CH4, 13CH4, CO2, CH2O, and C2H6, all of which present strong fundamental vibrational absorptions in this mid-infrared range. Currently, however, a massive technology gap exists in both CW and pulsed laser systems within this spectral window. Recent developments include the advancement of CW tunable diode technology using new solid state materials to improve electron hole localization, and the initial integration of these lasers into miniaturized optoelectronic systems ideal for in situ deployment. In addition, high-power pulsed light sources have been produced using optical parametric generation (OPG). A single-frequency Nd:YAG pumps a nonlinear crystal, injection seeded with a diode laser to enhance efficiency and reduce the bandwidth of the output radiation, creating a light source ideal for LIDAR and other remote sensing applications.

  19. Improved mid-infrared cross-sections for peroxyacetyl nitrate (PAN vapour

    Directory of Open Access Journals (Sweden)

    G. Allen

    2005-01-01

    Full Text Available Absorption spectra of peroxyacetyl nitrate (PAN, CH3C(OOONO2 vapour at room temperature (295K have been measured in the mid-infrared range, 550-2200cm-1 (18.2-4.55µm, using a Fourier Transform infrared spectrometer at instrument resolutions of 0.25 and 0.03cm-1 (unapodised. Between five and eight measurements were obtained for each spectral band of PAN in the pressure range 0.24-2.20mb showing good agreement with Beer's law. Both cross-section data and integrated absorption intensities for the five principal bands in the PAN spectra in this spectral range have been derived with peak cross-sections of the 794, 1163, 1302, 1741 and 1842cm-1 bands measured to be 0.95(±0.02, 1.21(±0.03, 0.92(±0.02, 2.39(±0.06 and 0.74(±0.03 (x10-18cm2molecule-1 respectively. Band intensities and band centre absorptivities are also reported for four weaker PAN absorption bands in the mid infrared for the first time. These observations are the highest spectral resolution measurements of PAN bands reported in the infrared to date. For three of the five strongest bands, the absolute integrated absorption intensities are in excellent agreement with previous studies. A 4.8% lower integrated intensity was found for the 1741cm-1νas(NO2 PAN absorption band, possibly as a result of the removal in this work of spectra affected by acetone contamination, while a 10.6% higher intensity was determined for the 1163cm-1ν(C-O absorption band. No resolution of fine structure in the PAN absorption bands was observed at the resolutions studied. The confirmation of absorption cross-sections and estimated errors in this work will allow more accurate investigations of PAN using infrared spectroscopy, particularly for remote sensing of PAN in the atmosphere.

  20. Terahertz and mid-infrared reflectance of epitaxial graphene

    Science.gov (United States)

    Santos, Cristiane N.; Joucken, Frédéric; De Sousa Meneses, Domingos; Echegut, Patrick; Campos-Delgado, Jessica; Louette, Pierre; Raskin, Jean-Pierre; Hackens, Benoit

    2016-01-01

    Graphene has emerged as a promising material for infrared (IR) photodetectors and plasmonics. In this context, wafer scale epitaxial graphene on SiC is of great interest in a variety of applications in optics and nanoelectronics. Here we present IR reflectance spectroscopy of graphene grown epitaxially on the C-face of 6H-SiC over a broad optical range, from terahertz (THz) to mid-infrared (MIR). Contrary to the transmittance, reflectance measurements are not hampered by the transmission window of the substrate, and in particular by the SiC Reststrahlen band in the MIR. This allows us to present IR reflectance data exhibiting a continuous evolution from the regime of intraband to interband charge carrier transitions. A consistent and simultaneous analysis of the contributions from both transitions to the optical response yields precise information on the carrier dynamics and the number of layers. The properties of the graphene layers derived from IR reflection spectroscopy are corroborated by other techniques (micro-Raman and X-ray photoelectron spectroscopies, transport measurements). Moreover, we also present MIR microscopy mapping, showing that spatially-resolved information can be gathered, giving indications on the sample homogeneity. Our work paves the way for a still scarcely explored field of epitaxial graphene-based THz and MIR optical devices. PMID:27102827

  1. Probing stellar accretion with mid-infrared hydrogen lines

    CERN Document Server

    Rigliaco, Elisabetta; Duchene, G; Edwards, S; Ardila, D R; Grady, C; Mendigutía, I; Montesinos, B; Mulders, G D; Najita, J R; Carpenter, J; Furlan, E; Gorti, U; Meijerink, R; Meyer, M R

    2015-01-01

    In this paper we investigate the origin of the mid-infrared (IR) hydrogen recombination lines for a sample of 114 disks in different evolutionary stages (full, transitional and debris disks) collected from the {\\it Spitzer} archive. We focus on the two brighter {H~{\\sc i}} lines observed in the {\\it Spitzer} spectra, the {H~{\\sc i}}(7-6) at 12.37$\\mu$m and the {H~{\\sc i}}(9-7) at 11.32$\\mu$m. We detect the {H~{\\sc i}}(7-6) line in 46 objects, and the {H~{\\sc i}}(9-7) in 11. We compare these lines with the other most common gas line detected in {\\it Spitzer} spectra, the {[Ne~{\\sc iii}]} at 12.81$\\mu$m. We argue that it is unlikely that the {H~{\\sc i}} emission originates from the photoevaporating upper surface layers of the disk, as has been found for the {[Ne~{\\sc iii}]} lines toward low-accreting stars. Using the {H~{\\sc i}}(9-7)/{H~{\\sc i}}(7-6) line ratios we find these gas lines are likely probing gas with hydrogen column densities of 10$^{10}$-10$^{11}$~cm$^{-3}$. The subsample of objects surrounded by ...

  2. Merging Galaxy Cluster Abell 2255 in Mid-Infrared

    CERN Document Server

    Shim, Hyunjin; Lee, Hyung Mok; Lee, Myung Gyoon; Kim, Seong Jin; Hwang, Ho Seong; Hwang, Narae; Ko, Jongwan; Lee, Jong Chul; Lim, Sungsoon; Matsuhara, Hideo; Seo, Hyunjong; Wada, Takehiko; Goto, Tomotsugu

    2010-01-01

    We present the mid-infrared (MIR) observation of a nearby galaxy cluster, Abell 2255 by the AKARI space telescope. Using the AKARI's continuous wavelength coverage between 3-24 micron and the wide field of view, we investigate the properties of cluster member galaxies to see how the infall of the galaxies, the cluster substructures, and the cluster-cluster merger influence their evolution. We show that the excess of MIR (11 micron) flux is a good indicator to discriminate galaxies at different evolutionary stages, and divide galaxies into three classes accordingly : strong MIR-excess (N3-S11>0.2) galaxies that include both unobscured and obscured star-forming galaxies, weak MIR-excess (-2.05 Gyr) galaxies where the MIR emission arises mainly from the circumstellar dust around AGB stars, and intermediate MIR-excess (-1.2

  3. Modeling Mid-Infrared Polarization from Protoplanetary Disks and YSOs

    Science.gov (United States)

    Zhang, Han; Pantin, Eric; Li, Dan; Telesco, Charles M.

    2017-01-01

    Imaging polarimetry has demonstrated its potential to map magnetic fields in star formation regions. To interpret high-resolution, mid-infrared (mid-IR) observations obtained with present or forthcoming instruments, such as GTC/CanariCam and SOFIA/HAWC+, we have developed a new package of codes to model mid-IR polarization from protoplanetary disks and YSOs. Based on RADMC-3D and DDSCAT, our package is the first of its kind that takes into account all polarization mechanisms known to be present in the mid-IR, including dichroic absorption, dichroic emission, and scattering. Mid-IR polarization arising from a disk or YSO depends on dust properties (e.g., the size distribution, shape, and composition), magnetic field configurations, and the geometry of the disk and/or envelope, all of which can be customized in our model. We have created synthetic maps of mid-IR linear polarization for a series of fiducial disk and YSO models to compare with observations. In general, we find 1) that emissive polarization arising from aligned dust grains in disk magnetic fields is at the level of a few percent and lower than previous expectations, and 2) that micron-sized dust particles are required to reproduce the observed level of polarization from dust scattering in the mid-IR for a typical Herbig Ae/Be disk. The research was support in part by NSF awards AST -0903672, AST-0908624, and AST-1515331 to CMT.

  4. The Mid-Infrared Emission of M87

    CERN Document Server

    Perlman, E S; Packham, Christopher; Levenson, N A; Elitzur, M; Schaefer, Justin J; Imanishi, Masatoshi; Sparks, William B; Radomski, James

    2007-01-01

    We discuss Subaru and Spitzer Space Telescope imaging and spectroscopy of M87 in the mid-infrared from 5-35 um. These observations allow us to investigate mid-IR emission mechanisms in the core of M87 and to establish that the flaring, variable jet component HST-1 is not a major contributor to the mid-IR flux. The Spitzer data include a high signal-to-noise 15-35 $\\mu$m spectrum of the knot A/B complex in the jet, which is consistent with synchrotron emission. However, a synchrotron model cannot account for the observed {\\it nuclear} spectrum, even when contributions from the jet, necessary due to the degrading of resolution with wavelength, are included. The Spitzer data show a clear excess in the spectrum of the nucleus at wavelengths longer than 25 um, which we model as thermal emission from cool dust at a characteristic temperature of 55 \\pm 10 K, with an IR luminosity \\sim 10^{39} {\\rm ~erg ~s^{-1}}. Given Spitzer's few-arcsecond angular resolution, the dust seen in the nuclear spectrum could be located ...

  5. YSOVAR: Mid-Infrared Variability in NGC 1333

    CERN Document Server

    Rebull, L M; Cody, A M; Guenther, H M; Hillenbrand, L A; Poppenhaeger, K; Wolk, S J; Hora, J; Hernandez, J; Bayo, A; Covey, K; Forbrich, J; Gutermuth, R; Morales-Calderon, M; Plavchan, P; Song, I; Bouy, H; Terebey, S; Cuillandre, J C; Allen, L

    2015-01-01

    As part of the Young Stellar Object VARiability (YSOVAR) program, we monitored NGC 1333 for ~35 days at 3.6 and 4.5 um using the Spitzer Space Telescope. We report here on the mid-infrared variability of the point sources in the ~10x~20arcmin area centered on 03:29:06, +31:19:30 (J2000). Out of 701 light curves in either channel, we find 78 variables over the YSOVAR campaign. About half of the members are variable. The variable fraction for the most embedded SEDs (Class I, flat) is higher than that for less embedded SEDs (Class II), which is in turn higher than the star-like SEDs (Class III). A few objects have amplitudes (10-90th percentile brightness) in [3.6] or [4.5]>0.2 mag; a more typical amplitude is 0.1-0.15 mag. The largest color change is >0.2 mag. There are 24 periodic objects, with 40% of them being flat SED class. This may mean that the periodic signal is primarily from the disk, not the photosphere, in those cases. We find 9 variables likely to be 'dippers', where texture in the disk occults the...

  6. Towards efficient mid-infrared integrated photonic-lanterns

    Science.gov (United States)

    Arriola, Alexander; Choudhury, Debaditya; Thomson, Robert R.

    2015-12-01

    We report the fabrication and characterization of a prototype integrated photonic-lantern for operation in the mid-IR (λ = 3.39 μm). The device was fabricated in a commercial gallium lanthanum sulphide chalcogenide glass substrate using ultrafast laser inscription. It was formed by inscribing a two-dimensional array of single-mode waveguides, which were then brought increasingly close together to form a single multimode waveguide. We demonstrate that the lantern successfully transforms particular single-mode states into well-defined coherent multimode states, with a loss comparable to that of a straight single-mode waveguide of the same length as the lantern (∼1.6 dB). We conclude, therefore, that the device should also work equally well in the reverse direction, thus enabling the low-loss conversion of mid-IR multimode states of light into discrete single-modes. This technology may be useful in a variety of emerging areas, including free-space laser communications and mid-infrared heterodyne spectroscopy.

  7. Dichroic polarization at mid-infrared wavelengths: a Bayesian approach

    CERN Document Server

    Lopez-Rodriguez, E

    2015-01-01

    A fast and general Bayesian inference framework to infer the physical properties of dichroic polarization using mid-infrared imaging- and spectro-polarimetric observations is presented. The Bayesian approach is based on a hierarchical regression and No-U-Turn Sampler method. This approach simultaneously infers the normalized Stokes parameters to find the full family of solutions that best describe the observations. In comparison with previous methods, the developed Bayesian approach allows the user to introduce a customized absorptive polarization component based on the dust composition, and the appropriate extinction curve of the object. This approach allows the user to obtain more precise estimations of the magnetic field strength and geometry for tomographic studies, and information about the dominant polarization components of the object. Based on this model, imaging-polarimetric observations using two or three filters located in the central 9.5-10.5 $\\mu$m, and the edges 8-9 $\\mu$m and/or 11-13 $\\mu$m, o...

  8. The Mid-Infrared Spectra of Normal Galaxies

    CERN Document Server

    Helou, G; Werner, M W; Malhotra, S; Silbermann, N A

    2000-01-01

    The mid-infrared spectra (2.5 to 5 and 5.7 to 11.6 mu) obtained by ISO-PHOT reveal the interstellar medium emission from galaxies powered by star formation to be strongly dominated by the aromatic features at 6.2, 7.7, 8.6 and 11.3 mu. Additional emission appears in-between the features, and an underlying continuum is clearly evident at 3-5 mu. This continuum would contribute about a third of the luminosity in the 3 to 13 mu range. The features together carry 5 to 30% of the 40-to-120 mu `FIR' luminosity. The relative fluxes in individual features depend very weakly on galaxy parameters such as the far-infrared colors, direct evidence that the emitting particles are not in thermal equilibrium. The dip at 10 mu is unlikely to result from silicate absorption, since its shape is invariant among galaxies. The continuum component has a f_nu its extrapolation to longer wavelengths falls well below the spectrum in the 6 to 12 mu range. This continuum component is almost certainly of non-stellar origin, and is probab...

  9. Mid-Infrared Extinction and its Variation with Galactic Longitude

    CERN Document Server

    Gao, Jian; Li, A

    2009-01-01

    Based on the data obtained from the Spitzer/GLIPMSE Legacy Program and the 2MASS project, we derive the extinction in the four IRAC bands, [3.6], [4.5], [5.8] and [8.0] micron, relative to the 2MASS Ks band (at 2.16 micron) for 131 GLIPMSE fields along the Galactic plane within |l|<65 deg, using red giants and red clump giants as tracers. As a whole, the mean extinction in the IRAC bands (normalized to the 2MASS Ks band), A_[3.6]/A_Ks=0.63, A_[4.5]/A_Ks=0.57, A_[5.8]/A_Ks=0.49, A_[8.0]/A_Ks=0.55, exhibits little variation with wavelength (i.e. the extinction is somewhat flat or gray). This is consistent with previous studies and agrees with that predicted from the standard interstellar grain model for R_V=5.5 by Weingartner & Draine (2001). As far as individual sightline is concerned, however, the wavelength dependence of the mid-infrared interstellar extinction A_{lambda}/A_Ks varies from one sightline to another, suggesting that there may not exist a "universal" IR extinction law. We, for the first t...

  10. A Comparison of X-ray and Mid-Infrared Selection of Obscured AGN

    CERN Document Server

    Eckart, Megan E; Stern, Daniel; Harrison, Fiona A; Helfand, David J

    2009-01-01

    We compare the relative merits of AGN selection at X-ray and mid-infrared wavelengths using data from moderately deep fields observed by both Chandra and Spitzer. The X-ray-selected AGN sample and associated optical follow-up are drawn from the SEXSI program. Mid-infrared data in these fields are derived from Spitzer imaging, and mid-infrared AGN selection is accomplished primarily through application of the IRAC color-color AGN `wedge' selection technique. Nearly all X-ray sources in these fields which exhibit clear spectroscopic signatures of AGN activity have mid-infrared colors consistent with IRAC AGN selection. These are predominantly the most luminous X-ray sources. X-ray sources that lack high-ionization and/or broad lines in their optical spectra are far less likely to be selected as AGN by mid-infrared color selection techniques. The fraction of X-ray sources identified as AGN in the mid-infrared increases monotonically as the X-ray luminosity increases. Conversely, only 22% of mid-infrared-selected...

  11. Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

    Science.gov (United States)

    Malerba, M.; Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; De Angelis, F.; Colombelli, R.

    2016-07-01

    We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

  12. Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

    Energy Technology Data Exchange (ETDEWEB)

    Malerba, M.; De Angelis, F., E-mail: francesco.deangelis@iit.it [Istituto Italiano di Tecnologia, Via Morego, 30, I-16163 Genova (Italy); Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr [Centre for Nanoscience and Nanotechnology (C2N Orsay), CNRS UMR9001, Univ. Paris Sud, Univ. Paris Saclay, 91405 Orsay (France)

    2016-07-11

    We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

  13. Source brightness fluctuation correction of solar absorption fourier transform mid infrared spectra

    Directory of Open Access Journals (Sweden)

    T. Ridder

    2011-06-01

    Full Text Available The precision and accuracy of trace gas observations using solar absorption Fourier Transform infrared spectrometry depend on the stability of the light source. Fluctuations in the source brightness, however, cannot always be avoided. Current correction schemes, which calculate a corrected interferogram as the ratio of the raw DC interferogram and a smoothed DC interferogram, are applicable only to near infrared measurements. Spectra in the mid infrared spectral region below 2000 cm−1 are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents the established source brightness fluctuation correction. This problem can be overcome by a determination of the offset using the modulation efficiency of the instrument. With known modulation efficiency the offset can be calculated, and the source brightness correction can be performed on the basis of offset-corrected interferograms. We present a source brightness fluctuation correction method which performs the smoothing of the raw DC interferogram in the interferogram domain by an application of a running mean instead of high-pass filtering the corresponding spectrum after Fourier transformation of the raw DC interferogram. This smoothing can be performed with the onboard software of commercial instruments. The improvement of MCT spectra and subsequent ozone profile and total column retrievals is demonstrated. Application to InSb interferograms in the near infrared spectral region proves the equivalence with the established correction scheme.

  14. KALI Camera: mid-infrared camera for the Keck Interferometer Nuller

    Science.gov (United States)

    Creech-Eakman, Michelle J.; Moore, James D.; Palmer, Dean L.; Serabyn, Eugene

    2003-03-01

    We present a brief overview of the KALI Camera, the mid-infrared camera for the Keck Interferometer Nulling Project, built at the Jet Propulsion Laboratory. The instrument utilizes mainly transmissive optics in four identical beam paths to spatially and spectrally filter, polarize, spectrally disperse and image the incoming 7-14 micron light from the four outputs of the Keck Nulling Beam Combiner onto a custom Boeing/DRS High Flux 128 X 128 BIB array. The electronics use a combination of JPL and Wallace Instruments boards to interface the array readout with the existing real-time control system of the Keck Interferometer. The cryogenic dewar, built by IR Laboratories, uses liquid nitrogen and liquid helium to cool the optics and the array, and includes six externally motorized mechanisms for aperture and pinhole control, focus, and optical component selection. The instrument will be assembled and tested through the summer of 2002, and is planned to be deployed as part of the Keck Interferometer Nulling experiment in 2003.

  15. Mid-infrared laser absorption spectroscopy of NO2 at elevated temperatures

    Science.gov (United States)

    Sur, Ritobrata; Peng, Wen Yu; Strand, Christopher; Mitchell Spearrin, R.; Jeffries, Jay B.; Hanson, Ronald K.; Bekal, Anish; Halder, Purbasha; Poonacha, Samhitha P.; Vartak, Sameer; Sridharan, Arun K.

    2017-01-01

    A mid-infrared quantum cascade laser absorption sensor was developed for in-situ detection of NO2 in high-temperature gas environments. A cluster of spin-split transitions near 1599.9 cm-1 from the ν3 absorption band of NO2 was selected due to the strength of these transitions and the low spectral interference from water vapor within this region. Temperature- and species-dependent collisional broadening parameters of ten neighboring NO2 transitions with Ar, O2, N2, CO2 and H2O were measured and reported. The spectral model was validated through comparisons with direct absorption spectroscopy measurements of NO2 seeded in various bath gases. The performance of the scanned wavelength modulation spectroscopy (WMS)-based sensor was demonstrated in a combustion exhaust stream seeded with varying flow rates of NO2, achieving reliable detection of 1.45 and 1.6 ppm NO2 by mole at 600 K and 800 K, respectively, with a measurement uncertainty of ±11%. 2σ noise levels of 360 ppb and 760 ppb were observed at 600 K and 800 K, respectively, in an absorption path length of 1.79 m.

  16. Mid-infrared spectroscopy of starbursts : from Spitzer-IRS to JWST-MIRI

    Science.gov (United States)

    Martínez-Galarza, Juan Rafael

    2012-06-01

    The Spectral Energy Distributions (SEDs) of star-forming regions and starburst galaxies are unique tracers of the star formation processes in these environments, since they contain information on the escaping and processed photons emitted by newly formed massive stars. Understanding these internal processes is crucial in our physical interpretation of observations of unresolved star formation in the Universe. In the first part of this thesis, we study the physical conditions in resolved starburst regions using Bayesian fitting of their spatially integrated infrared SEDs, including both the thermal continuum and the atomic emission lines. We then apply the method to unresolved starburst to learn about their star formation physics. Our approach leads to robust constraints on physical parameters such as age, compactness, and amount of currently ongoing star formation in starburst, which are otherwise biased by model degeneracies, and allows us to link the resolved properties of giant H II regions to the star formation process at larger scales. In the second part of this thesis, we discuss the wavelength calibration of the next instrument to study the midinfrared spectral properties of starbursts, with improved resolution and sensitivity: the mid-infrared instrument (MIRI), which will fly onboard the James Webb Space Telescope in 2018.

  17. M-type asteroids in the mid-infrared: thermal inertias and emissivity spectra

    Science.gov (United States)

    Landsman, Zoe A.; Emery, Joshua P.; Campins, Humberto

    2016-10-01

    The M-type asteroid taxon has been inferred to contain metallic asteroids. This inference comes mainly from spectral analogy to iron meteorites and from the observation of high radar albedos among M-types. There is, nevertheless, evidence for significant compositional diversity within the M-type population. Spectral signatures of both high-temperature silicates (λ~0.9 μm) and hydrated minerals (λ~3 μm) are common in this group. The nature of the M-types is, therefore, still not well understood. In order to further test the hypothesis that many M-types are metallic, we have undertaken an observational study at mid-infrared wavelengths (5.2 – 38 μm). Our aim is to characterize the silicate composition and the thermal properties of a sample of M-type asteroids. If metallic, we expect relatively high thermal inertia and an absence of silicate emissivity features. The spectra we analyze were measured with the InfraRed Spectrograph (IRS) on the Spitzer Space Telescope. We present emissivity spectra and the initial results of thermophysical modeling, including derived thermal inertias. We chose our sample because these asteroids have also been observed at complementary wavelengths, such as visible, near-infrared and radar, which places further constraints on the interpretation of our results.

  18. 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.

  19. The Mid-Infrared Spectrum of the Short Orbital Period Polar EF Eridani from the Spitzer Space Telescope

    CERN Document Server

    Hoard, D W; Brinkworth, Carolyn S; Ciardi, David R; Wachter, Stefanie

    2007-01-01

    We present the first mid-infrared (5.5-14.5 micron) spectrum of a highly magnetic cataclysmic variable, EF Eridani, obtained with the Infrared Spectrograph on the Spitzer Space Telescope. The spectrum displays a relatively flat, featureless continuum. A spectral energy distribution model consisting of a 9500 K white dwarf, L5 secondary star, cyclotron emission corresponding to a B~13 MG white dwarf magnetic field, and an optically thin circumbinary dust disk is in reasonable agreement with the extant 2MASS, IRAC, and IRS observations of EF Eri. Cyclotron emission is ruled out as a dominant contributor to the infrared flux density at wavelengths >3 microns. The spectral energy distribution longward of ~5 microns is dominated by dust emission. Even longer wavelength observations would test the model's prediction of a continuing gradual decline in the circumbinary disk-dominated region of the spectral energy distribution.

  20. The subarcsecond mid-infrared view of local active galactic nuclei: II. The mid-infrared--X-ray correlation

    CERN Document Server

    Asmus, D; Hoenig, S F; Smette, A; Duschl, W J

    2015-01-01

    We present an updated mid-infrared (MIR) versus X-ray correlation for the local active galactic nuclei (AGN) population based on the high angular resolution 12 and 18um continuum fluxes from the AGN subarcsecond MIR atlas and 2-10 keV and 14-195 keV data collected from the literature. We isolate a sample of 152 objects with reliable AGN nature and multi-epoch X-ray data and minimal MIR contribution from star formation. Although the sample is not homogeneous or complete, we show that our results are unlikely to be affected by biases. The MIR--X-ray correlation is nearly linear and within a factor of two independent of the AGN type and the wavebands used. The observed scatter is <0.4 dex. A possible flattening of the correlation slope at the highest luminosities probed (~ 10^45 erg/s) is indicated but not significant. Unobscured objects have, on average, an MIR--X-ray ratio that is only <= 0.15 dex higher than that of obscured objects. Objects with intermediate X-ray column densities (22 < log N_H <...

  1. Modeling Mid-infrared Diagnostics of Obscured Quasars and Starbursts

    Science.gov (United States)

    Snyder, Gregory F.; Hayward, Christopher C.; Sajina, Anna; Jonsson, Patrik; Cox, Thomas J.; Hernquist, Lars; Hopkins, Philip F.; Yan, Lin

    2013-05-01

    We analyze the link between active galactic nuclei (AGNs) and mid-infrared flux using dust radiative transfer calculations of starbursts realized in hydrodynamical simulations. Focusing on the effects of galaxy dust, we evaluate diagnostics commonly used to disentangle AGN and star formation in ultraluminous infrared galaxies (ULIRGs). We examine these quantities as a function of time, viewing angle, dust model, AGN spectrum, and AGN strength in merger simulations representing two possible extremes of the ULIRG population: one is a typical gas-rich merger at z ~ 0, and the other is characteristic of extremely obscured starbursts at z ~ 2-4. This highly obscured burst begins star-formation-dominated with significant polycyclic aromatic hydrocarbon (PAH) emission, and ends with a ~109 yr period of red near-IR colors. At coalescence, when the AGN is most luminous, dust obscures the near-infrared AGN signature, reduces the relative emission from PAHs, and enhances the 9.7 μm absorption by silicate grains. Although generally consistent with previous interpretations, our results imply none of these indicators can unambiguously estimate the AGN luminosity fraction in all cases. Motivated by the simulations, we show that a combination of the extinction feature at 9.7 μm, the PAH strength, and a near-infrared slope can simultaneously constrain the AGN fraction and dust grain distribution for a wide range of obscuration. We find that this indicator, accessible to the James Webb Space Telescope, may estimate the AGN power as tightly as the hard X-ray flux alone, thereby providing a valuable future cross-check and constraint for large samples of distant ULIRGs.

  2. MODELING MID-INFRARED DIAGNOSTICS OF OBSCURED QUASARS AND STARBURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Gregory F.; Jonsson, Patrik; Hernquist, Lars [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hayward, Christopher C. [Heidelberger Institut fuer Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg (Germany); Sajina, Anna [Department of Physics and Astronomy, Tufts University, 4 Colby Street, Medford, MA 02155 (United States); Cox, Thomas J. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Hopkins, Philip F. [Department of Astronomy, University of California at Berkeley, C-208 Hearst Field Annex, Berkeley, CA 94720 (United States); Yan Lin, E-mail: gsnyder@cfa.harvard.edu [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2013-05-10

    We analyze the link between active galactic nuclei (AGNs) and mid-infrared flux using dust radiative transfer calculations of starbursts realized in hydrodynamical simulations. Focusing on the effects of galaxy dust, we evaluate diagnostics commonly used to disentangle AGN and star formation in ultraluminous infrared galaxies (ULIRGs). We examine these quantities as a function of time, viewing angle, dust model, AGN spectrum, and AGN strength in merger simulations representing two possible extremes of the ULIRG population: one is a typical gas-rich merger at z {approx} 0, and the other is characteristic of extremely obscured starbursts at z {approx} 2-4. This highly obscured burst begins star-formation-dominated with significant polycyclic aromatic hydrocarbon (PAH) emission, and ends with a {approx}10{sup 9} yr period of red near-IR colors. At coalescence, when the AGN is most luminous, dust obscures the near-infrared AGN signature, reduces the relative emission from PAHs, and enhances the 9.7 {mu}m absorption by silicate grains. Although generally consistent with previous interpretations, our results imply none of these indicators can unambiguously estimate the AGN luminosity fraction in all cases. Motivated by the simulations, we show that a combination of the extinction feature at 9.7 {mu}m, the PAH strength, and a near-infrared slope can simultaneously constrain the AGN fraction and dust grain distribution for a wide range of obscuration. We find that this indicator, accessible to the James Webb Space Telescope, may estimate the AGN power as tightly as the hard X-ray flux alone, thereby providing a valuable future cross-check and constraint for large samples of distant ULIRGs.

  3. Toward Precision Mid-Infrared Spectroscopy on the OH Radical

    Science.gov (United States)

    Fast, Arthur; Furneaux, John; Meek, Samuel

    2016-06-01

    Measurements of vibrational transitions in small molecules can be used to test for a possible time variation of the electron-proton mass ratio. In our experiments, our goal is to measure two-photon v = 2 ← v = 0 vibrational transitions in the hydroxyl (OH) radical near 2 × 3500 wn with a relative accuracy of 10-14. Reaching this level of accuracy requires a mid-infrared laser with a linewidth of much less than 1 kHz, as well as the ability to compare the frequency of this laser with an absolute frequency standard. To achieve the high short-term stability necessary for such a narrow linewidth, we are implementing a 532-nm CW reference laser by locking a frequency-doubled Nd:YAG laser to a molecular iodine transition using saturated absorption spectroscopy. Similar setups have demonstrated relative stabilities of around 10-14 at the one-second timescale. The stability of this reference laser will then be transfered onto the idler of a 1064-nm-pumped optical parametric oscillator (OPO) using an optical frequency comb as a transfer oscillator. The frequency comb will also be used to measure the absolute optical frequencies of the various lasers and compare them to a GPS-linked radio frequency reference, providing long-term stability and absolute accuracy for the spectroscopic measurements. J.-P. Uzan. Rev. Mod. Phys. 75, 403-455 (2003). Döringshoff, K., Mohle, K., Nagel, M., Kovalchuk, E. V., Peters, A: High performance iodine frequency reference for tests of the LISA laser system. EFTF-2010 24th European Frequency and Time Forum (2010)

  4. TATP and TNT detection by mid-infrared transmission spectroscopy

    Science.gov (United States)

    Herbst, Johannes; Hildenbrand, Jürgen; Wöllenstein, Jürgen; Lambrecht, Armin

    2009-05-01

    Sensitive and fast detection of explosives remains a challenge in many threat scenarios. Fraunhofer IPM works on two different detection methods using mid-infrared absorption spectroscopy in combination with quantum cascade lasers (QCL). 1. stand-off detection for a spatial distance of several meters and 2. contactless extractive sampling for short distance applications. The extractive method is based on a hollow fiber that works as gas cell and optical waveguide for the QCL light. The samples are membranes contaminated with the explosives and real background. The low vapor pressure of TNT requires a thermal desorbtion to introduce gaseous TNT and TATP into the heated fiber. The advantage of the hollow fiber setup is the resulting small sample volume. This enables a fast gas exchange rate and fast detection in the second range. The presented measurement setup achieves a detection limit of around 58 ng TNT and 26 ng TATP for 1 m hollow fiber. TATP - an explosive with a very high vapor pressure in comparison to TNT or other explosives - shows potential for an adequate concentration in gas phase under normal ambient conditions and thus the possibility of an explosive detection using open path absorption of TATP at 8 μm wavelength. In order to lower the cross sensitivities or interferents with substances with an absorption in the wavelength range of the TATP absorption the probe volume is checked synchronously by a second QCL emitting beside the target absorption wavelength. In laboratory measurements a detection limit of 5 ppm*m TATP are achieved.

  5. Source brightness fluctuation correction of solar absorption Fourier Transform mid infrared spectra

    Directory of Open Access Journals (Sweden)

    T. Ridder

    2011-01-01

    Full Text Available Solar absorption Fourier Transform infrared spectrometry is considered a precise and accurate method for the observation of trace gases in the atmosphere. The precision and accuracy of such measurements are dependent on the stability of the light source. Fluctuations in the source brightness reduce the precision and accuracy of the trace gas concentrations, but cannot always be avoided. Thus, a strong effort is made within the community to reduce the impact of source brightness fluctuations by applying a correction on the spectra following the measurements. So far, it could be shown that the precision and accuracy of CO2 total column concentrations could be improved by applying a source brightness fluctuation correction to spectra in the near infrared spectral region.

    The analysis of trace gas concentrations obtained from spectra in the mid infrared spectral region is fundamental. However, spectra below 2000 cm−1 are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents a source brightness fluctuation correction.

    Here, we show a method of source brightness fluctuation correction, which can be applied on spectra in the whole infrared spectral region including spectra measured with a MCT detector. We present a solution to remove the unknown offset in MCT interferograms allowing MCT spectra for an application of source brightness fluctuation correction. This gives an improvement in the quality of MCT spectra and we demonstrate an improvement in the retrieval of O3 profiles and total column concentrations.

    For a comparison with previous studies, we apply our source brightness fluctuation correction method on spectra in the near infrared spectral region and show an improvement in the retrieval of CO2 total column concentrations.

  6. Cloud top structure of Venus revealed by Subaru/COMICS mid-infrared images

    Science.gov (United States)

    Sato, T. M.; Sagawa, H.; Kouyama, T.; Mitsuyama, K.; Satoh, T.; Ohtsuki, S.; Ueno, M.; Kasaba, Y.; Nakamura, M.; Imamura, T.

    2014-11-01

    We have investigated the cloud top structure of Venus by analyzing ground-based images taken at the mid-infrared wavelengths of 8.66 μm and 11.34 μm. Venus at a solar phase angle of ∼90°, with the morning terminator in view, was observed by the Cooled Mid-Infrared Camera and Spectrometer (COMICS), mounted on the 8.2-m Subaru Telescope, during the period October 25-29, 2007. The disk-averaged brightness temperatures for the observation period are ∼230 K and ∼238 K at 8.66 μm and 11.34 μm, respectively. The obtained images with good signal-to-noise ratio and with high spatial resolution (∼200 km at the sub-observer point) provide several important findings. First, we present observational evidence, for the first time, of the possibility that the westward rotation of the polar features (the hot polar spots and the surrounding cold collars) is synchronized between the northern and southern hemispheres. Second, after high-pass filtering, the images reveal that streaks and mottled and patchy patterns are distributed over the entire disk, with typical amplitudes of ∼0.5 K, and vary from day to day. The detected features, some of which are similar to those seen in past UV images, result from inhomogeneities of both the temperature and the cloud top altitude. Third, the equatorial center-to-limb variations of brightness temperatures have a systematic day-night asymmetry, except those on October 25, that the dayside brightness temperatures are higher than the nightside brightness temperatures by 0-4 K under the same viewing geometry. Such asymmetry would be caused by the propagation of the migrating semidiurnal tide. Finally, by applying the lapse rates deduced from previous studies, we demonstrate that the equatorial center-to-limb curves in the two spectral channels give access to two parameters: the cloud scale height H and the cloud top altitude zc. The acceptable models for data on October 25 are obtained at H = 2.4-4.3 km and zc = 66-69 km; this supports

  7. Mid-Infrared (8.1-12.5 μm) Imaging of Mercury

    Science.gov (United States)

    Sprague, A. L.; Deutsch, L. K.; Hora, J.; Fazio, G. G.; Ludwig, B.; Emery, J.; Hoffmann, W. F.

    2000-10-01

    The first images of Mercury to be obtained in thermal emission are discussed. Images at 22 wavelengths between 8.1 and 13.25 μm obtained with MIRAC (Mid-Infrared Array Camera) have been reduced and analyzed to obtain new information regarding the thermal and chemical makeup of Mercury's surface. The region observed is centered at ˜210-250° mercurian longitude, encompassing the location of a ˜1000-km-diameter radar-bright region on Mercury's surface that was not imaged by Mariner 10. We found some evidence supporting ground-based spectroscopy of alkali-rich feldspathoids. However, the large pixel size (at the sub-Earth point the area per square pixel is 28,000 km 2—8 μm; 63,000 km 2—12 μm), the diffraction limit of the telescope, and the small angular diameter of Mercury all conspired to prevent any compositional spatial discrimination on the Earth-facing disk. Our four results are: (1) data fits to rough surface thermal models indicate the surface is smoother at this location (Thetabar ˜8°-11°) than at previous locations (10-75° and 100-160° longitude) measured in the mid-infrared (Thetabar ˜20°); (2) with the spatial resolution of these data, color ratios of images do not reveal any locations of enhanced or depressed flux that can be associated with regions of different rock composition across the disk of Mercury; (3) 18-channel spectra generated from Mercury whole-disk averages exhibit emissivity features over part of the spectral range (8.1-10.5 μm) indicative of bronzite, a pyroxene composed of ˜2% CaSiO 3, 86% MgSiO 3, and 12% FeSiO 3. In addition, the overall spectrum was grossly matched by a spectrum of picrite (an ultra-mafic rock) with 25% MgO, 8% CaO, and 11% FeO, and other minor components including plagioclase feldspar (4). TIMS six-channel simulations have a best match to sodalite (Na 8Al 6Si 6O 24C 12), a mineral associated with nephaline syenite rocks. On Earth, all of these materials are found in association in the Teschenite

  8. Photothermal Mid-Infrared Microscopy: a new tool for hyperspectral chemical imaging

    Science.gov (United States)

    Mertiri, Alket; Hong, Mi; Sander, Michelle; Erramilli, Shyamsunder

    2014-03-01

    We describe a method for label free microscopy in the mid-infrared region of the electromagnetic spectrum based on the photothermal effect. A Quantum Cascade Laser (QCL) tuned to an infrared active vibrational molecular normal mode is used as the pump laser. A low-phase noise Erbium-doped fiber (EDF) laser (1.5 μm) is used as the probe. We demonstrate the method using a patterned image target with liquid crystal 4-cyano-4-octylbiphenyl (8CB) as the mid-infrared absorber. The QCL is tuned across the C-H scissoring band, with a peak absorption at 1607cm-1. Absorption of the modulated pump beam results in a change in the dielectric function and the refractive index at the probe beam frequency. The resultant scatter of the probe is observed in heterodyne lock-in detection. The combination of heterodyne detection, high brightness mid-infrared QCLs and low-phase noise stable EDF lasers provides an ultra-sensitive method for obtaining mid-infrared microscope images using short-wavelength optical detectors, whose performance far exceeds those of cryogenically cooled broadband mid-infrared detectors. The method provides a powerful new tool for hyperspectral label-free mid-infrared imaging.

