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Sample records for infrared wavelength photonic

  1. Silicon photonic crystal thermal emitter at near-infrared wavelengths.

    PubMed

    O'Regan, Bryan J; Wang, Yue; Krauss, Thomas F

    2015-08-21

    Controlling thermal emission with resonant photonic nanostructures has recently attracted much attention. Most of the work has concentrated on the mid-infrared wavelength range and/or was based on metallic nanostructures. Here, we demonstrate the experimental operation of a resonant thermal emitter operating in the near-infrared (≈1.5 μm) wavelength range. The emitter is based on a doped silicon photonic crystal consisting of a two dimensional square array of holes and using silicon-on-insulator technology with a device-layer thickness of 220 nm. The device is resistively heated by passing current through the photonic crystal membrane. At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18. A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection. The device demonstrates that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission.

  2. Superconducting nanowire single-photon detector on dielectric optical films for visible and near infrared wavelengths

    NASA Astrophysics Data System (ADS)

    You, Lixing; Li, Hao; Zhang, Weijun; Yang, Xiaoyan; Zhang, Lu; Chen, Sijing; Zhou, Hui; Wang, Zhen; Xie, Xiaoming

    2017-08-01

    The detection efficiency (DE) of superconducting nanowire single-photon detectors (SNSPDs) at 1550 nm has been significantly improved in the past decades as a result of evolution of the optical structure, the materials, and the fabrication process. We discuss the general optical design for a high-efficiency SNSPD based on dielectric optical films that can detect wavelengths from visible to near infrared regions. This structure shows close-to-unity absorption and good insensitivity to the fine wavelength and the incident angle. We demonstrate an SNSPD specifically fabricated for the detection of 1064 nm wavelength with a maximal system DE of 87.4% ± 3.7%. The DEs of the SNSPDs for visible and near infrared wavelengths are also summarized and compared with those of semiconducting detectors.

  3. Towards two-dimensional complete photonic bandgap structures below infrared wavelengths

    NASA Astrophysics Data System (ADS)

    van der Lem, Han; Moroz, Alexander

    2000-09-01

    Bandgaps in two- and three-dimensional photonic crystals are hard to achieve due to the limited contrast in the dielectric permeability available with conventional dielectric materials. The situation changes for periodic arrangements of scatterers consisting of materials with a Drude-like behaviour of the dielectric function. We show for two-dimensional square and triangular lattices that such systems have in-plane complete photonic bandgaps (CPBGs) below infrared wavelengths. Of the two geometries, the optimal one for ideal Drude-like behaviour is a square lattice, whereas for Drude-like behaviour in silver, using experimental data (Palik E D 1991 Handbook of Optical Constants of Solids vol 1 (San Diego: Academic)), the optimal geometry is a triangular lattice. If the lattice spacing is tuned to a characteristic plasma wavelength, several CPBGs open in the spectrum and their relative gap width can be as large as 36.9% (9.9% in a nonabsorptive window) even if the host dielectric constant ɛh = 1. Such structures can provide CPBG structures with bandgaps down to ultraviolet wavelengths.

  4. Doubly Resonant Photonic Antenna for Single Infrared Quantum Dot Imaging at Telecommunication Wavelengths

    NASA Astrophysics Data System (ADS)

    Xie, Zhihua; Lefier, Yannick; Suarez, Miguel Angel; Mivelle, Mathieu; Salut, Roland; Merolla, Jean-Marc; Grosjean, Thierry

    2017-04-01

    Colloidal Quantum dots (CQDs) are nowadays one of the cornerstones of modern photonics as they have led to the emergence of new optoelectronic and biomedical technologies. However, the full characterization of these quantum emitters is currently restricted to the visible wavelengths and it remains a key challenge to optically probe single CQDs operating in the infrared spectral domain which is targeted by a growing number of applications. Here, we report the first experimental detection and imaging at room temperature of single infrared CQDs operating at telecommunication wavelengths. Imaging was done with a doubly resonant bowtie nano-aperture antenna (BNA) written at the end of a fiber nanoprobe, whose resonances spectrally fit the CQD absorption and emission wavelengths. Direct near-field characterization of PbS CQDs reveal individual nanocrystals with a spatial resolution of 75 nm (lambda/20) together with their intrinsic 2D dipolar free-space emission properties and exciton dynamics (blinking phenomenon). Because the doubly resonant BNA is strongly transmissive at both the CQD absorption and emission wavelengths, we are able to perform all-fiber nano-imaging with a standard 20 % efficiency InGaAs avalanche photodiode (APD). Detection efficiency is predicted to be 3000 fold larger than with a conventional circular aperture tip of the same transmission area. Double resonance BNA fiber probes thus offer the possibility of exploring extreme light-matter interaction in low band gap CQDs with current plug-and-play detection techniques, opening up new avenues in the fields of infrared light emitting devices, photodetectors, telecommunications, bio-imaging and quantum information technology.