  9. Fully stabilized mid-infrared frequency comb for high-precision molecular spectroscopy.

    Science.gov (United States)

    Vainio, Markku; Karhu, Juho

    2017-02-20

    A fully stabilized mid-infrared optical frequency comb spanning from 2.9 to 3.4 µm is described in this article. The comb is based on half-harmonic generation in a femtosecond optical parametric oscillator, which transfers the high phase coherence of a fully stabilized near-infrared Er-doped fiber laser comb to the mid-infrared region. The method is simple, as no phase-locked loops or reference lasers are needed. Precise locking of optical frequencies of the mid-infrared comb to the pump comb is experimentally verified at sub-20 mHz level, which corresponds to a fractional statistical uncertainty of 2 × 10-16 at the center frequency of the mid-infrared comb. The fully stabilized mid-infrared comb is an ideal tool for high-precision molecular spectroscopy, as well as for optical frequency metrology in the mid-infrared region, which is difficult to access with other stabilized frequency comb techniques.

  10. Mid-Infrared ultra-high-Q resonators based on fluoride crystalline materials

    CERN Document Server

    Lecaplain, C; Gorodetsky, M L; Kippenberg, T J

    2016-01-01

    Decades ago, the losses of glasses in the near infrared (near-IR) were investigated in views of developments for optical telecommunications. Today, properties in the mid-infrared (mid-IR) are of interest for molecular spectroscopy applications. In particular, high-sensitivity spectroscopic techniques based on high-finesse mid-IR cavities hold high promise for medical applications. Due to exceptional purity and low losses, whispering gallery mode microresonators based on polished alkaline earth metal fluoride crystals (i.e the $\\mathrm{XF_2}$ family, where X $=$ Ca, Mg, Ba, Sr,...) have attained ultra-high quality (Q) factor resonances (Q$>$10$^{8}$) in the near-IR and visible spectral ranges. Here we report for the first time ultra-high Q factors in the mid-IR using crystalline microresonators. Using an uncoated chalcogenide (ChG) tapered fiber, light from a continuous wave quantum cascade laser (QCL) is efficiently coupled to several crystalline microresonators at 4.4 $\\mu$m wavelength. We measure the optica...

  11. Directly Imaged L-T Transition Exoplanets in the Mid-Infrared

    CERN Document Server

    Skemer, Andrew J; Hinz, Philip M; Morzinski, Katie M; Skrutskie, Michael F; Leisenring, Jarron M; Close, Laird M; Saumon, Didier; Bailey, Vanessa P; Briguglio, Runa; Defrere, Denis; Esposito, Simone; Follette, Katherine B; Hill, John M; Males, Jared R; Puglisi, Alfio; Rodigas, Timothy J; Xompero, Marco

    2013-01-01

    Gas-giant planets emit a large fraction of their light in the mid-infrared ($\\gtrsim$3$\\mu \\rm m$), where photometry and spectroscopy are critical to our understanding of the bulk properties of extrasolar planets. Of particular importance are the L and M-band atmospheric windows (3-5$\\mu \\rm m$), which are the longest wavelengths currently accessible to ground-based, high-contrast imagers. We present binocular LBT AO images of the HR 8799 planetary system in six narrow-band filters from 3-4$\\mu \\rm m$, and a Magellan AO image of the 2M1207 planetary system in a broader 3.3$\\mu \\rm m$ band. These systems encompass the five known exoplanets with luminosities consistent with L$\\rightarrow$T transition brown dwarfs. Our results show that the exoplanets are brighter and have shallower spectral slopes than equivalent temperature brown dwarfs in a wavelength range that contains the methane fundamental absorption feature. For 2M1207 b, we find that thick clouds and non-equilibrium chemistry caused by vertical mixing ...

  12. Probing the envelopes of massive young stellar objects with diffraction limited mid-infrared imaging

    CERN Document Server

    Wheelwright, H E; Oudmaijer, R D; Hoare, M G; Lumsden, S L; Fujiyoshi, T; Close, J L

    2012-01-01

    Massive stars form whilst they are still embedded in dense envelopes. As a result, the roles of rotation, mass loss and accretion in massive star formation are not well understood. This study evaluates the source of the Q-band, lambda=19.5 microns, emission of massive young stellar objects (MYSOs). This allows us to determine the relative importance of rotation and outflow activity in shaping the circumstellar environments of MYSOs on 1000 AU scales. We obtained diffraction limited mid-infrared images of a sample of 20 MYSOs using the VLT/VISIR and Subaru/COMICS instruments. For these 8 m class telescopes and the sample selected, the diffraction limit, ~0.6", corresponds to approximately 1000 AU. We compare the images and the spectral energy distributions (SEDs) observed to a 2D, axis-symmetric dust radiative transfer model that reproduces VLTI/MIDI observations of the MYSO W33A. We vary the inclination, mass infall rate, and outflow opening angle to simultaneously recreate the behaviour of the sample of MYSO...

  13. Young Stellar Object Variability (YSOVAR): Long Timescale Variations in the Mid-Infrared

    CERN Document Server

    Rebull, L M; Covey, K R; Guenther, H M; Hillenbrand, L A; Plavchan, P; Poppenhaeger, K; Stauffer, J R; Wolk, S J; Gutermuth, R; Morales-Calderon, M; Song, I; Barrado, D; Bayo, A; James, D; Hora, J L; Vrba, F J; de Oliveira, C Alves; Bouvier, J; Carey, S J; Carpenter, J M; Favata, F; Flaherty, K; Forbrich, J; Hernandez, J; McCaughrean, M J; Megeath, S T; Micela, G; Smith, H A; Terebey, S; Turner, N; Allen, L; Ardila, D; Bouy, H; Guieu, S

    2014-01-01

    The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (3.6 & 4.5 um) time-series photometry of the Orion Nebula Cluster plus smaller footprints in eleven other star-forming cores (AFGL490, NGC1333, MonR2, GGD 12-15, NGC2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. We present the data collection and reduction for the Spitzer and ancillary data, and define the "standard sample" on which we calculate statistics, consisting of fast cadence data, with epochs about twice per day for ~40d. We also define a "standard sample of members", consisting of all the IR-selected members and X-ray selected members. We characterize the standard sample in terms of other properties, such as spectral energy distribution shape. We use three mechanisms to identify variables in the fast cadence data--the Stetson ind...

  14. Prediction of protein composition of individual cow milk using mid-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Paolo Carnier

    2010-01-01

    Full Text Available This study investigated the application of mid-infrared spectroscopy for the prediction of protein composition in individual milk samples (n=1,336 of Simmental cows. Protein fractions were quantified by RP-HPLC and MIR data were recorded over the spectral range from 4,000 to 900 cm-1. Models were developed by partial least squares regression using untreated spectra. The most successful predictions were for protein, casein, αS1-casein, whey protein, and β-lactoglobulin contents. The models could discriminate between high and low values of protein composition (R2=0.50 to 0.58. The root mean square errors of cross-validation were 3.11g/l for protein (range 39.91g/l, 2.76g/l for casein (range 35.16g/l, 1.07 g/l for αS1-casein (range 12.82g/l, 0.51 g/l for whey protein (range 4.97g/l, and 0.43 for β-lactoglobulin (range 4.37. Application of MIR spectroscopy is possible for the routinely assessment of protein, casein, αS1-casein, whey protein, and β-lactoglobulin and its implementation might be in future a tool for improving protein composition of bovine milk through breeding programs.

  15. The Orion HII Region and the Orion Bar in the Mid-Infrared

    CERN Document Server

    Salgado, F; Adams, J D; Herter, T L; Tielens, A G G M

    2016-01-01

    We present mid-infrared photometry of the Orion Bar obtained with FORCAST aboard SOFIA at 6.4, 6.6, 7.7, 19.7, 31.5 and 37.1 \\um. By complementing this observations with archival FORCAST and \\emph{Herschel}/PACS images we are able to construct a complete infrared spectral energy distribution of the Huygens region in the Orion nebula By comparing the infrared images with gas tracers, we find that PACS maps trace the molecular cloud, while the FORCAST data trace the photodissociation region (PDR) and HII region. Analysis of the energetics of the region reveal that the PDR extends for 0.28~pc along the line-of-sight and that the Bar is inclined at an angle of $4\\degr$. The infrared and submillimeter images reveal that the Orion Bar represents a swept up shell with a thickness of 0.1~pc. The mass of the shell implies a shock velocity of $\\simeq 3$ km/s and an age of $\\simeq 10^5$ yr for the HII region. Our analysis shows that the UV and infrared dust opacities in the HII region and the PDR are a factor 5 to 10 lo...

  16. Young massive stars and their environment in the mid-infrared at high angular resolution

    Energy Technology Data Exchange (ETDEWEB)

    Wit, W J de; Hoare, M G; Oudmaijer, R D [School of Physics and Astronomy, University of Leeds, LS2 9JT (United Kingdom); Fujiyoshi, T [Subaru Telescope, NAOJ, 650 North A' ohoku Place, Hilo, HI 96720 (United States)], E-mail: w.j.m.dewit@leeds.ac.uk

    2008-10-15

    We present interferometric and single-dish mid-infrared observations of a sample of massive young stellar objects (BN-type objects), using VLTI-MIDI (10{mu}m) and Subaru-COMICS (24.5 {mu}m). We discuss the regions S140, Mon R2, M8E-IR, and W33A. The observations probe the inner regions of the dusty envelope at scales of 50 milli arcsecond and 0.6'' ({approx}100-1000 AU), respectively. Simultaneous model fits to spectral energy distributions and spatial data are achieved using self-consistent spherical envelope modelling. We conclude that those MYSO envelopes that are best described by a spherical geometry, the commensurate density distribution is a powerlaw with index -1.0. Such a powerlaw is predicted if the envelope is supported by turbulence on the 100-1000 AU scales probed with MIDI and COMICS, but the role of rotation at these spatial scales need testing.

  17. Mid-infrared (MIR) photonics: MIR passive and active fiberoptics chemical and biomedical, sensing and imaging

    Science.gov (United States)

    Seddon, Angela B.

    2016-10-01

    The case for new, portable, real-time mid-infrared (MIR) molecular sensing and imaging is discussed. We set a record in demonstrating extreme broad-band supercontinuum (SC) generated light 1.4-13.3 μm in a specially engineered, step-index MIR optical fiber of high numerical aperture. This was the first experimental demonstration truly to reveal the potential of MIR fibers to emit across the MIR molecular "fingerprint spectral region" and a key first step towards bright, portable, broadband MIR sources for chemical and biomedical, molecular sensing and imaging in real-time. Potential applications are in the healthcare, security, energy, environmental monitoring, chemical-processing, manufacturing and the agriculture sectors. MIR narrow-line fiber lasers are now required to pump the fiber MIR-SC for a compact all-fiber solution. Rare-earth-ion (RE-) doped MIR fiber lasers are not yet demonstrated >=4 μm wavelength. We have fabricated small-core RE-fiber with photoluminescence across 3.5-6 μm, and long excited-state lifetimes. MIR-RE-fiber lasers are also applicable as discrete MIR fiber sensors in their own right, for applications including: ship-to-ship free-space communications, aircraft counter-measures, coherent MIR imaging, MIR-optical coherent tomography, laser-cutting/ patterning of soft materials and new wavelengths for fiber laser medical surgery.

  18. Atomic-scale photonic hybrids for mid-infrared and terahertz nanophotonics

    Science.gov (United States)

    Caldwell, Joshua D.; Vurgaftman, Igor; Tischler, Joseph G.; Glembocki, Orest J.; Owrutsky, Jeffrey C.; Reinecke, Thomas L.

    2016-01-01

    The field of nanophotonics focuses on the ability to confine light to nanoscale dimensions, typically much smaller than the wavelength of light. The goal is to develop light-based technologies that are impossible with traditional optics. Subdiffractional confinement can be achieved using either surface plasmon polaritons (SPPs) or surface phonon polaritons (SPhPs). SPPs can provide a gate-tunable, broad-bandwidth response, but suffer from high optical losses; whereas SPhPs offer a relatively low-loss, crystal-dependent optical response, but only over a narrow spectral range, with limited opportunities for active tunability. Here, motivated by the recent results from monolayer graphene and multilayer hexagonal boron nitride heterostructures, we discuss the potential of electromagnetic hybrids -- materials incorporating mixtures of SPPs and SPhPs -- for overcoming the limitations of the individual polaritons. Furthermore, we also propose a new type of atomic-scale hybrid the crystalline hybrid -- where mixtures of two or more atomic-scale (~3 nm or less) polar dielectric materials lead to the creation of a new material resulting from hybridized optic phonon behaviour of the constituents, potentially allowing direct control over the dielectric function. These atomic-scale hybrids expand the toolkit of materials for mid-infrared to terahertz nanophotonics and could enable the creation of novel actively tunable, yet low-loss optics at the nanoscale.

  19. Fiber laser pumped high power mid-infrared laser with picosecond pulse bunch output.

    Science.gov (United States)

    Wei, Kaihua; Chen, Tao; Jiang, Peipei; Yang, Dingzhong; Wu, Bo; Shen, Yonghang

    2013-10-21

    We report a novel quasi-synchronously pumped PPMgLN-based high power mid-infrared (MIR) laser with picosecond pulse bunch output. The pump laser is a linearly polarized MOPA structured all fiberized Yb fiber laser with picosecond pulse bunch output. The output from a mode-locked seed fiber laser was directed to pass through a FBG reflector via a circulator to narrow the pulse duration from 800 ps to less than 50 ps and the spectral FWHM from 9 nm to 0.15 nm. The narrowed pulses were further directed to pass through a novel pulse multiplier through which each pulse was made to become a pulse bunch composing of 13 sub-pulses with pulse to pulse time interval of 1.26 ns. The pulses were then amplified via two stage Yb fiber amplifiers to obtain a linearly polarized high average power output up to 85 W, which were then directed to pass through an isolator and to pump a PPMgLN-based optical parametric oscillator via quasi-synchronization pump scheme for ps pulse bunch MIR output. High MIR output with average power up to 4 W was obtained at 3.45 micron showing the feasibility of such pump scheme for ps pulse bunch MIR output.

  20. Single-mode interband cascade laser sources for mid-infrared spectroscopic applications

    Science.gov (United States)

    Scheuermann, J.; von Edlinger, M.; Weih, R.; Becker, S.; Nähle, L.; Fischer, M.; Koeth, J.; Kamp, M.; Höfling, S.

    2016-05-01

    Compared to the near infrared, many technologically and industrially relevant gas species have more than an order of magnitude higher absorption features in the mid-infrared (MIR) wavelength range. These species include for example important hydrocarbons (methane, acetylene), nitrogen oxides and sulfur oxides. Tunable laser absorption spectroscopy (TLAS) has proven to be a versatile tool for gas sensing applications with significant advantages compared to other techniques. These advantages include real time measurement, standoff detection and ruggedness of the sensor. We present interband cascade lasers (ICLs), which have evolved into important laser sources for the MIR spectral range from 3 to 7 μm. ICLs achieve high efficiency by cascading optically active zones whilst using interband transitions, so they combine common diode laser as well as quantum cascade laser based technologies. Our application grade singlemode distributed feedback devices operate continuous wave at room temperature and are offering several features especially useful for high performance TLAS applications like: side mode suppression ratio of > 30 dB, continuous tuning ranges up to 30 nm, low threshold power densities and low overall power consumption. The devices are typically integrated in a thermoelectrically cooled TO-style package, hermetically sealed using a cap with anti-reflection coated window. This low power consumption as well as the compact size and ruggedness of the fabricated laser sources makes them perfectly suited for battery powered portable solutions for in field spectroscopy applications.

  1. Mid-infrared imaging and spectroscopy of the enigmatic cocoon stars in the Quintuplet Cluster

    CERN Document Server

    Moneti, A; Blommaert, J; Figer, D F; Najarro, F

    2000-01-01

    In an attempt to determine the nature of the enigmatic cocoon stars in the Quintuplet Cluster, we have obtained mid-infrared imaging and spectrophotometry of the cluster, using the CAM and SWS instruments on ISO, using SpectroCam-10 on the Palomar 5m telescope, and NICMOS on HST. The spectra show smooth continua with various dust and ice absorption features. These features are all consistent with an interstellar origin, and there is no clear evidence for any circumstellar contribution to these features. We find no spectral line or feature that could elucidate the nature of these sources. Detailed modeling of the silicate absorption features shows that they are best reproduced by the mu Cep profile, which is typical of the interstellar medium, with tau(sil) \\sim 2.9. The high spatial resolution mid-IR images show that three of the five cocoon stars have spatially extended and asymmetric envelopes, with diameters of \\sim 20,000 AUs. A reddening law similar to that of Lutz (1999) but with silicate features based...

  2. Mid-infrared imaging and spectrophotometry of N 66 in the SMC with ISOCAM

    CERN Document Server

    Contursi, A; Césarsky, C J

    2000-01-01

    We present observations with the mid-infrared camera ISOCAM on board ISO of the major star-forming region N66 in the Small Magellanic Cloud and of its surroundings. These observations were performed with broad filters and the CVF giving a spectral resolution of about 40. In addition, CO(2-1) data are presented, allowing us to identify and study how hot dust relates with the different phases of the Interstellar Medium present in N66. The spectra are dominated by the strong emission of fine structure line. Monochromatic maps have been made in the [NeIII] 15.6 microns and [SIV] 10.5 microns line. There are significant differences between their distributions, due to the effects of density and of shocks. Aromatic Infrared Bands are seen at various places in the field but they are generally faint. They exhibit a variety of shapes and relative intensities, suggesting that a diversity of carbonaceous materials are present. Silicate emission is also clearly visible in the central condensation and in a few others and e...

  3. METIS - the Mid-infrared E-ELT Imager and Spectrograph

    CERN Document Server

    Brandl, Bernhard R; Pantin, Eric; Glasse, Alistair; Blommaert, Joris; Venema, Lars; Molster, Frank; Siebenmorgen, Ralf; Boehnhardt, Hermann; van Dishoeck, Ewine; van der Werf, Paul; Henning, Thomas; Brandner, Wolfgang; Lagage, Pierre-Olivier; Moore, Toby J T; Baes, Maarten; Waelkens, Christoffel; Wright, Chris; Kaeufl, Hans Ulrich; Kendrew, Sarah; Stuik, Remko; Jolissaint, Laurent

    2008-01-01

    METIS, the Mid-infrared ELT Imager and Spectrograph (formerly called MIDIR), is a proposed instrument for the European Extremely Large Telescope (E-ELT), currently undergoing a phase-A study. The study is carried out within the framework of the ESO-sponsored E-ELT instrumentation studies. METIS will be designed to cover the E-ELT science needs at wavelengths longward of 3um, where the thermal background requires different operating schemes. In this paper we discuss the main science drivers from which the instrument baseline has been derived. Specific emphasis has been given to observations that require very high spatial and spectral resolution, which can only be achieved with a ground-based ELT. We also discuss the challenging aspects of background suppression techniques, adaptive optics in the mid-IR, and telescope site considerations. The METIS instrument baseline includes imaging and spectroscopy at the atmospheric L, M, and N bands with a possible extension to Q band imaging. Both coronagraphy and polarim...

  4. Recent advances of mid-infrared compact, field deployable sensors: principles and applications

    Science.gov (United States)

    Tittel, Frank; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Dong, Lei; Li, Chunguang; Patimisco, Pietro; Sampaolo, Angelo; Spagnolo, Vincenzo; Wojtas, Jacek

    2016-04-01

    The recent development of compact interband cascade lasers(ICLs) and quantum cascade lasers (QCLs) based trace gas sensors will permit the targeting of strong fundamental rotational-vibrational transitions in the mid-infrared which are one to two orders of magnitude more intense than transitions in the overtone and combination bands in the near-infrared. This has led to the design and fabrication of mid-infrared compact, field deployable sensors for use in the petrochemical industry, environmental monitoring and atmospheric chemistry. Specifically, the spectroscopic detection and monitoring of four molecular species, methane (CH4) [1], ethane (C2H6), formaldehyde (H2CO) [2] and hydrogen sulphide (H2S) [3] will be described. CH4, C2H6 and H2CO can be detected using two detection techniques: mid-infrared tunable laser absorption spectroscopy (TDLAS) using a compact multi-pass gas cell and quartz enhanced photoacoustic spectroscopy (QEPAS). Both techniques utilize state-of-the-art mid-IR, continuous wave (CW), distributed feedback (DFB) ICLs and QCLs. TDLAS was performed with an ultra-compact 54.6m effective optical path length innovative spherical multipass gas cell capable of 435 passes between two concave mirrors separated by 12.5 cm. QEPAS used a small robust absorption detection module (ADM) which consists of a quartz tuning fork (QTF), two optical windows, gas inlet/outlet ports and a low noise frequency pre-amplifier. Wavelength modulation and second harmonic detection were employed for spectral data processing. TDLAS and QEPAS can achieve minimum detectable absorption losses in the range from 10-8 to 10-11cm-1/Hz1/2. Several recent examples of real world applications of field deployable gas sensors will be described. For example, an ICL based TDLAS sensor system is capable of detecting CH4 and C2H6 concentration levels of 1 ppb in a 1 sec. sampling time, using an ultra-compact, robust sensor architecture. H2S detection was realized with a THz QEPAS sensor

  5. Merging Galaxy Cluster A2255 in Mid-infrared

    Science.gov (United States)

    Shim, Hyunjin; Im, Myungshin; Lee, Hyung Mok; Lee, Myung Gyoon; Kim, Seong Jin; Hwang, Ho Seong; Hwang, Narae; Ko, Jongwan; Lee, Jong Chul; Lim, Sungsoon; Matsuhara, Hideo; Seo, Hyunjong; Wada, Takehiko; Goto, Tomotsugu

    2011-01-01

    We present the mid-infrared (MIR) observation of a nearby galaxy cluster, A2255, by the AKARI space telescope. Using AKARI's continuous wavelength coverage between 3 and 24 μm and the wide field of view, we investigate the properties of cluster member galaxies to see how the infall of the galaxies, the cluster substructures, and the cluster-cluster merger influence their evolution. We show that the excess of MIR (~11 μm) flux is a good indicator for discriminating galaxies at different evolutionary stages and for dividing galaxies into three classes accordingly: strong MIR-excess (N3 - S11>0.2) galaxies that include both unobscured and obscured star-forming galaxies; weak MIR-excess (-2.0 S11 5 Gyr) galaxies where the MIR emission arises mainly from the circumstellar dust around AGB stars; and intermediate MIR-excess (-1.2 S11 < 0.2) galaxies in between the two classes that are less than a few Gyr old past the prime star formation activity. With the MIR-excess diagnostics, we investigate how local and cluster-scale environments affect the individual galaxies. We derive the total star formation rate (SFR) and the specific SFR of A2255 using the strong MIR-excess galaxies. The dust-free, total SFR of A2255 is ~130 M sun yr-1, which is consistent with the SFRs of other clusters of galaxies at similar redshifts and with similar masses. We find no strong evidence that supports enhanced star formation either inside the cluster or in the substructure region, suggesting that the infall or the cluster merging activities tend to suppress star formation. The intermediate MIR-excess galaxies, representing galaxies in transition from star-forming galaxies to quiescent galaxies, are located preferentially at the medium density region or cluster substructures with higher surface density of galaxies. Our findings suggest that galaxies are being transformed from star-forming galaxies into red, quiescent galaxies from the infall region through near the core which can be explained

  6. PROBING STELLAR ACCRETION WITH MID-INFRARED HYDROGEN LINES

    Energy Technology Data Exchange (ETDEWEB)

    Rigliaco, Elisabetta; Pascucci, I.; Mulders, G. D. [Department of Planetary Science, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85719 (United States); Duchene, G. [Astronomy Department, University of California, Berkeley, Hearst Field Annex B-20, Berkeley, CA 94720-3411 (United States); Edwards, S. [Five College Astronomy Department, Smith College, Northampton, MA 01063 (United States); Ardila, D. R. [NASA Herschel Science Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Grady, C. [Eureka Scientific, 2452 Delmer Street, Suite 100, Oakland, CA 94602-3017 (United States); Mendigutía, I. [School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Montesinos, B. [Departamento de Astrofísica, Centro de Astrobiología, ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Najita, J. R. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Carpenter, J. [Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Furlan, E. [Infrared Processing and Analysis Center, California Institute of Technology, 770 S. Wilson Ave., Pasadena, CA 91125 (United States); Gorti, U. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Meijerink, R. [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Meyer, M. R., E-mail: rigliaco@lpl.arizona.edu, E-mail: elisabetta.rigliaco@phys.ethz.ch [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland)

    2015-03-01

    In this paper we investigate the origin of the mid-infrared (IR) hydrogen recombination lines for a sample of 114 disks in different evolutionary stages (full, transitional, and debris disks) collected from the Spitzer archive. We focus on the two brighter H I lines observed in the Spitzer spectra, the H I (7-6) at 12.37 μm and the H I (9-7) at 11.32 μm. We detect the H I (7-6) line in 46 objects, and the H I (9-7) in 11. We compare these lines with the other most common gas line detected in Spitzer spectra, the [Ne II] at 12.81 μm. We argue that it is unlikely that the H I emission originates from the photoevaporating upper surface layers of the disk, as has been found for the [Ne II] lines toward low-accreting stars. Using the H I (9-7)/H I (7-6) line ratios we find these gas lines are likely probing gas with hydrogen column densities of 10{sup 10}-10{sup 11} cm{sup –3}. The subsample of objects surrounded by full and transitional disks show a positive correlation between the accretion luminosity and the H I line luminosity. These two results suggest that the observed mid-IR H I lines trace gas accreting onto the star in the same way as other hydrogen recombination lines at shorter wavelengths. A pure chromospheric origin of these lines can be excluded for the vast majority of full and transitional disks. We report for the first time the detection of the H I (7-6) line in eight young (<20 Myr) debris disks. A pure chromospheric origin cannot be ruled out in these objects. If the H I (7-6) line traces accretion in these older systems, as in the case of full and transitional disks, the strength of the emission implies accretion rates lower than 10{sup –10} M {sub ☉} yr{sup –1}. We discuss some advantages of extending accretion indicators to longer wavelengths, and the next steps required pinning down the origin of mid-IR hydrogen lines.

  7. Parque Astronómico de Atacama: An Ideal Site for Millimeter, Submillimeter, and Mid-Infrared Astronomy

    Science.gov (United States)

    Bustos, R.; Rubio, M.; Otárola, A.; Nagar, N.

    2014-12-01

    The area of Chajnantor, at more than 5000 meters altitude in northern Chile, offers unique atmospheric and operational conditions which arguably make it the best site in the world for millimeter, submillimeter, and mid-infrared observatories. Long-term monitoring of the precipitable water vapor (PWV) column on the Chajnantor plateau has shown its extreme dryness with annual median values of 1.1 mm. Simultaneous measurements of PWV on the Chajnantor plateau (5050 m) and on Cerro Chajnantor (5612 m) show that the latter is around 36% lower under normal atmospheric conditions and up to 80% lower than the plateau in the presence of temperature inversion layers. Recently, the Government of Chile has consolidated the creation of the Parque Astron\\'omico de Atacama (Atacama Astronomical Park), an initiative of the Chilean Commission for Science and Technology (CONICYT). This new Parque offers an opportunity for national and international projects to settle within its boundaries, gain access to an extremely dry site that is suitable for observations over a broad spectral range, especially in the millimeter to mid-infrared wavelengths, and benefit from operational and logistical support within a secure legal framework.

  8. Few-cycle, Broadband, Mid-infrared Optical Parametric Oscillator Pumped by a 20-fs Ti:sapphire Laser

    CERN Document Server

    Kumar, Suddapalli Chaitanya; Ideguchi, Takuro; Yan, Ming; Holzner, Simon; Hänsch, Theodor W; Picqué, Nathalie; Ebrahim-Zadeh, Majid

    2014-01-01

    We report a few-cycle, broadband, singly-resonant optical parametric oscillator (OPO) for the mid-infrared based on MgO-doped periodically-poled LiNbO3 (MgO:PPLN), synchronously pumped by a 20-fs Ti:sapphire laser. By using crystal interaction lengths as short as 250 um, and careful dispersion management of input pump pulses and the OPO resonator, near-transform-limited, few-cycle idler pulses tunable across the mid-infrared have been generated, with as few as 3.7 optical cycles at 2682 nm. The OPO can be continuously tuned over 2179-3732 nm by cavity delay tuning, providing up to 33 mW of output power at 3723 nm. The idler spectra exhibit stable broadband profiles with bandwidths spaning over 422 nm (FWHM) recorded at 3732 nm. We investigate the effect of crystal length on spectral bandwidth and pulse duration at a fixed wavelength, confirming near-transform-limited idler pulses for all grating interaction lengths. By locking the repetition frequency of the pump laser to a radio-frequency reference, and with...

  9. Seasonal variation of the radial brightness contrast of Saturn's rings viewed in mid-infrared by Subaru/COMICS

    Science.gov (United States)

    Fujiwara, Hideaki; Morishima, Ryuji; Fujiyoshi, Takuya; Yamashita, Takuya

    2017-02-01

    Aims: This paper investigates the mid-infrared (MIR) characteristics of Saturn's rings. Methods: We collected and analyzed MIR high spatial resolution images of Saturn's rings obtained in January 2008 and April 2005 with the COoled Mid-Infrared Camera and Spectrometer (COMICS) mounted on the Subaru Telescope, and investigated the spatial variation in the surface brightness of the rings in multiple bands in the MIR. We also composed the spectral energy distributions (SEDs) of the C, B, and A rings and the Cassini Division, and estimated the temperatures of the rings from the SEDs assuming the optical depths. Results: We found that the C ring and the Cassini Division were warmer than the B and A rings in 2008, which could be accounted for by their lower albedos, lower optical depths, and smaller self-shadowing effect. We also fonud that the C ring and the Cassini Division were considerably brighter than the B and A rings in the MIR in 2008 and the radial contrast of the ring brightness is the inverse of that in 2005, which is interpreted as a result of a seasonal effect with changing elevations of the Sun and observer above the ring plane. The reduced images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A29

  10. Temperature stable mid-infrared GaInAsSb/GaSb Vertical Cavity Surface Emitting Lasers (VCSELs)

    Science.gov (United States)

    Ikyo, A. B.; Marko, I. P.; Hild, K.; Adams, A. R.; Arafin, S.; Amann, M.-C.; Sweeney, S. J.

    2016-01-01

    GaInAsSb/GaSb based quantum well vertical cavity surface emitting lasers (VCSELs) operating in mid-infrared spectral range between 2 and 3 micrometres are of great importance for low cost gas monitoring applications. This paper discusses the efficiency and temperature sensitivity of the VCSELs emitting at 2.6 μm and the processes that must be controlled to provide temperature stable operation. We show that non-radiative Auger recombination dominates the threshold current and limits the device performance at room temperature. Critically, we demonstrate that the combined influence of non-radiative recombination and gain peak – cavity mode de-tuning determines the overall temperature sensitivity of the VCSELs. The results show that improved temperature stable operation around room temperature can only be achieved with a larger gain peak – cavity mode de-tuning, offsetting the significant effect of increasing non-radiative recombination with increasing temperature, a physical effect which must be accounted for in mid-infrared VCSEL design.

  11. Multi-millijoule few-cycle mid-infrared pulses through nonlinear self-compression in bulk.

    Science.gov (United States)

    Shumakova, V; Malevich, P; Ališauskas, S; Voronin, A; Zheltikov, A M; Faccio, D; Kartashov, D; Baltuška, A; Pugžlys, A

    2016-09-13

    The physics of strong-field applications requires driver laser pulses that are both energetic and extremely short. Whereas optical amplifiers, laser and parametric, boost the energy, their gain bandwidth restricts the attainable pulse duration, requiring additional nonlinear spectral broadening to enable few or even single cycle compression and a corresponding peak power increase. Here we demonstrate, in the mid-infrared wavelength range that is important for scaling the ponderomotive energy in strong-field interactions, a simple energy-efficient and scalable soliton-like pulse compression in a mm-long yttrium aluminium garnet crystal with no additional dispersion management. Sub-three-cycle pulses with >0.44 TW peak power are compressed and extracted before the onset of modulation instability and multiple filamentation as a result of a favourable interplay between strong anomalous dispersion and optical nonlinearity around the wavelength of 3.9 μm. As a manifestation of the increased peak power, we show the evidence of mid-infrared pulse filamentation in atmospheric air.

  12. Multi-millijoule few-cycle mid-infrared pulses through nonlinear self-compression in bulk

    Science.gov (United States)

    Shumakova, V.; Malevich, P.; Ališauskas, S.; Voronin, A.; Zheltikov, A. M.; Faccio, D.; Kartashov, D.; Baltuška, A.; Pugžlys, A.

    2016-09-01

    The physics of strong-field applications requires driver laser pulses that are both energetic and extremely short. Whereas optical amplifiers, laser and parametric, boost the energy, their gain bandwidth restricts the attainable pulse duration, requiring additional nonlinear spectral broadening to enable few or even single cycle compression and a corresponding peak power increase. Here we demonstrate, in the mid-infrared wavelength range that is important for scaling the ponderomotive energy in strong-field interactions, a simple energy-efficient and scalable soliton-like pulse compression in a mm-long yttrium aluminium garnet crystal with no additional dispersion management. Sub-three-cycle pulses with >0.44 TW peak power are compressed and extracted before the onset of modulation instability and multiple filamentation as a result of a favourable interplay between strong anomalous dispersion and optical nonlinearity around the wavelength of 3.9 μm. As a manifestation of the increased peak power, we show the evidence of mid-infrared pulse filamentation in atmospheric air.

  13. Low temperature mid-infrared cross-sections for peroxyacetyl nitrate (PAN vapour

    Directory of Open Access Journals (Sweden)

    G. Allen

    2005-01-01

    Full Text Available Laboratory absorption spectra of peroxyacetyl nitrate (PAN, CH3C(OOONO2 vapour have been measured in the mid-infrared range 550 cm-1 to 1400 cm-1 (18.2 to 7.14 µm at both 250 K and 273 K, using a Fourier transform infrared spectrometer at a nominal spectral resolution of 0.25 cm-1 (unapodised. In addition, the 1600 cm-1 to 2200 cm-1 (6.25 to 4.54 µm spectral region has been measured at 250 K. Cross-sectional data at each temperature, as well as integrated band intensities and peak infrared absorptivities for nine absorption bands of PAN in this spectral range, have been derived from a total of twelve separately measured PAN transmission spectra. A general increase in the peak absorption cross-section for all bands is noted with decreasing temperature, with cross-sectional increases in the range 6% (for the 1842 cm-1 band and 30% (for the 991 cm-1 band at 250K, relative to those previously reported at 295K. Differences in integrated band intensities range from -22% to +16% for the 1741 cm-1 and 991 cm-1 bands respectively over the same temperature range. These new absorption cross-sections for PAN are the first to be reported at temperatures below 295 K, allowing the possibility of improved retrievals of the atmospherically important PAN species from remotely sensed infrared spectra of the cold upper troposphere. These new cross-sectional data accompany this paper as an electronic supplement.

  14. Pitchfork Bifurcation and Zharov Splitting in Nonlinear Mid-infrared Photothermal Spectroscopy in a liquid crystal using a Quantum Cascade Laser

    CERN Document Server

    Mertiri, Alket; Hong, M K; Mehta, P; Mertz, J; Ziegler, L D; Erramilli, Shyamsunder

    2013-01-01

    We report on the mid-infrared nonlinear photothermal spectrum of the neat liquid crystal 4-Octyl-4'-Cyanobiphenyl (8CB) using a tunable Quantum Cascade Laser (QCL). The nonequilibrium steady state characterized by the nonlinear photothermal infrared response undergoes a supercritical pitchfork bifurcation. The bifurcation, observed in heterodyne two-color pump-probe detection, leads to ultrasharp nonlinear infrared spectra similar to those reported in the visible region. A systematic study of the peak splitting as function of absorbed infrared power shows the bifurcation has a critical exponent of 0.5. The surprising observation of an apparently universal critical exponent in a nonequilibrium state is explained using a simple model reminiscent of mean field theory. Apart from the intrinsic interest for nonequilibrium studies, nonlinear photothermal methods lead to a dramatic narrowing of spectral lines, giving rise to a potential new contrast mechanism for the rapidly emerging new field of mid-infrared micros...

  15. SPHEREx: An All-Sky Spectral Survey

    Science.gov (United States)

    Bock, James; SPHEREx Science Team

    2016-01-01

    SPHEREx, a mission in NASA's Small Explorer (SMEX) program that was selected for Phase A in July 2015, is an all-sky survey satellite designed to address all three science goals in NASA's astrophysics division, in a single survey, with a single instrument. We will probe the physics of inflation by measuring non-Gaussianity by studying large-scale structure, surveying a large cosmological volume at low redshifts, complementing high-z surveys optimized to constrain dark energy. The origin of water and biogenic molecules will be investigated in all phases of planetary system formation - from molecular clouds to young stellar systems with protoplanetary disks - by measuring ice absorption spectra. We will chart the origin and history of galaxy formation through a deep survey mapping large-scale spatial power. Finally, SPHEREx will be the first all-sky near-infrared spectral survey, creating a legacy archive of spectra (0.75 - 4.8 um at R = 41.5 and 150) with high sensitivity using a cooled telescope with large mapping speed.SPHEREx will observe from a sun-synchronous low-earth orbit, covering the entire sky in a manner similar to IRAS, COBE and WISE. During its two-year mission, SPHEREx will produce four complete all-sky maps for constraining the physics of inflation. These same maps contain numerous high signal-to-noise absorption spectra to study water and biogenic ices. The orbit naturally covers two deep regions at the celestial poles, which we use for studying galaxy evolution. All aspects of the SPHEREx instrument and spacecraft have high heritage. SPHEREx requires no new technologies and carries large technical and resource margins on every aspect of the design. The projected instrument sensitivity, based on conservative performance estimates, meets the driving point source sensitivity requirement with 300 % margin.SPHEREx is a partnership between Caltech and JPL, following the successful management structure of the NuSTAR and GALEX SMEX missions. The spacecraft

  16. A Systematic Study of Mid-Infrared Emission from Core-Collapse Supernovae with SPIRITS

    Science.gov (United States)

    Tinyanont, Samaporn; Kasliwal, Mansi M.; Dosovitz Fox, Ori; Lau, Ryan M.; Smith, Nathan; Williams, Robert E.; Jencson, Jacob; Perley, Daniel A.; Dykhoff, Devin; Gehrz, Robert D.; Johansson, Joel; Van Dyk, Schuyler D.; Masci, Frank J.; Cody, Ann Marie; Prince, Thomas Allen; SPIRITS

    2017-01-01

    Late-time mid-infrared emission from core-collpase supernovae tells stories of circumstellar interaction and dust formation. We present a systematic study of mid-infrared emission from 141 nearby supernovae observed with Spitzer/IRAC as part of the ongoing SPIRITS survey. We detect 8 Type Ia and 36 core-collapse SNe. While all SNe-Ia fade away within 3 years post explosion, about 20% of SNe-II remain detectable. Five SNe-II are detected two decades after discovery (SN 1974E, 1979C, 1980K, 1986J, and 1993J). From the two-band photometry, we can fit for IR luminosity and temperature, and the inferred dust mass assuming that all mid-IR emission comes from an optically thin shell of warm dust. We derive warm dust masses between 10-6 and 10-2 \\msol and dust color temperatures between 200 and 1280 K. This observed warm dust could be pre-existing or newly created. We note that either case represents a lower limit to the dust mass because cooler dust may be present. We present three case studies of extreme SNe. SN 2011ja (II-P) was over-luminous ([4.5] = -15.6 mag) at 900 days post-explosion with increasing hot dust mass, suggesting either an episode of dust formation or intensifying CSM interactions heating up pre-existing dust. SN 2014bi (II-P) showed a factor of 10 decrease in dust mass over one month suggesting either dust destruction or reduced dust heating. The IR luminosity of SN 2014C (Ib) stays constant over 800 days, possibly due to strong CSM interaction with H rich shell, which is rare among stripped-envelope SNe. The observations suggest that this CSM shell originated from an LBV-like eruption roughly 100 years pre-explosion. The observed diversity demonstrates the power of mid-IR observations of a large sample of SNe.