  5. Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications

    NASA Astrophysics Data System (ADS)

    Gol'Tsman, G. N.; Korneev, A.; Rubtsova, I.; Milostnaya, I.; Chulkova, G.; Minaeva, O.; Smirnov, K.; Voronov, B.; Sysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, Roman

    2005-03-01

    We present our progress on the research and development of NbN superconducting single-photon detectors (SSPD's) for ultrafast counting of near-infrared photons for secure quantum communications. Our SSPD's operate in the quantum detection mode based on the photon-induced hotspot formation and subsequent development of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 4-nm-thick NbN films and kept in the 4.2- to 2-K temperature range. The detector experimental quantum efficiency in the photon-counting mode reaches above 40% for the visible light and up to 30% in the 1.3- to 1.55-μm wavelength range with dark counts below 0.01 per second. The experimental real-time counting rate is above 2 GHz and is limited by our readout electronics. The SSPD's timing jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 5 × 10-21 W/Hz1/2 at 1.3 μm. In terms of quantum efficiency, timing jitter, and maximum counting rate, our NbN SSPD's significantly outperform semiconductor avalanche photodiodes and photomultipliers in the 1.3- to 1.55-μm range.

  6. Wavelength-tunable mid-infrared femtosecond Raman soliton generation in birefringent ZBLAN photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Sharma, Sneha; Kumar, Jitendra

    2016-03-01

    A solid core high birefringent ZrF4-BaF2-LaF3-AlF3-NaF photonic crystal fiber (PCF) with low confinement loss is proposed for the generation of Raman soliton source in the mid-infrared region. The birefringence value of the PCF reaches the magnitude of 10- 3 and confinement loss is 0.05 dB/m at 3000 nm wavelength. Numerical simulation of femtosecond Raman soliton generation based on soliton self-frequency shift in the birefringent PCF is analyzed using the coupled nonlinear Schrodinger equation and split-step Fourier method. We investigate the dependence of output pulse width, wavelength shift, and conversion efficiency of Raman soliton formation on several input parameters. A femtosecond Raman soliton source with its wavelength tunable from 1500 to 3600 nm can be obtained. It is found that the maximum conversion efficiency is 93% when the wavelength is tuned by varying the initial input chirp.

  7. Kerr nonlinearity and multi-photon absorption in germanium at mid-infrared wavelengths

    NASA Astrophysics Data System (ADS)

    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.

  8. Design of near-infrared single photon detector at 1550nm wavelength

    NASA Astrophysics Data System (ADS)

    Gao, Jiali

    2016-09-01

    Technology of near-infrared single photon detection is used in quantum communication, laser ranging and weak light detection. Present single photon detectors are usually expensive and bulky. To overcome their disadvantages, a hand-held single photon detector based on InGaAs/InP avalanche photo diode (APD) is developed. A circuit program for temperature control and bias voltage is offered. The gating signal is generated and the avalanche signal is extracted by FPGA. Experiment results show that, the single photon detector yields only 8.2×10-6/ns dark count rate (DCR) when photon detection efficiency is 12%, and the maximum photon detection efficiency of 16% is obtained at temperature of -55°C.

  9. Fabrication of Ceramic Layer-by-Layer Infrared Wavelength Photonic Band Gap Crystals

    SciTech Connect

    Kang, Henry Hao-Chuan

    2004-12-19

    Photonic band gap (PBG) crystals, also known as photonic crystals, are periodic dielectric structures which form a photonic band gap that prohibit the propagation of electromagnetic (EM) waves of certain frequencies at any incident angles. Photonic crystals have several potential applications including zero-threshold semiconductor lasers, the inhibition of spontaneous emission, dielectric mirrors, and wavelength filters. If defect states are introduced in the crystals, light can be guided from one location to another or even a sharp bending of light in micron scale can be achieved. This generates the potential for optical waveguide and optical circuits, which will contribute to the improvement in the fiber-optic communications and the development of high-speed computers.

  10. Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications

    NASA Astrophysics Data System (ADS)

    Verevkin, A.; Pearlman, A.; Słysz, W.; Zhang, J.; Currie, M.; Korneev, A.; Chulkova, G.; Okunev, O.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol'Tsman, G. N.; Sobolewski, Roman

    2004-09-01

    The paper reports progress on the design and development of niobium-nitride, superconducting single-photon detectors (SSPDs) for ultrafast counting of near-infrared photons for secure quantum communications. The SSPDs operate in the quantum detection mode, based on photon-induced hotspot formation and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-width superconducting stripe. The devices are fabricated from 3.5 nm thick NbN films and kept at cryogenic (liquid helium) temperatures inside a cryostat. The detector experimental quantum efficiency in the photon-counting mode reaches above 20% in the visible radiation range and up to 10% at the 1.3-1.55 µm infrared range. The dark counts are below 0.01 per second. The measured real-time counting rate is above 2 GHz and is limited by readout electronics (the intrinsic response time is below 30 ps). The SSPD jitter is below 18 ps, and the best-measured value of the noise-equivalent power (NEP) is 2 × 10-18 W/Hz1/2 at 1.3 µm. In terms of photon-counting efficiency and speed, these NbN SSPDs significantly outperform semiconductor avalanche photodiodes and photomultipliers.

  11. Photon path depth in tissue phantoms: a comparison of visible and near-infrared (NIR) wavelengths

    NASA Astrophysics Data System (ADS)

    Asplund, Karin M.; Schenkman, Kenneth A.; Ciesielski, Wayne A.; Arakaki, Lorilee S. L.

    2014-03-01

    Optical spectroscopy is being used increasingly in medical applications to noninvasively investigate tissues below the skin. In order to assure adequate sampling of tissues underlying the skin, photon penetration depth must be known. Photon penetration in tissues has been studied with near-infrared (NIR) light, but experimental study of visible light propagation in tissue has been limited. In this study, a micro-motion system coupled with a reflectance spectroscopy system was used to determine the penetration depth of visible-range and NIR photons (535-800 nm) in phantoms composed of Intralipid and hemoglobin. An absorbing target was placed at intervals of 0.1mm along a 15mm line perpendicular to and bisecting the line between the ends of the source and detector optical fiber bundles. Comparisons between detected light intensities at different target positions were used to determine the most probable photon path depths at 576 nm and at 760 nm. Scattering coefficients, hemoglobin concentrations, and source-detector separations were varied to evaluate their effects on the penetration depth of photons. Results from phantoms containing Intralipid only showed that the most-probable penetration depth at 576 nm was comparable to that at 760 nm. Larger sourcedetector separations resulted in deeper photon penetration depths for both spectral regions. Changes in scattering over a 4-fold range did not affect the photon path depth appreciably. In the presence of hemoglobin with a source-detector separation of 13 mm, the most probable depth of photon penetration in the visible range was greater than 2.5 mm, and was within 1 mm of the most probable depth of photon penetration in the NIR. This study demonstrates the feasibility of using the visible and NIR regions in transcutaneous reflectance spectroscopy.

  12. Doubly Resonant Photonic Antenna for Single Infrared Quantum Dot Imaging at Telecommunication Wavelengths.

    PubMed

    Xie, Zhihua; Lefier, Yannick; Suarez, Miguel Angel; Mivelle, Mathieu; Salut, Roland; Merolla, Jean-Marc; Grosjean, Thierry

    2017-03-24

    Colloidal quantum dots (CQDs) have drawn strong interest in the past for their high prospects in scientific, medical, and industrial applications. However, the full characterization of these quantum emitters is currently restricted to the visible wavelengths, and it remains a key challenge to optically probe single CQDs operating in the infrared spectral domain, which is targeted by a growing number of applications. Here, we report the first experimental detection and imaging at room temperature of single infrared CQDs operating at telecommunication wavelengths. Imaging was done with a doubly resonant bowtie nanoaperture antenna (BNA) written at the end of a fiber nanoprobe, whose resonances spectrally fit the CQD absorption and emission wavelengths. Direct near-field characterization of PbS CQDs reveal individual nanocrystals with a spatial resolution of 75 nm (λ/20) together with their intrinsic 2D dipolar free-space emission properties and exciton dynamics (blinking phenomenon). Because the doubly resonant BNA is strongly transmissive at both the CQD absorption and the emission wavelengths, we are able to perform all-fiber nanoimaging with a standard 20% efficiency InGaAs avalanche photodiode (APD). The detection efficiency is predicted to be 3000 fold larger than with a conventional circular aperture tip of the same transmission area. Double resonance BNA fiber probes thus offer the possibility of exploring extreme light-matter interaction in low band gap CQDs with current plug-and-play detection techniques, opening up new avenues in the fields of infrared light-emitting devices, photodetectors, telecommunications, bioimaging, and quantum information technology.

  13. APDs as single-photon detectors for visible and near-infrared wavelengths down to Hz rates

    NASA Astrophysics Data System (ADS)

    Jöhren, R.; Berendes, R.; Buglak, W.; Hampf, D.; Hannen, V.; Mader, J.; Nörtershäuser, W.; Sánchez, R.; Weinheimer, C.

    2012-02-01

    For the SPECTRAP experiment at GSI, Germany, detectors with single-photon counting capability in the visible and near-infrared regime are required. For the wavelength region up to 1100 nm we investigate the performance of 2 × 2 mm2 avalanche photo diodes (APDs) of type S0223 manufactured by Radiation Monitoring Devices. To minimize thermal noise, the APDs are cooled to approximately -170°C using liquid nitrogen. By operating the diodes close to the breakdown voltage it is possible to achieve relative gains in excess of 2ṡ104. Custom-made low noise preamplifiers are used to read out the devices. The measurements presented in this paper have been obtained at a relative gain of 2.2ṡ104. At a discriminator threshold of 6 mV the resulting dark count rate is in the region of 230 s-1. With these settings the studied APDs are able to detect single-photons at 628 nm wavelength with a photo detection efficiency of (67±7)%. Measurements at 1020 nm wavelength have been performed using the attenuated output of a grating spectrograph with a light bulb as photon source. With this setup the photo detection efficiency at 1020 nm has been determined to be (13±3)%, again at a threshold of 6 mV.