  17. Mercury And The Moon: Mid-infrared Spectroscopic Measurements Of The Surface

    Science.gov (United States)

    Donaldson Hanna, Kerri L.; Sprague, A. L.; Kozlowski, R. W.; Boccafolo, K.; Helbert, J.; Maturilli, A.; Warell, J.

    2006-09-01

    Spectroscopic observations (7.5 - 13 μm) of Mercury and the Moon obtained with MIRSI (Mid-Infrared Spectrometer and Imager) at the NASA Infrared Telescope Facility (IRTF) are presented. The spectra were acquired at mercurian W. longitudes 172 - 282° covering north polar to south polar latitudes. Also acquired were lunar surface measurements of the Apollo 16 landing site and Grimaldi basin and highlands. Mercury measurements covered Caloris Basin, Basin S, and other regions on the side not imaged by Mariner 10. Lunar locations were chosen for their known surface compositions determined from near-infrared spectral telescopic observations and Apollo return samples. Spectra for both bodies were reduced with the same calibration star to minimize reduction differences. Spectral differences between the mercurian locations indicate a heterogeneous composition and differences between Mercury and lunar spectra indicate compositional differences between the two bodies. All collected spectra from Mercury and the Moon show distinct and recognizable features including the Christiansen emissivity maximum and one or more transmission minima. Other features have yet to be identified. True emission spectra of rock and mineral powders with varying grain sizes will be presented for comparison with the data. Acknowledgements: The authors of this paper were Visiting Astronomers at the Infrared Telescope Facility, which is operated by the University of Hawaii under Cooperative Agreement no. NCC 5-538 with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program. We are especially grateful to Alan Tokunaga and Eric Tollestrup for useful engineering time on the telescope and Don Hunten for helpful discussions. This work was supported by NSF grant AST-0406796.

  18. Galaxy And Mass Assembly (GAMA): Mid-Infrared Properties and Empirical Relations from $WISE$

    CERN Document Server

    Cluver, M E; Hopkins, A M; Driver, S P; Liske, J; Gunawardhana, M L P; Taylor, E N; Robotham, A S G; Alpaslan, M; Baldry, I; Brown, M J I; Peacock, J A; Popescu, C C; Tuffs, R J; Bauer, A E; Bland-Hawthorn, J; Colless, M; Holwerda, B W; Lara-Lopez, M A; Leschinski, K; Lopez-Sanchez, A R; Norberg, P; Owers, M; Wang, L; Wilkins, S M

    2014-01-01

    The Galaxy And Mass Assembly (GAMA) survey furnishes a deep redshift catalog that, when combined with the Wide-field Infrared Explorer ($WISE$), allows us to explore for the first time the mid-infrared properties of $> 110, 000$ galaxies over 120 deg$^2$ to $z\\simeq 0.5$. In this paper we detail the procedure for producing the matched GAMA-$WISE$ catalog for the G12 and G15 fields, in particular characterising and measuring resolved sources; the complete catalogs for all three GAMA equatorial fields will be made available through the GAMA public releases. The wealth of multiwavelength photometry and optical spectroscopy allows us to explore empirical relations between optically determined stellar mass (derived from synthetic stellar population models) and 3.4micron and 4.6micron WISE measurements. Similarly dust-corrected Halpha-derived star formation rates can be compared to 12micron and 22micron luminosities to quantify correlations that can be applied to large samples to $z<0.5$. To illustrate the appli...

  19. The Spatial Extent of (U)LIRGs in the mid-Infrared I: The Continuum Emission

    CERN Document Server

    Diaz-Santos, T; Armus, L; Petric, A O; Howell, J H; Murphy, E J; Mazzarella, J M; Veilleux, S; Bothun, G; Inami, H; Appleton, P N; Evans, A S; Haan, S; Marshall, J A; Sanders, D B; Stierwalt, S; Surace, J A

    2010-01-01

    We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey (GOALS) sample based on 5-15um low resolution spectra obtained with the IRS on Spitzer. We calculate the fraction of extended emission as a function of wavelength for the galaxies in the sample, FEE_lambda. We can identify 3 general types of FEE_lambda: one where it is constant, one where features due to emission lines and PAHs appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7um. More than 30% of the galaxies have a median FEE_lambda larger than 0.5 implying that at least half of their MIR emission is extended. Luminous Infrared Galaxies (LIRGs) display a wide range of FEE in their warm dust continuum (0~10^11.25Lsun strongly increases in those classified as mergers in their final stage of interaction. The FEE_13.2um is also related to the contribution of an active galactic nucleus (AGN) to the MIR. Galaxies which are more ...

  20. Morphologies of Radio, X-Ray, and Mid-Infrared Selected AGN

    CERN Document Server

    Griffith, Roger L

    2010-01-01

    We investigate the optical morphologies of candidate active galaxies identified at radio, X-ray, and mid-infrared wavelengths. We use the Advanced Camera for Surveys General Catalog (ACS-GC) to identify 372, 1360, and 1238 AGN host galaxies from the VLA, XMM-Newton and Spitzer Space Telescope observations of the COSMOS field, respectively. We investigate both quantitative (GALFIT) and qualitative (visual) morphologies of these AGN host galaxies, split by brightness in their selection band. We find that the radio-selected AGN are most distinct, with a very low incidence of having unresolved optical morphologies and a high incidence of being hosted by early-type galaxies. In comparison to X-ray selected AGN, mid-IR selected AGN have a slightly higher incidence of being hosted by disk galaxies. These morphological results conform with the results of Hickox et al. 2009 who studied the colors and large-scale clustering of AGN, and found a general association of radio-selected AGN with ``red sequence'' galaxies, mi...

  1. The Mid-Infrared Polarization of the Herbig Ae Star WL 16: An Interstellar Origin?

    CERN Document Server

    Zhang, Han; Pantin, Eric; Li, Dan; Wright, Christopher M; Mariñas, Naibí; Barnes, Peter; Li, Aigen; Packham, Christopher

    2016-01-01

    We present high-resolution (0".4) mid-infrared (mid-IR) polarimetric images and spectra of WL 16, a Herbig Ae star at a distance of 125 pc. WL 16 is surrounded by a protoplanetary disk of $\\sim$ 900 AU in diameter, making it one of the most extended Herbig Ae/Be disks as seen in the mid-IR. The star is behind, or embedded in, the $\\rho$ Ophiuchus molecular cloud, and obscured by 28 magnitudes of extinction at optical wavelengths by the foreground cloud. Mid-IR polarization of WL 16, mainly arises from aligned elongated dust grains present along the line of sight, suggesting a uniform morphology of polarization vectors with an orientation of 33\\degr (East from North) and a polarization fraction of $\\sim$ 2.0\\%. This orientation is consistent with previous polarimetric surveys in the optical and near-IR bands to probe large-scale magnetic fields in the Ophiuchus star formation region, indicating that the observed mid-IR polarization toward WL 16 is produced by the dichroic absorption of magnetically aligned for...

  2. A mid-infrared exploration of the dusty environments of active galactic nuclei

    CERN Document Server

    Alonso-Herrero, Almudena

    2013-01-01

    We present the first results from a mid-infrared survey of local Active Galactic Nuclei (AGN) using the CanariCam (CC) instrument on the 10.4m Gran Telescopio Canarias (GTC). We are obtaining sub-arcsecond angular resolution (0.3-0.6 arcsec) mid-IR imaging and spectroscopic observations of a sample of 100 local AGN, which are complemented with data taken with T-ReCS, VISIR, and Michelle. The full sample contains approximately 140 AGN, covers nearly six orders of magnitude in AGN luminosity, and includes low-luminosity AGN (LLAGN), Seyfert 1s and 2s, QSO, radio galaxies, and (U)LIRGs. The main goals of this project are: (1) to test whether the properties of the dusty tori of the AGN Unified Model depend on the AGN type, (2) to study the nuclear star formation activity and obscuration of local AGN, and (3) to explore the role of the dusty torus in LLAGN.

  3. Theoretical Modeling of Emission-Line galaxies: New Classification Parameters for Mid-Infrared and Optical Spectroscopy

    CERN Document Server

    Meléndez, M; Martínez-Paredes, M; Kraemer, S B; Mendoza, C

    2014-01-01

    We have carried out extensive and detailed photoionization modeling to successfully constrain the locations of different emission-line galaxies in optical and mid-infrared diagnostic diagrams. Our model grids cover a wide range in parameter space for the active galaxy continuum and starburst galaxies with different stellar population laws and metallicities. We compare the predicted AGN and star-formation mid-infrared line ratios [Ne III]15.56mm/[Ne II]12.81mm and [O IV]25.89mm/[Ne III]15.56mm to the observed values, and find that the best fit for the AGN is via a two-zone approximation. This two-zone approximation is a combination of a matter-bounded component, where [Ne III] and [O IV] are emitted efficiently, and a radiation-bounded component that maximizes [Ne II] emission. We overlay the predictions from this two-zone approximation onto the optical [O III]l5007/Hbeta and [N II]l6583/Halpha diagnostic diagram derived from the Sloan Digital Sky Survey, to find that the high-density and low-ionization radiat...

  4. A comprehensive search for stellar bowshock nebulae in the Milky Way: a catalog of 709 mid-infrared selected candidates

    CERN Document Server

    Kobulnicky, Henry A; Schurhammer, Danielle P; Andrews, Julian E; Povich, Matthew S; Munari, Stephan A; Olivier, Grace M; Sorber, Rebecca L; Wernke, Heather N; Dale, Daniel A; Dixon, Don M

    2016-01-01

    We identify 709 arc-shaped mid-infrared nebula in 24 micron Spitzer Space Telescope or 22 micron Wide Field Infrared Explorer surveys of the Galactic Plane as probable dusty interstellar bowshocks powered by early-type stars. About 20% are visible at 8 microns or shorter mid-infrared wavelengths as well. The vast majority (660) have no previous identification in the literature. These extended infrared sources are strongly concentrated near Galactic mid-Plane with an angular scale height of ~0.6 degrees. All host a symmetrically placed star implicated as the source of a stellar wind sweeping up interstellar material. These are candidate "runaway" stars potentially having high velocities in the reference frame of the local medium. Among the 286 objects with measured proper motions, we find an unambiguous excess having velocity vectors aligned with the infrared morphology --- kinematic evidence that many of these are "runaway" stars with large peculiar motions responsible for the bowshock signature. We discuss a...

  5. WISE TF: A Mid-infrared, 3.4-micron Extension of the Tully-Fisher Relation Using WISE Photometry

    CERN Document Server

    Lagattuta, David J; Staveley-Smith, Lister; Hong, Tao; Springob, Christopher M; Masters, Karen L; Koribalski, Bärbel S; Jones, D Heath

    2013-01-01

    We present a mid-infrared Tully-Fisher (TF) relation using photometry from the 3.4-micron W1 band of the Wide-field Infrared Survey Explorer (WISE) satellite. The WISE TF relation is formed from 568 galaxies taken from the all-sky 2MASS Tully-Fisher (2MTF) galaxy catalog, spanning a range of environments including field, group, and cluster galaxies. This constitutes the largest mid-infrared TF relation constructed, to date. After applying a number of corrections to galaxy magnitudes and line widths, we measure a master TF relation given by M_corr = -22.24 - 10.05[log(W_corr) - 2.5], with an average dispersion of sigma_WISE = 0.686 magnitudes. There is some tension between WISE TF and a preliminary 3.6-micron relation, which has a shallower slope and almost no intrinsic dispersion. However, our results agree well with a more recent relation constructed from a large sample of cluster galaxies. We additionally compare WISE TF to the near-infrared 2MTF template relations, finding a good agreement between the TF p...

  6. Mid-infrared Period-Luminosity Relations of RR Lyrae Stars Derived from the WISE Preliminary Data Release

    CERN Document Server

    Klein, Christopher R; Butler, Nathaniel R; Bloom, Joshua S

    2011-01-01

    Interstellar dust presents a significant challenge to extending parallax-determined distances of optically observed pulsational variables to larger volumes. Distance ladder work at mid-infrared wavebands, where dust effects are negligible and metallicity correlations are minimized, have been largely focused on few-epoch Cepheid studies. Here we present the first determination of mid-infrared period-luminosity (PL) relations of RR Lyrae stars from phase-resolved imaging using the preliminary data release of the Wide-Field Infrared Survey Explorer (WISE). We present a novel statistical framework to predict posterior distances of 76 well-observed RR Lyrae that uses the optically constructed prior distance moduli while simultaneously imposing a power-law PL relation to WISE-determined mean magnitudes. We find that the absolute magnitude in the bluest WISE filter is M_W1 = (-0.421+-0.014) - (1.681+-0.147)*log(P/0.50118 day), with no evidence for a correlation with metallicity. Combining the results from the three ...

  7. Visible spectral slope survey of Jupiter Trojans

    Science.gov (United States)

    Erasmus, Nicolas; Rivkin, Andrew S.; Sickafoose, Amanda A.

    2016-10-01

    Jupiter's Trojans are predicted by the Nice Model [1,2] to be Trans-Neptunian Objects (TNOs) that moved from 30+ AU to 5.2 AU during the early evolution period of the Solar System. This model, predicting giant planet migration and widespread transport of material throughout the Solar System, is however still lacking important constraints. Correlations between the composition, size, and orbital geometry of Jupiter's Trojans can provide additional information to test predicted migration and evolution models.Two main colour groups have been observed, roughly equivalent to the C (plus low-albedo X) and D classes with distinguishable spectral slopes, and one interpretation is that the two groups have different compositions [3]. Independent compositions together with hints of differing orbital inclination distributions could imply separate formation locations; therefore, determining the relative fractions of C and D asteroids at different sizes would provide a key test for Solar System dynamical models. However, there is a caveat: the distinct colour groups could also arise by other means. Regolith processes or "space weathering" such as micrometeorite impacts and UV irradiation of ice are also plausible explanations for a range of spectrographic slopes from C-like to D-like [4].Here we report on our latest survey observations at Sutherland, South Africa of approximately 50 Trojan targets using the Sutherland High Speed Optical Camera (SHOC) [5] on the 74" telescope. These observations are part of a larger multi-telescope survey to determine the spectral slopes (C-like or D-like) for multiple Trojans, focusing on those of small size. These slopes can be used to determine the relative fraction of C+X and D asteroids at different sizes to determine whether what is seen is more consistent with regolith processes or different compositions.References:[1] A. Morbidelli, et al. Nature, 435, 462-465, (2005)[2] R. Gomes, et al. Nature 435, 466-469 (2005)[3] J.P. Emery, et al. The

  8. Mid-infrared properties of luminous infrared galaxies. II. Probing the dust and gas physics of the goals sample

    Energy Technology Data Exchange (ETDEWEB)

    Stierwalt, S.; Armus, L.; Diaz-Santos, T.; Marshall, J.; Haan, S.; Howell, J.; Murphy, E. J.; Inami, H.; Petric, A. O. [Spitzer Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Charmandaris, V. [Department of Physics, University of Crete, GR-71003 Heraklion (Greece); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Iwasawa, K. [INAF-Observatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Kim, D. C. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Rich, J. A. [The Observatories, Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Spoon, H. W. W. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); U, V., E-mail: sabrinas@virginia.edu [Department of Physics and Astronomy, University of California, Riverside, CA 92507 (United States)

    2014-08-01

    The Great Observatories All-sky LIRG Survey (GOALS) is a comprehensive, multiwavelength study of luminous infrared galaxies (LIRGs) in the local universe. Here, we present the results of a multi-component, spectral decomposition analysis of the low-resolution mid-infrared (MIR) Spitzer Infrared Spectrograph spectra from 5-38 μm of 244 LIRG nuclei. The detailed fits and high-quality spectra allow for characterization of the individual polycyclic aromatic hydrocarbon (PAH) features, warm molecular hydrogen emission, and optical depths for both silicate dust grains and water ices. We find that starbursting LIRGs, which make up the majority of the GOALS sample, are very consistent in their MIR properties (i.e., τ{sub 9.7μm}, τ{sub ice}, neon line ratios, and PAH feature ratios). However, as their EQW{sub 6.2{sub μm}} decreases, usually an indicator of an increasingly dominant active galactic nucleus (AGN), LIRGs cover a larger spread in these MIR parameters. The contribution from PAH emission to the total IR luminosity (L(PAH)/L(IR)) in LIRGs varies from 2%-29% and LIRGs prior to their first encounter show significantly higher L(PAH)/L(IR) ratios on average. We observe a correlation between the strength of the starburst (represented by IR8 = L{sub IR}/L{sub 8{sub μm}}) and the PAH fraction at 8 μm but no obvious link between IR8 and the 7.7 to 11.3 PAH ratio, suggesting that the fractional photodissociation region (PDR) emission, and not the overall grain properties, is associated with the rise in IR8 for galaxies off the starburst main sequence. We detect crystalline silicate features in ∼6% of the sample but only in the most obscure sources (s{sub 9.7{sub μm}} < –1.24). Ice absorption features are observed in ∼11% (56%) of GOALS LIRGs (ULIRGs) in sources with a range of silicate depths. Most GOALS LIRGs have L(H{sub 2})/L(PAH) ratios elevated above those observed for normal star-forming galaxies and exhibit a trend for increasing L(H{sub 2})/L

  9. Upconversion based continuous-wave mid-infrared detection

    DEFF Research Database (Denmark)

    Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin; Pedersen, Christian

    2013-01-01

    We present theoretical and experimental work on upconversion based mid-wavelength infrared detection using silicon detectors without the need for cryogenic cooling. We consider both multi-spectral imaging and point spectroscopy targeting several specific applications.......We present theoretical and experimental work on upconversion based mid-wavelength infrared detection using silicon detectors without the need for cryogenic cooling. We consider both multi-spectral imaging and point spectroscopy targeting several specific applications....

  10. Low-Threshold Mid-Infrared Optical Parametric Oscillator Using Periodically Poled LiNbO3

    Institute of Scientific and Technical Information of China (English)

    林学春; 张瑛; 孔宇鹏; 张杰; 姚爱云; 侯玮; 崔大复; 李瑞宁; 许祖彦; 李健

    2004-01-01

    We report the generation of tunable mid-infrared optical pulses using all-solid-state pumped optical parametric oscillator in a periodically poled lithium niobate. Several ways were used to lower the threshold, resulting in a mean threshold as low as 6.5m W and an achievement of wavelength conversion in the 2.77-4.04μm spectral range. Continuous tuning range from 2.97 to 3.25 μm was achieved. The maximum idler output power of 466 m W at the wavelength of 3.41 μm was obtained, which represents an optical-to-optical conversion efficiency of 19%from incident pump power to the idler output.

  11. Mid-Infrared Optical Parametric Oscillator Based on All-Solid-State-Pumped Periodically Poled LiNbO

    Institute of Scientific and Technical Information of China (English)

    林学春; 毕勇; 姚爱云; 孔宇鹏; 张瑛; 孙志培; 李瑞宁; 崔大复; 许祖彦; 李健

    2003-01-01

    We report the tunable mid-infrared generation with a periodically poled LiNbO3 (PPLN). Using an all-solid-statepumped Nd: YVO4 laser as the pump source and a PPLN nonlinear crystal with grating periods of 28.2-30.8 μm,we have achieved wavelength conversion in the 2.90-4.05 μm spectral range by period tuning. The use of confocal cavity design has brought a compact, all-solid-state configuration with an average output powers of idler up to ~ 200 mW. The maximum power of 277mW was obtained at the wavelength of 3.35μm.

  12. Generation of parabolic similaritons in tapered silicon photonic wires: comparison of pulse dynamics at telecom and mid-infrared wavelengths.

    Science.gov (United States)

    Lavdas, Spyros; Driscoll, Jeffrey B; Jiang, Hongyi; Grote, Richard R; Osgood, Richard M; Panoiu, Nicolae C

    2013-10-01

    We study the generation of parabolic self-similar optical pulses in tapered Si photonic nanowires (Si-PhNWs) at both telecom (λ=1.55 μm) and mid-infrared (λ=2.2 μm) wavelengths. Our computational study is based on a rigorous theoretical model, which fully describes the influence of linear and nonlinear optical effects on pulse propagation in Si-PhNWs with arbitrarily varying width. Numerical simulations demonstrate that, in the normal dispersion regime, optical pulses evolve naturally into parabolic pulses upon propagation in millimeter-long tapered Si-PhNWs, with the efficiency of this pulse-reshaping process being strongly dependent on the spectral and pulse parameter regime in which the device operates, as well as the particular shape of the Si-PhNWs.

  13. Room temperature mid-infrared InAsSbN multi-quantum well photodiodes grown by MBE

    Science.gov (United States)

    Kesaria, M.; de la Mare, M.; Krier, A.

    2016-11-01

    Room temperature photoresponse in the mid-infrared spectral region is demonstrated from InAsSbN/InAs multi-quantum well photodiodes grown by nitrogen plasma assisted molecular beam epitaxy. The structural quality of the InAsSbN MQWs was ascertained in situ by reflection high energy electron diffraction and ex situ by high resolution x-ray diffraction and photoluminescence measurements. The extended long wavelength photoresponse is identified to originate from the electron-heavy hole (e1-hh1) and electron-light hole (e1-lh1) transitions in the InAsSbN MQW, with a cut off wavelength ~4.20 µm and peak detectivity D *  =  1.25  ×  109 cm Hz1/2 W-1.

  14. [Study on Trace Water Influence on Electrical Properties of Insulating Oil Based on the Mid-Infrared Spectrum Analysis].

    Science.gov (United States)

    Chen, Bin; Wu, Hong-yang; Han, Chao; Yan, Huan; Liu, Ge

    2015-10-01

    Trace water has a significant impact on the electrical performances of the insulating oil, such as the dielectric loss factor, resistivity. So there is an important significance to investigate the influence of insulating oil by trace water, and monitor its operating status with effective measures. First, it is necessary to prepare the insulating oil samples with different water content and treat them 8 hours with ultrasonic oscillator, and observe microscopic images about the water-oil mixtures in order to study their relative uniformity and stable time, in the way it can be concluded that the relative uniformity can be kept favorable during the 25 min stable time for free water and emulsification water in oil; Based on this conclusion, the dielectric loss factor, resistivity were tested and the electrical performances of insulating oil with different water content in oil can obtained by analyzing these data; Then, the absorbance value of the different water content in oil at the spectral wave number of 1 640, 3 400, 3 450, 3 615 cm(-1), with the mid-infrared spectral scanning and analyzing to the different water content in oil, Therefore, combined the water absorbance values by the mid-infrared spectral scanning and analyzing with the experimental data of dielectric loss factor value, resistivity value of oil samples. The results shows that the absorbance value of the different water content in oil has a significant difference at the spectral wave number of 1 640, 3 400, 3450, 3 615 cm(-1), their correlation coefficient are 0.964 1, 0.984 8, 0.984 5, 0.944 0 between the absorbance value and water content at the spectral wave number of 1 640, 3 400, 3 450, 3 615 cm(-1), it can be obtained that the absorbance value of sample of moisture in the corresponding characteristic wave number can better reflect the change trend of water content; there is the highly relative of water absorbance values at the spectral wave number of 3 400 and 3 450 cm(-1) with the trends of

  15. Injection seeded tunable mid-infrared pulses by difference frequency mixing

    CERN Document Server

    Miyamoto, Yuki; Masuda, Takahiko; Sasao, Noboru; Uetake, Satoshi

    2015-01-01

    We report on generation of nanosecond mid-infrared pulses having frequency tunability, narrow linewidth and high intensity. They are obtained by frequency mixing between injection seeded near-infrared pulses in potassium titanyl arsenate crystals. A continuous-wave external cavity laser diode or a Ti:Sapphire ring laser are used as a tunable seeding source for the near-infrared pulses. Typical energy and pulse duration of the generated mid-infrared pulses is 0.4 mJ/pulse and 2 ns, respectively. Narrow linewidth of about 1 GHz and good frequency reproducibility of the mid-infrared pulses are confirmed by observing a ro-vibrational absorption line of gaseous carbon monoxide.

  16. Spitzer Mid-Infrared Spectra of Cool-Core Galaxy Clusters

    CERN Document Server

    de Messières, G E; McNamara, B R; Donahue, M; Nulsen, P E J; Voit, G M; Wise, M W

    2009-01-01

    We have obtained mid-infrared spectra of nine cool-core galaxy clusters with the Infrared Spectrograph aboard the Spitzer Space Telescope. X-ray, ultraviolet and optical observations have demonstrated that each of these clusters hosts a cooling flow which seems to be fueling vigorous star formation in the brightest cluster galaxy. Our goal is to use the advantages of the mid-infrared band to improve estimates of star formation. Our spectra are characterized by diverse morphologies ranging from classic starbursts to flat spectra with surprisingly weak dust features. Although most of our sample are known from optical/UV data to be active star-formers, they lack the expected strong mid-infrared continuum. Star formation may be proceeding in unusually dust-deficient circumgalactic environments such as the interface between the cooling flow and the relativistic jets from the active galactic nucleus.

  17. Efficient Dielectric Metasurface Collimating Lenses for Mid-Infrared Quantum Cascade Lasers

    CERN Document Server

    Arbabi, Amir; Horie, Yu; Bagheri, Mahmood; Faraon, Andrei

    2015-01-01

    Light emitted from single-mode semiconductor lasers generally has large divergence angles, and high numerical aperture lenses are required for beam collimation. Visible and near infrared lasers are collimated using aspheric glass or plastic lenses, yet collimation of mid-infrared quantum cascade lasers typically requires more costly aspheric lenses made of germanium, chalcogenide compounds, or other infrared-transparent materials. Here we report mid-infrared dielectric metasurface flat lenses that efficiently collimate the output beam of single-mode quantum cascade lasers. The metasurface lenses are composed of amorphous silicon posts on a flat sapphire substrate and can be fabricated at low cost using a single step conventional UV binary lithography. Mid-infrared radiation from a 4.8 $\\mu$m distributed-feedback quantum cascade laser is collimated using a polarization insensitive metasurface lens with 0.86 numerical aperture and 79% transmission efficiency. The collimated beam has a half divergence angle of 0...

  18. A graphene-based Fabry-Pérot spectrometer in mid-infrared region

    Science.gov (United States)

    Wang, Xiaosai; Chen, Chen; Pan, Liang; Wang, Jicheng

    2016-08-01

    Mid-infrared spectroscopy is of great importance in many areas and its integration with thin-film technology can economically enrich the functionalities of many existing devices. In this paper we propose a graphene-based ultra-compact spectrometer (several micrometers in size) that is compatible with complementary metal-oxide-semiconductor (CMOS) processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Pérot cavity. By varying the voltage acting on the cavity, we can control the transmitted wavelength of the spectrometer at room temperature. This design has potential applications in the graphene-silicon-based optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region.

  19. Mid-infrared mapping of Jupiter's temperatures, aerosol opacity and chemical distributions with IRTF/TEXES

    Science.gov (United States)

    Fletcher, Leigh N.; Greathouse, T. K.; Orton, G. S.; Sinclair, J. A.; Giles, R. S.; Irwin, P. G. J.; Encrenaz, T.

    2016-11-01

    Global maps of Jupiter's atmospheric temperatures, gaseous composition and aerosol opacity are derived from a programme of 5-20 μm mid-infrared spectroscopic observations using the Texas Echelon Cross Echelle Spectrograph (TEXES) on NASA's Infrared Telescope Facility (IRTF). Image cubes from December 2014 in eight spectral channels, with spectral resolutions of R ∼2000 - 12 , 000 and spatial resolutions of 2-4° latitude, are inverted to generate 3D maps of tropospheric and stratospheric temperatures, 2D maps of upper tropospheric aerosols, phosphine and ammonia, and 2D maps of stratospheric ethane and acetylene. The results are compared to a re-analysis of Cassini Composite Infrared Spectrometer (CIRS) observations acquired during Cassini's closest approach to Jupiter in December 2000, demonstrating that this new archive of ground-based mapping spectroscopy can match and surpass the quality of previous investigations, and will permit future studies of Jupiter's evolving atmosphere. The visibility of cool zones and warm belts varies from channel to channel, suggesting complex vertical variations from the radiatively-controlled upper troposphere to the convective mid-troposphere. We identify mid-infrared signatures of Jupiter's 5-μm hotspots via simultaneous M, N and Q-band observations, which are interpreted as temperature and ammonia variations in the northern Equatorial Zone and on the edge of the North Equatorial Belt (NEB). Equatorial plumes enriched in NH3 gas are located south-east of NH3-desiccated 'hotspots' on the edge of the NEB. Comparison of the hotspot locations in several channels across the 5-20 μm range indicate that these anomalous regions tilt westward with altitude. Aerosols and PH3 are both enriched at the equator but are not co-located with the NH3 plumes. The equatorial temperature minimum and PH3/aerosol maxima have varied in amplitude over time, possibly as a result of periodic equatorial brightenings and the fresh updrafts of

  20. ISO Mid-Infrared Observations of Giant HII Regions in M33

    Science.gov (United States)

    Skelton, B. P.; Waller, W. H.; Hodge, P. W.; Boulanger, F.; Cornett, R. H.; Fanelli, M. N.; Lequeux, J.; Stecher, T. P.; Viallefond, F.; Hui, Y.

    1999-01-01

    We present Infrared Space Observatory Camera (ISOCAM) Circular Variable Filter scans of three giant HII regions in M33. IC 133, NGC 595, and CC 93 span a wide range of metallicity, luminosity, nebular excitation, and infrared excess; three other emission regions (CC 43, CC 99, and a region to the northeast of the core of NGC 595) are luminous enough in the mid-infrared to be detected in the observed fields. ISOCAM CVF observations provide spatially resolved observations (5'') of 151 wavelengths between 5.1 and 16.5 microns with a spectral resolution R = 35 to 50. We observe atomic emission lines ([Ne II], [Ne III], and [S IV]), several "unidentified infrared bands" (UIBs; 6.2, 7.7, 8.6, 11.3, 12.0, and 12.7 microns), and in some cases a continuum which rises steeply at longer wavelengths. We conclude that the spectra of these three GHRs are well explained by combinations of ionized gas, PAHs, and very small grains in various proportions and with different spatial distributions. Comparisons between observed ratios of the various UIBs with model ratios indicate that the PAHs in all three of the GHRs are dehydrogenated and that the small PAHs have been destroyed in IC 133 but have survived in NGC 595 and CC 93. The [Ne III]/[Ne II] ratios observed in IC 133 and NGC 595 are consistent with their ages of 5 and 4.5 Myr, respectively; the deduced ionization parameter is higher in IC 133, consistent with its more compact region of emission.

  1. The Orion HII Region and the Orion Bar in the Mid-infrared

    Science.gov (United States)

    Salgado, F.; Berné, O.; Adams, J. D.; Herter, T. L.; Keller, L. D.; Tielens, A. G. G. M.

    2016-10-01

    We present mid-infrared photometry of the Orion bar obtained with the Faint Object infraRed Camera for the SOFIA Telescope (FORCAST) on board SOFIA at 6.4, 6.6, 7.7, 19.7, 31.5, and 37.1 μm. By complementing this observation with archival FORCAST and Herschel/PACS images, we are able to construct a complete infrared spectral energy distribution of the Huygens region in the Orion nebula. Comparing the infrared images with gas tracers, we find that PACS maps trace the molecular cloud, while the FORCAST data trace the photodissociation region (PDR) and the H ii region. Analysis of the energetics of the region reveal that the PDR extends for 0.28 pc along the line of sight and that the bar is inclined at an angle of 4°. The infrared and submillimeter images reveal that the Orion bar represents a swept-up shell with a thickness of 0.1 pc. The mass of the shell implies a shock velocity of ≃3 km s-1 and an age of ≃105 years for the H ii region. Our analysis shows that the UV and infrared dust opacities in the H ii region and the PDR are a factor 5 to 10 lower than in the diffuse interstellar medium. In the ionized gas, Lyα photons are a major source of dust heating at distances larger than ≃0.06 pc from θ 1 Ori C. Dust temperatures can be explained if the size of the grains is between 0.1 and 1 μm. We derive the photoelectric heating efficiency of the atomic gas in the Orion bar. The results are in good qualitative agreement with models and the quantitative differences indicate a decreased polycyclic aromatic hydrocarbon abundance in this region.

  2. Directly imaged L-T transition exoplanets in the mid-infrared {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Skemer, Andrew J.; Hinz, Philip M.; Morzinski, Katie M.; Leisenring, Jarron M.; Close, Laird M.; Bailey, Vanessa P.; Defrere, Denis; Follette, Katherine B.; Males, Jared R.; Rodigas, Timothy J. [Steward Observatory, Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Marley, Mark S. [NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States); Skrutskie, Michael F. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Saumon, Didier [Los Alamos National Laboratory, Mail Stop F663, Los Alamos, NM 87545 (United States); Briguglio, Runa; Esposito, Simone; Puglisi, Alfio; Xompero, Marco [Istituto Nazionale di Astrofisica, Osservatorio Astrofisico di Arcetri Largo E. Fermi 5 50125 Firenze (Italy); Hill, John M. [Large Binocular Telescope Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2014-09-01

    Gas-giant planets emit a large fraction of their light in the mid-infrared (≳3 μm), where photometry and spectroscopy are critical to our understanding of the bulk properties of extrasolar planets. Of particular importance are the L- and M-band atmospheric windows (3-5 μm), which are the longest wavelengths currently accessible to ground-based, high-contrast imagers. We present binocular LBT adaptive optics (AO) images of the HR 8799 planetary system in six narrow-band filters from 3 to 4 μm, and a Magellan AO image of the 2M1207 planetary system in a broader 3.3 μm band. These systems encompass the five known exoplanets with luminosities consistent with L → T transition brown dwarfs. Our results show that the exoplanets are brighter and have shallower spectral slopes than equivalent temperature brown dwarfs in a wavelength range that contains the methane fundamental absorption feature (spanned by the narrow-band filters and encompassed by the broader 3.3 μm filter). For 2M1207 b, we find that thick clouds and non-equilibrium chemistry caused by vertical mixing can explain the object's appearance. For the HR 8799 planets, we present new models that suggest the atmospheres must have patchy clouds, along with non-equilibrium chemistry. Together, the presence of a heterogeneous surface and vertical mixing presents a picture of dynamic planetary atmospheres in which both horizontal and vertical motions influence the chemical and condensate profiles.

  3. ISO Mid-Infrared Observations of Giant HII Regions in M33

    Science.gov (United States)

    Skelton, B. P.; Waller, W. H.; Hodge, P. W.; Boulanger, F.; Cornett, R. H.; Fanelli, M. N.; Lequeux, J.; Stecher, T. P.; Viallefond, F.; Hui, Y.

    1999-01-01

    We present Infrared Space Observatory Camera (ISOCAM) Circular Variable Filter scans of three giant HII regions in M33. IC 133, NGC 595, and CC 93 span a wide range of metallicity, luminosity, nebular excitation, and infrared excess; three other emission regions (CC 43, CC 99, and a region to the northeast of the core of NGC 595) are luminous enough in the mid-infrared to be detected in the observed fields. ISOCAM CVF observations provide spatially resolved observations (5'') of 151 wavelengths between 5.1 and 16.5 microns with a spectral resolution R = 35 to 50. We observe atomic emission lines ([Ne II], [Ne III], and [S IV]), several "unidentified infrared bands" (UIBs; 6.2, 7.7, 8.6, 11.3, 12.0, and 12.7 microns), and in some cases a continuum which rises steeply at longer wavelengths. We conclude that the spectra of these three GHRs are well explained by combinations of ionized gas, PAHs, and very small grains in various proportions and with different spatial distributions. Comparisons between observed ratios of the various UIBs with model ratios indicate that the PAHs in all three of the GHRs are dehydrogenated and that the small PAHs have been destroyed in IC 133 but have survived in NGC 595 and CC 93. The [Ne III]/[Ne II] ratios observed in IC 133 and NGC 595 are consistent with their ages of 5 and 4.5 Myr, respectively; the deduced ionization parameter is higher in IC 133, consistent with its more compact region of emission.

  4. 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 (dielectric constant and loss tangent of MAPTMS sol-gel films were measured over a wide range of microwave frequencies. The test structures were prepared by spin-coating sol-gel films onto metallized glass substrates. The dielectric properties of the sol-gel were probed with several different sets of coplanar waveguides (CPWs) electroplated onto sol-gel films. The dielectric constant and loss-tangent of these films were determined to be ˜3.1 and 3 x 10-3 at 35GHz. These results are very promising indicating that sol-gels are viable cladding materials for high-speed electro-optic polymer modulators (>40GHz).

  5. Towards mid-infrared fiber-optic devices and systems for sensing, mapping and imaging

    Science.gov (United States)

    Jayasuriya, D.; Wilson, B.; Furniss, D.; Tang, Z.; Barney, E.; Benson, T. M.; Seddon, A. B.

    2016-03-01

    Novel chalcogenide glass-based fiber opens up the mid-infrared (MIR) range for real-time monitoring and control in medical diagnostics and chemical processing. Fibers with long wavelength cut-off are of interest here. Sulfide, selenide and telluride based chalcogenide glass are candidates, but there are differences in their glass forming region, thermal stability and in the short and long wavelength cut-off positions. In general sulfide and selenide glasses have greater glass stability, but shorter long-wavelength cut-off edge, compared to telluride glasses; selenide-telluride glasses are a good compromise. Low optical loss selenide-telluride based long wavelength fibers could play a substantial role in improving medical diagnostic systems, chemical sensing, and processing, and in security and agriculture. For biological tissue, the molecular finger print lies between ~3-15 μm wavelengths in the MIR region. Using MIR spectral mapping, information about diseased tissue may be obtained with improved accuracy and in vivo using bright broadband MIR super-continuum generation (SCG) fiber sources and low optical loss fiber for routing. The Ge-As-Se-Te chalcogenide glass system is a potential candidate for both MIR SCG and passive-routing fiber, with good thermal stability, wide intrinsic transparency from ~1.5 to 20 μm and low phonon energy. This paper investigates Ge-As-Se-Te glass system pairs for developing high numerical aperture (NA) small-core, step-index optical fiber for MIR SCG and low NA passive step-index optical fiber for an in vivo fiber probe. Control of fiber geometry of small-core optical fiber and methods of producing the glass material are also included in this paper.

  6. Efficient femtosecond mid-infrared pulse generation by dispersivewave radiation in bulk lithium niobate crystal

    DEFF Research Database (Denmark)

    Zhou, Binbin; Guo, Hairun; Bache, Morten

    2014-01-01

    We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm.......We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm....