  14. Hyperuniform disordered photonic bandgap materials, from microwave to infrared wavelength regime

    NASA Astrophysics Data System (ADS)

    Man, Weining

    Recently, we have introduced a new class of hyperuniform disordered (HUD) photonic bandgap (PBG) materials enabled by a novel constrained optimization method for engineering the material's Fourier transform to be continuous, isotropic and stealthy. Their structure factor S (k) is equal to zero for small kand exhibits a broad ring of maximum values around a characteristic wave-length range. Experimentally, an isotropic complete PBG (at all angles and for all polarizations) in an alumina-based HUD structure and single-polarized PBGs for plastic-based HUD structure have been demonstrated. Using measured and simulated transmission and phase delay information through these HUD structures, we also unfolded their band structures and reconstructed the effective dispersion relations of propagating electromagnetic modes in them. The intrinsic isotropy in these disordered structures is an inherent advantage associated with the lack of crystalline order, offering unprecedented freedom for functional defect design impossible to achieve in photonic crystals. In the microwave regime, we have shown the creation of freeform waveguides, which can channel photons robustly along arbitrarily curved paths and around sharp bends, and be decorated with defects to produce sharply resonant structures useful for filtering and frequency splitting. Recent simulation and experimental results for waveguides and modulators based on submicron-scale planar hyperuniform disordered PBG structures further highlight their ability to serve as highly compact, flexible and energy-efficient platforms for photonic integrated circuits. NSF DMR-1308084, EPSRC (UK) DTG Grant KD5050, EPSRC (UK) Strategic Equipment Grant EP/M008576/1, NSF SBIR-1345168, NSF MRI-1040444.

  15. Long wavelength infrared detector

    NASA Technical Reports Server (NTRS)

    Vasquez, Richard P. (Inventor)

    1993-01-01

    Long wavelength infrared detection is achieved by a detector made with layers of quantum well material bounded on each side by barrier material to form paired quantum wells, each quantum well having a single energy level. The width and depth of the paired quantum wells, and the spacing therebetween, are selected to split the single energy level with an upper energy level near the top of the energy wells. The spacing is selected for splitting the single energy level into two energy levels with a difference between levels sufficiently small for detection of infrared radiation of a desired wavelength.

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

    PubMed

    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.

  17. Multiple-return single-photon counting of light in flight and sensing of non-line-of-sight objects at shortwave infrared wavelengths.

    PubMed

    Laurenzis, Martin; Klein, Jonathan; Bacher, Emmanuel; Metzger, Nicolas

    2015-10-15

    Time-of-flight sensing with single-photon sensitivity enables new approaches for the localization of objects outside a sensor's field of view by analyzing backscattered photons. In this Letter, the authors have studied the application of Geiger-mode avalanche photodiode arrays and eye-safe infrared lasers, and provide experimental data of the direct visualization of backscattering light in flight, and direct vision and indirect vision of targets in line-of-sight and non-line-of-sight configurations at shortwave infrared wavelengths.

  18. Plasmonic Photon Sorters and Their Potential for Use in Compact Multispectral Imagers at Visible and Infrared Wavelengths

    DTIC Science & Technology

    2009-10-01

    the thermal infrared due to the thermal radiation emitted from uncooled parts of the optics, which must be prevented from reaching the detector ...format HgCdTe focal plane arrays for dual-band long-wavelength infrared detection, Proc. SPIE 7298, 72981Y (2009) [3] Tyo, J. S., Goldstein, D.L...spectral band. This leads to subsampling of the image data cube, with loss of light and loss of information. In the thermal infrared , multiband detectors

  19. Ultra-small near-infrared multi-wavelength light source using a heterojunction photonic crystal waveguide and self-assembled InAs quantum dots

    NASA Astrophysics Data System (ADS)

    Uchida, Sho; Ozaki, Nobuhiko; Nakahama, Teruyuki; Oda, Hisaya; Ikeda, Naoki; Sugimoto, Yoshimasa

    2017-05-01

    We herein propose and verify an ultra-small near-infrared (NIR) multi-wavelength light source using a heterojunction photonic crystal waveguide (PC-WG) and quantum dots (QDs). A heterojunction two-dimensional PC-WG, which consists of multiple PC-WGs with sequentially shifted structural parameters, is fabricated on a GaAs-slab including InAs QDs. Spontaneous emission (SE) from embedded InAs QDs was enhanced at multiple wavelengths resonating with slow-light regions of the PC-WG modes. The enhanced SE was propagated and detected through the heterojunction PC-WG. These results indicate the feasibility of the proposed light source.

  20. Phototransistors For Long-Wavelength Infrared

    NASA Technical Reports Server (NTRS)

    Borenstain, Shmuel I.

    1991-01-01

    Phototransistors of proposed new type used to detect photons having wavelengths of 8 to 150 micrometers. Detection based on impurity-to-continuum transitions. Integrated-circuit imaging arrays of such phototransistors useful in infrared remote sensing. Device of this type silicon, germanium, or silicon/germanium phototransistor in which junction between collector and base lightly doped with impurities.

  1. Efficient and broadband Stokes wave generation by degenerate four-wave mixing at the mid-infrared wavelength in a silica photonic crystal fiber.