  7. Mid-infrared lasers for energy frontier plasma accelerators

    Directory of Open Access Journals (Sweden)

    I. V. Pogorelsky

    2016-09-01

    Full Text Available Plasma wake field accelerators driven with solid-state near-IR lasers have been considered as an alternative to conventional rf accelerators for next-generation TeV-class lepton colliders. Here, we extend this study to the mid-IR spectral domain covered by CO_{2} lasers. We conclude that the increase in the laser driver wavelength favors the regime of laser wake field acceleration with a low plasma density and high electric charge. This regime is the most beneficial for gamma colliders to be converted from lepton colliders via inverse Compton scattering. Selecting a laser wavelength to drive a Compton gamma source is essential for the design of such a machine. The revealed benefits from spectral diversification of laser drivers for future colliders and off-spring applications validate ongoing efforts in advancing the ultrafast CO_{2} laser technology.

  8. Mid-infrared lasers for energy frontier plasma accelerators

    Science.gov (United States)

    Pogorelsky, I. V.; Polyanskiy, M. N.; Kimura, W. D.

    2016-09-01

    Plasma wake field accelerators driven with solid-state near-IR lasers have been considered as an alternative to conventional rf accelerators for next-generation TeV-class lepton colliders. Here, we extend this study to the mid-IR spectral domain covered by CO2 lasers. We conclude that the increase in the laser driver wavelength favors the regime of laser wake field acceleration with a low plasma density and high electric charge. This regime is the most beneficial for gamma colliders to be converted from lepton colliders via inverse Compton scattering. Selecting a laser wavelength to drive a Compton gamma source is essential for the design of such a machine. The revealed benefits from spectral diversification of laser drivers for future colliders and off-spring applications validate ongoing efforts in advancing the ultrafast CO2 laser technology.

  9. Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy.

    Science.gov (United States)

    Palukuru, Uday P; Hanifi, Arash; McGoverin, Cushla M; Devlin, Sean; Lelkes, Peter I; Pleshko, Nancy

    2016-07-05

    Disease or injury to articular cartilage results in loss of extracellular matrix components which can lead to the development of osteoarthritis (OA). To better understand the process of disease development, there is a need for evaluation of changes in cartilage composition without the requirement of extensive sample preparation. Near infrared (NIR) spectroscopy is a chemical investigative technique based on molecular vibrations that is increasingly used as an assessment tool for studying cartilage composition. However, the assignment of specific molecular vibrations to absorbance bands in the NIR spectrum of cartilage, which arise from overtones and combinations of primary absorbances in the mid infrared (MIR) spectral region, has been challenging. In contrast, MIR spectroscopic assessment of cartilage is well-established, with many studies validating the assignment of specific bands present in MIR spectra to specific molecular vibrations. In the current study, NIR imaging spectroscopic data were obtained for compositional analysis of tissues that served as an in vitro model of OA. MIR spectroscopic data obtained from the identical tissue regions were used as the gold-standard for collagen and proteoglycan (PG) content. MIR spectroscopy in transmittance mode typically requires a much shorter pathlength through the sample (≤10 microns thick) compared to NIR spectroscopy (millimeters). Thus, this study first addressed the linearity of small absorbance bands in the MIR region with increasing tissue thickness, suitable for obtaining a signal in both the MIR and NIR regions. It was found that the linearity of specific, small MIR absorbance bands attributable to the collagen and PG components of cartilage (at 1336 and 856 cm(-1), respectively) are maintained through a thickness of 60 μm, which was also suitable for NIR data collection. MIR and NIR spectral data were then collected from 60 μm thick samples of cartilage degraded with chondroitinase ABC as a model

  10. Use of photoacoustic mid-infrared spectroscopy to characterize soil properties and soil organic matter stability

    Science.gov (United States)

    Peltre, Clement; Bruun, Sander; Du, Changwen; Stoumann Jensen, Lars

    2014-05-01

    The persistence of soil organic matter (SOM) is recognized as a major ecosystem property due to its key role in earth carbon cycling, soil quality and ecosystem services. SOM stability is typically studied using biological methods such as measuring CO2-C evolution from microbial decomposition of SOM during laboratory incubation or by physical or chemical fractionation methods, allowing the separation of a labile fraction of SOM. However these methods are time consuming and there is still a need for developing reliable techniques to characterize SOM stability, providing both quantitative measurements and qualitative information, in order to improve our understanding of the mechanisms controlling SOM persistence. Several spectroscopic techniques have been used to characterize and predict SOM stability, such as near infrared reflectance spectroscopy (NIRS) and diffuse reflectance mid-infrared spectroscopy (DRIFT). The latter allows a proper identification of spectral regions corresponding to vibrations of specific molecular or functional groups associated with SOM lability. However, reflectance spectroscopy for soil analyses raises some difficulties related to the low reflectance of soils, and to the high influence of particle size. In the last three decades, the progresses in microphone sensitivity dramatically increased the performance of photoacoustic Fourier transform mid-infrared spectroscopy (FTIR-PAS). This technique offers benefits over reflectance spectroscopy techniques, because particle size and the level of sample reflectance have little effect of on the PAS signal, since FTIR-PAS is a direct absorption technique. Despite its high potential for soil analysis, only a limited number of studies have so far applied FTIR-PAS for soil characterization and its potential for determining SOM degradability still needs to be investigated. The objective of this study was to assess the potential of FTIR-PAS for the characterization of SOM decomposability during

  11. Femtosecond few-cycle mid-infrared laser pulses

    DEFF Research Database (Denmark)

    Liu, Xing

    efficiency is possible for a high effective soliton order. The near-IR self-defocusing soliton can form in a quadratic nonlinear crystal (beta-barium borate) in the normal dispersion regime due to cascaded (phase-mismatched) second-harmonic generation, and the mid-IR converted wave is formed in the anomalous...... a large nonlinear Kerr coefficient and two zero dispersion wavelengths giving broadband anomalous dispersion centered around the pump wavelength. This is achieved by slightly increasing the silicon content over stoichiometric silicon nitride and waveguide geometry engineering. The spectral broadening...

  12. Establishing the mid-infrared selection of AGN

    Science.gov (United States)

    Haas, Martin; Chini, Rolf; Huchra, John P.; Leipski, Christian; Mueller, Sven A. H.; Ott, Stephan; Schartel, Norbert; Siebenmorgen, Ralf; Wilkes, Belinda

    2004-09-01

    Since a large fraction of AGN is missed in common UV-excess surveys, and even in radio, near-IR and X-ray surveys, we have searched for AGN via mid-IR emission from their nuclear dust at T>300 K. This is a new AGN selection technique, and one not affected by extinction. Among 3000 high galactic latitude sources randomly detected by ISO at 6.7 microns we have discovered a population of extremly infra-red, mostly unknown objects. This population is not detected on IRAS-ADDSCANs and very few of these sources show up in the NVSS and FIRST radio surveys. Various colour criteria from 2MASS and optical wavebands and the comparison with known object types show that the sources have a higher MIR excess than those seen in the ELAIS survey. Our analysis suggests that we have, in fact, found AGN with a pronounced MIR emission. We estimate that, if this is true, the number counts of AGN will have to be revised dramatically upwards. In order to verify our hypothesis on the AGN nature of the sources, we have selected MIR-excess AGN candidates with unknown classification from our ISO survey. First results from optical spectrocopy show some to be AGN, but also that many of the sources are extremely reddened. Therefore, we here apply for 5-40 micron IRS spectroscopy of 30 of the remaining unidentified sources to establish their nature as AGN, to determine the fraction of type 1 and 2 AGN among this MIR selected sample, and to constrain their additional starburst contribution. While new IR surveys from Spitzer are expected to find more such interesting objects, we have already identified a promising sample. The requested observations will make a significant contribution to the debate on the entire AGN population.

  13. The Mid-Infrared Extinction Law in the Large Magellanic Cloud

    CERN Document Server

    Gao, Jian; Li, Aigen; Xue, M Y

    2013-01-01

    Based on the photometric data from the Spitzer/SAGE survey and with red giants as the extinction tracers, the mid-infrared (MIR) extinction laws in the Large Magellanic Cloud (LMC) are derived for the first time in the form of A_\\lambda/A_Ks, the extinction in the four IRAC bands (i.e., [3.6], [4.5], [5.8] and [8.0]um) relative to the 2MASS Ks band at 2.16um. We obtain the near-infrared (NIR) extinction coefficient to be E(J-H)/E(H-Ks)=1.29\\pm0.04 and E(J-Ks)/E(H-Ks)=1.94\\pm0.04. The wavelength dependence of the MIR extinction A_\\lambda/A_Ks in the LMC varies from one sightline to another. The overall mean MIR extinction is A_[3.6]/A_Ks=0.72\\pm0.03, A_[4.5]/A_Ks=0.94\\pm0.03, A_[5.8]/A_Ks=0.58\\pm0.04, and A_[8.0]/A_Ks=0.62\\pm0.05. Except for the extinction in the IRAC [4.5] band which may be contaminated by the 4.6um CO gas absorption of red giants (which are used to trace the LMC extinction), the extinction in the other three IRAC bands show a flat curve, close to the Milky Way Rv = 5.5 model extinction curve...

  14. The Spatial Extent of (U)LIRGs in the Mid-infrared. I. The Continuum Emission

    Science.gov (United States)

    Díaz-Santos, T.; Charmandaris, V.; Armus, L.; Petric, A. O.; Howell, J. H.; Murphy, E. J.; Mazzarella, J. M.; Veilleux, S.; Bothun, G.; Inami, H.; Appleton, P. N.; Evans, A. S.; Haan, S.; Marshall, J. A.; Sanders, D. B.; Stierwalt, S.; Surace, J. A.

    2010-11-01

    We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey sample based on 5-15 μm low-resolution spectra obtained with the Infrared Spectrograph on Spitzer. We calculate the fraction of extended emission (FEE) as a function of wavelength for the galaxies in the sample, FEEλ, defined as the fraction of the emission which originates outside of the unresolved component of a source at a given distance. We find that the FEEλ varies from one galaxy to another, but we can identify three general types of FEEλ: one where FEEλ is constant, one where features due to emission lines and polycyclic aromatic hydrocarbons appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7 μm. More than 30% of the galaxies have a median FEEλ larger than 0.5, implying that at least half of their MIR emission is extended. Luminous Infrared Galaxies (LIRGs) display a wide range of FEE in their warm dust continuum (0 ~ 1011.25 L sun strongly increases in those classified as mergers in their final stage of interaction. The FEE13.2 μm is also related to the contribution of an active galactic nucleus (AGN) to the MIR emission. Galaxies which are more AGN dominated are less extended, independently of their L IR. We finally find that the extent of the MIR continuum emission is correlated with the far-IR IRAS log(f 60 μm/f 100 μm) color. This enables us to place a lower limit to the area in a galaxy from where the cold dust emission may originate, a prediction which can be tested soon with the Herschel Space Telescope.

  15. The mid-infrared polarization of the Herbig Ae star WL 16: an interstellar origin?

    Science.gov (United States)

    Zhang, Han; Telesco, Charles M.; Pantin, Eric; Li, Dan; Wright, Christopher M.; Mariñas, Naibí; Barnes, Peter; Li, Aigen; Packham, Christopher

    2017-03-01

    We present high-resolution (0.4 arcsec) mid-infrared (mid-IR) polarimetric images and spectra of WL 16, a Herbig Ae star at a distance of 125 pc. WL 16 is surrounded by a protoplanetary disc of ∼ 900 au in diameter, making it one of the most extended Herbig Ae/Be discs as seen in the mid-IR. The star is behind, or embedded in, the ρ Ophiuchus molecular cloud, and obscured by 28 mag of extinction at optical wavelengths by the foreground cloud. Mid-IR polarization of WL 16 mainly arises from aligned elongated dust grains present along the line of sight, suggesting a uniform morphology of polarization vectors with an orientation of 33°(east from north) and a polarization fraction of ∼ 2.0 per cent. This orientation is consistent with previous polarimetric surveys in the optical and near-IR bands to probe large-scale magnetic fields in the Ophiuchus star formation region, indicating that the observed mid-IR polarization towards WL 16 is produced by the dichroic absorption of magnetically aligned foreground dust grains by a uniform magnetic field. Using polarizations of WL 16 and Elias 29, a nearby polarization standard star, we constrain the polarization efficiency, p10.3/A10.3, for the dust grains in the ρ Ophiuchus molecular cloud to be ≃1.0 per cent mag-1. WL 16 has polycyclic aromatic hydrocarbon (PAH) emission features detected at 8.6, 11.2, 12.0, and 12.7 μm by our spectroscopic data, and we find an anticorrelation between the PAH surface brightness and the PAH ionization fraction between the north-west and south-west sides of the disc.

  16. Spitzer mid-infrared spectra of cool-core galaxy clusters

    NARCIS (Netherlands)

    G.E. de Messières; R.W. O'Connell; B.R. McNamara; M. Donahue; P.E.J. Nulsen; G.M. Voit; M.W. Wise; B. Smith; J. Higdon; S. Higdon; N. Bastian

    2009-01-01

    We have obtained mid-infrared spectra of nine cool-core galaxy clusters with the Infrared Spectrograph aboard the Spitzer Space Telescope. X-ray, ultraviolet and optical observations have demonstrated that each of these clusters hosts a cooling flow which seems to be fueling vigorous star formation

  17. Supercontinuum - broad as a lamp, bright as a laser, now in the mid-infrared

    DEFF Research Database (Denmark)

    Moselund, Peter M.; Petersen, Christian; Dupont, Sune

    2012-01-01

    Based on the experience gained developing our market leading visible spectrum supercontinuum sources NKT Photonics has built the first mid-infrared supercontinuum source based on modelocked picosecond fiber lasers. The source is pumped by a ≈ 2 um laser based on a combination of erbium and thuliu...

  18. Conductive Oxides Trench Structures as Hyperbolic Metamaterials in Mid-infrared Range

    DEFF Research Database (Denmark)

    Takayama, Osamu; Shkondin, Evgeniy; Panah, Mohammad Esmail Aryaee;

    ,2]. Moreover plasmonics for mid-infrared offer unique applications such as bio-sensing, thermal imaging and quest for novel materials and structures has been continuing [3]. In this report we show that vertical trench structures made of, for example, aluminum-doped ZnO (AZO) or other transparent conductive...

  19. 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...

  20. Mid-infrared plasmonic resonances exploiting heavily-doped Ge on Si

    Science.gov (United States)

    Biagioni, P.; Sakat, E.; Baldassarre, L.; Calandrini, E.; Samarelli, A.; Gallacher, K.; Frigerio, J.; Isella, G.; Paul, D. J.; Ortolani, M.

    2015-03-01

    We address the behavior of mid-infrared localized plasmon resonances in elongated germanium antennas integrated on silicon substrates. Calculations based on Mie theory and on the experimentally retrieved dielectric constant allow us to study the tunability and the figures of merit of plasmon resonances in heavily-doped germanium and to preliminarily compare them with those of the most established plasmonic material, gold.

  1. Near-Infrared Versus Mid-Infrared for the Quantitative and Qualitative Analysis of Soils

    Science.gov (United States)

    Over several decades, near-infrared reflectance spectroscopy has been shown to be extremely versatile for the rapid analysis of many agricultural materials including forages, foods and grains. More recently, mid-infrared and near-infrared diffuse reflectance spectroscopy (DRIFTS and NIRS, respective...

  2. Near- and Mid-Infrared Reflectance Spectroscopy for the Quantitative and Qualitative Analysis of Agricultural Products

    Science.gov (United States)

    For several decades near-infrared diffuse reflectance spectroscopy (NIRS) has been used to determine the composition of a variety of agricultural products. More recently, diffuse reflectance Fourier transform mid-infrared spectroscopy (DRIFTS) has similarly been shown to be able to determine the co...

  3. The obscured mid-infrared continuum of NGC 4418 : A dust- and ice-enshrouded AGN

    NARCIS (Netherlands)

    Spoon, HWW; Keane, JV; Tielens, AGGM; Lutz, D; Moorwood, AFM

    2001-01-01

    We report the detection of absorption features in the 6-8 mum region superimposed on a featureless mid-infrared continuum in NGC 4418. For several of these features this is the first detection in an external galaxy We compare the absorption spectrum of NGC4418 to that; of embedded massive protostars

  4. Mid-infrared emission of galactic nuclei - TIMMI2 versus ISO observations and models

    NARCIS (Netherlands)

    Siebenmorgen, R; Krugel, E; Spoon, HWW

    2004-01-01

    We investigate the mid-infrared radiation of galaxies that are powered by a starburst or by an AGN. For this end, we compare the spectra obtained at different spatial scales in a sample of infrared bright galaxies. ISO observations which include emission of the nucleus as well as most of the host ga

  5. Mid-infrared lasers: Challenges imposed by the population dynamics of the gain system

    NARCIS (Netherlands)

    Pollnau, Markus

    2010-01-01

    This paper discusses the influence of the population dynamics on mid-infrared lasers. Specifically, the typically longer lifetime of the lower compared to the upper laser level has to be addressed in order to achieve highly efficient laser operation in this wavelength range. Examples of different

  6. A robust and tuneable mid-infrared optical switch enabled by bulk Dirac fermions

    Science.gov (United States)

    Zhu, Chunhui; Wang, Fengqiu; Meng, Yafei; Yuan, Xiang; Xiu, Faxian; Luo, Hongyu; Wang, Yazhou; Li, Jianfeng; Lv, Xinjie; He, Liang; Xu, Yongbing; Liu, Junfeng; Zhang, Chao; Shi, Yi; Zhang, Rong; Zhu, Shining

    2017-01-01

    Pulsed lasers operating in the mid-infrared (3-20 μm) are important for a wide range of applications in sensing, spectroscopy, imaging and communications. Despite recent advances with mid-infrared gain platforms, the lack of a capable pulse generation mechanism remains a significant technological challenge. Here we show that bulk Dirac fermions in molecular beam epitaxy grown crystalline Cd3As2, a three-dimensional topological Dirac semimetal, constitutes an exceptional ultrafast optical switching mechanism for the mid-infrared. Significantly, we show robust and effective tuning of the scattering channels of Dirac fermions via an element doping approach, where photocarrier relaxation times are found flexibly controlled over an order of magnitude (from 8 ps to 800 fs at 4.5 μm). Our findings reveal the strong impact of Cr doping on ultrafast optical properties in Cd3As2 and open up the long sought parameter space crucial for the development of compact and high-performance mid-infrared ultrafast sources.

  7. Cross-phase modulation in visible-pump/mid-infrared-probe spectroscopy

    Science.gov (United States)

    Lapini, Andrea; Vázquez, Sandra Mosquera; Touceda, Patricia Tourón; Lima, Manuela

    2011-05-01

    One of the most powerful tools to investigate the structural dynamics of electronically excited molecular systems is visible-pump/mid-infrared-probe spectroscopy. When performing this kind of experiments one must be aware of the artifacts deriving from the non-linear response of the solvent and of the sample cell itself. Cross-phase modulation (XPM) is observed when a strong visible-pump pulse modulates the refraction index seen by the mid-infrared-probe. The effect is enhanced when the probe pulse is chirped and causes the distortion of the transient signal in both the frequency and the time domains. We undertook a detailed simulation of XPM in the mid-infrared region where a visible pulse modulates the MIR pulse by XPM and in close conditions to the experimental ones. Our simulation takes into account the different group velocities of the pump and probe pulses and includes the influence of the linear chirp of the mid-infrared pulse and its asymmetry. The results of our numerical calculations fit very well the experimental signals measured in a 2 mm thick CaF 2 window.

  8. Efficient Mid-Infrared Supercontinuum Generation in Tapered Large Mode Area Chalcogenide Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Petersen, Christian Rosenberg; Engelsholm, Rasmus Dybbro; Markos, Christos

    2017-01-01

    Mid-infrared supercontinuum spanning from 1.8-9  μm with an output power of 41.5 mW is demonstrated by pumping tapered large mode area chalcogenide photonic crystal fibers using a 4 μm optical parametric source....

  9. High Average Power Mid-infrared Supercontinuum Generation in a Suspended Core Chalcogenide Fiber

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Yu, Yi; Petersen, Christian Rosenberg

    2014-01-01

    Mid-infrared supercontinuum spanning from 2.0 to 6.1 μm is generated in a 9 cm suspended core chalcogenide fiber by pumping close to the fiber zero-dispersion wavelength at 3.5 μm with an OPA system...

  10. High Average Power Mid-infrared Supercontinuum Generation in a Suspended Core Chalcogenide Fiber

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Yu, Yi; Petersen, Christian Rosenberg;

    2014-01-01

    Mid-infrared supercontinuum spanning from 2.0 to 6.1 μm is generated in a 9 cm suspended core chalcogenide fiber by pumping close to the fiber zero-dispersion wavelength at 3.5 μm with an OPA system...

  11. Mid-infrared ultra-high-Q resonators based on fluoride crystalline materials

    Science.gov (United States)

    Lecaplain, C.; Javerzac-Galy, C.; Gorodetsky, M. L.; Kippenberg, T. J.

    2016-11-01

    The unavailability of highly transparent materials in the mid-infrared has been the main limitation in the development of ultra-sensitive molecular sensors or cavity-based spectroscopy applications. Whispering gallery mode microresonators have attained ultra-high-quality (Q) factor resonances in the near-infrared and visible. Here we report ultra-high Q factors in the mid-infrared using polished alkaline earth metal fluoride crystals. Using an uncoated chalcogenide tapered fibre as a high-ideality coupler in the mid-infrared, we study via cavity ringdown technique the losses of BaF2, CaF2, MgF2 and SrF2 microresonators. We show that MgF2 is limited by multiphonon absorption by studying the temperature dependence of the Q factor. In contrast, in SrF2 and BaF2 the lower multiphonon absorption leads to ultra-high Q factors at 4.5 μm. These values correspond to an optical finesse of , the highest value achieved for any type of mid-infrared resonator to date.

  12. Rugged and compact mid-infrared solid-state laser for avionics applications

    CSIR Research Space (South Africa)

    Esser, MJD

    2009-11-01

    Full Text Available In order to demonstrate the feasibility of a helicopter-based application using advanced laser technology, the authors have developed a rugged and compact mid-infrared solid-state laser. The requirement for the laser was to simultaneously emit at 2...

  13. Pulse Wavelength Scan of Room-Temperature Mid-Infrared Distributed Feedback Quantum Cascade Lasers for N2O Gas Detection

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-Gang; XU Gang-Yi; LI Ai-Zhen; LI Yao-Yao; GU Yi; LIU Sheng; WEI Lin

    2006-01-01

    @@ The tunable diode laser absorption spectroscopy under a pulse wavelength scan scheme is adapted to home-made room-temperature mid-infrared distributed feedback quantum cascade lasers; and identification of N2 O spectral fingerprint is demonstrated experimentally. By driving the laser at 800ns pulse duration, a wave number tuning of about 1.6 cm- 1 is produced, which make both 1289.04 cm- 1 and 1289.86 cm- 1 absorption fingerprints of N2 O gas to be definitely assigned. The measured relative absorption intensity is consistent with the HITRAN data precisely.

  14. Damage threshold and focusability of mid-infrared free-electron laser pulses gated by a plasma mirror with nanosecond switching pulses

    CERN Document Server

    Wang, Xiaolong; Zen, Heishun; Kii, Toshiteru; Ohgaki, Hideaki

    2013-01-01

    The presence of a pulse train structure of an oscillator-type free-electron laser (FEL) results in the immediate damage of a solid target upon focusing. We demonstrate that the laser-induced damage threshold can be significantly improved by gating the mid-infrared (MIR) FEL pulses with a plasma mirror. Although the switching pulses we employ have a nanosecond duration which does not guarantee the clean wavefront of the gated FEL pulses, the high focusablity is experimentally confirmed through the observation of spectral broadening by a factor of 2.1 when we tightly focus the gated FEL pulses onto the Ge plate.

  15. Mid-Infrared interferometry of dust around massive evolved stars

    CERN Document Server

    Rajagopal, Jayadev; Wallace, D; Danchi, W C; Chesneau, O; López, B; Monnier, J D; Ireland, M; Tuthill, P G

    2007-01-01

    We report long-baseline interferometric measurements of circumstellar dust around massive evolved stars with the MIDI instrument on the Very Large Telescope Interferometer and provide spectrally dispersed visibilities in the 8-13 micron wavelength band. We also present diffraction-limited observations at 10.7 micron on the Keck Telescope with baselines up to 8.7 m which explore larger scale structure. We have resolved the dust shells around the late type WC stars WR 106 and WR 95, and the enigmatic NaSt1 (formerly WR 122), suspected to have recently evolved from a Luminous Blue Variable (LBV) stage. For AG Car, the protoypical LBV in our sample, we marginally resolve structure close to the star, distinct from the well-studied detached nebula. The dust shells around the two WC stars show fairly constant size in the 8-13 micron MIDI band, with gaussian half-widths of ~ 25 to 40 mas. The compact dust we detect around NaSt1 and AG Car favors recent or ongoing dust formation. Using the measured visibilities, we bu...

  16. The near-to-mid infrared spectrum of quasars

    CERN Document Server

    Hernán-Caballero, Antonio; Alonso-Herrero, Almudena; Mateos, Silvia

    2016-01-01

    We analyse a sample of 85 luminous L3um > 10^45.5 erg/s quasars with restframe ~2-11um spectroscopy from AKARI and Spitzer. Their high luminosity allows a direct determination of the near-infrared quasar spectrum free from host galaxy emission. A semi-empirical model consisting of a single template for the accretion disk and two blackbodies for the dust emission successfully reproduces the 0.1-10um spectral energy distributions (SEDs). Excess emission at 1-2um over the best-fitting model suggests that hotter dust is necessary in addition to the ~1200K blackbody and the disk to reproduce the entire near-infrared spectrum. Variation in the extinction affecting the disk and in the relative strength of the disk and dust components accounts for the diversity of individual SEDs. Quasars with higher dust-to-disk luminosity ratios show slightly redder infrared continua and less prominent silicate emission. We find no luminosity dependence in the shape of the average infrared quasar spectrum. The equivalent width of P...

  17. Definition of spectrally separable classes for soil survey research

    Science.gov (United States)

    Cipra, J. E.; Swain, P. H.; Gill, J. H.; Baumgardner, M. F.; Kristof, S. J.

    1972-01-01

    A procedure is outlined for defining spectral classes such that the differences between classes can be quantified. It also facilitates determination of a number of classes such that the classes are spectrally discriminable. This is accomplished by partitioning the data into many classes and then combining similar spectral classes on the basis of appropriate criteria. Multispectral data were collected over a 12-mile flightline in White County, Indiana, in connection with the 1971 Corn Blight Watch Experiment. Data were collected in May by the University of Michigan airborne scanning spectrometer at an altitude of 5000 feet. Spectral maps resulting from the analysis were compared to existing soil surveys of the National Cooperative Soil Survey. The method should help determine the extent to which spectral properties of soil surfaces can be associated with morphologic and topographic differences of interest to soil surveyors engaged in operational soil mapping.

  18. Eight-Dimensional Mid-Infrared/Optical Bayesian Quasar Selection

    CERN Document Server

    Richards, Gordon T; Lacy, Mark; Myers, Adam D; Nichol, Robert C; Zakamska, Nadia L; Brunner, Robert J; Brandt, W N; Gray, Alexander G; Parejko, John K; Ptak, Andrew; Schneider, Donald P; Storrie-Lombardi, Lisa J; Szalay, Alexander S

    2008-01-01

    We explore the multidimensional, multiwavelength selection of quasars from mid-IR (MIR) plus optical data, specifically from Spitzer-IRAC and the Sloan Digital Sky Survey (SDSS). We apply modern statistical techniques to combined Spitzer MIR and SDSS optical data, allowing up to 8-D color selection of quasars. Using a Bayesian selection method, we catalog 5546 quasar candidates to an 8.0um depth of 56uJy over an area of ~24 sq. deg; ~70% of these candidates are not identified by applying the same Bayesian algorithm to 4-color SDSS optical data alone. Our selection recovers 97.7% of known type 1 quasars in this area and greatly improves the effectiveness of identifying 3.5

  19. Mid-Infrared OPO for High Resolution Measurements of Trace Gases in the Mars Atmosphere

    Science.gov (United States)

    Yu, Anthony W.; Numata,Kenji; Riris, haris; Abshire, James B.; Allan, Graham; Sun, Xiaoli; Krainak, Michael A.

    2008-01-01

    The Martian atmosphere is composed primarily (>95%) of CO2 and N2 gas, with CO, O2, CH4, and inert gases such as argon comprising most of the remainder. It is surprisingly dynamic with various processes driving changes in the distribution of CO2, dust, haze, clouds and water vapor on global scales in the meteorology of Mars atmosphere [I]. The trace gases and isotopic ratios in the atmosphere offer important but subtle clues as to the origins of the planet's atmosphere, hydrology, geology, and potential for biology. In the search for life on Mars, an important process is the ability of bacteria to metabolize inorganic substrates (H2, CO2 and rock) to derive energy and produce methane as a by-product of anaerobic metabolism. Trace gases have been measured in the Mars atmosphere from Earth, Mars orbit, and from the Mars surface. The concentration of water vapor and various carbon-based trace gases are observed in variable concentrations. Within the past decade multiple groups have reported detection of CH4, with concentrations in the 10's of ppb, using spectroscopic observations from Earth [2]. Passive spectrometers in the mid-infrared (MIR) are restricted to the sunlit side of the planet, generally in the mid latitudes, and have limited spectral and spatial resolution. To accurately map the global distribution and to locate areas of possibly higher concentrations of these gases such as plumes or vents requires an instrument with high sensitivity and fine spatial resolution that also has global coverage and can measure during both day and night. Our development goal is a new MIR lidar capable of measuring, on global scales, with sensitivity, resolution and precision needed to characterize the trace gases and isotopic ratios of the Martian atmosphere. An optical parametric oscillator operating in the MIR is well suited for this instrument. The sufficient wavelength tuning range of the OPO can extend the measurements to other organic molecules, CO2, atmospheric water

  20. Young stellar object variability (YSOVAR): Long timescale variations in the mid-infrared

    Energy Technology Data Exchange (ETDEWEB)

    Rebull, L. M.; Cody, A. M.; Stauffer, J. R.; Morales-Calderón, M.; Carey, S. J. [Spitzer Science Center (SSC), Infrared Processing and Analysis Center (IPAC), 1200 East California Boulevard, California Institute of Technology, Pasadena, CA 91125 (United States); Covey, K. R. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Günther, H. M.; Poppenhaeger, K.; Wolk, S. J.; Hora, J. L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Plavchan, P. [NASA Exoplanet Science Institute (NExScI), Infrared Processing and Analysis Center (IPAC), 1200 East California Boulevard, California Institute of Technology, Pasadena, CA 91125 (United States); Gutermuth, R. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Song, I. [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States); Barrado, D. [Departamento de Astrofísica, Centro de Astrobiología (INTA-CSIC), ESAC campus, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Bayo, A. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); James, D. [Cerro Tololo InterAmerican Observatory (CTIO), Casilla 603, La Serena (Chile); Vrba, F. J. [US Naval Observatory, Flagstaff Station 10391 West Naval Observatory Road, Flagstaff, AZ 86005 (United States); Alves de Oliveira, C. [European Space Agency (ESA/ESAC), P.O. Box 78, E-28691 Villanueva de la Caãda, Madrid (Spain); Bouvier, J., E-mail: rebull@ipac.caltech.edu [Univ. Grenoble Alpes, IPAG, F-38000 Grenoble (France); and others

    2014-11-01

    The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (3.6 and 4.5 μm) time series photometry of the Orion Nebula Cluster plus smaller footprints in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ∼29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. We present the data collection and reduction for the Spitzer and ancillary data, and define the 'standard sample' on which we calculate statistics, consisting of fast cadence data, with epochs roughly twice per day for ∼40 days. We also define a 'standard sample of members' consisting of all the IR-selected members and X-ray-selected members. We characterize the standard sample in terms of other properties, such as spectral energy distribution shape. We use three mechanisms to identify variables in the fast cadence data—the Stetson index, a χ{sup 2} fit to a flat light curve, and significant periodicity. We also identified variables on the longest timescales possible of six to seven years by comparing measurements taken early in the Spitzer mission with the mean from our YSOVAR campaign. The fraction of members in each cluster that are variable on these longest timescales is a function of the ratio of Class I/total members in each cluster, such that clusters with a higher fraction of Class I objects also have a higher fraction of long-term variables. For objects with a YSOVAR-determined period and a [3.6]-[8] color, we find that a star with a longer period is more likely than those with shorter periods to have an IR excess. We do not find any evidence for variability that causes [3.6]-[4.5] excesses to appear or vanish within our data set; out of members and field objects combined, at most 0.02% may have transient IR excesses.

  1. Generation of broadband mid-infrared supercontinuum radiation in cascaded soft-glass fibers

    Science.gov (United States)

    Kneis, C.; Robin, T.; Cadier, B.; Brilland, Laurent; Caillaud, Celine; Troles, Johann; Manek-Hönninger, I.; Eichhorn, M.; Kieleck, C.

    2016-03-01

    The generation of mid-infrared (mid-IR) radiation, ranging from 2 - 5 μm, is getting much attention in recent years thanks to many applications it can be used for, e.g. in free space optical communication, range finding, counter measures and remote chemical sensing systems. It also plays an increasing role in medicine, for instance in optical tissue ablation or optical coherence tomography, owing to the high water absorption in that wavelength range. In this research study, a ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fluoride fiber is pumped by a Q-switched mode-locked (QML) thulium (Tm3+)- doped double-clad silica fiber laser, emitting at around 2 μm, to generate mid-IR supercontinuum (SC). Further spectral broadening of this SC radiation is achieved by coupling it into a chalcogenide arsenide-selenide (AsSe) photonic crystal fiber (PCF). An output power of 24 W at 2 μm has been achieved in QML operation for the Tm3+-doped fiber laser. The SC output power from the ZBLAN fiber has been 7.8 W with a spectrum extending to approximately 4.1 μm. For further wavelength broadening experiments, a long-wave-pass filter with a 3 dB edge around 3.6 μm has been implemented between the ZBLAN and the AsSe fiber to cut out the residual pump light at 2 μm and the radiation between 2 μm and 3.5 μm. The pump power was approximately 120 mW with a spectrum from 3.5 μm to 3.9 μm. First proof of principal experiments has been performed with 20 mW of averaged output power and a spectrum extending to 4.9 μm. The coupling efficiency of the SC radiation from the ZBLAN fiber into the AsSe fiber has been around 30%.

  2. Mid-infrared prediction of lactoferrin content in bovine milk: potential indicator of mastitis.

    Science.gov (United States)

    Soyeurt, H; Bastin, C; Colinet, F G; Arnould, V M-R; Berry, D P; Wall, E; Dehareng, F; Nguyen, H N; Dardenne, P; Schefers, J; Vandenplas, J; Weigel, K; Coffey, M; Théron, L; Detilleux, J; Reding, E; Gengler, N; McParland, S

    2012-11-01

    Lactoferrin (LTF) is a milk glycoprotein favorably associated with the immune system of dairy cows. Somatic cell count is often used as an indicator of mastitis in dairy cows, but knowledge on the milk LTF content could aid in mastitis detection. An inexpensive, rapid and robust method to predict milk LTF is required. The aim of this study was to develop an equation to quantify the LTF content in bovine milk using mid-infrared (MIR) spectrometry. LTF was quantified by enzyme-linked immunosorbent assay (ELISA), and all milk samples were analyzed by MIR. After discarding samples with a coefficient of variation between 2 ELISA measurements of more than 5% and the spectral outliers, the calibration set consisted of 2499 samples from Belgium (n = 110), Ireland (n = 1658) and Scotland (n = 731). Six statistical methods were evaluated to develop the LTF equation. The best method yielded a cross-validation coefficient of determination for LTF of 0.71 and a cross-validation standard error of 50.55 mg/l of milk. An external validation was undertaken using an additional dataset containing 274 Walloon samples. The validation coefficient of determination was 0.60. To assess the usefulness of the MIR predicted LTF, four logistic regressions using somatic cell score (SCS) and MIR LTF were developed to predict the presence of mastitis. The dataset used to build the logistic regressions consisted of 275 mastitis records and 13 507 MIR data collected in 18 Walloon herds. The LTF and the interaction SCS × LTF effects were significant (P validation) and data collected from a research herd at the University of Wisconsin - Madison (i.e. 5886 Wisconsin MIR records related to 93 mastistis events - external validation). Model specificity was better when LTF was included in the regression along with SCS when compared with SCS alone. Correct classification of non-mastitis records was 95.44% and 92.05% from Wisconsin and Walloon data, respectively. The same conclusion was formulated from the

  3. Hollow glass waveguide for mid-infrared applications

    Science.gov (United States)

    Rabii, Christopher Daniel

    This study is an effort to characterize the optical and mechanical properties of hollow glass waveguides (HGWs) with inner metallic and dielectric layers. The theoretical base behind the light-guiding principle of a hollow metallic waveguide has been extended to address the optical properties of dielectric-coated hollow metallic waveguides in both straight and bent configurations. The dependencies of attenuation on bore- size, bend radius, and transmitted mode are predicted by this analysis. HGWs with silver metallic layers and silver iodide dielectric films have been fabricated in bore sizes ranging from 250 /mu m to 1000 /mu m. The spectral response has been measured, and can be arbitrarily tailored lo show minimum loss at any wavelength between 2 and 11 /mu m. Spectroscopic analysis has been used to determine the uniformity and thickness variation in the dielectric layer. Process modifications have reduced this variation from 14% to approximately 1%. The effect of laser coupling condition has been modeled, and optimum coupling occurs for spot-size to bore-size ratios between 0.55 and 0.64. These theoretical predictions have been verified using laser loss measurements on 530, 700 and 1000 /mu m bore waveguides, with the largest bore showing the least sensitivity to launch condition. Continuous CO2 laser power has been transmitted through HGWs with 250, 320, 530, and 700 /mu m bore. The 250 and 320 /mu m sizes transmitted 35 and 50 W of input power respectively, while both larger sizes successfully transmitted 85 W. Similarly, the larger scores showed the ability to transmit high pulsed energy, up to 80 J. Laser loss has been shown to be sensitive to input laser beam quality, with most sensitivity observed for small bore waveguides. The preservation of low loss and spatial purity has been achieved by increasing the wall thickness of the substrate tubing. Losses above the theoretically predicted minimum values have been attributed to scattering from film roughness

  4. The Mid-infrared Extinction Law in the Large Magellanic Cloud

    Science.gov (United States)

    Gao, Jian; Jiang, B. W.; Li, Aigen; Xue, M. Y.

    2013-10-01

    Based on photometric data from the Spitzer/SAGE survey, using red giants as extinction tracers, the mid-infrared (MIR) extinction laws in the Large Magellanic Cloud (LMC) are derived for the first time in the form of A_\\lambda /A_{K_S}. This quantity refers to the extinction in the four Infrared Array Camera (IRAC) bands (i.e., [3.6], [4.5], [5.8], and [8.0] μm) relative to the Two Micron All Sky Survey KS band at 2.16 μm. We obtain the near-infrared extinction coefficient to be E(J - H)/E(H - KS ) ≈ 1.29 ± 0.04 and E(J - KS )/E(H - KS ) ≈ 1.94 ± 0.04. The wavelength dependence of the MIR extinction A_{\\lambda }/A_{K_S} in the LMC varies from one sightline to another. The overall mean MIR extinction is A_{[3.6]}/A_{K_S}\\approx 0.72+/- 0.03, A_{[4.5]}/A_{K_S}\\approx 0.94+/- 0.03, A_{[5.8]}/A_{K_S}\\approx 0.58+/- 0.04, and A_{[8.0]}/A_{K_S}\\approx 0.62+/- 0.05. Except for the extinction in the IRAC [4.5] μm band, which may be contaminated by the 4.6 μm CO gas absorption of red giants used to trace LMC extinction, the extinction in the other three IRAC bands show a flat curve, close to the Milky Way RV = 5.5 model extinction curve, where RV is the optical total-to-selective extinction ratio. The possible systematic bias caused by the correlated uncertainties of KS - λ and J - KS is explored in terms of Monte Carlo simulations. We find that this bias could lead to an overestimation of A_{\\lambda }/A_{K_S} in the MIR.