    PubMed

    Yuan, Jinhui; Sang, Xinzhu; Wu, Qiang; Zhou, Guiyao; Yu, Chongxiu; Wang, Kuiru; Yan, Binbin; Han, Ying; Farrell, Gerald; Hou, Lantian

    2013-12-15

    Based on degenerate four-wave mixing (FWM), the broadband Stokes waves are efficiently generated at the mid-infrared wavelength above 2 μm, for the first time to our knowledge, by coupling the femtosecond pulses into the fundamental mode of a silica photonic crystal fiber designed and fabricated in our laboratory. Influences of the power and wavelength of pump pulses on the phase-matched frequency conversion process are discussed. When pump pulses with central wavelength of 815 nm and average power of 300 mW are used, the output power ratio of the Stokes wave generated at 2226 nm and the residual pump wave P(s)/P(res) is estimated to be 10.8:1, and the corresponding conversion efficiency η(s) and bandwidth B(s) of the Stokes wave can be up to 26% and 33 nm, respectively. The efficient and broadband Stokes waves can be used as the ultrashort pulse sources for mid-infrared photonics and spectroscopy.

  2. Enhanced intermodal four-wave mixing for visible and near-infrared wavelength generation in a photonic crystal fiber.

    PubMed

    Yuan, Jinhui; Sang, Xinzhu; Wu, Qiang; Zhou, Guiyao; Li, Feng; Zhou, Xian; Yu, Chongxiu; Wang, Kuiru; Yan, Binbin; Han, Ying; Tam, Hwa Yaw; Wai, P K A

    2015-04-01

    We demonstrate experimentally an enhanced intermodal four-wave mixing (FWM) process through coupling positively chirped femtosecond pulses into the deeply normal dispersion region of the fundamental mode of an in-house fabricated photonic crystal fiber (PCF). In the intermodal phase-matching scheme, the energy of the pump waves at 800 nm in the fundamental mode is efficiently converted into the anti-Stokes waves around 553 nm and the Stokes waves within the wavelength range of 1445-1586 nm in the second-order mode. The maximum conversion efficiency of η(as) and η(s) of anti-Stokes and Stokes waves can be up to 21% and 16%, respectively. The Stokes frequency shift Ω is 5580  cm(-1). The fiber bending and intermodal walk-off effect of pulses do not have significant influence on the nonlinear optical process.

  3. High peak power continuum generation by high-order solitons at the mid-infrared wavelength in a photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Yuan, Jinhui; Zhou, Guiyao; Liu, Hongzhan; Xia, Changming; Sang, Xinzhu; Yu, Chongxiu; Wang, Kuiru; Yan, Binbin; Han, Ying; Hou, Lantian

    2015-04-01

    A photonic crystal fiber (PCF) is fabricated from silica material purified by the complexing method of rectification and adsorption in our laboratory. The parameters of pump pulses and fiber length are optimized in the experiment, and the nonlinear optical process of the high-order soliton generation is studied. The high peak power continuums at the mid-infrared wavelength are generated by the overlap among the high-order soliton peaks. Specifically, when a PCF with a length of 60 cm is used, the conversion efficiency η and bandwidth B of the continuum generated can be up to 65% and 358 nm, and the corresponding peak power Ppeak-o and pulse width Wp are 144 kW and 30 fs. It is believed that the high peak power and broadband mid-infrared continuum can be used as short pulse sources, which will find important applications in biophotonics and ultrafast science and technology.

  4. Demonstration of a mid-wavelength infrared narrowband thermal emitter based on GaN/AlGaN quantum wells and a photonic crystal

    NASA Astrophysics Data System (ADS)

    Kang, Dongyeon Daniel; Inoue, Takuya; Asano, Takashi; Noda, Susumu

    2017-05-01

    We experimentally demonstrate a thermal emitter with a narrow-bandwidth and low background emission, operating in the mid-wavelength infrared (MWIR) range, based on a combination of intersubband transitions in GaN/AlGaN multiple quantum wells and optical resonance in a photonic crystal slab. The fabricated device exhibits single-peak narrowband thermal emission with a Q factor of 93 at a wavelength of 4.0 μm. Stable operation at high temperatures over 700 °C has been demonstrated owing to the good thermal stability of GaN/AlGaN, which enables the generation of strong peak emission intensity as high as 93 mW/μm/sr/cm2. Such a narrow-band and low-background emitter in the MWIR range has been difficult to realize by metal or heavily doped semiconductor-based emitters due to the broadband emission characteristics of the materials and by GaAs/AlGaAs-based emitters due to the thermal instability of the materials. Our device can be applied to various MWIR applications including CO2 and NOx gas sensing systems.

  5. trans/cis-Isomerization of fluorene-bridged azo chromophore with significant two-photon absorbability at near-infrared wavelength.