  5. Mid-infrared prediction of bovine milk fatty acids across multiple breeds, production systems, and countries.

    Science.gov (United States)

    Soyeurt, H; Dehareng, F; Gengler, N; McParland, S; Wall, E; Berry, D P; Coffey, M; Dardenne, P

    2011-04-01

    Increasing consumer concern exists over the relationship between food composition and human health. Because of the known effects of fatty acids on human health, the development of a quick, inexpensive, and accurate method to directly quantify the fatty acid (FA) composition in milk would be valuable for milk processors to develop a payment system for milk pertinent to their customer requirements and for farmers to adapt their feeding systems and breeding strategies accordingly. The aim of this study was (1) to confirm the ability of mid-infrared spectrometry (MIR) to quantify individual FA content in milk by using an innovative procedure of sampling (i.e., samples were collected from cows belonging to different breeds, different countries, and in different production systems); (2) to compare 6 mathematical methods to develop robust calibration equations for predicting the contents of individual FA in milk; and (3) to test interest in using the FA equations developed in milk as basis to predict FA content in fat without corrections for the slope and the bias of the developed equations. In total, 517 samples selected based on their spectral variability in 3 countries (Belgium, Ireland, and United Kingdom) from various breeds, cows, and production systems were analyzed by gas chromatography (GC). The samples presenting the largest spectral variability were used to calibrate the prediction of FA by MIR. The remaining samples were used to externally validate the 28 FA equations developed. The 6 methods were (1) partial least squares regression (PLS); (2) PLS+repeatability file (REP); (3) first derivative of spectral data+PLS; (4) first derivative+REP+PLS; (5) second derivative of spectral data+PLS; and (6) second derivative+REP+PLS. Methods were compared on the basis of the cross-validation coefficient of determination (R2cv), the ratio of standard deviation of GC values to the standard error of cross-validation (RPD), and the validation coefficient of determination (R2

  6. Multi-species sensing using multi-mode absorption spectroscopy with mid-infrared interband cascade lasers

    Science.gov (United States)

    O'Hagan, S.; Northern, J. H.; Gras, B.; Ewart, P.; Kim, C. S.; Kim, M.; Merritt, C. D.; Bewley, W. W.; Canedy, C. L.; Vurgaftman, I.; Meyer, J. R.

    2016-06-01

    The application of an interband cascade laser, ICL, to multi-mode absorption spectroscopy, MUMAS, in the mid-infrared region is reported. Measurements of individual mode linewidths of the ICL, derived from the pressure dependence of lineshapes in MUMAS signatures of single, isolated, lines in the spectrum of HCl, were found to be in the range 10-80 MHz. Multi-line spectra of methane were recorded using spectrally limited bandwidths, of approximate width 27 cm-1, defined by an interference filter, and consist of approximately 80 modes at spectral locations spanning the 100 cm-1 bandwidth of the ICL output. Calibration of the methane pressures derived from MUMAS data using a capacitance manometer provided measurements with an uncertainty of 1.1 %. Multi-species sensing is demonstrated by the simultaneous detection of methane, acetylene and formaldehyde in a gas mixture. Individual partial pressures of the three gases are derived from best fits of model MUMAS signatures to the data with an experimental error of 10 %. Using an ICL, with an inter-mode interval of ~10 GHz, MUMAS spectra were recorded at pressures in the range 1-10 mbar, and, based on the data, a potential minimum detection limit of the order of 100 ppmv is estimated for MUMAS at atmospheric pressure using an inter-mode interval of 80 GHz.

  7. Taming the Invisible Monster: System Parameter Constraints for Epsilon Aurigae from the Far-Ultraviolet to the Mid-Infrared

    CERN Document Server

    Hoard, D W; Stencel, R E

    2010-01-01

    We have assembled new Spitzer Space Telescope Infrared Array Camera observations of the mysterious binary star Epsilon Aurigae, along with archival far-ultraviolet to mid-infrared data, to form an unprecedented spectral energy distribution spanning three orders of magnitude in wavelength from 0.1 microns to 100 microns. The observed spectral energy distribution can be reproduced using a three component model consisting of a 2.2+0.9/-0.8 Msun F type post-asymptotic giant branch star, and a 5.9+/-0.8 Msun B5+/-1 type main sequence star that is surrounded by a geometrically thick, but partially transparent, disk of gas and dust. At the nominal HIPPARCOS parallax distance of 625 pc, the model normalization yields a radius of 135+/-5 Rsun for the F star, consistent with published interferometric observations. The dusty disk is constrained to be viewed at an inclination of i > 87 deg, and has effective temperature of 550+/-50 K with an outer radius of 3.8 AU and a thickness of 0.95 AU. The dust content of the disk ...

  8. Ge-Sb-Se glass fiber-optics for in-vivo mid-infrared optical biopsy

    Science.gov (United States)

    Parnell, H.; Butterworth, J. H.; Sakr, H.; Tang, Z.; Furniss, D.; Benson, T. M.; Scotchford, C.; Seddon, A. B.

    2016-03-01

    In the UK, it is now recognised that 1 in 2 people born after 1960 will develop some form of cancer during their lifetime. Diagnosing patients whilst in the early stages drastically improves their chances of survival but up until now the gold standard for cancer detection is via a lengthy excision biopsy procedure, which relies on the skill of a histopathologist. Evidently, the need for a faster solution is paramount. The mid-infrared (MIR) spectral region covers the wavelengths 3-25 μm and characteristic vibrational spectra unique to each molecular type. Subtle changes in the specific spectral response within this region are indicative of changes within the cells relative to normal cells, signifying the presence or absence of a disease. Our goal is to carry out disease diagnosis in vivo. Reaching these wavelengths has previously presented difficulties as conventional MIR blackbody light sources are weak and optical fibers for transmitting MIR light to/from tissue in vivo can be limited by strong material absorption such as silica glass >2.4 μm and tellurite, and heavy metal fluoride, >4.75 μm. However, chalcogenide glasses have been shown to transmit MIR light out to 25 μm. This paper reports on a glass composition in the Ge-Sb-Se system and its suitability as an optical fiber for the transmission of MIR to and from tissue samples, enabling in vivo mapping for an immediate diagnostic response- a technique termed `optical biopsy'.

  9. The systematic spectral analysis of radio surveys

    CERN Document Server

    Harwood, Jeremy J

    2016-01-01

    Current and future continuum surveys being undertaken by the new generation of radio telescopes are now poised to address many important science questions, ranging from the earliest galaxies, to the physics of nearby AGN, as well as potentially providing new and unexpected discoveries. However, how to efficiently analyse the large quantities of data collected by these studies in order to maximise their scientific output remains an open question. In these proceedings we present details of the surveys module for the Broadband Radio Astronomy Tools (BRATS) software package which will combine new observations with existing multi-frequency data in order to automatically analyse and select sources based on their spectrum. We show how these methods can been applied to investigate objects observed on a variety of spatial scales, and suggest a pathway for how this can be used in the wider context of surveys and large samples.

  10. Signature of multi-channel interference in high-order harmonic generation from N2 driven by intense mid-infrared pulses

    CERN Document Server

    Li, Guihua; Xie, Xinhua; Xie, Hongqiang; Zeng, Bin; Chu, Wei; Jing, Chenrui; Ni, Jielei; Zhang, Haisu; Liu, Xiaojun; Chen, Jing; Cheng, Ya; Xu, Zhizhan

    2013-01-01

    We investigate the multi-electron dynamics in high-order harmonic generation (HHG) from N2 molecules. Clear spectral minima are observed in the cutoff region at all three mid-infrared wavelengths (i.e., 1300, 1400 and 1500 nm) chosen in our experiment. It is found that the positions of the spectral minima do not depend on the alignment angles of molecules. In addition, the spectral minima shift almost linearly with the increasing laser intensity at all three wavelengths, which provides a strong evidence on the dynamic multi-channel interference origin of these minima. The advantages of observation of dynamic multi-channel interference based on HHG driven by long wavelength lasers are discussed.

  11. Mid-infrared diffuse reflectance spectroscopic examination of charred pine wood, bark, cellulose, and lignin: Implications for the quantitative determination of charcoal in soils

    Science.gov (United States)

    Reeves, J. B.; McCarty, G.W.; Rutherford, D.W.; Wershaw, R. L.

    2008-01-01

    Fires in terrestrial ecosystems produce large amounts of charcoal that persist in the environment and represent a substantial pool of sequestered carbon in soil. The objective of this research was to investigate the effect of charring on mid-infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred organic matter in soils. Four materials (cellulose, lignin, pine bark, and pine wood) and char from these materials, created by charring for various durations (1 to 168 h) and at various temperatures (200 to 450 ??C), were studied. Mid-infrared spectra and measures of acidity (total acids, carboxylic acids, lactones, and phenols as determined by titration) were determined for 56 different samples (not all samples were charred at all temperatures/durations). Results showed spectral changes that varied with the material, temperature, and duration of charring. Despite the wide range of spectral changes seen with the differing materials and length/temperature of charring, partial least squares calibrations for total acids, carboxylic acids, lactones, and phenols were successfully created (coefficient of determination and root mean squared deviation of 0.970 and 0.380; 0.933 and 0.227; 0.976 and 0.120; and 0.982 and 0.101 meq/g, respectively), indicating that there is a sufficient commonality in the changes to develop calibrations without the need for unique calibrations for each specific material or condition of char formation. ?? 2008 Society for Applied Spectroscopy.

  12. Mid-infrared broadband absorber of full semiconductor epi-layers

    Science.gov (United States)

    Wang, Shaohua; Wang, Yufei; Zhang, Siriguleng; Zheng, Wanhua

    2017-04-01

    We demonstrate mid-infrared dual channel near-perfect absorbers based on full semiconductor epi-layers theoretically. Strong absorption (>99.9%) is observed at 25.04 THz. Through introducing composite grating and controlling the thickness of the dielectric layer, we can get a broadband absorption with absorptivity above 80% at the range from 8 μm to 12 μm with a good incidence angle tolerance. The structure investigated in this paper shows a broadband, all-semiconductor, plasmonic architecture, which is of great importance for many applications such as bolometers, cloaking, imaging devices and also can be used in enhancing interaction of mid-infrared radiation with integrated semiconductor optoelectronic elements.

  13. Cascade-coupled racetrack resonators based on the Vernier effect in the mid-infrared.

    Science.gov (United States)

    Troia, Benedetto; Khokhar, Ali Z; Nedeljkovic, Milos; Penades, Jordi Soler; Passaro, Vittorio M N; Mashanovich, Goran Z

    2014-10-06

    In this paper we report the experimental demonstration of racetrack resonators in silicon-on-insulator technology platform operating in the mid-infrared wavelength range of 3.7-3.8 μm. Insertion loss lower than 1 dB and extinction ratio up to 30 dB were measured for single resonators. The experimental characterization of directional couplers and bending losses in silicon rib waveguides are also reported. Furthermore, we present the design and fabrication of cascade-coupled racetrack resonators based on the Vernier effect. Experimental spectra of Vernier architectures were demonstrated for the first time in the mid-infrared with insertion loss lower than 1 dB and maximum interstitial peak suppression of 10 dB.

  14. Gold triple-helix mid-infrared metamaterial by STED-inspired laser lithography.

    Science.gov (United States)

    Kaschke, Johannes; Wegener, Martin

    2015-09-01

    In analogy to wire-grid polarizers for linear polarization, metal-helix metamaterials can act as broadband circular polarizers. This concept has brought circular-polarization capabilities to mid-infrared and terahertz frequencies, which were previously difficult to access. Due to the lack of rotational symmetry, however, single-helix metamaterials exhibit unwanted circular-polarization conversions. Recent theoretical work showed that conversions can be fully eliminated by intertwining N=3 or 4 helices within each unit cell. While direct laser writing in positive-tone photo-resist yielded good results for single-helix metamaterials operating at mid-infrared frequencies, the axial resolution is insufficient for N-helix metamaterials. Here, we use stimulated emission depletion-inspired three-dimensional laser lithography to fabricate such microstructures. We measure all entries of the Jones transmission and reflection matrices and show experimentally that polarization conversions are minimized, in good agreement with theory.

  15. Tunable mid-infrared emission from acetylene-filled hollow-core fiber

    Science.gov (United States)

    Wang, Zefeng; Zhou, Zhiyue; Li, Zhixian; Zhang, Naiqian; Chen, Yubin

    2016-11-01

    We report here a step tunable mid-infrared laser emission from acetylene-filled hollow-core fiber. Two kinds of anti-resonant hollow-core fibers are filled with mbar level of acetylene gas, and pumped with a modulated, amplified, narrow linewidth, fine tunable, 1.5 μm diode laser, then 3 μm laser emissions are generated by the intrinsic absorption of acetylene molecules. The laser wavelength is step-tunable in the range of 3.1 3.2 μm when the pump laser is precisely tuned to different absorption lines of P-branch of acetylene. By properly designing the fiber's transmission bands, and carefully selecting active gases and pump lasers, this paper provides a novel method for efficient, compact and tunable mid-infrared fiber lasers over a broad spectrum range.

  16. Two-octave mid-infrared supercontinuum generation in As-Se suspended core fibers

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Petersen, Christian Rosenberg; Kubat, Irnis

    2015-01-01

    A more than two-octave mid-infrared supercontinuum with an average output power of 15.6 mW covering 1.7-7.5 μm (1,333-5,900 cm-1) is generated in a low-loss As38Se62 suspended core fiber with core diameter of 4.5 μm.......A more than two-octave mid-infrared supercontinuum with an average output power of 15.6 mW covering 1.7-7.5 μm (1,333-5,900 cm-1) is generated in a low-loss As38Se62 suspended core fiber with core diameter of 4.5 μm....

  17. A systematic investigation of high harmonic generation using mid-infrared driving laser pulses

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We report on a systematic investigation of the influences of gas pressure,focal position and focusing geometry on high harmonic generation by use of mid-infrared femtosecond laser pulses. We also discuss the spatial characteristics of harmonics under different focusing conditions. By optimizing the parameters,we experimentally observed the generation of 1 kHz,low divergence coherent X-ray beams in the water-window region.

  18. Genetic parameters for methane emissions predicted from milk mid-infrared spectra in dairy cows

    OpenAIRE

    Kandel, Purna Bhadra; Vanrobays, Marie-Laure; Vanlierde, Amélie; Dehareng, Frédéric; Froidmont, Eric; Pierre DARDENNE; Lewis, E.; Buckley, F.; Deighton, MH; McParland, S.; Gengler, Nicolas; Soyeurt, Hélène

    2013-01-01

    Genetic selection of low methane (CH4) emitting animals is additive and permanent but the difficulties associated with individual CH4 measurement result in a paucity of records required to estimate genetic variability of CH4 traits. Recently, it was shown that direct quantification of CH4 emissions by mid-infrared spectroscopy (MIR) from milk. The CH4 prediction equation was developed using 452 SF6 CH4 measurements with associated milk spectra and the calibration equation wa...

  19. Potential estimation of titratable acidity in cow milk using mid-infrared spectrometry

    OpenAIRE

    Colinet, Frédéric; Soyeurt, Hélène; Anceau, Christine; Vanlierde, Amélie; Keyen, Nicolas; Pierre DARDENNE; Gengler, Nicolas; Sindic, Marianne

    2010-01-01

    Milk coagulation has a direct effect on cheese yield. Several factors influence the milk coagulation kinetics. In addition to calcium and milk protein concentrations, titratable acidity influences all the phases of milk coagulation. The objective of this research was to study the feasibility of prediction of titratable acidity directly in bovine milk using mid-infrared spectrometry. In order to maximize the variability in the measurements of titratable acidity, milk samples were collected on ...

  20. The use of mid-infrared spectrometry to predict body energy status of Holstein cows

    OpenAIRE

    McParland, S.; G. Banos; Wall, E.; Coffey, M. P.; Soyeurt, H.; Veerkamp, R F; Berry, D. P.

    2011-01-01

    Energy balance, especially in early lactation, is known to be associated with subsequent health and fertility in dairy cows. However, its inclusion in routine management decisions or breeding programs is hindered by the lack of quick, easy, and inexpensive measures of energy balance. The objective of this study was to evaluate the potential of mid-infrared (MIR) analysis of milk, routinely available from all milk samples taken as part of large-scale milk recording and milk payment operations;...

  1. Genetic variability of lactoferrin content estimated by mid-infrared spectrometry in bovine milk

    OpenAIRE

    Soyeurt, Hélène; Colinet, Frédéric; Arnould, Valérie; Dardenne, Pierre; Bertozzi, Carlo; Renaville, Robert; Portetelle, Daniel; Gengler, Nicolas

    2007-01-01

    The effects of lactoferrin (LF) on the immune system have already been shown by many studies. Unfortunately, the current methods used to measure LF levels in milk do not permit the study of the genetic variability of lactoferrin or the performance of routine genetic evaluations. The first aim of this research was to derive a calibration equation permitting the prediction of LF in milk by mid-infrared spectrometry (MIR). The calibration with partial least squares on 69 ...

  2. Multi-milliwatt mid-infrared supercontinuum generation in a suspended core chalcogenide fiber

    DEFF Research Database (Denmark)

    Møller, Uffe Visbech; Yu, Yi; Kubat, Irnis

    2015-01-01

    A low-loss suspended core As38Se62 fiber with core diameter of 4.5 μm and a zero-dispersion wavelength of 3.5 μm was used for mid-infrared supercontinuum generation. The dispersion of the fiber was measured from 2.9 to 4.2 μm and was in good correspondence with the calculated dispersion. An optic...

  3. The Mid-Infrared Emission of Seyfert Galaxies: A New Analysis of ISOCAM Data

    Science.gov (United States)

    Ramos Almeida, C.; Pérez García, A. M.; Acosta-Pulido, J. A.; Rodríguez Espinosa, J. M.

    2007-11-01

    We present mid-infrared data of a sample of 57 AGNs obtained with the instrument ISOCAM on board the Infrared Space Observatory (ISO) satellite. The images were obtained through the LW2 (6.75 μm) and LW7 (9.62 μm) filters. This is a new analysis of the Clavel et al. galaxy sample, which is divided into 26 type 1 (1.5) Seyfert galaxies, plus three QSOs. The spatial resolution of the images allows us to separate the nuclear and the extended contributions to the total emission after decomposing the brightness profiles into different morphological components. The most common components are a central point source (identified as the active nucleus) and an exponential disk. In some cases a bulge, a bar, or a ring are needed. The relative contribution of the nucleus to the total emission appears larger in Seyfert 1 than in Seyfert 2 types. This result confirms that both types of Seyfert galaxies are different in the mid-infrared wavelength range and supports the existence of a structure which produces anisotropic emission in this wavelength range. We have also explored correlations between the mid-infrared and the radio and X-ray wavelength ranges. The well-established radio/infrared correlation is maintained in our sample for the global emission of the galaxies. If only the nuclear infrared emission is considered, then a nonlinear correlation is apparent in the luminosity-luminosity scatter diagram. The ratio between the intrinsic hard X-ray and the nuclear mid-infrared emission presents large scatter and slightly larger values for type 2 Seyfert galaxies. These results seem to be consistent with the presence of a clumpy dusty torus surrounding the active nucleus. Based on observations with the Infrared Space Observatory, an ESA project with instruments funded by the ESA member states (especially the PI countries: France, Germany, the Netherlands, and the United Kingdom) and with the participation of ISAS and NASA.

  4. Measurement of the nonlinear refractive index of air constituents at mid-infrared wavelengths

    CERN Document Server

    Zahedpour, S; Milchberg, H M

    2015-01-01

    We measure the nonlinear refractive index coefficients in N$_2$, O$_2$ and Ar from visible through mid-infrared wavelengths (\\lambda = 0.4 - 2.4 {\\mu}m). The wavelengths investigated correspond to transparency windows in the atmosphere. Good agreement is found with theoretical models of $\\chi^{(3)}$. Our results are essential for accurately simulating the propagation of ultrashort mid-IR pulses in the atmosphere.

  5. Converting mid-infrared signals to near-infrared through optomechanical transduction

    Science.gov (United States)

    Kapsalis, A.; Mesaritakis, C.; Bogris, A.; Syvridis, D.

    2015-01-01

    Mid-infrared silicon photonics emerge as the dominant technology to bridge photonics and electronics in multifunctional high-speed integrated chips. The transmission and processing of optical signals lying at the mid-infrared wavelength region is ideal for sensing, absorption-spectroscopy and free-space communications and the use of group IV materials becomes principally promising as the vehicle towards their realization. In parallel, optical forces originating from modes and cavities can reach to outstandingly large values when sizes drop into the nanoscale. In this work, we propose the exploitation of large gradient optical forces generated between suspended silicon beams and optomechanical transduction as a means of converting signals from the mid-infrared to the near-infrared region. A midinfrared signal is injected into the waveguide system so as to excite the fundamental symmetric mode. In the 2-5μm wavelength range, separation gaps in the 100nm order and waveguide widths ranging from 300-600nm, the mode is mostly guided in the air slot between the waveguides which maximizes the optomechanical coupling coefficient and optical force. The resulting attractive force deflects the waveguides and the deflection is linearly dependent on the midinfrared optical power. A simple read-out technique using 1.55μm signals with conventional waveguiding in the directional coupler formed by the two beams is analyzed. A positive conversion efficiency (index unconventional guiding in mid-infrared could be a key component towards multifunctional lab-on-a-chip devices.

  6. The Gˆ Mid-Infrared Search for Extraterrestrial Civilizations with Large Power Supplies: First Results

    Science.gov (United States)

    Povich, M. S.; Wright, J. T.; Griffith, R.; Sigurdsson, S.; Maldonado, J. T.; Mullan, B.

    2014-03-01

    We present initial results from the Glimpsing Heat from Alien Technologies ("G-HAT" or Gˆ), in which we use the WISE all-sky mid-infrared (MIR) Source Catalog to search for and place constraints on the abundance of extraterrestrial civilizations with large power supplies. A civilization consuming a significant fraction of the luminous power of their host star (Kardashev type II civilization or K2; Kardashev 1964) or galaxy (K3) and operating at a temperature similar to the equilibrium temperatures in or near stellar habitable zones will produce MIR excess emission in the form of waste heat. Searches for such MIR excesses from K2s have been performed in the past, notably by Carrigan (2009) using the IRAS source catalog. Taking advantage of the 103 improvement in sensitivity over IRAS provided by WISE, Gˆ has enabled the first systematic search for waste heat from galaxy-spanning K3 civilizations and will search for K2s throughout a significant fraction of the Milky Way's volume. We find that a galaxy-spanning (K III) civilization with an power supply of more than about one percent of its stellar luminosity will have detectable mid-infrared excess. We have produced a catalog of 32,000 WISE extended sources and visually reviewed the data and literature on the reddest 4000 of them, identifying several hundred candidates worthy of detailed observational follow-up. Mid-infrared spectra, far-infrared photometry, and radio emission from CO could be used to distinguish extraterrestrial mid-infrared radiation from dust. We will extend this analysis to WISE point sources to search for K2s.

  7. Mid-infrared vibrational spectroscopic characterization of 5,6-dihydroxyindole and eumelanin derived from it

    Science.gov (United States)

    Hyogo, Ryosuke; Nakamura, Atsushi; Okuda, Hidekazu; Wakamatsu, Kazumasa; Ito, Shosuke; Sota, Takayuki

    2011-12-01

    Mid-infrared vibrational spectroscopic study has been made on 5,6-dihydroxyindole (DHI) and DHI-derived eumelanin. It has been revealed for DHI monomer that measured infrared absorption spectrum is well reproduced by that predicted from ab initio calculations. Thus, vibrational modes of DHI monomer causing dominant absorption bands have been successfully assigned. It has been also reconfirmed that DHI-derived eumelanin includes indolequinone and/or quinone methide units in addition to DHI units.

  8. Mid-infrared absorption spectra of dimethyl methylphosphonate as molecular simulant of nerve agents

    Institute of Scientific and Technical Information of China (English)

    Yonggang Zhang; Zhenxing Cheng; Aizhen Li; Songlin Feng

    2006-01-01

    The fine mid-infrared absorption features of dimethyl methylphosphonate vapor have been characterized by using Fourier transforms infrared spectroscopy, and the nitrous oxide was used for calibration purpose. The results show that the main P-O-C and P=O bonds related absorption bands of dimethyl methylphosphonate vapor are peaked at 1050.01 and 1275.76 cm-1 respectively, those two bands show continuous characteristics at resolution of 0.125 cm-1.

  9. Fiber Based Mid Infrared Supercontinuum Source for Spectroscopic Analysis in Food Production

    DEFF Research Database (Denmark)

    Ramsay, Jacob; Dupont, Sune Vestergaard Lund; Keiding, Søren Rud

    Optimization of sustainable food production is a worldwide challenge that is undergoing continuous development as new technologies emerge. Applying solutions for food analysis with novel bright and broad mid-infrared (MIR) light sources has the potential to meet the increasing demands for food...... quality and production optimization. By combining a new MIR supercontinuum source with spectroscopy and chemometrics, we seek to enable faster and more precise analysis of grains, soils and dairy products....

  10. On-chip mid-infrared gas detection using chalcogenide glass waveguide

    Science.gov (United States)

    Han, Z.; Lin, P.; Singh, V.; Kimerling, L.; Hu, J.; Richardson, K.; Agarwal, A.; Tan, D. T. H.

    2016-04-01

    We demonstrate an on-chip sensor for room-temperature detection of methane gas using a broadband spiral chalcogenide glass waveguide coupled with off-chip laser and detector. The waveguide is fabricated using UV lithography patterning and lift-off after thermal evaporation. We measure the intensity change due to the presence and concentration of methane gas in the mid-infrared (MIR) range. This work provides an approach for broadband planar MIR gas sensing.

  11. Dy{sup 3+}-doped Ga–Sb–S chalcogenide glasses for mid-infrared lasers

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Mingjie [Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou, Jiangsu 221116 (China); Yang, Anping, E-mail: apyang@jsnu.edu.cn [Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou, Jiangsu 221116 (China); Peng, Yuefeng [Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Zhang, Bin; Ren, He; Guo, Wei; Yang, Yan; Zhai, Chengcheng; Wang, Yuwei; Yang, Zhiyong; Tang, Dingyuan [Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou, Jiangsu 221116 (China)

    2015-10-15

    Highlights: • Novel Ga–Sb–S chalcogenide glasses doped with Dy{sup 3+} ions were synthesized. • The glasses show good thermal stability and excellent infrared transparency. • The glasses show low phonon energy and intense mid-infrared emissions. • The mid-infrared emissions have high quantum efficiency. • The mid-infrared emissions have large stimulated emission cross sections. - Abstract: Novel Ga–Sb–S chalcogenide glasses doped with different amount of Dy{sup 3+} ions were prepared. Their thermal stability, optical properties, and mid-infrared (MIR) emission properties were investigated. The glasses show good thermal stability, excellent infrared transparency, very low phonon energy (∼306 cm{sup −1}), and intense emissions centered at 2.95, 3.59, 4.17 and 4.40 μm. Three Judd–Ofelt intensity parameters (Ω{sub 2} = 8.51 × 10{sup −20} cm{sup 2}, Ω{sub 4} = 2.09 × 10{sup −20} cm{sup 2}, and Ω{sub 6} = 1.60 × 10{sup −20} cm{sup 2}) are obtained, and the related radiative transition properties are evaluated. The high quantum efficiencies and large stimulated emission cross sections of the MIR emissions (88.10% and 1.11 × 10{sup −20} cm{sup 2} for 2.95 μm emission, 75.90% and 0.38 × 10{sup −20} cm{sup 2} for 4.40 μm emission, respectively) in the Dy{sup 3+}-doped Ga–Sb–S glasses make them promising gain materials for the MIR lasers.

  12. Generation and application of ultrashort coherent mid-infrared electromagnetic radiation

    Science.gov (United States)

    Wandel, Scott

    Particle accelerators are useful instruments that help address critical issues for the future development of nuclear energy. Current state-of-the-art accelerators based on conventional radio-frequency (rf) cavities are too large and expensive for widespread commercial use, and alternative designs must be considered for supplying relativistic beams to small-scale applications, including medical imaging, secu- rity screening, and scientific research in a university-scale laboratory. Laser-driven acceleration using micro-fabricated dielectric photonic structures is an attractive approach because such photonic microstructures can support accelerating fields that are 10 to 100 times higher than that of rf cavity-based accelerators. Dielectric laser accelerators (DLAs) use commercial lasers as a driving source, which are smaller and less expensive than the klystrons used to drive current rf-based accelerators. Despite the apparent need for compact and economical laser sources for laser-driven acceleration, the availability of suitable high-peak-power lasers that cover a broad spectral range is currently limited. To address the needs of several innovative acceleration mechanisms like DLA, it is proposed to develop a coherent source of mid-infrared (IR) electromagnetic radiation that can be implemented as a driving source of laser accelerators. The use of ultrashort mid-IR high peak power laser systems in various laser-driven acceleration schemes has shown the potential to greatly reduce the optical pump intensities needed to realize high acceleration gradients. The optical intensity needed to achieve a given ponderomotive potential is 25 times less when using a 5-mum mid-IR laser as compared to using a 1-mum near-IR solid-state laser. In addition, dielectric structure breakdown caused by multiphoton ionization can be avoided by using longer-wavelength driving lasers. Current mid-IR laser sources do not produce sufficiently short pulse durations, broad spectral bandwidths

  13. Laboratory demonstration of a mid-infrared AGPM vector vortex coronagraph

    CERN Document Server

    Delacroix, Christian; Forsberg, Pontus; Mawet, Dimitri; Christiaens, Valentin; Karlsson, Michael; Boccaletti, Anthony; Baudoz, Pierre; Kuittinen, Markku; Vartiainen, Ismo; Surdej, Jean; Habraken, Serge

    2013-01-01

    Coronagraphy is a powerful technique to achieve high contrast imaging and hence to image faint companions around bright targets. Various concepts have been used in the visible and near-infrared regimes, while coronagraphic applications in the mid-infrared remain nowadays largely unexplored. Vector vortex phase masks based on concentric subwavelength gratings show great promise for such applications. We aim at producing and validating the first high-performance broadband focal plane phase mask coronagraphs for applications in the mid-infrared regime, and in particular the L band with a fractional bandwidth of ~16% (3.5-4.1 \\mu m). Based on rigorous coupled wave analysis, we designed an annular groove phase mask (AGPM) producing a vortex effect in the L band, and etched it onto a series of diamond substrates. The grating parameters were measured by means of scanning electron microscopy. The resulting components were then tested on a mid-infrared coronagraphic test bench. A broadband raw null depth of 2 x 10^{-3...

  14. Mid-infrared spectrometry of milk as a predictor of energy intake and efficiency in lactating dairy cows.

    Science.gov (United States)

    McParland, S; Lewis, E; Kennedy, E; Moore, S G; McCarthy, B; O'Donovan, M; Butler, S T; Pryce, J E; Berry, D P

    2014-09-01

    Interest is increasing in the feed intake complex of individual dairy cows, both for management and animal breeding. However, energy intake data on an individual-cow basis are not routinely available. The objective of the present study was to quantify the ability of routinely undertaken mid-infrared (MIR) spectroscopy analysis of individual cow milk samples to predict individual cow energy intake and efficiency. Feed efficiency in the present study was described by residual feed intake (RFI), which is the difference between actual energy intake and energy used (e.g., milk production, maintenance, and body tissue anabolism) or supplied from body tissue mobilization. A total of 1,535 records for energy intake, RFI, and milk MIR spectral data were available from an Irish research herd across 36 different test days from 535 lactations on 378 cows. Partial least squares regression analyses were used to relate the milk MIR spectral data to either energy intake or efficiency. The coefficient of correlation (REX) of models to predict RFI across lactation ranged from 0.48 to 0.60 in an external validation data set; the predictive ability was, however, strongest (REX=0.65) in early lactation (milk). The inclusion of milk yield as a predictor variable improved the accuracy of predicting energy intake across lactation (REX=0.70). The correlation between measured RFI and measured energy balance across lactation was 0.85, whereas the correlation between RFI and energy balance, both predicted from the MIR spectrum, was 0.65. Milk MIR spectral data are routinely generated for individual cows throughout lactation and, therefore, the prediction equations developed in the present study can be immediately (and retrospectively where MIR spectral data have been stored) applied to predict energy intake and efficiency to aid in management and breeding decisions.

  15. The Exosat spectral survey of AGN

    Science.gov (United States)

    Turner, T. J.; Pounds, K. A.

    1989-01-01

    Results are presented from Exosat observations of 48 hard X-ray selected Seyfert-type active galactic nuclei (AGN). These include all 30 of the emission line AGN in the Piccinotti (1981) sample. Combining Exosat LE and ME data has yielded X-ray spectra over the broad energy range 0.1-10 keV. Spectra in the about 2-10 keV range are found to be well described by a simple power law, with a narrow distribution of spectral indices across the sample about a mean energy index alpha = 0.70. Exosat has also revealed a substantial number of sources with complex soft X-ray spectra. Evidence that soft emission components occur in many Seyferts, together with detection of rapid variability in the soft component, provides a quantitative support for an accretion disk model for AGN. Approximately half of the present sample of AGN show low-energy absorption attributable to substantial cold matter within the host galaxy. A few cases show evidence for column variability and reduced low-energy opacity (by photo-ionization). These results and the observed rarity of intrinsic absorption in the higher luminosity sources suggest the absorbing matter lies close to the central continuum source.

  16. LOFAR Cassiopeia A spectral line survey

    CERN Document Server

    Oonk, J B R; Salas, P; Salgado, F; Morabito, L K; Toribio, M C; Tielens, A G G M; Rottgering, H J A

    2016-01-01

    We use the Low Frequency Array to perform a systematic high spectral resolution investigation of the low-frequency 33-78 MHz spectrum along the line of sight to Cassiopeia A. We complement this with a 304-386 MHz Westerbork Synthesis Radio telescope observation. In this first paper we focus on the carbon radio recombination lines. We detect Cn$\\alpha$ lines at -47 and -38 km s$^{-1}$ in absorption for quantum numbers n=438-584 and in emission for n=257-278 with high signal to noise. These lines are associated with cold clouds in the Perseus spiral arm component. Hn$\\alpha$ lines are detected in emission for n=257-278. In addition, we also detect Cn$\\alpha$ lines at 0 km s$^{-1}$ associated with the Orion arm. We analyze the optical depth of these transitions and their line width. Our models show that the carbon line components in the Perseus arm are best fit with an electron temperature 85 K and an electron density 0.04 cm$^{-3}$ and can be constrained to within 15\\%. The electron pressure is constrained to w...

  17. Investigation of laser radar systems based on mid-infrared semiconductor lasers

    Science.gov (United States)

    Rybaltowski, Adam

    This dissertation deals with the possibility of utilizing mid-infrared semiconductor lasers in systems of optical remote sensing with range resolution, called laser radar or lidar. The main subject investigated in this dissertation is two-fold: firstly, an analysis of the signal-to-noise ratio (SNR) and related maximum sensing range calculations in this type of lidar based on available system components, and---secondly---improvements in the Random-Modulation Continuous-Wave (RM-CW) lidar technique to better utilize available mid-infrared semiconductor lasers. As far as the SNR analysis is concerned, an appropriate framework has been constructed to analyze post-demodulation noise in mid-infrared direct-detection RM-CW lidar. It is based on a generalization of the Wiener-Khintchine theorem; noise is assumed to be additive, stationary, and have an arbitrary power spectrum. This is in contrast to the SNR analysis in the literature on this subject, which is inadequate for mid-infrared RM-CW lidar as it only considers Poissonian fluctuations of the number of detected photons. In addition to regular SNR analysis, the framework derived in this dissertation allows treatment of singularities such as demodulation with an unbalanced sequence in 1/f noise. To calculate maximum lidar sensing range, the following detection limits have been considered: signal shot noise, background blackbody radiation shot noise based on the Background-Limited Photodetection (BLIP) detectivity limit, and minimum-size detector noise given by diffraction-limited focusing. The latter is found to be of greatest practical interest. Furthermore, a lidar figure of merit has been introduced, and all quantities related to lidar performance and its detection limits have been presented graphically. Since pseudo-random sequences discussed in the literature have been found highly non-optimal for most applications of RM-CW lidar, a framework for the construction of new pseudo-random sequences of desired

  18. SPHEREx: An All-Sky Spectral Survey

    CERN Document Server

    Doré, Olivier; Capak, Peter; de Putter, Roland; Eifler, Tim; Hirata, Chris; Korngut, Phil; Krause, Elisabeth; Masters, Daniel; Raccanelli, Alvise; Zemcov, Mike; Cooray, Asantha; Flagey, Nicolas; Gong, Yan; Katti, Raj; Melnick, Gary; Mennesson, Bertrand; Unwin, Steve; Viero, Marco; Werner, Mike; Ashby, Matthew; Habib, Salman; Heitmann, Katrin; Lee, Dae-Hee; Jeong, Woong-Seob; Mauskopf, Phil; Nguyen, Hien; Öberg, Karin; Smith, Roger; Song, Yong-Seon; Tolls, Volker; Venumadhav, Tejaswi

    2014-01-01

    SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) is a proposed all-sky spectroscopic survey satellite designed to address all three science goals in NASA's Astrophysics Division: probe the origin and destiny of our Universe; explore whether planets around other stars could harbor life; and explore the origin and evolution of galaxies. SPHEREx will scan a series of Linear Variable Filters systematically across the entire sky. The SPHEREx data-set will contain R=40 spectra spanning the near infrared (0.75$\\mu$m$<\\lambda<$ 4.83$\\mu$m) for every 6.2 arcsecond pixel over the the entire-sky. In this paper, we detail the extra-galactic and cosmological studies SPHEREx will enable and present detailed systematic effect evaluations.

  19. Compact, High Power, Multi-Spectral Mid-Infrared Semiconductor Laser Package

    Science.gov (United States)

    2001-10-01

    ABSTRACT Unclassified c. THIS PAGE Unclassified 19b. TELEPHONE NUMBER International Area Code Area Code Telephone Number DSN Standard Form 298 (Rev. 8-98...Unclassified b. ABSTRACT Unclassified c. THIS PAGE Unclassified 19b. TELEPHONE NUMBER International Area Code Area Code Telephone Number DSN Standard Form...optical- CDMA Fig. 42. System block diagram. Figure. 43. Return signal-to-noise ratio (1 kHz-bandwidth) vs. distance for different transmitter power

  20. Spectral design of temperature-invariant narrow bandpass filters for the mid-infrared

    DEFF Research Database (Denmark)

    Stolberg-Rohr, Thomine Kirstine; Hawkins, Gary J.

    2015-01-01

    The ability of narrow bandpass filters to discriminatewavelengths between closely-separated gas absorption lines is crucial inmany areas of infrared spectroscopy. As improvements to the sensitivity ofinfrared detectors enables operation in uncontrolled high-temperature environments, this imposes...... demands on the explicit bandpass design to provide temperature-invariant behavior. The unique negative temperature coefficient (dn/dTfilters with exclusive immunity to shifts in wave length with temperature. This paper...... presents the results of an investigation into the interdependence between multilayer bandpass designand optical materials together with a review on invariance at elevated temperatures....

  1. A Spitzer high resolution mid-infrared spectral atlas of starburst galaxies

    CERN Document Server

    Bernard-Salas, J; Charmandaris, V; Lebouteiller, V; Farrah, D; Devost, D; Brandl, B R; Wu, Yanling; Armus, L; Hao, L; Sloan, G C; Weedman, D; Houck, J R

    2009-01-01

    We present an atlas of Spitzer/IRS high resolution (R~600) 10-37um spectra for 24 well known starburst galaxies. The spectra are dominated by fine-structure lines, molecular hydrogen lines, and emission bands of polycyclic aromatic hydrocarbons. Six out of the eight objects with a known AGN component show emission of the high excitation [NeV] line. This line is also seen in one other object (NGC4194) with, a priori, no known AGN component. In addition to strong polycyclic aromatic hydrocarbon emission features in this wavelength range (11.3, 12.7, 16.4um), the spectra reveal other weak hydrocarbon features at 10.6, 13.5, 14.2um, and a previously unreported emission feature at 10.75um. An unidentified absorption feature at 13.7um is detected in many of the starbursts. We use the fine-structure lines to derive the abundance of neon and sulfur for 14 objects where the HI 7-6 line is detected. We further use the molecular hydrogen lines to sample the properties of the warm molecular gas. Several basic diagrams ch...

  2. High energy femtosecond mid-infrared generation pumped by a two-color Ti:sapphire multipass amplifier

    Institute of Scientific and Technical Information of China (English)

    XIA JiangFan; SONG Jie; Donna T. Strickland

    2008-01-01

    Intense mid-infrared was generated by direct frequency mixing two pulses from a dual-wavelength Ti:sapphire system. From a multipass amplifier we generated two tunable wavelength femtosecond pulses with a total energy of 15 mJ. Pulse energy of 1.6 μJ and 7.4 μJ of mid-infrared light is achieved with and without its multipass amplifier at 9-11 μm, with pulse duration of 500 fs.

  3. A Review of Mid-Infrared and Near-Infrared Imaging: Principles, Concepts and Applications in Plant Tissue Analysis

    Directory of Open Access Journals (Sweden)

    Sevgi Türker-Kaya

    2017-01-01

    Full Text Available Plant cells, tissues and organs are composed of various biomolecules arranged as structurally diverse units, which represent heterogeneity at microscopic levels. Molecular knowledge about those constituents with their localization in such complexity is very crucial for both basic and applied plant sciences. In this context, infrared imaging techniques have advantages over conventional methods to investigate heterogeneous plant structures in providing quantitative and qualitative analyses with spatial distribution of the components. Thus, particularly, with the use of proper analytical approaches and sampling methods, these technologies offer significant information for the studies on plant classification, physiology, ecology, genetics, pathology and other related disciplines. This review aims to present a general perspective about near-infrared and mid-infrared imaging/microspectroscopy in plant research. It is addressed to compare potentialities of these methodologies with their advantages and limitations. With regard to the organization of the document, the first section will introduce the respective underlying principles followed by instrumentation, sampling techniques, sample preparations, measurement, and an overview of spectral pre-processing and multivariate analysis. The last section will review selected applications in the literature.

  4. The subarcsecond mid-infrared view of local active galactic nuclei: I. The N- and Q-band imaging atlas

    CERN Document Server

    Asmus, D; Gandhi, P; Smette, A; Duschl, W J

    2013-01-01

    We present the first subarcsecond-resolution mid-infrared (MIR) atlas of local active galactic nuclei (AGN) containing 253 objects with a median redshift of z = 0.016. It comprises all available MIR imaging observations performed to date with ground-based 8-meter class telescopes and includes in total 895 independent photometric measurements, of which more than 60% are previously unpublished.We detect extended nuclear emission in at least 21% of the objects, while another 19% appear clearly point-like, and the remaining objects cannot be constrained. Subarcsecond resolution allows us to isolate the emission of the AGN on scales of a few tens of parsecs for the bulk of the sample and obtain nuclear photometry in multiple filters for the objects. The photometry is used to construct median spectral energy distributions (SEDs) for the different optical AGN types and estimate the individual MIR 12 and 18 um continuum luminosities, which range over more than six orders of magnitude. We also analyse the arcsecond-sc...

  5. Mid-infrared reflectlance spectra (2.3-22 micions) of sulfur, gold, KBr, MgO, and halon

    Science.gov (United States)

    Nash, D. B.

    1986-01-01

    Biconical diffuse reflectance spectra in the mid-infrared are presented for powder and other solid forms of sulfur, gold, potassium bromide, magnesium oxide, and halon. Comparisons are made with previously published results of other investigators, and recommendations are made regarding the relative usefulnees of these materials as reflectance standards in the mid-IR. Sulfur has strong intrinsic bands at wavelengths greater than 7 microns that must be taken into account for its use as a reflectance standard. Some sulfur samples have hydrocarbon contaminants and in powder form may have adsorbed water, both of which produce bands in the 3-4-micron region. Potassium bromide has several weak intrinsic bands and is very sensitive to adsorbed water contamination; otherwise it is a good IR reference material. Magnesium oxide and halon have major bands structure and low reflectivity at wavelengths greater than 2.6 microns and thus are unsuitable as reference materials in the mid-IR. Vapor-deposited gold on fine sandpaper (600 grit) is very bright, spectrally flat, and fairly diffuse, so it is the superior material (of those examined) for reflectance reference material throughout the IR. Fine gold powder, on the other hand, is much less bright than evaporated gold, and its reflectivity at wavelengths greater than its particle size is highly sensitive to particle packing density.

  6. Ecological risk assessment on heavy metals in soils: Use of soil diffuse reflectance mid-infrared Fourier-transform spectroscopy

    Science.gov (United States)

    Wang, Cheng; Li, Wei; Guo, Mingxing; Ji, Junfeng

    2017-02-01

    The bioavailability of heavy metals in soil is controlled by their concentrations and soil properties. Diffuse reflectance mid-infrared Fourier-transform spectroscopy (DRIFTS) is capable of detecting specific organic and inorganic bonds in metal complexes and minerals and therefore, has been employed to predict soil composition and heavy metal contents. The present study explored the potential of DRIFTS for estimating soil heavy metal bioavailability. Soil and corresponding wheat grain samples from the Yangtze River Delta region were analyzed by DRIFTS and chemical methods. Statistical regression analyses were conducted to correlate the soil spectral information to the concentrations of Cd, Cr, Cu, Zn, Pb, Ni, Hg and Fe in wheat grains. The principal components in the spectra influencing soil heavy metal bioavailability were identified and used in prediction model construction. The established soil DRIFTS-based prediction models were applied to estimate the heavy metal concentrations in wheat grains in the mid-Yangtze River Delta area. The predicted heavy metal concentrations of wheat grain were highly consistent with the measured levels by chemical analysis, showing a significant correlation (r2 > 0.72) with acceptable root mean square error RMSE. In conclusion, DRIFTS is a promising technique for assessing the bioavailability of soil heavy metals and related ecological risk.

  7. Attosecond lighthouse above 100 eV from high-harmonic generation of mid-infrared pulses

    Science.gov (United States)

    Kovács, K.; Negro, M.; Vozzi, C.; Stagira, S.; Tosa, V.

    2017-10-01

    In this paper, we numerically investigate the possibility to obtain a lighthouse emission for the attosecond pulses produced by high-order harmonics of a strong mid-infrared fundamental pulse without any optical element inserted in the path of the generating beam. The parameters of the driving pulse, focusing geometry, gas medium and detection configuration are currently experimentally feasible. Here, we study in detail the specific propagation conditions of the laser beam, and describe the exact mechanism of the sensitive space-time variation of the medium’s refractive index that lead to the dynamic wavefront rotation. This basic requirement for the lighthouse phenomenon is transmitted to the harmonic bursts, which are emitted with different divergence in successive optical half-cycles, thus can be detected in the far field at increasing distances from the optical axis. In this configuration, spectral filtering of the harmonics is not necessary, therefore the total harmonic pulse power might be used in further pump-probe experiments.

  8. Independently tunable dual-band plasmonically induced transparency based on hybrid metal-graphene metamaterials at mid-infrared frequencies.

    Science.gov (United States)

    Sun, Chen; Dong, Zhewei; Si, Jiangnan; Deng, Xiaoxu

    2017-01-23

    A tunable dual-band plasmonically induced transparency (PIT) device based on hybrid metal-graphene nanostructures is proposed theoretically and numerically at mid-infrared frequencies, which is composed of two kinds of gold dolmen-like structures with different sizes placed on separate graphene interdigitated finger sets respectively. The coupled Lorentz oscillator model is used to explain the physical mechanism of the PIT effect at multiple frequency domains. The finite-difference time-domain (FDTD) solutions are employed to simulate the characteristics of the hybrid metal-graphene dual-band PIT device. The simulated spectral locations of multiple transparency peaks are separately and dynamically modulated by varying the Fermi energy of corresponding graphene finger set, which is in good accordance with the theoretical analysis. Distinguished from the conventional metallic PIT devices, multiple PIT resonances in the hybrid metal-graphene PIT device are independently modulated by electrostatically changing bias voltages applied on corresponding graphene fingers, which can be widely applied in optical information processing as tunable sensors, switches, and filters.

  9. High Spatial Resolution of the Mid-Infrared Emission of Compton-Thick Seyfert 2 Galaxy Mrk3

    CERN Document Server

    Sales, Dinalva A; Pastoriza, M G; Riffel, R; Winge, Cláudia

    2014-01-01

    Mid-infrared (MIR) spectra observed with Gemini/Michelle were used to study the nuclear region of the Compton-thick Seyfert 2 (Sy 2) galaxy Mrk 3 at a spatial resolution of $\\sim$200 pc. No polycyclic aromatic hydrocarbons (PAHs) emission bands were detected in the N-band spectrum of Mrk 3. However, intense [Ar III] 8.99 $\\mu$m, [S IV] 10.5 $\\mu$m and [Ne II] 12.8 $\\mu$m ionic emission-lines, as well as silicate absorption feature at 9.7$\\mu$m have been found in the nuclear extraction ($\\sim$200 pc). We also present subarcsecond-resolution Michelle N-band image of Mrk 3 which resolves its circumnuclear region. This diffuse MIR emission shows up as a wings towards East-West direction closely aligned with the S-shaped of the Narrow Line Region (NLR) observed at optical [O III]$\\lambda$5007\\AA image with Hubble/FOC. The nuclear continuum spectrum can be well represented by a theoretical torus spectral energy distribution (SED), suggesting that the nucleus of Mrk 3 may host a dusty toroidal structure predicted by...

  10. [A trace methane gas sensor using mid-infrared quantum cascaded laser at 7.5 microm].

    Science.gov (United States)

    Chen, Chen; Dang, Jing-Min; Huang, Jian-Qiang; Yang, Yue; Wang, Yi-Ding

    2012-11-01

    Presented is a compact instrument developed for in situ high-stable and sensitive continuous measurement of trace gases in air, with results shown for ambient methane (CH4) concentration accurate, real-time and in-situ. This instrument takes advantage of recent technology in thermoelectrically cooling (TEC) pulsed Fabry-Perot (FP) quantum cascaded laser (QCL) driving in a pulse mode operating at 7.5 microm ambient temperature to cover a fundamental spectral absorption band near v4 of CH4. A high quality Liquid Nitrogen (LN) cooled Mercury Cadmium Telluride (HgCdTe) mid-infrared (MIR) detector is used along with a total reflection coated gold ellipsoid mirror offering 20 cm single pass optical absorption in an open-path cell to achieve stability of 5.2 x 10(-3) under experimental condition of 200 micromol x mol(-1) measured ambient CH4. The instrument integrated software via time discriminating electronics technology to control QCL provides continuous quantitative trace gas measurements without calibration. The results show that the instrument can be applied to field measurements of gases of environmental concern. Additional, operator could substitute a QCL operating at a different wavelength to measure other gases.

  11. Mid-infrared microlensing of accretion disc and dusty torus in quasars: effects on flux ratio anomalies

    CERN Document Server

    Sluse, D; Anguita, T; Wucknitz, O; Wambsganss, J

    2013-01-01

    Multiply-imaged quasars and AGNs observed in the mid-infrared (MIR) range are commonly assumed to be unaffected by the microlensing produced by the stars in their lensing galaxy. In this paper, we investigate the validity domain of this assumption. Indeed, that premise disregards microlensing of the accretion disc in the MIR range, and does not account for recent progress in our knowledge of the dusty torus. To simulate microlensing, we first built a simplified image of the quasar composed of an accretion disc, and of a larger ring-like torus. The mock quasars are then microlensed using an inverse ray-shooting code. We simulated the wavelength and size dependence of microlensing for different lensed image types and fraction of compact objects projected in the lens. This allows us to derive magnification probabilities as a function of wavelength, as well as to calculate the microlensing-induced deformation of the spectral energy distribution of the lensed images. We find that microlensing variations as large a...

  12. Fiber-optic fourier transform mid-infrared reflectance spectroscopy: a suitable technique for in situ studies of mural paintings.

    Science.gov (United States)

    Miliani, C; Rosi, F; Borgia, I; Benedetti, P; Brunetti, B G; Sgamellotti, A

    2007-03-01

    A prototypical in situ noninvasive study of ancient mural painting materials has been carried out using an easily manageable fiber-optic Fourier transform mid-infrared (mid-FT-IR) reflectance spectrophotometer. The reported object of the study is the Renaissance fresco by Pietro Vannucci, called il Perugino, located in the church of Santa Maria delle Lacrime (1521, Trevi, Perugia Italy). For the first classification and interpretation of infrared spectra, principal components analysis was used. Spectral artifacts due to lacunas, restoration materials, or alteration products have been identified, as well as two different secco refinements bound in a tempera medium. For the characterization of inorganic pigments, mid-FT-IR spectra have been integrated with other data obtained through in situ X-ray fluorescence (XRF) elemental analysis. This complementary noninvasive approach led to the characterization of Perugino's pigments, even in the presence of complex mixtures. The mid-FT-IR noninvasive technique, in combination with XRF, is thus recommended as a valuable first approach for the examination of mural paintings, permitting the assessment of the execution technique as well as contributing to the evaluation of the conservation state.

  13. Ecological risk assessment on heavy metals in soils: Use of soil diffuse reflectance mid-infrared Fourier-transform spectroscopy

    Science.gov (United States)

    Wang, Cheng; Li, Wei; Guo, Mingxing; Ji, Junfeng

    2017-01-01

    The bioavailability of heavy metals in soil is controlled by their concentrations and soil properties. Diffuse reflectance mid-infrared Fourier-transform spectroscopy (DRIFTS) is capable of detecting specific organic and inorganic bonds in metal complexes and minerals and therefore, has been employed to predict soil composition and heavy metal contents. The present study explored the potential of DRIFTS for estimating soil heavy metal bioavailability. Soil and corresponding wheat grain samples from the Yangtze River Delta region were analyzed by DRIFTS and chemical methods. Statistical regression analyses were conducted to correlate the soil spectral information to the concentrations of Cd, Cr, Cu, Zn, Pb, Ni, Hg and Fe in wheat grains. The principal components in the spectra influencing soil heavy metal bioavailability were identified and used in prediction model construction. The established soil DRIFTS-based prediction models were applied to estimate the heavy metal concentrations in wheat grains in the mid-Yangtze River Delta area. The predicted heavy metal concentrations of wheat grain were highly consistent with the measured levels by chemical analysis, showing a significant correlation (r2 > 0.72) with acceptable root mean square error RMSE. In conclusion, DRIFTS is a promising technique for assessing the bioavailability of soil heavy metals and related ecological risk. PMID:28198802

  14. A Review of Mid-Infrared and Near-Infrared Imaging: Principles, Concepts and Applications in Plant Tissue Analysis.

    Science.gov (United States)

    Türker-Kaya, Sevgi; Huck, Christian W

    2017-01-20

    Plant cells, tissues and organs are composed of various biomolecules arranged as structurally diverse units, which represent heterogeneity at microscopic levels. Molecular knowledge about those constituents with their localization in such complexity is very crucial for both basic and applied plant sciences. In this context, infrared imaging techniques have advantages over conventional methods to investigate heterogeneous plant structures in providing quantitative and qualitative analyses with spatial distribution of the components. Thus, particularly, with the use of proper analytical approaches and sampling methods, these technologies offer significant information for the studies on plant classification, physiology, ecology, genetics, pathology and other related disciplines. This review aims to present a general perspective about near-infrared and mid-infrared imaging/microspectroscopy in plant research. It is addressed to compare potentialities of these methodologies with their advantages and limitations. With regard to the organization of the document, the first section will introduce the respective underlying principles followed by instrumentation, sampling techniques, sample preparations, measurement, and an overview of spectral pre-processing and multivariate analysis. The last section will review selected applications in the literature.

  15. Stand-off detection of solid targets with diffuse reflection spectroscopy using a high-power mid-infrared supercontinuum source.

    Science.gov (United States)

    Kumar, Malay; Islam, Mohammed N; Terry, Fred L; Freeman, Michael J; Chan, Allan; Neelakandan, Manickam; Manzur, Tariq

    2012-05-20

    We measure the diffuse reflection spectrum of solid samples such as explosives (TNT, RDX, PETN), fertilizers (ammonium nitrate, urea), and paints (automotive and military grade) at a stand-off distance of 5 m using a mid-infrared supercontinuum light source with 3.9 W average output power. The output spectrum extends from 750-4300 nm, and it is generated by nonlinear spectral broadening in a 9 m long fluoride fiber pumped by high peak power pulses from a dual-stage erbium-ytterbium fiber amplifier operating at 1543 nm. The samples are distinguished using unique spectral signatures that are attributed to the molecular vibrations of the constituents. Signal-to-noise ratio (SNR) calculations demonstrate the feasibility of increasing the stand-off distance from 5 to ~150 m, with a corresponding drop in SNR from 28 to 10 dB.

  16. Technical Note: Recipe for monitoring of total ozone with a precision of around 1 DU applying mid-infrared solar absorption spectra

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2008-01-01

    Full Text Available Mid-infrared solar absorption spectra recorded by a state-of-the-art ground-based FTIR system have the potential to provide precise total O3 amounts. The currently best-performing retrieval approaches use a combination of small and broad spectral O3 windows between 780 and 1015 cm−1. We show that for these approaches the uncertainties of the temperature profile are by far the major error sources. We demonstrate that a joint optimal estimation of temperature and O3 profiles widely eliminates this error. The improvements are documented by an extensive theoretical error estimation. Our results suggest that mid-infrared FTIR measurements can provide total O3 amounts with a precision of around 1 DU, placing this method among the most precise ground-based O3 monitoring techniques. We recapitulate the requirements on the instrumental hardware and on the retrieval that are needed to achieve this high precision.

  17. Air-Stable, Near- to Mid-Infrared Emitting Solids of PbTe/CdTe Core-Shell Colloidal quantum dots.

    Science.gov (United States)

    Protesescu, Loredana; Zünd, Tanja; Bodnarchuk, Maryna I; Kovalenko, Maksym V

    2016-03-03

    Light emitters and detectors operating in the near- and mid-infrared spectral regions are important to many applications, such as telecommunications, high-resolution gas analysis, atmospheric pollution monitoring, medical diagnostics, and night vision. Various lead chalcogenides (binary, ternary, and quaternary alloys) in the form of quantum dots (QDs) or quantum wells provide narrow bandgap energies that cover the broad infrared region corresponding to wavelengths of 1-30 μm. Here, we report an inexpensive, all-solution-based synthesis strategy to thin-film solids consisting of 5-16 nm PbTe QDs encapsulated by CdTe shells. Colloidally synthesized PbTe QDs were first converted into core-shell PbTe/CdTe QDs, and then deposited as thin films. The subsequent fusion of the CdTe shells is achieved by ligand removal and annealing in the presence of CdCl2 . Contrary to highly unstable bare PbTe QDs, PbTe/CdTe QD solids exhibit bright and stable near- to mid-infrared emission at wavelengths of 1-3 μm, which is also retained upon prolonged storage at ambient conditions for one year.

  18. Cavity-enhanced optical frequency comb spectroscopy in the mid-infrared - application to trace detection of H2O2

    CERN Document Server

    Foltynowicz, Aleksandra; Fleisher, Adam J; Bjork, Bryce; Ye, Jun

    2012-01-01

    We demonstrate the first cavity-enhanced optical frequency comb spectroscopy in the mid-infrared wavelength region and report the sensitive real-time trace detection of hydrogen peroxide in the presence of a large amount of water. The experimental apparatus is based on a mid-infrared optical parametric oscillator synchronously pumped by a high power Yb:fiber laser, a high finesse broadband cavity, and a fast-scanning Fourier transform spectrometer with autobalancing detection. The comb spectrum with a bandwidth of 200 nm centered around 3.75 {\\mu}m is simultaneously coupled to the cavity and both degrees of freedom of the comb, i.e., the repetition rate and carrier envelope offset frequency, are locked to the cavity to ensure stable transmission. The autobalancing detection scheme reduces the intensity noise by a factor of 300, and a sensitivity of 5.4 {\\times} 10^-9 cm^-1 Hz^-1/2 with a resolution of 800 MHz is achieved (corresponding to 6.9 {\\times} 10^-11 cm^-1 Hz^-1/2 per spectral element for 6000 resolve...

  19. An In-Depth View of the Mid-Infrared Properties of Point Sources and the Diffuse ISM in the SMC Giant HII Region, N66

    CERN Document Server

    Whelan, David G; Galliano, Frederic; Peeters, Els; Bernard-Salas, Jeronimo; Johnson, Kelsey E; Indebetouw, Remy; Brandl, Bernhard

    2013-01-01

    (abridged)The focus of this work is to study mid-infrared point sources and the diffuse interstellar medium (ISM) in the low-metallicity (~0.2 solar) giant HII region N66 using the Spitzer Space Telescope's Infrared Spectrograph. We study 14 targeted infrared point sources as well as spectra of the diffuse ISM that is representative of both the photodissociation regions (PDRs) and the HII regions. Among the point source spectra, we spectroscopically confirm that the brightest mid-infrared point source is a massive embedded young stellar object, we detect silicates in emission associated with two young stellar clusters, and we observe spectral features of a known B[e] supergiant that are more commonly associated with Herbig Be stars. In the diffuse ISM, we provide additional evidence that the very small grain population is being photodestroyed in the hard radiation field. The 11.3 um PAH complex emission exhibits an unexplained centroid shift in both the point source and ISM spectra that should be investigated...

  20. Spectral Confusion for Cosmological Surveys of Redshifted C II Emission

    Science.gov (United States)

    Kogut, A.; Dwek, E.; Moseley, S. H.

    2015-01-01

    Far-infrared cooling lines are ubiquitous features in the spectra of star-forming galaxies. Surveys of redshifted fine-structure lines provide a promising new tool to study structure formation and galactic evolution at redshifts including the epoch of reionization as well as the peak of star formation. Unlike neutral hydrogen surveys, where the 21 cm line is the only bright line, surveys of redshifted fine-structure lines suffer from confusion generated by line broadening, spectral overlap of different lines, and the crowding of sources with redshift. We use simulations to investigate the resulting spectral confusion and derive observing parameters to minimize these effects in pencilbeam surveys of redshifted far-IR line emission. We generate simulated spectra of the 17 brightest far-IR lines in galaxies, covering the 150-1300 µm wavelength region corresponding to redshifts 0 C II] line and other lines. Although the [C II] line is a principal coolant for the interstellar medium, the assumption that the brightest observed lines in a given line of sight are always [C II] lines is a poor approximation to the simulated spectra once other lines are included. Blind line identification requires detection of fainter companion lines from the same host galaxies, driving survey sensitivity requirements. The observations require moderate spectral resolution 700 < R < 4000 with angular resolution between 20? and 10', sufficiently narrow to minimize confusion yet sufficiently large to include a statistically meaningful number of sources.

  1. The composition of Titan's stratosphere from Cassini/CIRS mid-infrared spectra

    Science.gov (United States)

    Coustenis, Athena; Achterberg, Richard K.; Conrath, Barney J.; Jennings, Donald E.; Marten, André; Gautier, Daniel; Nixon, Conor A.; Flasar, F. Michael; Teanby, Nick A.; Bézard, Bruno; Samuelson, Robert E.; Carlson, Ronald C.; Lellouch, Emmanuel; Bjoraker, Gordon L.; Romani, Paul N.; Taylor, Fred W.; Irwin, Patrick G. J.; Fouchet, Thierry; Hubert, Augustin; Orton, Glenn S.; Kunde, Virgil G.; Vinatier, Sandrine; Mondellini, Jacqueline; Abbas, Mian M.; Courtin, Regis

    2007-07-01

    We have analyzed data recorded by the Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft during the Titan flybys T0-T10 (July 2004-January 2006). The spectra characterize various regions on Titan from 70° S to 70° N with a variety of emission angles. We study the molecular signatures observed in the mid-infrared CIRS detector arrays (FP3 and FP4, covering roughly the 600-1500 cm -1 spectral range with apodized resolutions of 2.54 or 0.53 cm -1). The composite spectrum shows several molecular signatures: hydrocarbons, nitriles and CO 2. A firm detection of benzene (C 6H 6) is provided by CIRS at levels of about 3.5×10 around 70° N. We have used temperature profiles retrieved from the inversion of the emission observed in the methane ν band at 1304 cm -1 and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan's stratosphere. No longitudinal variations were found for these gases. Little or no change is observed generally in their abundances from the south to the equator. On the other hand, meridional variations retrieved for these trace constituents from the equator to the North ranged from almost zero (no or very little meridional variations) for C 2H 2, C 2H 6, C 3H 8, C 2H 4 and CO 2 to a significant enhancement at high northern (early winter) latitudes for HCN, HC 3N, C 4H 2, C 3H 4 and C 6H 6. For the more important increases in the northern latitudes, the transition occurs roughly between 30 and 50 degrees north latitude, depending on the molecule. Note however that the very high-northern latitude results from tours TB-T10 bear large uncertainties due to few available data and problems with latitude smearing effects. The observed variations are consistent with some, but not all, of the predictions from dynamical-photochemical models. Constraints are set on the vertical distribution of C 2H 2, found to be compatible with 2-D equatorial predictions by global circulation

  2. Tunability of the dielectric function of heavily doped germanium thin films for mid-infrared plasmonics

    Science.gov (United States)

    Frigerio, Jacopo; Ballabio, Andrea; Isella, Giovanni; Sakat, Emilie; Pellegrini, Giovanni; Biagioni, Paolo; Bollani, Monica; Napolitani, Enrico; Manganelli, Costanza; Virgilio, Michele; Grupp, Alexander; Fischer, Marco P.; Brida, Daniele; Gallacher, Kevin; Paul, Douglas J.; Baldassarre, Leonetta; Calvani, Paolo; Giliberti, Valeria; Nucara, Alessandro; Ortolani, Michele

    2016-08-01

    Heavily doped semiconductor thin films are very promising for application in mid-infrared plasmonic devices because the real part of their dielectric function is negative and broadly tunable in the 5 to 50 μ m wavelength range at least. In this work, we investigate the electrodynamics of heavily n -type-doped germanium epilayers at infrared frequencies beyond the assumptions of the Drude model. The films are grown on silicon and germanium substrates, are in situ doped with phosphorous in the 1017 to 1019 cm-3 range, then screened plasma frequencies in the 100 to 1200 cm-1 range were observed. We employ infrared spectroscopy, pump-probe spectroscopy, and dc transport measurements to determine the tunability of the plasma frequency. Although no plasmonic structures have been realized in this work, we derive estimates of the decay time of mid-infrared plasmons and of their figures of merit for field confinement and for surface plasmon propagation. The average electron scattering rate increases almost linearly with excitation frequency, in agreement with quantum calculations based on a model of the ellipsoidal Fermi surface at the conduction band minimum of germanium accounting for electron scattering with optical phonons and charged impurities. Instead, we found weak dependence of plasmon losses on neutral impurity density. In films where a transient plasma was generated by optical pumping, we found significant dependence of the energy relaxation times in the few-picosecond range on the static doping level of the film, confirming the key but indirect role played by charged impurities in energy relaxation. Our results indicate that underdamped mid-infrared plasma oscillations are attained in n -type-doped germanium at room temperature.

  3. Atmospheric transmission and thermal background emission in the mid-infrared at Mauna Kea

    Science.gov (United States)

    Otárola, A.; Richter, M.; Packham, C.; Chun, M.

    2015-04-01

    We present results of a preliminary study intended to quantitatively estimate the atmospheric transmission and thermal background emission in the mid-infrared (MIR), 7 μm - 26 μm, at the 13N TMT site in Mauna Kea. This is in the interest of supporting the planning of MIR instrumentation for the posible second-generation of astronomical instruments for the Thirty Meter Telescope (TMT) project. Mauna Kea, located at high altitude (4,050 m above sea level), enjoys natural conditions that make it an outstanding location for astronomical observations in the mid-infrared. The goal of this work is to produce a dataset and model that shows the atmospheric transmission and thermal emission for two cases of precipitable water vapor (PWV), a low value of 0.3 mm, and at 1.5 mm which represent near median conditions at the site. Besides, and driven by the interest of the MIR community to exploit the daily twilight times, we look at the specific atmospheric conditions around twilight as a function of season. The best conditions are found for cold and dry winter days, and in particular the morning twilight offers the best conditions. The analysis of PWV data, shows the median value for the site (all year conditions between 6:00 PM and 7:30AM) is 1.8 mm and that periods of water vapor lower than 1.0 mm are common, these supports the opportunity and discovery potential of the TMT project in the mid-infrared bands.

  4. Giant Photoresponsivity of Mid-Infrared Hyperbolic Metamaterials in the Quantum Regime

    CERN Document Server

    Chen, Pai-Yen; Sakhdari, Maryam; Alù, Andrea

    2015-01-01

    We explore broadband, wide-angle mid-infrared rectification based on nanopatterned hyperbolic metamaterials (HMM), composed of two dissimilar metals separated by a sub-nanometer tunnel barrier. The exotic slow-light modes supported by such periodically trenched HMMs efficiently trap incident radiation in massively parallel metal-insulator-metal tunnel junctions supporting ultrafast optical rectification induced by photon-assisted tunneling. This leads to highly efficient photon-to-electron conversion, orders of magnitude larger than conventional rectennas. Our results promise an impact on infrared energy harvesters and plasmonic photodetectors.

  5. Demonstration of high-Q mid-infrared chalcogenide glass-on-silicon resonators.

    Science.gov (United States)

    Lin, Hongtao; Li, Lan; Zou, Yi; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Kozacik, Stephen; Murakowski, Maciej; Prather, Dennis; Lin, Pao T; Singh, Vivek; Agarwal, Anu; Kimerling, Lionel C; Hu, Juejun

    2013-05-01

    We demonstrated high-index-contrast, waveguide-coupled As2Se3 chalcogenide glass resonators monolithically integrated on silicon fabricated using optical lithography and a lift-off process. The resonators exhibited a high intrinsic quality factor of 2×10(5) at 5.2 μm wavelength, which is among the highest values reported in on-chip mid-infrared (mid-IR) photonic devices. The resonator can serve as a key building block for mid-IR planar photonic circuits.

  6. FIRST SCIENCE OBSERVATIONS WITH SOFIA/FORCAST: THE FORCAST MID-INFRARED CAMERA

    Energy Technology Data Exchange (ETDEWEB)

    Herter, T. L.; Adams, J. D.; Gull, G. E.; Schoenwald, J.; Henderson, C. P.; Nikola, T.; Stacey, G. [Astronomy Department, 202 Space Sciences Building, Cornell University, Ithaca, NY 14853-6801 (United States); De Buizer, J. M.; Vacca, W. D. [Universities Space Research Association, NASA Ames Research Center, MS 211-3, Moffett Field, CA 94035 (United States); Keller, L. D. [Department of Physics, Ithaca College, Ithaca, NY 14850 (United States)

    2012-04-20

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) completed its first light flight in May of 2010 using the facility mid-infrared instrument FORCAST. Since then, FORCAST has successfully completed 13 science flights on SOFIA. In this Letter, we describe the design, operation, and performance of FORCAST as it relates to the initial three Short Science flights. FORCAST was able to achieve near-diffraction-limited images for {lambda} > 30 {mu}m allowing unique science results from the start with SOFIA. We also describe ongoing and future modifications that will improve overall capabilities and performance of FORCAST.

  7. Indirect absorption spectroscopy using quantum cascade lasers: mid-infrared refractometry and photothermal spectroscopy.

    Science.gov (United States)

    Pfeifer, Marcel; Ruf, Alexander; Fischer, Peer

    2013-11-04

    We record vibrational spectra with two indirect schemes that depend on the real part of the index of refraction: mid-infrared refractometry and photothermal spectroscopy. In the former, a quantum cascade laser (QCL) spot is imaged to determine the angles of total internal reflection, which yields the absorption line via a beam profile analysis. In the photothermal measurements, a tunable QCL excites vibrational resonances of a molecular monolayer, which heats the surrounding medium and changes its refractive index. This is observed with a probe laser in the visible. Sub-monolayer sensitivities are demonstrated.

  8. Evidence for Dynamical Changes in a Transitional Protoplanetary Disk with Mid-infrared Variability

    CERN Document Server

    Muzerolle, James; Balog, Zoltan; Furlan, Elise; Smith, Paul S; Allen, Lori; Calvet, Nuria; D'Alessio, Paola; Megeath, S Thomas; Muench, August; Rieke, George H; Sherry, William H

    2009-01-01

    We present multi-epoch Spitzer Space Telescope observations of the transitional disk LRLL 31 in the 2-3 Myr-old star forming region IC 348. Our measurements show remarkable mid-infrared variability on timescales as short as one week. The infrared continuum emission exhibits systematic wavelength-dependent changes that suggest corresponding dynamical changes in the inner disk structure and variable shadowing of outer disk material. We propose several possible sources for the structural changes, including a variable accretion rate or a stellar or planetary companion embedded in the disk. Our results indicate that variability studies in the infrared can provide important new constraints on protoplanetary disk behavior.

  9. Mid-Infrared Conductivity from Mid-Gap States Associated with Charge Stripes

    OpenAIRE

    Homes, C. C.; Tranquada, J. M.; Li, Q; Moodenbaugh, A. R.; Buttrey, D. J.

    2002-01-01

    The optical conductivity of La(2-x)Sr(x)NiO(4) has been interpreted in various ways, but so far the proposed interpretations have neglected the fact that the holes doped into the NiO(2) planes order in diagonal stripes, as established by neutron and X-ray scattering. Here we present a study of optical conductivity in La(2)NiO(4+d) with d=2/15, a material in which the charge stripes order three-dimensionally. We show that the conductivity can be decomposed into two components, a mid-infrared p...

  10. Improving the mid-infrared energy absorption efficiency by using a dual-band metamaterial absorber

    Institute of Scientific and Technical Information of China (English)

    Nan Zhang; Peiheng Zhoun; Shifeng Zou; Xiaolong Weng; Jianliang Xie; Longjiang Deng

    2014-01-01

    In this paper, a dual-band mid-infrared metamaterial absorber was proposed to improve the energy absorption efficiency. Up to 99%absorption was obtained at 9.03 and 11.83μm in the simulation, and each absorption band can be tuned by the dielectric spacing layer, i.e., the dielectric constant and its thickness. The dual-band absorption mechanism was analyzed, and the quite well absorption performance at large incident angles was also presented. The results of this study can be applied in the field of thermal absorbing and solar energy harvesting.

  11. Terahertz Generation in Nonlinear Crystals with Mid-Infrared CO2 Laser

    Institute of Scientific and Technical Information of China (English)

    LU Yan-Zhao; WANG Xin-Bing; MIAO Liang; ZUO Du-Luo; CHENG Zu-Hai

    2011-01-01

    The terahertz(THz)generation based on difference frequency generation in nonlinear optical crystals pumped by mid-infrared C02 laser has been investigated.We present a comprehensive study of the phase-matching conditions in the GaSe, ZnGeP2 and GaAs crystals. A comparison of the characteristics of these crystals as the THz frequency generator is also presented. The investigation of the conversion efficiency shows that GaSe and GaAs are the most promising nonlinear crystals for the efficient and widely tunable THz generation.

  12. First Science Observations with SOFIA/FORCAST: The FORCAST Mid-infrared Camera

    CERN Document Server

    Herter, T L; De Buizer, J M; Gull, G E; Schoenwald, J; Henderson, C P; Keller, L D; Nikola, T; Stacey, G; Vacca, W D

    2012-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) completed its first light flight in May of 2010 using the facility mid-infrared instrument FORCAST. Since then, FORCAST has successfully completed thirteen science flights on SOFIA. In this paper we describe the design, operation and performance of FORCAST as it relates to the initial three Short Science flights. FORCAST was able to achieve near diffraction-limited images for lambda > 30 microns allowing unique science results from the start with SOFIA. We also describe ongoing and future modifications that will improve overall capabilities and performance of FORCAST.

  13. Mid-infrared intersubband absorption from p-Ge quantum wells grown on Si substrates

    Energy Technology Data Exchange (ETDEWEB)

    Gallacher, K.; Millar, R. W.; Paul, D. J., E-mail: Douglas.Paul@glasgow.ac.uk [School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT (United Kingdom); Ballabio, A.; Frigerio, J.; Isella, G. [L-NESS, Dipartimento di Fisica del Politecnico di Milano, Polo Territoriale di Como, Via Anzani 42, Como I-22100 (Italy); Bashir, A.; MacLaren, I. [School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow G12 8QQ (United Kingdom); Ortolani, M. [Center for Life NanoScience@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena 291, Rome I-00161 (Italy)

    2016-02-29

    Mid-infrared intersubband absorption from p-Ge quantum wells with Si{sub 0.5}Ge{sub 0.5} barriers grown on a Si substrate is demonstrated from 6 to 9 μm wavelength at room temperature and can be tuned by adjusting the quantum well thickness. Fourier transform infra-red transmission and photoluminescence measurements demonstrate clear absorption peaks corresponding to intersubband transitions among confined hole states. The work indicates an approach that will allow quantum well intersubband photodetectors to be realized on Si substrates in the important atmospheric transmission window of 8–13 μm.

  14. Widely Tunable Monolithic Mid-Infrared Quantum Cascade Lasers Using Super-Structure Grating Reflectors

    OpenAIRE

    Dingkai Guo; Jiun-Yun Li; Liwei Cheng; Xing Chen; Terry Worchesky; Fow-Sen Choa

    2016-01-01

    A monolithic, three-section, and widely tunable mid-infrared (mid-IR) quantum cascade laser (QCL) is demonstrated. This electrically tuned laser consists of a gain section placed between two super structure grating (SSG) distributed Bragg reflectors (DBRs). By varying the injection currents to the two grating sections of this device, its emission wavelength can be tuned from 4.58 μm to 4.77 μm (90 cm−1) with a supermode spacing of 30 nm. This type of SSG-DBR QCLs can be a compact replacement ...