    PubMed

    Chu, Chih-Chien; Chang, Ya-Chi; Tsai, Bo-Kai; Lin, Tzu-Chau; Lin, Ja-Hon; Hsiao, Vincent K S

    2014-12-01

    Azo-containing materials have been proven to possess second-order nonlinear optical (NLO) properties, but their third-order NLO properties, which involves two-photon absorption (2PA), has rarely been reported. In this study, we demonstrate a significant 2PA behavior of the novel azo chromophore incorporated with bilateral diphenylaminofluorenes (DPAFs) as a π framework. The electron-donating DPAF moieties cause a redshifted π-π* absorption band centered at 470 nm, thus allowing efficient blue-light-induced trans-to-cis photoisomerization with a rate constant of 2.04 × 10(-1) min(-1) at the photostationary state (PSS). The open-aperture Z-scan technique that adopted a femtosecond (fs) pulse laser as excitation source shows an appreciably higher 2PA cross-section for the fluorene-derived azo chromophore than that for common azobenzene dyes at near-infrared wavelength (λex =800 nm). Furthermore, the fs 2PA response is quite uniform regardless of the molecular geometry. On the basis of the computational modeling, the intramolecular charge-transfer (ICT) process from peripheral diphenylamines to the central azo group through a fluorene π bridge is crucial to this remarkable 2PA behavior.

  6. Room temperature photon number resolving detector for infared wavelengths.

    PubMed

    Pomarico, Enrico; Sanguinetti, Bruno; Thew, Rob; Zbinden, Hugo

    2010-05-10

    In this paper we present a photon number resolving detector at infrared wavelengths, operating at room temperature and with a large dynamic range. It is based on the up-conversion of a signal at 1559 nm into visible wavelength and on its detection by a thermoelectrically cooled multi-pixel silicon avalanche photodiodode, also known as a Silicon Photon Multiplier. With the appropriate up-conversion this scheme can be implemented for arbitrary wavelengths above the visible spectral window. The preservation of the poissonian statistics when detecting coherent states is studied and the cross-talk effects on the detected signal can be easily estimated in order to calibrate the detector. This system is well suited for measuring very low intensities at infrared wavelengths and for analyzing multiphoton quantum states. (c) 2010 Optical Society of America.

  7. Nanoantenna Enhancement for Telecom-Wavelength Superconducting Single Photon Detectors

    NASA Astrophysics Data System (ADS)

    Heath, Robert M.; Tanner, Michael G.; Drysdale, Timothy D.; Miki, Shigehito; Giannini, Vincenzo; Maier, Stefan A.; Hadfield, Robert H.

    2015-02-01

    Superconducting nanowire single photon detectors are rapidly emerging as a key infrared photon-counting technology. Two front-side-coupled silver dipole nanoantennas, simulated to have resonances at 1480 nm and 1525 nm, were fabricated in a two-step process. An enhancement of 50% to 130% in the system detection efficiency was observed when illuminating the antennas. This offers a pathway to increasing absorption into superconducting nanowires, creating larger active areas, and achieving more efficient detection at longer wavelengths.

  8. Nanoantenna enhancement for telecom-wavelength superconducting single photon detectors.

    PubMed

    Heath, Robert M; Tanner, Michael G; Drysdale, Timothy D; Miki, Shigehito; Giannini, Vincenzo; Maier, Stefan A; Hadfield, Robert H

    2015-02-11

    Superconducting nanowire single photon detectors are rapidly emerging as a key infrared photon-counting technology. Two front-side-coupled silver dipole nanoantennas, simulated to have resonances at 1480 and 1525 nm, were fabricated in a two-step process. An enhancement of 50 to 130% in the system detection efficiency was observed when illuminating the antennas. This offers a pathway to increasing absorption into superconducting nanowires, creating larger active areas, and achieving more efficient detection at longer wavelengths.

  9. Parametric wavelength conversion in photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Yang, Sigang; Wu, Zhaohui; Yang, Yi; Chen, Minghua; Xie, Shizhong

    2016-11-01

    Nonlinear wavelength conversion provides flexible solutions for generating wideband tunable radiation in novel wavelength band. Parametric process in photonic crystal fibers (PCFs) has attracted comprehensive interests since it can act as broadband tunable light sources in non-conventional wavelength bands. The current state-of-the-art photonic crystal fibers can provide more freedom for customizing the dispersion and nonlinearity which is critical to the nonlinear process, such as four wave mixing (FWM), compared with the traditional fibers fabricated with doping techniques. Here we demonstrate broadband parametric wavelength conversion in our homemade photonic crystal fibers. The zero dispersion wavelength (ZDW) of PCFs is critical for the requirement of phase matching condition in the parametric four wave mixing process. Firstly a procedure of the theoretical design of PCF with the ZDW at 1060 nm is proposed through our homemade simulation software. A group of PCF samples with gradually variable parameters are fabricated according to the theoretical design. The broadband parametric gain around 1060 nm band is demonstrated pumped with our homemade mode locked fiber laser in the anomalous dispersion region. Also a narrow gain band with very large wavelength detune with the pump wavelength in the normal dispersion region is realized. Wavelength conversion with a span of 194 nm is realized. Furthermore a fiber optical parametric oscillator based on the fabricated PCF is built up. A wavelength tunable range as high as 340 nm is obtained. This report demonstrates a systematic procedure to realize wide band wavelength conversion based on PCFs.