  15. Design of mid-infrared ultra-wideband metallic absorber based on circuit theory

    Science.gov (United States)

    Arik, Kamalodin; Abdollahramezani, Sajjad; Farajollahi, Saeed; Khavasi, Amin; Rejaei, Behzad

    2016-12-01

    An ultra-broadband absorber of light is proposed by using periodic array of ultra-thin metallic ribbons on top of a lossless quarter-wavelength dielectric spacer placed on a metallic reflector. We propose a fully analytical circuit model for the structure, and then the absorber is duly designed based on the impedance matching concept. As a result, normalized bandwidth of 99.5% is realized by the proposed absorbing structure in mid-infrared regime. Performing a numerical optimization algorithm, we could also reach to normalized bandwidth of 103%.

  16. Mid-infrared observations of sungrazing comet C/2012 S1 (ISON) with the Subaru Telescope

    Science.gov (United States)

    Ootsubo, T.; Usui, F.; Takita, S.; Watanabe, J.; Yanamandra-Fisher, P.; Honda, M.; Kawakita, H.; Furusho, R.

    2014-07-01

    Comets are the frozen reservoirs of the early solar nebula and are made of ice and dust. The determination of the properties for cometary dust provides us insight into both the early-solar-nebula environment and the formation process of the planetary system. A silicate feature is often observed in comet spectra in the mid-infrared region and may be used for probing the early history of the solar system. In most cases, the feature shows the existence of crystalline silicate (for example, 11.3 microns) together with amorphous silicate [1,2]. Since the crystallization of silicates from amorphous ones generally requires high-temperature annealing above 800 K (e.g., [3,4]), it is believed that the crystalline silicate grains produced at the inner part of the disk were transported to the outer cold regions where the comet nuclei formed. Comet C/2012 S1 (ISON) is a long-period Oort Cloud comet, discovered in September 2012. In particular, comet ISON is a sungrazing comet, which was predicted to pass close by the Sun and the Earth and becoming a bright object. Mid-infrared observations of this new comet and investigation of the 10-micron silicate feature help us understand the formation of crystalline silicate grains in the early solar nebula. We conducted observations of comet ISON in the mid-infrared wavelength region with the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on the Subaru Telescope on Mauna Kea, Hawaii [5,6,7]. The observation of comet ISON was carried out on 2013 October 19 and 21 UT. Since the weather conditions were not so good when we observed, we carried out N-band imaging observations (8.8 and 12.4 microns) and N-band low-resolution spectroscopy. The spectrum of comet ISON can be fit with the 260--265-K blackbody spectrum when we use the regions of 7.8--8.2 and 12.4--13.0 microns as the continuum. The spectrum has only a weak silicate excess feature, which may be able to attribute to small amorphous olivine grains. We could not detect a clear

  17. Prediction of bovine milk true protein content by mid-infrared spectroscopy

    OpenAIRE

    Botaro,Bruno Garcia; CORTINHAS, Cristina Simões; Mestieri, Lucinéia; Machado,Paulo Fernando; Santos, Marcos Veiga dos

    2011-01-01

    The aim of this study was to estimate the concentration of milk true protein (TP) by mid-infrared absorbance method (MIR) in samples from bulk tank of dairy herds, and to determine the correlation between the results of TP of milk determined by Kjeldahl and MIR. Forty nine dairy herds were selected (17 Holstein, 6 Jersey and 26 Girolando) for monthly collections of samples from bulk tanks during the period of one year (284 samples). Fat, lactose, crude protein and total solids were firstly de...

  18. Validation of MODIS-derived bidirectional reflectivity retrieval algorithm in mid-infrared channel with field measurements.

    Science.gov (United States)

    Tang, Bo-Hui; Wu, Hua-; Li, Zhao-Liang; Nerry, Françoise

    2012-07-30

    This work addressed the validation of the MODIS-derived bidirectional reflectivity retrieval algorithm in mid-infrared (MIR) channel, proposed by Tang and Li [Int. J. Remote Sens. 29, 4907 (2008)], with ground-measured data, which were collected from a field campaign that took place in June 2004 at the ONERA (Office National d'Etudes et de Recherches Aérospatiales) center of Fauga-Mauzac, on the PIRRENE (Programme Interdisciplinaire de Recherche sur la Radiométrie en Environnement Extérieur) experiment site [Opt. Express 15, 12464 (2007)]. The leaving-surface spectral radiances measured by a BOMEM (MR250 Series) Fourier transform interferometer were used to calculate the ground brightness temperatures with the combination of the inversion of the Planck function and the spectral response functions of MODIS channels 22 and 23, and then to estimate the ground brightness temperature without the contribution of the solar direct beam and the bidirectional reflectivity by using Tang and Li's proposed algorithm. On the other hand, the simultaneously measured atmospheric profiles were used to obtain the atmospheric parameters and then to calculate the ground brightness temperature without the contribution of the solar direct beam, based on the atmospheric radiative transfer equation in the MIR region. Comparison of those two kinds of brightness temperature obtained by two different methods indicated that the Root Mean Square Error (RMSE) between the brightness temperatures estimated respectively using Tang and Li's algorithm and the atmospheric radiative transfer equation is 1.94 K. In addition, comparison of the hemispherical-directional reflectances derived by Tang and Li's algorithm with those obtained from the field measurements showed that the RMSE is 0.011, which indicates that Tang and Li's algorithm is feasible to retrieve the bidirectional reflectivity in MIR channel from MODIS data.

  19. Rising from the Ashes: Mid-Infrared Re-Brightening of the Impostor SN 2010da in NGC 300

    CERN Document Server

    Lau, Ryan M; Bond, Howard E; Smith, Nathan; Fox, Ori D; Carlon, Robert; Cody, Ann Marie; Contreras, Carlos; Dykhoff, Devin; Gerhz, Robert; Hsiao, Eric; Jencson, Jacob; Khan, Rubab; Masci, Frank; Monard, L A G; Monson, Andrew J; Morrell, Nidia; Phillips, Mark; Ressler, Michael E

    2016-01-01

    We present multi-epoch mid-infrared (IR) photometry and the optical discovery observations of the "impostor" supernova (SN) 2010da in NGC 300 using new and archival Spitzer Space Telescope images and ground-based observatories. The mid-IR counterpart of SN 2010da was detected as SPIRITS 14bme in the SPitzer InfraRed Intensive Transient Survey (SPIRITS), an ongoing systematic search for IR transients. A sharp increase in the 3.6 $\\mu$m flux followed by a rapid decrease measured ~150 d before and ~80 d after the initial outburst, respectively, reveal a mid-IR counterpart to the coincident optical and high luminosity X-ray outbursts. At late times after the outburst (~2000 d), the 3.6 and 4.5 $\\mu$m emission increased to over a factor of 2 times the progenitor flux. We attribute the re-brightening mid-IR emission to continued dust production and increasing luminosity of the surviving system associated with SN 2010da. We analyze the evolution of the dust temperature, mass, luminosity, and equilibrium temperature ...

  20. Mid-infrared dust in two nearby radio galaxies, NGC 1316 (Fornax A) and NGC 612 (PKS 0131-36)

    CERN Document Server

    Asabere, B Duah; Jarrett, T; Winkler, H

    2016-01-01

    Most radio galaxies are hosted by giant gas-poor ellipticals, but some contain significant amounts of dust, which is likely to be of external origin. In order to characterize the mid-IR properties of two of the most nearby and brightest merger-remnant radio galaxies of the Southern hemisphere, NGC 1316 (Fornax A) and NGC 612 (PKS 0131-36), we used observations with the Wide-field Infrared Survey Explorer (WISE) at wavelengths of 3.4, 4.6, 12 and 22 micron and Spitzer mid-infrared spectra. By applying a resolution-enhancement technique, new WISE images were produced at angular resolutions ranging from 2.6" to 5.5". Global measurements were performed in the four WISE bands, and stellar masses and star-formation rates were estimated using published scaling relations. Two methods were used to uncover the distribution of dust, one relying on two-dimensional fits to the 3.4 micron images to model the starlight, and the other one using a simple scaling and subtraction of the 3.4 micron images to estimate the stellar...

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

    Picosecond optical parametric generation and amplification in the near-infrared region within 1.361-1.656 μm and the mid-infrared region within 2.976-4.875 μm is constructed on the basis of bulk MgO:LiNbO3 crystals pumped at 1.064 μm.The maximum pulse energy reaches 1.3 mJ at 1.464 μm and 0.47 mJ at 3.894 μm,corresponding to a pumpto-idler photon conversion efficiency of 25%.By seeding the hard-to-measure mid-infrared radiation as the idler in the optical parametric amplification and measuring the amplified and frequency up-converted signal in the near-infrared or even visible region,one can measure very week mid-infrared radiation with ordinary detectors,which are insensitive to mid-infrared radiation,with a very high gain.A maximum gain factor of about 7 x 107 is achieved at the mid-infrared wavelength of 3.374 μm and the corresponding energy detection limit is as low as about 390 aJ per pulse.

  2. Mid-Infrared Imaging of Exo-Earths: Impact of Exozodiacal Disk Structures

    Science.gov (United States)

    Defrere, Denis; Absil, O.; Stark, C.; den Hartog, R.; Danchi, W.

    2011-01-01

    The characterization of Earth-like extrasolar planets in the mid-infrared is a significant observational challenge that could be tackled by future space-based interferometers. The presence of large amounts of exozodiacal dust around nearby main sequence stars represents however a potential hurdle to obtain mid-infrared spectra of Earth-like planets. Whereas the disk brightness only affects the integration time, the emission of resonant dust structures mixes with the planet signal at the output of the interferometer and could jeopardize the spectroscopic analysis of an Earth-like planet. Fortunately, the high angular resolution provided by space-based interferometry is sufficient to spatially distinguish most of the extended exozodiacal emission from the planetary signal and only the dust located near the planet significantly contributes to the noise level. Considering modeled resonant structures created by Earth-like planets, we address in this talk the role of exozodiacal dust in two different cases: the characterization of Super-Earth planets with single space-based Bracewell interferometers (e.g., the FKSI mission) and the characterization of Earth-like planets with 4-telescope space-based nulling interferometers (e.g., the TPF-I and Darwin projects). In each case, we derive constraints on the disk parameters that can be tolerated without jeopardizing the detection of Earth-like planets

  3. Long-period suspended silicon Bragg grating filter for hybrid near- and mid-infrared operation

    CERN Document Server

    Alonso-Ramos, Carlos; Benedikovic, Daniel; Vakarin, Vladyslav; Duran-Valdeiglesias, Elena; Perez-Galacho, Diego; Cassan, Eric; Marris-Morini, Delphine; Cheben, Pavel; Vivien, Laurent

    2016-01-01

    The large transparency window of silicon, covering the 1.1 um 8 um wavelength range, makes it a promising platform for the implementation of photothermal-based absorption spectrometers. These devices indirectly sense absorption in the mid-infrared (MIR) by using near-infrared (NIR) wavelengths, thereby enabling the realization of MIR absorption spectrometers without the need for MIR photodetectors. Nevertheless, due to their comparatively large index contrast and cross-sections, MIR Si strip waveguides are multi-mode at NIR wavelengths, hindering device implementation. Here we present, for the first time, an integrated Bragg grating waveguide filter for hybrid near- and mid-infrared operation. Specifically, the filter is implemented in a single-etch suspended silicon corrugated waveguide with an effectively single-mode operation in NIR region for a waveguide cross-section as large as 0.5 um x 1.1 um. At the same time, the waveguide supports single-mode propagation in MIR region. We demonstrate a long-period w...

  4. Invited review: Mid-infrared spectroscopy as phenotyping tool for milk traits.

    Science.gov (United States)

    De Marchi, M; Toffanin, V; Cassandro, M; Penasa, M

    2014-03-01

    Interest in methods that routinely and accurately measure and predict animal characteristics is growing in importance, both for quality characterization of livestock products and for genetic purposes. Mid-infrared spectroscopy (MIRS) is a rapid and cost-effective tool for recording phenotypes at the population level. Mid-infrared spectroscopy is based on crossing matter by electromagnetic radiation and on the subsequent measure of energy absorption, and it is commonly used to determine traditional milk quality traits in official milk laboratories. The aim of this review was to focus on the use of MIRS to predict new milk phenotypes of economic relevance such as fatty acid and protein composition, coagulation properties, acidity, mineral composition, ketone bodies, body energy status, and methane emissions. Analysis of the literature demonstrated the feasibility of MIRS to predict these traits, with different accuracies and with margins of improvement of prediction equations. In general, the reviewed papers underlined the influence of data variability, reference method, and unit of measurement on the development of robust models. A crucial point in favor of the application of MIRS is to stimulate the exchange of data among countries to develop equations that take into account the biological variability of the studied traits under different conditions. Due to the large variability of reference methods used for MIRS calibration, it is essential to standardize the methods used within and across countries.

  5. An interferometric study of the Fomalhaut inner debris disk II. Keck Nuller mid-infrared observations

    CERN Document Server

    Mennesson, B; Lebreton, J; Augereau, J -C; Serabyn, E; Colavita, M M; Millan-Gabet, R; Liu, W; Hinz, P; Thebault, P

    2012-01-01

    We report on high contrast mid-infrared observations of Fomalhaut obtained with the Keck Interferometer Nuller (KIN) showing a small resolved excess over the level expected from the stellar photosphere. The measured null excess has a mean value of 0.35% +/- 0.10% between 8 and 11 microns and increases from 8 to 13 microns. Given the small field of view of the instrument, the source of this marginal excess must be contained within 2AU of Fomalhaut. This result is reminiscent of previous VLTI K-band observations, which implied the presence of a ~ 0.88% excess, and argued that thermal emission from hot dusty grains located within 6 AU from Fomalhaut was the most plausible explanation. Using a parametric 2D radiative transfer code and a Bayesian analysis, we examine different dust disk structures to reproduce both the near and mid-infrared data simultaneously. While not a definitive explanation of the hot excess of Fomalhaut, our model suggests that the most likely inner few AU disk geometry consists of a two-com...

  6. The mid-infrared emission of Seyfert galaxies. A new analysis of ISOCAM data

    CERN Document Server

    Almeida, Cristina Ramos; Acosta-Pulido, Jose Antonio; Espinosa, Jose Miguel Rodriguez

    2007-01-01

    We present mid-infrared data of a sample of 57 AGNs obtained with the instrument ISOCAM on board the satellite ISO. The images were obtained through the LW2 (6.75 microns) and LW7 (9.62 microns) filters. This is a new analysis of Clavel et al. (2000) galaxy sample, which is divided into 26 type 1 ( 1.5) Seyfert galaxies, plus three QSOs. The spatial resolution of the images allow us to separate the nuclear and the extended contributions to the total emission after decomposing the brightness profiles into different morphological components. The most common components are a central point source (identified as the active nucleus) and an exponential disk. In some cases a bulge, a bar or a ring are needed. The relative contribution of the nucleus to the total emission appears larger in Seyfert 1 than in Seyfert 2. This result confirms that both types of Seyfert galaxies are different in the mid-infrared and supports the existence of an structure which produces anisotropic emission in this wavelength range. We have...

  7. Widely tunable rapid-scanning mid-infrared laser spectrometer for industrial gas process stream analysis.

    Science.gov (United States)

    Bamford, Douglas J; Cook, David J; Sharpe, Scott J; Van Pelt, Aaron D

    2007-07-01

    A mid-infrared spectrometer with a tuning range of >400 cm(-1) in the C-H stretching region of the spectrum has been designed and constructed. The spectrometer is based on the difference-frequency generation of two tunable diode lasers in periodically poled lithium niobate waveguides. Tuning is achieved by varying a single parameter, the wavelength of one of the near-infrared input lasers. The instrument can be tuned over the entire tuning range in less than 1 s. By taking advantage of the wide tuning range, the instrument has been used to analyze a mixture of methane, ethylene, and propylene. Each of these major components was measured with an accuracy of better than 2% (where the error is defined as a percentage of the measured value) in a single 30 s long scan. When optimized, the spectrometer has the potential to meet both the performance requirements and the practical requirements for real-time process control in petrochemical manufacturing. The general principles for the design of mid-infrared spectrometers with wide tuning ranges are explained, including the use of variable waveguide fabrication recipes to create broad phase-matching resonances (which lead to broad tuning) in the desired location.

  8. Mid-infrared interferometry of 23 AGN tori: On the significance of polar-elongated emission

    CERN Document Server

    López-Gonzaga, N; Tristram, K R W; Meisenheimer, K; Schartmann, M

    2016-01-01

    Context. Detailed high resolution studies of AGN with mid-infrared (MIR) interferometry have revealed parsec-sized dust emission elongated in the polar direction in four sources. Aims. Using a larger, coherently analyzed sample of AGN observed with MIR interferometry, we aim to identify elongated mid-infrared emission in a statistical sample of sources. More specifically we wish to determine if there is indeed a preferred direction of the elongation and whether this direction is consistent with a torus-like structure or with a polar emission. Methods. We investigate the significance of the detection of an elongated shape in the MIR emission by fitting elongated Gaussian models to the interferometric data at 12 um. We pay special attention to 1) the uncertainties caused by an inhomogeneous (u,v) coverage, 2) the typical errors in the measurements and 3) the spatial resolution achieved for each object. Results. From our sample of 23 sources we are able to find elongated parsec-scale MIR emission in five sources...

  9. Discovery of a strong Baldwin effect in mid-infrared AGN lines

    CERN Document Server

    Hoenig, S F; Beckert, T; Horst, H; Duschl, W; Gandhi, P; Kishimoto, M; Weigelt, G

    2008-01-01

    We present the discovery of a Baldwin effect in 8 nearby Seyfert galaxies for the three most prominent mid-infrared forbidden emission lines observable from the ground that are commonly found in AGN, [ArIII](8.99 micron), [SIV](10.51 micron), and [NeII](12.81 micron). The observations were carried out using the VLT/VISIR imager and spectroraph at the ESO/Paranal observatory. The bulk of the observed line emission comes from the inner <0.4 arcsec which corresponds to spatial scales <100 pc in our object sample. The correlation index is approximately -0.6 without significant difference among the lines. This is the strongest anti-correlation between line equivalent width and continuum luminosity found so far. In the case of Circinus, we show that despite the use of mid-infrared lines, obscuration by either the host galaxy or the circumnuclear dust torus might affect the equivalent widths. Given the small observed spatial scales from which most of the line emission emanates, it is unclear how these observat...

  10. Wireless Mid-Infrared Spectroscopy Sensor Network for Automatic Carbon Dioxide Fertilization in a Greenhouse Environment

    Directory of Open Access Journals (Sweden)

    Jianing Wang

    2016-11-01

    Full Text Available In this paper, a wireless mid-infrared spectroscopy sensor network was designed and implemented for carbon dioxide fertilization in a greenhouse environment. A mid-infrared carbon dioxide (CO2 sensor based on non-dispersive infrared (NDIR with the functionalities of wireless communication and anti-condensation prevention was realized as the sensor node. Smart transmission power regulation was applied in the wireless sensor network, according to the Received Signal Strength Indication (RSSI, to realize high communication stability and low-power consumption deployment. Besides real-time monitoring, this system also provides a CO2 control facility for manual and automatic control through a LabVIEW platform. According to simulations and field tests, the implemented sensor node has a satisfying anti-condensation ability and reliable measurement performance on CO2 concentrations ranging from 30 ppm to 5000 ppm. As an application, based on the Fuzzy proportional, integral, and derivative (PID algorithm realized on a LabVIEW platform, the CO2 concentration was regulated to some desired concentrations, such as 800 ppm and 1200 ppm, in 30 min with a controlled fluctuation of <±35 ppm in an acre of greenhouse.

  11. How useful is the mid-infrared spectroscopy in the assessment of black carbon in soils

    Directory of Open Access Journals (Sweden)

    J.M. de la Rosa

    2013-09-01

    Full Text Available Black carbon (BC, the recalcitrant continuum of products from incomplete combustion, includes char, charcoal and soot, being considered an important component of the global C cycle. However due to measurement uncertainties, the magnitude and distribution of BC is hardly known. In this study, a rapid and inexpensive spectroscopic technique, as it is mid-infrared spectroscopy in combination with oxidation procedures is proposed to quantify the recalcitrant aromatic fraction resistant, which can effectively determine the proportion of BC in soils. This method was tested by using a wide variety soil samples of various origin, composition and properties. Results were contrasted by those obtained by applying solid-state Nuclear Magnetic Resonance (NMR spectroscopy. Mid-infrared spectroscopy showed a very high predicting potential in the case of samples with large concentrations of BC by taking advantage of the relative optical density of the 2920 cm-1 C–H stretching band. In the case of soils with low BC contents, the application of Partial Least Square Regression to baseline-subtracted, second-derivative Fourier-Transformed Infra-red (FT-IR spectra lead to significant (P<0.05 cross-validation models. By this procedure a considerable improvement in forecasting the aromatic fraction resistant to the chemical oxidation steps (BC-like material was obtained.

  12. Nanoparticle probes and mid-infrared chemical imaging for DNA microarray detection.

    Science.gov (United States)

    Mossoba, Magdi M; Al-Khaldi, Sufian F; Schoen, Brianna; Yakes, Betsy Jean

    2010-11-01

    To date most mid-infrared spectroscopic studies have been limited, due to lack of sensitivity, to the structural characterization of a single oligonucleotide probe immobilized over the entire surface of a gold-coated slide or other infrared substrate. By contrast, widely used and commercially available glass slides and a microarray spotter that prints approximately 120-μm-diameter DNA spots were employed in the present work. To our knowledge, mid-infrared chemical imaging (IRCI) in the external reflection mode has been applied in the present study for the first time to the detection of nanostructure-based DNA microarrays spotted on glass slides. Alkyl amine-modified oligonucleotide probes were immobilized on glass slides that had been prefunctionalized with succinimidyl ester groups. This molecular fluorophore-free method entailed the binding of gold-nanoparticle-streptavidin conjugates to biotinylated DNA targets. Hybridization was visualized by the silver enhancement of gold nanoparticles. The adlayer of silver, selectively bound only to hybridized spots in a microarray, formed the external reflective infrared substrate that was necessary for the detection of DNA hybridization by IRCI in the present proof-of-concept study. IRCI made it possible to discriminate between diffuse and specular external reflection modes. The promising qualitative results are presented herein, and the implications for quantitative determination of DNA microarrays are discussed.

  13. [The correlation based mid-infrared temperature and emissivity separation algorithm].

    Science.gov (United States)

    Cheng, Jie; Nie, Ai-Xiu; Du, Yong-Ming

    2009-02-01

    Temperature and emissivity separation is the key problem in infrared remote sensing. Based on the analysis of the relationship between the atmospheric downward radiance and surface emissivity containing atmosphere residue without the effects of sun irradiation, the present paper puts forward a temperature and emissivity separation algorithm for the ground-based mid-infrared hyperspectral data. The algorithm uses the correlation between the atmospheric downward radiance and surface emissivity containing atmosphere residue as a criterion to optimize the surface temperature, and the correlation between the atmospheric downward radiance and surface emissivity containing atmosphere residue depends on the bias between the estimated surface temperature and true surface temperature. The larger the temperature bias, the greater the correlation. Once we have obtained the surface temperature, the surface emissivity can be calculated easily. The accuracy of the algorithm was evaluated with the simulated mid-infrared hyperspectral data. The results of simulated calculation show that the algorithm can achieve higher accuracy of temperature and emissivity inversion, and also has broad applicability. Meanwhile, the algorithm is insensitive to the instrumental random noise and the change in atmospheric downward radiance during the field measurements.

  14. Wireless Mid-Infrared Spectroscopy Sensor Network for Automatic Carbon Dioxide Fertilization in a Greenhouse Environment.

    Science.gov (United States)

    Wang, Jianing; Niu, Xintao; Zheng, Lingjiao; Zheng, Chuantao; Wang, Yiding

    2016-11-18

    In this paper, a wireless mid-infrared spectroscopy sensor network was designed and implemented for carbon dioxide fertilization in a greenhouse environment. A mid-infrared carbon dioxide (CO₂) sensor based on non-dispersive infrared (NDIR) with the functionalities of wireless communication and anti-condensation prevention was realized as the sensor node. Smart transmission power regulation was applied in the wireless sensor network, according to the Received Signal Strength Indication (RSSI), to realize high communication stability and low-power consumption deployment. Besides real-time monitoring, this system also provides a CO₂ control facility for manual and automatic control through a LabVIEW platform. According to simulations and field tests, the implemented sensor node has a satisfying anti-condensation ability and reliable measurement performance on CO₂ concentrations ranging from 30 ppm to 5000 ppm. As an application, based on the Fuzzy proportional, integral, and derivative (PID) algorithm realized on a LabVIEW platform, the CO₂ concentration was regulated to some desired concentrations, such as 800 ppm and 1200 ppm, in 30 min with a controlled fluctuation of <±35 ppm in an acre of greenhouse.

  15. Towards an Understanding of the Mid-Infrared Surface Brightness of Normal Galaxies

    CERN Document Server

    Dale, D A; Silbermann, N A; Contursi, A; Malhotra, S; Rubin, R H; Dale, Daniel A.; Helou, George; Silbermann, Nancy A.; Contursi, Alessandra; Malhotra, Sangeeta; Rubin, Robert H.

    1999-01-01

    We report a mid-infrared color and surface brightness analysis of IC 10, NGC 1313, and NGC 6946, three of the nearby galaxies studied under the Infrared Space Observatory Key Project on Normal Galaxies. Images with < 9 arcsecond (170 pc) resolution of these nearly face-on, late-type galaxies were obtained using the LW2 (6.75 mu) and LW3 (15 mu) ISOCAM filters. Though their global I_nu(6.75 mu)/I_nu(15 mu) flux ratios are similar and typical of normal galaxies, they show distinct trends of this color ratio with mid-infrared surface brightness. We find that I_nu(6.75 mu)/I_nu(15 mu) ~< 1 only occurs for regions of intense heating activity where the continuum rises at 15 micron and where PAH destruction can play an important role. The shape of the color-surface brightness trend also appears to depend, to the second-order, on the hardness of the ionizing radiation. We discuss these findings in the context of a two-component model for the phases of the interstellar medium and suggest that star formation inte...

  16. Mathematical Modeling on Combined Mid-infrared and Hot Air Drying of Beef Meat

    Directory of Open Access Journals (Sweden)

    Xiao-Lei Xie

    2015-05-01

    Full Text Available To investigate the drying models and characteristics of Combined Mid-Infrared and Hot Air (CMIHA drying BEEF MEAT (BM, a laboratory scale CMIHA dryer was applied to the treatment of BM samples in a temperature range from 40-70°C, with air velocity of 1m/s and mid-infrared of 2.8-3.1 m. Microsoft visual C sharp (C# was used to develop a Moisture Prediction System (MPS to digitize the prediction process. The results indicated that the Modified Henderson and Pabis model could present better predictions for the moisture transfer than others and the MPS could predict the moisture ratio through the whole drying process conveniently. Besides, higher temperature could accelerate effective diffusivities to increase drying rate, thus shorten the drying time. The activation energy of BM dried with CMIHA was 32.83 kJ/mol. All of these could be used in the design and operation of the combination drying beef meat.

  17. Mid-Infrared Resolution of a 3 AU Radius Debris Disk around ζ Leporis

    Science.gov (United States)

    Moerchen, M. M.; Telesco, C. M.; Packham, C.; Kehoe, T. J. J.

    2007-02-01

    We present subarcsecond-resolution mid-infrared images of the debris disk surrounding the 230 Myr old A star ζ Lep. Our data obtained with T-ReCS at Gemini South show the source to be unresolved at 10.4 μm but clearly extended at 18.3 μm. Quadratic subtraction of the PSF profile from that of ζ Lep implies a characteristic radius for the dust disk of 3 AU, which is comparable in size to our solar system's asteroid belt. Simple models suggest that the 18 μm flux is well approximated by two contiguous annuli of mid-infrared-emitting dust from 2-4 and 4-8 AU with a 3:1 flux ratio for the annuli, respectively. We consider two scenarios for the collisions that must be resupplying the dust population: (1) continuous ``steady state'' grinding of planetesimals and (2) an isolated cataclysmic collision. We determine that radiation pressure and subsequent collisions are the dominant determinants of the disk morphology in either case and that Poynting-Robertson drag is comparatively insignificant. Observations were obtained at the Gemini Observatory, operated by AURA, Inc., under agreement with the NSF on behalf of the Gemini partnership: NSF (US), PPARC (UK), NRC (Canada), CONICYT (Chile), ARC (Australia), CNPq (Brazil), and CONICET (Argentina).

  18. Large scale prediction of soil properties in the West African yam belt based on mid-infrared soil spectroscopy

    Science.gov (United States)

    Baumann, Philipp; Lee, Juhwan; Paule Schönholzer, Laurie; Six, Johan; Frossard, Emmanuel

    2016-04-01

    Yam (Dioscorea sp.) is an important staple food in West Africa. Fertilizer applications have variable effects on yam tuber yields, and a management option solely based on application of mineral NPK fertilizers may bear the risk of increased organic matter mineralization. Therefore, innovative and sustainable nutrient management strategies need to be developed and evaluated for yam cultivation. The goal of this study was to establish a mid-infrared soil spectroscopic library and models to predict soil properties relevant to yam growth. Soils from yam fields at four different locations in Côte d'Ivoire and Burkina Faso that were representative of the West African yam belt were sampled. The project locations ranged from the humid forest zone (5.88 degrees N) to the northern Guinean savannah (11.07 degrees N). At each location, soils of 20 yam fields were sampled (0-30 cm). For the location in the humid forest zone additional 14 topsoil samples from positions that had been analyzed in the Land Degradation Surveillance Framework developed by ICRAF were included. In total, 94 soil samples were analyzed using established reference analysis protocols. Besides soils were milled and then scanned by fourier transform mid-infrared spectroscopy in the range between 400 and 4000 reciprocal cm. Using partial least squares (PLS) regression, PLS1 calibration models that included soils from the four locations were built using two thirds of the samples selected by Kennard-Stones sampling algorithm in the spectral principal component space. Models were independently validated with the remaining data set. Spectral models for total carbon, total nitrogen, total iron, total aluminum, total potassium, exchangeable calcium, and effective cation exchange capacity performed very well, which was indicated by R-squared values between 0.8 and 1.0 on both calibration and validation. For these soil properties, spectral models can be used for cost-effective, rapid, and accurate predictions

  19. Development of a Broadly Tunable Mid-Infrared Laser Source for Highly Sensitive Multiple Trace Gas Detection

    Institute of Scientific and Technical Information of China (English)

    Xiao-Juan Cui; Feng-Zhong Dong; Yu-Jun Zhang; Rui-Feng Kan; Yi-Ben Cui; Min Wang; Dong Chen; Jian-Guo Liu; Wen-Qing Liu

    2008-01-01

    A room-temperature broadly tunable mid-infrared difference frequency laser source for highly sensitive trace gas detection has been developed recently in our laboratory. The mid-infrared laser system is based on quasi-phase-matched (QPM) difference frequency generation (DFG) in a multi-grating, temperature-controlled periodically poled LiNbO3 (PPLN) crystal and employs two near-infrared diode lasers as pump sources. The mid-infrared coherent radiation generated is tunable from 3.2 μm to 3.7 μm with an output power of about 100 μW. By changing one of the pump laser head with another wavelength range, we can readily obtain other needed mid-infrared wavelength range cover. The performance of the mid-infrared laser system and its application to highly sensitive spectroscopic detection of CH4, HCI, CH2O, and NO2 has been carried out. A multi-reflection White cell was used in the experiment gaining ppb-level sensitivity. The DFG laser system has the features of compact, room-temperature operation, narrow line-width, and broadly continuous tunable range for potential applications in industry and environmental monitoring.

  20. Mid-Infrared Observations of Normal Star-Forming Galaxies The Infrared Space Observatory Key Project Sample

    CERN Document Server

    Dale, D A; Helou, G; Dale, Daniel A.; Silbermann, Nancy A.; Helou, George

    2000-01-01

    We present mid-infrared maps and preliminary analysis for 61 galaxies observed with the ISOCAM instrument aboard the Infrared Space Observatory. Many of the general features of galaxies observed at optical wavelengths---spiral arms, disks, rings, and bright knots of emission---are also seen in the mid-infrared, except the prominent optical bulges are absent at 6.75 and 15 microns. In addition, the maps are quite similar at 6.75 and 15 microns, except for a few cases where a central starburst leads to lower 6.75/15 ratios in the inner region. We also present infrared flux densities and mid-infrared sizes for these galaxies. The mid-infrared color 6.75/15 shows a distinct trend with the far-infrared color 60/100. The quiescent galaxies in our sample (60/100 < 0.6) show 6.75/15 near unity, whereas this ratio drops significantly for galaxies with higher global heating intensity levels. Azimuthally-averaged surface brightness profiles indicate the extent to which the mid-infrared flux is centrally concentrated,...

  1. Brightness and Fluctuation of the Mid-Infrared Sky from AKARI Observations towards the North Ecliptic Pole

    CERN Document Server

    Pyo, Jeonghyun; Jeong, Woong-Seob; Matsuura, Shuji

    2012-01-01

    We present the smoothness of the mid-infrared sky from observations by the Japanese infrared astronomical satellite AKARI. AKARI monitored the north ecliptic pole (NEP) during its cold phase with nine wavebands covering from 2.4 to 24 \\mu m, out of which six mid-infrared bands were used in this study. A simple sinusoidal fit to the seasonal variation of the sky brightness shows that the mid-infrared brightness towards the NEP is not affected by small-scale features of the interplanetary dust cloud. We applied power spectrum analysis to the images in order to search for the fluctuation of the sky brightness. Observed fluctuation is explained by fluctuation of photon noise, shot noise of faint sources, and Galactic cirrus. The fluctuations at a few arcminutes scales at short mid-infrared wavelengths (7, 9, and 11 \\mum) are largely caused by the diffuse Galactic light of the interstellar dust cirrus. At long mid-infrared wavelengths (15, 18, and 24 \\mum), photon noise is the dominant source of fluctuation over t...

  2. Prediction of individual milk proteins including free amino acids in bovine milk using mid-infrared spectroscopy and their correlations with milk processing characteristics.

    Science.gov (United States)

    McDermott, A; Visentin, G; De Marchi, M; Berry, D P; Fenelon, M A; O'Connor, P M; Kenny, O A; McParland, S

    2016-04-01

    The aim of this study was to evaluate the effectiveness of mid-infrared spectroscopy in predicting milk protein and free amino acid (FAA) composition in bovine milk. Milk samples were collected from 7 Irish research herds and represented cows from a range of breeds, parities, and stages of lactation. Mid-infrared spectral data in the range of 900 to 5,000 cm(-1) were available for 730 milk samples; gold standard methods were used to quantify individual protein fractions and FAA of these samples with a view to predicting these gold standard protein fractions and FAA levels with available mid-infrared spectroscopy data. Separate prediction equations were developed for each trait using partial least squares regression; accuracy of prediction was assessed using both cross validation on a calibration data set (n=400 to 591 samples) and external validation on an independent data set (n=143 to 294 samples). The accuracy of prediction in external validation was the same irrespective of whether undertaken on the entire external validation data set or just within the Holstein-Friesian breed. The strongest coefficient of correlation obtained for protein fractions in external validation was 0.74, 0.69, and 0.67 for total casein, total β-lactoglobulin, and β-casein, respectively. Total proteins (i.e., total casein, total whey, and total lactoglobulin) were predicted with greater accuracy then their respective component traits; prediction accuracy using the infrared spectrum was superior to prediction using just milk protein concentration. Weak to moderate prediction accuracies were observed for FAA. The greatest coefficient of correlation in both cross validation and external validation was for Gly (0.75), indicating a moderate accuracy of prediction. Overall, the FAA prediction models overpredicted the gold standard values. Near-unity correlations existed between total casein and β-casein irrespective of whether the traits were based on the gold standard (0.92) or mid-infrared

  3. Retrieval of xCO2 from ground-based mid-infrared (NDACC solar absorption spectra and comparison to TCCON

    Directory of Open Access Journals (Sweden)

    M. Buschmann

    2015-10-01

    Full Text Available High resolution solar absorption spectra, taken within the Network for the Detection of Atmospheric Composition Change (NDACC in the mid-infrared spectral region are used to infer partial or total column abundances of many gases. In this paper we present the retrieval of a column averaged mole fraction of carbon dioxide from NDACC-IRWG spectra taken with a Fourier-Transform-Infra-Red (FTIR spectrometer at the site in Ny-Ålesund, Spitsbergen. The retrieved time series is compared to co-located standard TCCON measurements of total column CO2. Comparing the NDACC and TCCON retrievals we find that the sensitivity of the NDACC retrieval is lower in the troposphere (by a factor of two and higher in the stratosphere, compared to TCCON. Thus, the NDACC retrieval is less sensitive to tropospheric changes (e.g. the seasonal cycle in the column average.

  4. Influence of temperature on water and aqueous glucose absorption spectra in the near- and mid-infrared regions at physiologically relevant temperatures

    DEFF Research Database (Denmark)

    Jensen, P.S.; Bak, J.; Andersson-Engels, S.

    2003-01-01

    Near- and mid-infrared absorption spectra of pure water and aqueous 1.0 g/dL glucose solutions in the wavenumber range 8000-950 cm(-1) were measured in the temperature range 30-42 C in steps of 2 degreesC. Measurements were carried out with an FT-IR spectrometer and a variable pathlength...... degreesC water spectrum from the spectra measured at other temperatures. The difference spectra reveal that the effect of temperature is highest in the vicinity of the strong absorption bands, with a number of isosbestic points with no temperature dependence and relatively flat plateaus in between...... transmission cell controlled within 0.02 degreesC. Pathlengths of 50 mum and 0.4 mm were used in the mid- and near-infrared spectral region, respectively. Difference spectra were used to determine the effect of temperature on the water spectra quantitatively. These spectra were obtained by subtracting the 37...

  5. Frequency-tunable sub-two-cycle 60-MW-peak-power free-space waveforms in the mid-infrared.

    Science.gov (United States)

    Lanin, A A; Voronin, A A; Stepanov, E A; Fedotov, A B; Zheltikov, A M

    2014-11-15

    A physical scenario whereby freely propagating mid-infrared pulses can be compressed to pulse widths close to the field cycle is identified. Generation of tunable few-cycle pulses in the wavelength range from 4.2 to 6.8 μm is demonstrated at a 1-kHz repetition rate through self-focusing-assisted spectral broadening in a normally dispersive, highly nonlinear semiconductor material, followed by pulse compression in the regime of anomalous dispersion, where the dispersion-induced phase shift is finely tuned by adjusting the overall thickness of anomalously dispersive components. Sub-two-cycle pulses with a peak power up to 60 MW are generated in the range of central wavelengths tunable from 5.9 to 6.3 μm.

  6. Three-dimensional mid-infrared tomographic imaging of endogenous and exogenous molecules in a single intact cell with subcellular resolution.