  10. Negative refraction at telecommunication wavelengths through plasmon-photon hybridization.

    PubMed

    Kalusniak, Sascha; Sadofev, Sergey; Henneberger, Fritz

    2015-11-16

    We demonstrate negative refraction at telecommunication wavelengths through plasmon-photon hybridization on a simple microcavity with metallic mirrors. Instead of using conventional metals, the plasmonic excitations are provided by a heavily doped semiconductor which enables us to tune them into resonance with the infrared photon modes of the cavity. In this way, the dispersion of the resultant hybrid cavity modes can be widely adjusted. In particular, negative dispersion and negative refraction at telecommunication wavelengths on an all-ZnO monolithical cavity are demonstrated.

  11. Wavelength-domain RF photonic signal processing

    NASA Astrophysics Data System (ADS)

    Gao, Lu

    This thesis presents a novel approach to RF-photonic signal processing applications based on wavelength-domain optical signal processing techniques using broadband light sources as the information carriers, such as femtosecond lasers and white light sources. The wavelength dimension of the broadband light sources adds an additional degree of freedom to conventional optical signal processing systems. Two novel wavelength-domain optical signal processing systems are presented and demonstrated in this thesis. The first wavelength-domain RF photonic signal processing system is a wavelength-compensated squint-free photonic multiple beam-forming system for wideband RF phased-array antennas. Such a photonic beam-forming system employs a new modulation scheme developed in this thesis, which uses traveling-wave tunable filters to modulate wideband RF signals onto broadband optical light sources in a frequency-mapped manner. The wavelength dimension of the broadband light sources provides an additional dimension in the wavelength-compensated Fourier beam-forming system for mapping the received RF frequencies to the linearly proportional optical frequencies, enabling true-time-delay beam forming, as well as other novel RF-photonic signal processing functions such as tunable filtering and frequency down conversion. A new slow-light mechanism, the SLUGGISH light, has also been discovered with an effective slow-light velocity of 86 m/s and a record time-bandwidth product of 20. Experimental demonstration of true-time-delay beam forming based on the SLUGGISH light effect has also been presented in this thesis. In the second wavelength-domain RF photonic signal processing system, the wavelength dimension increases the information carrying capacity by spectrally multiplexing multiple wavelength channels in a wavelength-division-multiplexing fiber-optic communication system. A novel ultrafast all-optical 3R (Re-amplification, Retiming, Re-shaping) wavelength converter based on

  12. Wavelength multicasting in silicon photonic nanowires.

    PubMed

    Biberman, Aleksandr; Lee, Benjamin G; Turner-Foster, Amy C; Foster, Mark A; Lipson, Michal; Gaeta, Alexander L; Bergman, Keren

    2010-08-16

    We demonstrate a scalable, energy-efficient, and pragmatic method for high-bandwidth wavelength multicasting using FWM in silicon photonic nanowires. We experimentally validate up to a sixteen-way multicast of 40-Gb/s NRZ data using spectral and temporal responses, and evaluate the resulting data integrity degradation using BER measurements and power penalty performance metrics. We further examine the impact of this wavelength multicasting scalability on conversion efficiency. Finally, we experimentally evaluate up to a three-way multicast of 160-Gb/s pulsed-RZ data using spectral and temporal responses, representing the first on-chip wavelength multicasting of pulsed-RZ data.

  13. Differentiation of closely related isomers: application of data mining techniques in conjunction with variable wavelength infrared multiple photon dissociation mass spectrometry for identification of glucose-containing disaccharide ions.

    PubMed

    Stefan, Sarah E; Ehsan, Mohammad; Pearson, Wright L; Aksenov, Alexander; Boginski, Vladimir; Bendiak, Brad; Eyler, John R

    2011-11-15

    Data mining algorithms have been used to analyze the infrared multiple photon dissociation (IRMPD) patterns of gas-phase lithiated disaccharide isomers irradiated with either a line-tunable CO(2) laser or a free electron laser (FEL). The IR fragmentation patterns over the wavelength range of 9.2-10.6 μm have been shown in earlier work to correlate uniquely with the asymmetry at the anomeric carbon in each disaccharide. Application of data mining approaches for data analysis allowed unambiguous determination of the anomeric carbon configurations for each disaccharide isomer pair using fragmentation data at a single wavelength. In addition, the linkage positions were easily assigned. This combination of wavelength-selective IRMPD and data mining offers a powerful and convenient tool for differentiation of structurally closely related isomers, including those of gas-phase carbohydrate complexes.

  14. Progress towards photon-counting infrared arrays for interferometry

    NASA Astrophysics Data System (ADS)

    Buscher, David F.; Seneta, Eugene B.; Sun, Xiaowei; Young, John S.; Finger, Gert

    2016-08-01

    The advent of low-dark-current eAPD arrays in the near infrared ushers in the possibility for photon-counting, high quantum efficiency detectors at these wavelengths. Such detectors would revolutionise the sensitivity of interferometry because near-infrared wavelengths are at the "sweet spot" between the corrupting effects of atmospheric seeing at shorter wavelengths and thermal noise at longer wavelengths. We report on laboratory experiments with cooled Selex Saphira detectors aimed at demonstrating photon-counting performance with these devices by exploiting enhanced avalanche gain and multiple non-destructive readouts. We explain the optimum modes for employing these detectors in interferometry.