    Science.gov (United States)

    Quaroni, Luca; Obst, Martin; Nowak, Marcus; Zobi, Fabio

    2015-01-02

    Microscopy in the mid-infrared spectral range provides detailed chemical information on a sample at moderate spatial resolution and is being used increasingly in the characterization of biological entities as challenging as single cells. However, a conventional cellular 2D imaging measurement is limited in its ability to associate specific compositional information to subcellular structures because of the interference from the complex topography of the sample. Herein we provide a method and protocols that overcome this challenge in which tilt-series infrared tomography is used with a standard benchtop infrared microscope. This approach gives access to the quantitative 3D distribution of molecular components based on the intrinsic contrast provided by the sample. We demonstrate the method by quantifying the distribution of an exogenous metal carbonyl complex throughout the cell and by reporting changes in its coordination sphere in different locations in the cell. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Quantification of SOC and Clay Content Using Visible Near-Infrared Reflectance–Mid-Infrared Reflectance Spectroscopy With Jack-Knifing Partial Least Squares Regression

    DEFF Research Database (Denmark)

    Peng, Yi; Knadel, Maria; Gislum, René;

    2014-01-01

    A total of 125 soil samples were collected from a Danish field varying in soil texture from sandy to loamy. Visible near-infrared reflectance (Vis-NIR) and mid-infrared reflectance (MIR) spectroscopy combined with chemometric methods were used to predict soil organic carbon (SOC) and clay contents....... The main objective of this study was to find the best model for predicting SOC and clay content in the sampled field using Vis-NIR, MIR, and the combination of Vis-NIR and MIR and using different model development techniques. The secondary objectives were (i) to use iterations of calculation to find...... the optimal number of replicates for MIR measurements based on the root mean square error of cross validation (RMSECV) and (ii) to apply partial least squares regression in combination with jackknifing (JK) to identify the most important part of spectral variables and the best model for predicting SOC...

  8. SPECTRAL CONFUSION FOR COSMOLOGICAL SURVEYS OF REDSHIFTED C II EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Kogut, A.; Dwek, E.; Moseley, S. H., E-mail: Alan.J.Kogut@nasa.gov [Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2015-06-20

    Far-infrared cooling lines are ubiquitous features in the spectra of star-forming galaxies. Surveys of redshifted fine-structure lines provide a promising new tool to study structure formation and galactic evolution at redshifts including the epoch of reionization as well as the peak of star formation. Unlike neutral hydrogen surveys, where the 21 cm line is the only bright line, surveys of redshifted fine-structure lines suffer from confusion generated by line broadening, spectral overlap of different lines, and the crowding of sources with redshift. We use simulations to investigate the resulting spectral confusion and derive observing parameters to minimize these effects in pencil-beam surveys of redshifted far-IR line emission. We generate simulated spectra of the 17 brightest far-IR lines in galaxies, covering the 150–1300 μm wavelength region corresponding to redshifts 0 < z < 7, and develop a simple iterative algorithm that successfully identifies the 158 μm [C ii] line and other lines. Although the [C ii] line is a principal coolant for the interstellar medium, the assumption that the brightest observed lines in a given line of sight are always [C ii] lines is a poor approximation to the simulated spectra once other lines are included. Blind line identification requires detection of fainter companion lines from the same host galaxies, driving survey sensitivity requirements. The observations require moderate spectral resolution 700 < R < 4000 with angular resolution between 20″ and 10′, sufficiently narrow to minimize confusion yet sufficiently large to include a statistically meaningful number of sources.

  9. Spectral Confusion for Cosmological Surveys of Redshifted C II Emission

    Science.gov (United States)

    Kogut, A.; Dwek, E.; Moseley, S. H.

    2015-01-01

    Far-infrared cooling lines are ubiquitous features in the spectra of star-forming galaxies. Surveys of redshifted fine-structure lines provide a promising new tool to study structure formation and galactic evolution at redshifts including the epoch of reionization as well as the peak of star formation. Unlike neutral hydrogen surveys, where the 21 cm line is the only bright line, surveys of redshifted fine-structure lines suffer from confusion generated by line broadening, spectral overlap of different lines, and the crowding of sources with redshift. We use simulations to investigate the resulting spectral confusion and derive observing parameters to minimize these effects in pencilbeam surveys of redshifted far-IR line emission. We generate simulated spectra of the 17 brightest far-IR lines in galaxies, covering the 150-1300 µm wavelength region corresponding to redshifts 0 < z < 7, and develop a simple iterative algorithm that successfully identifies the 158 µm [C II] line and other lines. Although the [C II] line is a principal coolant for the interstellar medium, the assumption that the brightest observed lines in a given line of sight are always [C II] lines is a poor approximation to the simulated spectra once other lines are included. Blind line identification requires detection of fainter companion lines from the same host galaxies, driving survey sensitivity requirements. The observations require moderate spectral resolution 700 < R < 4000 with angular resolution between 20? and 10', sufficiently narrow to minimize confusion yet sufficiently large to include a statistically meaningful number of sources.

  10. [Evaluation of nutrient release profiles from polymer coated fertilizers using Fourier transform mid-infrared photoacoustic spectroscopy].

    Science.gov (United States)

    Shen, Ya-zhen; Du, Chang-wen; Zhou, Jian-min; Wang, Huo-yan; Chen, Xiao-qin

    2012-02-01

    The acrylate-like materials were used to develop the polymer coated controlled release fertilizer, the nutrients release profiles were determined, meanwhile the Fourier transform mid-infrared photoacoustic spectra of the coatings were recorded and characterized; GRNN model was used to predict the nutrients release profiles using the principal components of the mid-infrared photoacoustic spectra as input. Results showed that the GRNN model could fast and effectively predict the nutrient release profiles, and the predicted calibration coefficients were more than 0.93; on the whole, the prediction errors (RMSE) were influenced by the profiling depth of the spectra, the average prediction error was 10.28%, and the spectra from the surface depth resulted in a lowest prediction error with 7.14%. Therefore, coupled with GRNN modeling, Fourier transform mid-infrared photoacoustic spectroscopy can be used as an alternative new technique in the fast and accurate prediction of nutrient release from polymer coated fertilizer.

  11. High-power mid-infrared frequency comb source based on a femtosecond Er:fiber oscillator

    CERN Document Server

    Zhu, Feng; Kolomenskii, Alexandre A; Strohaber, James; Holzwarth, Ronald; Schuessler, Hans A

    2013-01-01

    We report on a high-power mid-infrared frequency comb source based on a femtosecond Er:fiber oscillator with a stabilized repetition rate at 250 MHz. The mid-infrared frequency comb is produced through difference frequency generation in a periodically poled MgO-doped lithium niobate crystal. The output power is about 120 mW with a pulse duration of about 80 fs, and spectrum coverage from 2.9 to 3.6 um. The coherence properties of the produced high-power broadband mid-infrared frequency comb are maintained, which was verified by heterodyne measurements. As the first application, the spectrum of a ~200 ppm methane-air mixture in a short 20 cm glass cell at ambient atmospheric pressure and temperature was measured.

  12. Spatial distribution of particulate organic matter pools, quantified and characterized by mid-infrared spectroscopy

    Science.gov (United States)

    Bornemann, L.; Welp, G.; Amelung, W.

    2009-04-01

    Comprising more than 60 % of the terrestrial carbon pool, soil organic carbon (SOC) is one of the principal factors regulating the global C-cycle. Against the background of worldwide increasing CO2 emissions, much effort has been put to the modelling of soil-C turnover in order to evaluate its potential for mitigation of climate change. Soil organic matter is an ever changing assemblage of various organic components that interact with the mineral matrix and in dependence of its ecological environment. Carbon storage is thereby assumed to propagate by hierarchical saturation of different carbon pools. A homogeneous distribution of the respective pools within natural environments is unlikely as the controlling soil parameters are subject to spatial and temporal heterogeneity. Several attempts to operationalize this complex soil compartment have been proposed, most of them resting upon a concept of pools with different stability and varying turnover times. Among these pools, particulate organic matter (POM) is considered to be most sensitive to environmental changes and has been shown to explain major parts of the SOC variations. Until today, rather laborious physical and physico-chemical fractionation procedures are most commonly applied for the initialization and validation of POM in C-turnover models. Mid-infrared spectroscopy (MIRS) in combination with partial least squares regression (PLSR) could overcome this problem. The technique is fast, cheap, and requires little sample preparation. All the same, it is an appropriate technique not only for the determination of gross parameters like total soil organic carbon contents, but also for the determination and characterization of minor constituents like black carbon in soils. Basically, the infrared radiation is absorbed by molecules that express a dipole-moment during vibration. As virtually all constituents of soil organic matter and also a multitude of inorganic soil constituents express such a dipole

  13. Chemometric quality inspection control of pyrantel pamoate, febantel and praziquantel in veterinary tablets by mid infrared spectroscopy

    Science.gov (United States)

    Piantavini, Mário S.; Pontes, Flávia L. D.; Uber, Caroline P.; Stremel, Dile P.; Sena, Marcelo M.; Pontarolo, Roberto

    This paper describes the development and validation of a new multivariate calibration method based on diffuse reflectance mid infrared spectroscopy for direct and simultaneous determination of three veterinary pharmaceutical drugs, pyrantel pamoate, praziquantel and febantel, in commercial tablets. The best synergy interval partial least squares (siPLS) model was obtained by selecting three spectral regions, 3715-3150, 2865-2583, and 2298-1733 cm-1, preprocessed by first derivative and Savitzky-Golay smoothing followed by mean centering. This model was built with five latent variables and provided root mean square errors of prediction (RMSEP) equal or lower than 0.69 mg per 100 mg of powder for the three analytes. The method was validated according the appropriate regulations through the estimate of figures of merit, such as trueness, precision, linearity, analytical sensitivity, bias and residual prediction deviation (RPD). Then, it was applied to three different veterinary pharmaceutical formulations found in the Brazilian market, in a situation of multi-product calibration, since the excipient composition of these commercial products, which was not known a priori, was modeled by an experimental design that scanned the likely content range of the possible constituents. The results were verified with high performance liquid chromatography with diode array detection (HPLC-DAD) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and were in agreement with the predicted values at 95% confidence level. The developed method presented the advantages of being simple, rapid, solvent free, and about ten times faster than the HPLC ones.

  14. A low cost mid-infrared sensor for on line contamination monitoring of lubricating oils in marine engines

    Science.gov (United States)

    Ben Mohammadi, L.; Kullmann, F.; Holzki, M.; Sigloch, S.; Klotzbuecher, T.; Spiesen, J.; Tommingas, T.; Weismann, P.; Kimber, G.

    2010-04-01

    The chemical and physical condition of oils in marine engines must be monitored to ensure optimum performance of the engine and to avoid damage by degraded oil not adequately lubricating the engine. Routine monitoring requires expensive laboratory testing and highly skilled analysts. This work describes the adaptation and implementation of a mid infrared (MIR) sensor module for continued oil condition monitoring in two-stroke and four-stroke diesel engines. The developed sensor module will help to reduce costs in oil analysis by eliminating the need to collect and send samples to a laboratory for analysis. The online MIR-Sensor module measures the contamination of oil with water, soot, as well as the degradation indicated by the TBN (Total Base Number) value. For the analysis of water, TBN, and soot in marine engine oils, four spectral regions of interest have been identified. The optical absorption in these bands correlating with the contaminations is measured simultaneously by using a four-field thermopile detector, combined with appropriate bandpass filters. Recording of the MIR-absorption was performed in a transmission mode using a flow-through cell with appropriate path length. Since in this case no spectrometer is required, the sensor including the light source, the flowthrough- cell, and the detector can be realised at low cost and in a very compact manner. The optical configuration of the sensor with minimal component number and signal intensity optimisation at the four-field detector was implemented by using non-sequential ray tracing simulation. The used calibration model was robust enough to predict accurately the value for soot, water, and TBN concentration for two-stroke and four-stroke engine oils. The sensor device is designed for direct installation on the host engine or machine and, therefore, becoming an integral part of the lubrication system. It can also be used as a portable stand-alone system for machine fluid analysis in the field.

  15. Effects of heating on the secondary structure of proteins in milk powders using mid-infrared spectroscopy.

    Science.gov (United States)

    Ye, M P; Zhou, R; Shi, Y R; Chen, H C; Du, Y

    2017-01-01

    Milk powder is an important source of protein for adults and children. Protein is very sensitive to heat, which may influence people's usage of nutrients in milk powder. In this study, we describe the temperature-induced secondary structure of protein in milk powders. In this study, whole milk powder containing 24% protein and infant formula containing 11% protein were heated from 25 to 100°C. Attenuated total reflectance (ATR) spectra in the mid-infrared range 400-4,000cm(-1) were used to evaluate the heat effect on the secondary structure of protein in these 2 milk powders. The spectral changes as a function of temperature were maintained by difference spectra, second-derivative spectra and Gauss curve-fitted spectra. The secondary structures of protein in the whole milk powder began to change at 70°C and in the infant formula at 50°C. The β-sheet and β-turn structures in the whole milk powder both decreased in the range of 70 to 85°C, whereas α-helix structures increased. The loss of β-sheet and β-turn may contribute to the formation of α-helix in the whole milk powder. In infant formula powder, the β-sheet structure showed a decrease and then increase, whereas the β-turn structure showed an increase and then decrease in the range of 50 to 75°C, and no change was found for α-helix structures. This implies that heating may induce the transformation from β-sheet to β-turn. Overall, whole milk powder had better temperature stability than infant formula powder, probably because of the lower content of lipid in the former than in the latter. These results help us understand the thermal stability of protein in milk powder. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. THIS -- next-generation mid-infrared remote sensing of planetary atmospheres using a tuneable heterodyne infrared spectrometer

    Science.gov (United States)

    Sonnabend, G.; Wirtz, D.; Vetterle, V.; Schieder, R.

    2003-12-01

    The Cologne spectrometer THIS (Tuneable Heterodyne Infrared Spectrometer) opens the mid-infrared wavelength region from 8 to 17 microns to ultra-high-resolution spectroscopy. The main scientific goal of THIS is to analyze highly resolved lineshape data of molecules (e.g. O3, NH3, CH4, N2O, HxCy etc.) to deduce physical parameters like wind velocities or height profiles of gases in either the Earth's or other planetary atmospheres. Also astronomical observations of non-solar-system IR-sources like IRC+10216 as well as the measurement of pure rotational transitions of H2 in the interstellar-medium from ground based telescopes are planned in the near future. THIS is a proposed second-generation instrument for the stratospheric observatory SOFIA. With a system noise temperature of less than three times the quantum limit THIS is the first widely tuneable and transportable infrared heterodyne receiver having a sensitivity equivalent to CO2-laser based heterodyne systems. A quantum-cascade-laser is used as local oscillator. Its radiation is superimposed to that from the signal by use of a Fabry-Perot ring-resonator to provide optimum efficiency. The frequency mixing is done by a Mercury-Cadmium-Telluride photomixer and spectral analysis with a resolution of up to 3x107 is performed by means of an Acousto-Optical spectrometer. We report on THIS' successful first observing run performed at the west auxiliary telescope at McMath-Pierce solar observatory on Kitt Peak/Arizona in 11/2002. Very weak non-LTE CO2 emission from the atmosphere of Venus have been observed as well as trace gases in Earth's atmosphere and molecular features in sunspots.

  17. Survey of spectral response measurements for photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, J.S.; Lind, M.A.

    1981-11-01

    A survey of the photovoltaic community was conducted to ascertain the present state-of-the-art for PV spectral response measurements. Specific topics explored included measurement system designs, good and bad features of the systems, and problems encountered in the evaluation of specific cell structures and materials. The survey showed that most spectral response data are used in diagnostic analysis for the optimization of developmental solar cells. Measurement systems commonly utilize a chopped narrowband source in conjunction with a constant bias illumination which simulates the ambient end use environment. Researchers emphasized the importance of bias illumination for all types of cells in order to minimize the effects of nonlinearities in cell response. Not surprisingly single crystal silicon cells present the fewest measurement problems to the researcher and have been studied more thoroughly than any other type of solar cell. But, the accurate characterization of silicon cells is still difficult and laboratory intercomparison studies have yielded data scatter ranging from +-5% to +-15%. The measurement experience with other types of cells is less extensive. The development of reliable data bases for some solar cells is complicated by problems of cell nonuniformity, environmental instability, nonlinearity, etc. Cascade cells present new problems associated with their structue (multiple cells in series) which are just beginning to be understood. In addition, the importance of many measurement parameters (spectral content of bias light, bias light intensity, bias voltage, chopping frequency, etc.) are not fully understood for most types of solar cells.

  18. Mid-infrared (λ = 8.4-9.9 μm) light scattering from porcine tissue

    Science.gov (United States)

    Liakat, Sabbir; Michel, Anna P. M.; Bors, Kevin A.; Gmachl, Claire F.

    2012-08-01

    Back-scattering of mid-infrared light from porcine skin is studied versus wavelength and angle for a Quantum Cascade laser and a broadband infrared light source. Scattering is detected over 30° away from the specular angle for both sources, and modulation patterns with angle are seen when using the laser. A nonlinear increase in scattered light intensity versus input power indicates that directional scattering from within the skin is dominant. Collagen fibers in the dermis layer, over 200 μm deep into the skin, are conducive to such scattering. We conclude that mid-infrared light penetrates deep enough for potential glucose detection in dermal interstitial fluid.

  19. Coupling mid-infrared light from a photonic crystal waveguide to metallic transmission lines

    Energy Technology Data Exchange (ETDEWEB)

    Blanco-Redondo, Andrea, E-mail: andrea.blanco@tecnalia.com, E-mail: r.hillenbrand@nanogune.eu [ICT-European Software Institute Division, Tecnalia, Ibaizabal Bidea, Ed. 202, 48170 Zamudio, Bizkaia (Spain); Dpto. Electronica y Telecom., E.T.S. Ingeniería Bilbao, UPV/EHU, Alda. Urquijo, 48103 Bilbao, Bizkaia (Spain); Sarriugarte, Paulo [Nanooptics Group, CIC nanoGUNE Consolider, 20018 Donostia–San Sebastian, Gipuzkoa (Spain); Garcia-Adeva, Angel [Dpto. Fisica Aplicada I, E.T.S. Ingeniería de Bilbao, UPV-EHU, Alda. Urquijo, 48103 Bilbao, Bizkaia (Spain); Zubia, Joseba [Dpto. Electronica y Telecom., E.T.S. Ingeniería Bilbao, UPV/EHU, Alda. Urquijo, 48103 Bilbao, Bizkaia (Spain); Hillenbrand, Rainer, E-mail: andrea.blanco@tecnalia.com, E-mail: r.hillenbrand@nanogune.eu [Nanooptics Group, CIC nanoGUNE Consolider, 20018 Donostia–San Sebastian, Gipuzkoa (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Bizkaia (Spain)

    2014-01-06

    We propose and theoretically study a hybrid structure consisting of a photonic crystal waveguide (PhC-wg) and a two-wire metallic transmission line (TL), engineered for efficient transfer of mid-infrared (mid-IR) light between them. An efficiency of 32% is obtained for the coupling from the transverse magnetic (TM) photonic mode to the symmetric mode of the TL, with a predicted intensity enhancement factor of 53 at the transmission line surface. The strong coupling is explained by the small phase velocity mismatch and sufficient spatial overlapping between the modes. This hybrid structure could find applications in highly integrated mid-IR photonic-plasmonic devices for biological and gas sensing, among others.

  20. Short-period InAs/GaSb superlattices for mid-infrared photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Haugan, H.J.; Szmulowicz, F.; Brown, G.J.; Munshi, S.R. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States); Ullrich, B. [Department of Physics and Astronomy, Bowling Green State University, Ohio 45433 (United States); Wickett, J.C.; Stokes, D.W. [Department of Physics, University of Houston, Texas 77204 (United States)

    2007-04-15

    Using a newly developed envelope function approximation model that includes interface effects, several InAs/GaSb type-II superlattices (SLs) were designed for uncooled mid-infrared detector applications. The 4 micron cutoff could be achieved with several SL designs. Superlattices with shorter periods have larger intervalence band separations than larger-ones, which could increase the optical signal and reduce the detector noise, thus making room temperature operation possible. To test these possibilities, several short-period SLs were grown by molecular-beam epitaxy and their optical properties with reducing SL period were studied by band-edge absorption, photoconductivity and photoluminescence measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Simulation of an erbium-doped chalcogenide micro-disk mid-infrared laser source.

    Science.gov (United States)

    Al Tal, Faleh; Dimas, Clara; Hu, Juejun; Agarwal, Anu; Kimerling, Lionel C

    2011-06-20

    The feasibility of mid-infrared (MIR) lasing in erbium-doped gallium lanthanum sulfide (GLS) micro-disks was examined. Lasing condition at 4.5 µm signal using 800 nm pump source was simulated using rate equations, mode propagation and transfer matrix formulation. Cavity quality (Q) factors of 1.48 × 10(4) and 1.53 × 10(6) were assumed at the pump and signal wavelengths, respectively, based on state-of-the-art chalcogenide micro-disk resonator parameters. With an 80 µm disk diameter and an active erbium concentration of 2.8 × 10(20) cm(-3), lasing was shown to be possible with a maximum slope efficiency of 1.26 × 10(-4) and associated pump threshold of 0.5 mW.

  2. A polarization-sensitive mid-infrared plasmonic absorber for multi-band resonance

    Science.gov (United States)

    Li, Yongqian; Wang, Binbin; Xu, Xiaolun; Su, Lei; Zhou, Zili

    2014-05-01

    The aim of this work is to present a multi-band absorption metamaterials. One dual cross-shape perfect absorber metamaterials (PAMs) was developed to obtain multi-band spectrum at mid-infrared. The PAMs possess three distinct resonant peaks standing independently, which are attributed to the polarization sensitive excitation of plasmonic resonance. The optical parameters retrieved by S-parameters method were investigated, which provides a satisfactory qualitative description of the multiple-band spectra responses. On the other hand, the near-field plasmonic behaviors and redistribution of the electromagnetic field were probed theoretically and numerically into the PAMs structure, which also explains the observed absorption behavior of the PAMs ensemble based upon the microscopic perspective. The multiplex spectrum enables the infrared perfect absorber metamaterials (PAMs) a powerful tool for direct access to vibrational fingerprints of single molecular structure.

  3. Mid-Infrared Evidence for Accelerated Evolution in Compact Group Galaxies

    CERN Document Server

    Walker, Lisa May; Gallagher, Sarah C; Hibbard, John E; Hornschemeier, Ann E; Charlton, Jane C; Jarrett, Thomas H

    2009-01-01

    We find evidence for accelerated evolution in compact group galaxies from the distribution in mid-infrared colorspace of 42 galaxies from 12 Hickson Compact Groups (HCGs) compared to the the distributions of several other samples including the LVL+SINGS galaxies, interacting galaxies, and galaxies from the Coma Cluster. We find that the HCG galaxies are not uniformly distributed in colorspace, as well as quantitative evidence for a gap. Galaxies in the infall region of the Coma cluster also exhibit a non-uniform distribution and a less well defined gap, which may reflect a similarity with the compact group environment. Neither the Coma Center or interacting samples show evidence of a gap, leading us to speculate that the gap is unique to the environment of high galaxy density where gas has not been fully processed or stripped.

  4. Mode-selective phonon excitation in gallium nitride using mid-infrared free-electron laser

    Science.gov (United States)

    Kagaya, Muneyuki; Yoshida, Kyohei; Zen, Heishun; Hachiya, Kan; Sagawa, Takashi; Ohgaki, Hideaki

    2017-02-01

    The single-phonon mode was selectively excited in a solid-state sample. A mid-infrared free-electron laser, which was tuned to the target phonon mode, was irradiated onto a crystal cooled to a cryogenic temperature, where modes other than the intended excitation were suppressed. An A 1(LO) vibrational mode excitation on GaN(0001) face was demonstrated. Anti-Stokes Raman scattering was used to observe the excited vibrational mode, and the appearance and disappearance of the scattering band at the target wavenumber were confirmed to correspond to on and off switching of the pump free-electron laser and were fixed to the sample vibrational mode. The sum-frequency generation signals of the pump and probe lasers overlapped the Raman signals and followed the wavenumber shift of the pump laser.

  5. Ambient temperature-independent dual-band mid-infrared radiation thermometry.

    Science.gov (United States)

    Lü, You; He, Xin; Wei, Zhong-Hui; Sun, Zhi-Yuan; Chang, Song-Tao

    2016-03-20

    For temperature measurements of targets at low temperatures, dual-band radiation thermometry using mid-infrared detectors has been investigated extensively. However, the accuracy is greatly affected by the reflected ambient radiation and stray radiation, which depend on the ambient temperature. To ensure measurement accuracy, an improved dual-band measurement model is established by considering the reflected ambient radiation and the stray radiation. The effect of ambient temperature fluctuation on temperature measurement is then further analyzed in detail. Experimental results of measuring a gray-body confirm that the proposed method yields high accuracy at varying ambient temperatures. This method provides a practical approach to remove the effect of ambient temperature fluctuations on temperature measurements.

  6. Kerr nonlinearity and multi-photon absorption in germanium at mid-infrared wavelengths

    Science.gov (United States)

    Sohn, B.-U.; Monmeyran, C.; Kimerling, L. C.; Agarwal, A. M.; Tan, D. T. H.

    2017-08-01

    Multiphoton absorption coefficients and nonlinear refractive indices of germanium in the near and mid-infrared (2-5 μm) are reported. The nonlinear coefficients are measured by open and closed aperture Z-scan with 150 fs pulses at a repetition rate of 1 kHz. The nonlinear refractive index of Ge has a peak value of 9.1 ×10-5cm2/GW at a wavelength of 3 μm. The effect of free electrons generated by multiphoton absorption is discussed by investigating the variation of multiphoton absorption coefficients at different input powers. Kramers-Kronig relations are also discussed with regard to the relationship between nonlinear refractive index and two photon absorption coefficient.

  7. Comb-assisted subkilohertz linewidth quantum cascade laser for high-precision mid-infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Galli, I.; Cappelli, F.; Bartalini, S.; Mazzotti, D.; Giusfredi, G.; Cancio, P.; De Natale, P. [CNR-INO-Istituto Nazionale di Ottica, Largo E. Fermi 6, 50125 Firenze, FI (Italy); LENS-European Laboratory for Non-Linear Spectroscopy, Via Carrara 1, 50019 Sesto Fiorentino, FI (Italy); Siciliani de Cumis, M. [CNR-INO-Istituto Nazionale di Ottica, Largo E. Fermi 6, 50125 Firenze, FI (Italy); Borri, S. [CNR-IFN-Istituto di Fotonica e Nanotecnologie, Via Amendola 173, 70126 Bari, BA (Italy); Montori, A. [LENS-European Laboratory for Non-Linear Spectroscopy, Via Carrara 1, 50019 Sesto Fiorentino, FI (Italy); Akikusa, N. [Development Bureau Laser Device R and D Group, Hamamatsu Photonics KK, Shizuoka 434-8601 (Japan); Yamanishi, M. [Central Research Laboratories, Hamamatsu Photonics KK, Shizuoka 434-8601 (Japan)

    2013-03-25

    We report on the linewidth narrowing of a room-temperature mid-infrared quantum cascade laser by phase-locking to a difference-frequency-generated radiation referenced to an optical frequency comb synthesizer. A locking bandwidth of 250 kHz, with a residual rms phase-noise of 0.56 rad, has been achieved. The laser linewidth is narrowed by more than 2 orders of magnitude below 1 kHz, and its frequency is stabilized with an absolute traceability of 2 Multiplication-Sign 10{sup -12}. This source has allowed the measurement of the absolute frequency of a CO{sub 2} molecular transition with an uncertainty of about 1 kHz.

  8. Mid-infrared supercontinuum generation in tapered As2S3 chalcogenide planar waveguide

    Science.gov (United States)

    Zhang, Xiang; Hu, Hongyu; Li, Wenbo; Dutta, Niloy K.

    2016-10-01

    We numerically demonstrate mid-infrared supercontinuum generation in a non-uniformly tapered chalcogenide planar waveguide. This planar rib waveguide of As2S3 glass on MgF2 is 2 cm long with increasing etch depth longitudinally to manage the total dispersion. This waveguide has zero dispersion at two wavelengths. The dispersion profile varies along the propagation distance, leading to continuous modification of the phase-matching condition for dispersive wave emission and enhancement of energy transfer efficiency between solitons and dispersive waves. Numerical simulations are conducted for secant input pulses at a wavelength of 1.55 μm with a width of 50 fs and peak power of 2 kW. Results show this proposed scheme significantly broadens the generated continuum, extending from ~1 to ~7 μm.

  9. The influence of melt purification and structure defects on mid-infrared light emitting diodes

    CERN Document Server

    Krier, A

    2003-01-01

    Mid-infrared light emitting diodes which exhibit more than 7 mW (pulsed) and 0.35 mW dc output power at 3.3 mu m and at room temperature have been fabricated by liquid phase epitaxy using Pb as a neutral solvent. Using Pb solution an increase in pulsed output power of between two and three times was obtained compared with InAs light emitting diodes (LEDs) made using rare-earth gettering. The performance improvements were attributed to a reduction in residual carrier concentration arising from the removal of un-intentional donors and structure defects in the InAs active region material. These LEDs are well matched to the CH sub 4 absorption spectrum and potentially could form the basis of a practical infrared CH sub 4 gas sensor.

  10. Coherent broadband mid-infrared supercontinuum generation in As2Se3 photonic crystal fiber

    CERN Document Server

    Yuan, Wu

    2013-01-01

    The generation of fully coherent broadband mid-infrared (MIR) supercontinuum (SC) from 2.3 um to 8.3 um is demonstrated by using a 4.1 um pump and an As2Se3 photonic crystal fiber (PCF).By introducing the random quantum noise and the power instability on the input pulse and by numerically implementing the Young,s double slits experiment, we examine the coherence properties across the SC spectrum. It is found that the coherence of this MIR SC source depends strongly on the input pulse duration, the peak power, the power stability, and the zero-dispersion wavelength (ZDW) of the As2Se3 PCF.The optimal conditions for the MIR SC with a maximal coherent bandwidth are identified.

  11. Mid-Infrared Photoluminescence of CdS and CdSe Colloidal Quantum Dots.

    Science.gov (United States)

    Jeong, Kwang Seob; Guyot-Sionnest, Philippe

    2016-02-23

    Mid-infrared intraband photoluminescence is observed from CdSe and CdS colloidal quantum dots (CQDs) and core/shell systems when excited by a visible laser. The CQDs show more intraband photoluminescence with dodecanethiol than with other ligands. Core/shells show an increase of the intraband photoluminescence with increasing shell thickness. The detected emission is restricted to below 2900 cm(-1), bounded by the C-H vibrational modes of the organic ligands. Upon photoexcitation in air for all dodecanethiol ligands capped CQD systems studied, the intraband photoluminescence is quenched over time, and emission at lower frequency is observed, which is assigned to laser heating and thermal emission from oxides.

  12. Enhancing extraction efficiency of mid-infrared fluorescence in chalcogenide glass via photonic crystal

    Science.gov (United States)

    Zhang, Jun; Zhang, Peiqing; Ma, Beijiao; Dai, Shixun; Zhang, Wei; Nie, Qiuhua

    2016-04-01

    The use of rare earth-doped chalcogenide glass is an attractive method to develop mid-infrared sources. In this work, Er3+-doped chalcogenide glass is prepared, and photonic crystal (PC) pattern is designed to improve the extraction efficiency of light emission from the sample surface. The finite difference time domain simulation shows that the light extraction efficiency from the sample surface can be 1.62 times stronger than that from the sample without PC structure by introducing a simple two-dimensional (2D) PC structure into glass samples. This improvement was the result of the efficient light diffraction on the surface because of the integrated 2D PC. Results in this work offer a potential in developing midinfrared light sources.

  13. Off-axis QEPAS using a pulsed nanosecond Mid-Infrared Optical Parametric Oscillator

    CERN Document Server

    Lassen, Mikael; Feng, Yuyang; peremans, Andre; Petersen, Jan C

    2016-01-01

    A trace gas sensor, based on quartz-enhanced photoacoustic spectroscopy (QEPAS), consisting of two acoustically coupled micro-resonators (mR) with an o?-axis 20 kHz quartz tuning fork (QTF) is demonstrated. The complete acoustically coupled mR system is optimized based on finite element simulations and experimentally verified. The QEPAS sensor is pumped resonantly by a nanosecond pulsed single-mode mid-infrared optical parametric oscillator (MIR OPO). The sensor is used for spectroscopic measurements on methane in the 3.1 um to 3.5 um 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 optimum integration time for the QEPAS sensor is 32 ppbv@190s and that the background noise is solely due to the thermal noise of the QTF.

  14. Importance of coherence in models of mid-infrared quantum cascade laser gain spectra

    Science.gov (United States)

    Cui, Yuzhang I.; Harter, Michael P.; Dikmelik, Yamac; Hoffman, Anthony J.

    2017-09-01

    We present a three-level model based on a density matrix to examine the influence of coherence and dephasing on the gain spectrum of mid-infrared quantum cascade lasers. The model is used to examine a quantum cascade active region with multiple optical transitions. We show how coherence can explain the origin of additional peaks in the gain spectrum. We also analyze the spectra calculated using the three-level model with a rate equation formalism to demonstrate the importance of considering interface roughness and limitations of the rate equation formalism. Specifically, we present how interface roughness influences the broadening and oscillator strength that are recovered using a rate equation analysis. The results of this work are important when considering the design of active regions with multiple optical transitions and could lead to devices with improved performance.

  15. High-speed mid-infrared hyperspectral imaging using quantum cascade lasers

    Science.gov (United States)

    Kelley, David B.; Goyal, Anish K.; Zhu, Ninghui; Wood, Derek A.; Myers, Travis R.; Kotidis, Petros; Murphy, Cara; Georgan, Chelsea; Raz, Gil; Maulini, Richard; Müller, Antoine

    2017-05-01

    We report on a standoff chemical detection system using widely tunable external-cavity quantum cascade lasers (ECQCLs) to illuminate target surfaces in the mid infrared (λ = 7.4 - 10.5 μm). Hyperspectral images (hypercubes) are acquired by synchronously operating the EC-QCLs with a LN2-cooled HgCdTe camera. The use of rapidly tunable lasers and a high-frame-rate camera enables the capture of hypercubes with 128 x 128 pixels and >100 wavelengths in acetaminophen) on a variety of surfaces (e.g., aluminum, plastic, glass). Signature spectra are obtained for particulate loadings of RDX on glass of <1 μg/cm2.

  16. Three-dimensional single gyroid photonic crystals with a mid-infrared bandgap

    CERN Document Server

    Peng, Siying; Chen, Valerian H; Khabiboulline, Emil T; Braun, Paul; Atwater, Harry A

    2016-01-01

    A gyroid structure is a distinct morphology that is triply periodic and consists of minimal isosurfaces containing no straight lines. We have designed and synthesized amorphous silicon (a-Si) mid-infrared gyroid photonic crystals that exhibit a complete bandgap in infrared spectroscopy measurements. Photonic crystals were synthesized by deposition of a-Si/Al2O3 coatings onto a sacrificial polymer scaffold defined by two-photon lithography. We observed a 100% reflectance at 7.5 \\mum for single gyroids with a unit cell size of 4.5 \\mum, in agreement with the photonic bandgap position predicted from full-wave electromagnetic simulations, whereas the observed reflection peak shifted to 8 um for a 5.5 \\mum unit cell size. This approach represents a simulation-fabrication-characterization platform to realize three-dimensional gyroid photonic crystals with well-defined dimensions in real space and tailored properties in momentum space.

  17. Corneal morphology after ex-vivo UV and mid-infrared laser ablation

    Science.gov (United States)

    Spyratou, E.; Voloudakis, G. E.; Moutsouris, K.; Asproudis, I.; Baltatzis, S.; Makropoulou, M.; Bacharis, C.; Serafetinides, A. A.

    2008-12-01

    In this work, ablation experiments of ex vivo porcine cornea tissue were conducted with two solid state lasers (an Er:YAG laser and the 4th harmonic of an Nd:YAG laser, both in the ns pulse width range) emitting in mid infrared and ultraviolet part of the spectrum respectively, at moderate laser fluences. The cornea epithelium of each porcine eye was manually removed before the ablation. Histology analysis of the specimens was performed, in order to examine the microscopic appearance of the ablated craters and the existence of any thermal or mechanical damage caused by the midinfrared and the UV laser irradiation. For a detailed and complete examination of the morphology of the laser ablated corneal tissue, the surface roughness was investigated by scanning electron microscopy.

  18. Two-color mid-infrared thermometer with a hollow glass optical fiber.

    Science.gov (United States)

    Small, W; Celliers, P M; Da Silva, L B; Matthews, D L; Soltz, B A

    1998-10-01

    We have developed a low-temperature optical-fiber-based two-color infrared thermometer. A single 700-mum-bore hollow glass optical fiber collects and transmits radiation that is then modulated and split into two paths by a reflective optical chopper. Two different thermoelectrically cooled mid-infrared HgCdZnTe photoconductors monitor the chopped signals that are recovered with lock-in amplification. With the two previously obtained blackbody calibration equations, a computer algorithm calculates the true temperature and emissivity of a target in real time, taking into account reflection of the ambient radiation field from the target surface. The small numerical aperture of the hollow glass fiber and the fast response of the detectors, together with the two-color principle, permit high spatial and temporal resolution while allowing the user to dynamically alter the fiber-to-target distance.

  19. Active Multiple Plasmon-Induced Transparency with Graphene Sheets Resonators in Mid-Infrared Frequencies

    Directory of Open Access Journals (Sweden)

    Jicheng Wang

    2016-01-01

    Full Text Available A multiple plasmon-induced transparency (PIT device operated in the mid-infrared region has been proposed. The designed model is comprised of one graphene ribbon as main waveguide and two narrow graphene sheets resonators. The phase coupling between two graphene resonators has been investigated. The multimode PIT resonances have been found in both cases and can be dynamically tuned via varying the chemical potential of graphene resonators without optimizing its geometric parameters. In addition, this structure can get multiple PIT effect by equipping extra two sheets on the symmetric positions of graphene waveguide. The simulation results based on finite element method (FEM are in good agreement with the resonance theory. This work may pave new way for graphene-based thermal plasmonic devices applications.

  20. Optical and mid-infrared neon abundance determinations in star-forming regions

    CERN Document Server

    Dors, Oli L; Cardaci, Monica V; Perez-Montero, Enrique; Krabbe, Angela C; Vilchez, Jose M; Sales, Dinalva A; Riffel, Rogerio; Riffel, Rogemar A

    2013-01-01

    We employed observational spectroscopic data of star-forming regions compiled from the literature and photoionization models to analyse the neon ionic abundances obtained using both optical and mid-infrared emission-lines. Comparing Ne++/H+ ionic abundances from distinct methods, we found that, in average, the abundances obtained via IR emission-lines are higher than those obtained via optical lines by a factor of 4. Photoionization models with abundance variations along the radius of the hypothetical nebula provide a possible explanation for a large part of the difference between ionic abundances via optical and infrared emission-lines. Ionization Correction Factor (ICF) for the neon is obtained from direct determinations of ionic fractions using infrared emission-lines. A constant Ne/O ratio (logNe/O \\approx -0.70) for a large range of metallicity, independently of the ICF used to compute the neon total abundance is derived.