  15. Compact fixed wavelength femtosecond oscillators for multi-photon imaging

    NASA Astrophysics Data System (ADS)

    Hakulinen, T.; Klein, J.; Zadoyan, R.; Baldacchini, T.; Franke, T.

    2015-03-01

    In recent years two-photon microscopy with fixed-wavelength has raised increasing interest in life-sciences: Two-photon (2P) absorption spectra of common dyes are broader than single-photon ones. Therefore, excitation of several dyes simultaneously with a single IR laser wavelength is feasible and could be seen as an advantage in 2P microscopy. We used pulsed fixed-wavelength infrared lasers with center wavelength at 1040 nm, for two-photon microscopy in a variety of biologically relevant samples, among these a mouse brain sample, a mouse artery (within the animal, acute preparation), and a preparation of mouse bladder. The 1040 nm laser proved to be efficient not only in exciting fluorescence from yellow fluorescent protein (YFP) and red fluorescent dyes, but also for second harmonic generation (SHG) signals from muscle tissue and collagen. With this work we demonstrate that economical, small-footprint fixedwavelength lasers can present an interesting alternative to tunable lasers that are commonly used in multiphoton microscopy.

  16. Wavelength selective uncooled infrared sensor by plasmonics

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Okada, Kazuya; Fukushima, Naoki; Kimata, Masafumi

    2012-01-01

    A wavelength selective uncooled infrared (IR) sensor using two-dimensional plasmonic crystals (2D PLCs) has been developed. The numerical investigation of 2D PLCs demonstrates that the wavelength of absorption can be mainly controlled by the period of the surface structure. A microelectromechanical systems-based uncooled IR sensor with 2D PLCs as the IR absorber was fabricated through a complementary metal oxide semiconductor and a micromachining technique. The selective enhancement of responsivity was observed at the wavelength that coincided with the period of the 2D-PLC absorber.

  17. SDIO long wavelength infrared detector requirements

    NASA Technical Reports Server (NTRS)

    Duston, Dwight

    1990-01-01

    The Strategic Defense Initiative Organization (SDIO) has a significant requirement for infrared sensors for surveillance, tracking and discrimination of objects in space. Projected SDIO needs cover the range from short wavelengths out to 30 microns. Large arrays are required, and producibility and cost are major factors. The SDIO is pursuing several approaches including innovative concepts based on semiconductors and superconductors.

  18. Compact silicon photonic wavelength-tunable laser diode with ultra-wide wavelength tuning range

    SciTech Connect

    Kita, Tomohiro Tang, Rui; Yamada, Hirohito

    2015-03-16

    We present a wavelength-tunable laser diode with a 99-nm-wide wavelength tuning range. It has a compact wavelength-tunable filter with high wavelength selectivity fabricated using silicon photonics technology. The silicon photonic wavelength-tunable filter with wide wavelength tuning range was realized using two ring resonators and an asymmetric Mach-Zehnder interferometer. The wavelength-tunable laser diode fabricated by butt-joining a silicon photonic filter and semiconductor optical amplifier shows stable single-mode operation over a wide wavelength range.

  19. Compact silicon photonic wavelength-tunable laser diode with ultra-wide wavelength tuning range

    NASA Astrophysics Data System (ADS)

    Kita, Tomohiro; Tang, Rui; Yamada, Hirohito

    2015-03-01

    We present a wavelength-tunable laser diode with a 99-nm-wide wavelength tuning range. It has a compact wavelength-tunable filter with high wavelength selectivity fabricated using silicon photonics technology. The silicon photonic wavelength-tunable filter with wide wavelength tuning range was realized using two ring resonators and an asymmetric Mach-Zehnder interferometer. The wavelength-tunable laser diode fabricated by butt-joining a silicon photonic filter and semiconductor optical amplifier shows stable single-mode operation over a wide wavelength range.

  20. Room-temperature short-wavelength infrared Si photodetector

    PubMed Central

    Berencén, Yonder; Prucnal, Slawomir; Liu, Fang; Skorupa, Ilona; Hübner, René; Rebohle, Lars; Zhou, Shengqiang; Schneider, Harald; Helm, Manfred; Skorupa, Wolfgang

    2017-01-01

    The optoelectronic applications of Si are restricted to the visible and near-infrared spectral range due to its 1.12 eV-indirect band gap. Sub-band gap light detection in Si, for instance, has been a long-standing scientific challenge for many decades since most photons with sub-band gap energies pass through Si unabsorbed. This fundamental shortcoming, however, can be overcome by introducing non-equilibrium deep-level dopant concentrations into Si, which results in the formation of an impurity band allowing for strong sub-band gap absorption. Here, we present steady-state room-temperature short-wavelength infrared p-n photodiodes from single-crystalline Si hyperdoped with Se concentrations as high as 9 × 1020 cm−3, which are introduced by a robust and reliable non-equilibrium processing consisting of ion implantation followed by millisecond-range flash lamp annealing. We provide a detailed description of the material properties, working principle and performance of the photodiodes as well as the main features in the studied wavelength region. This work fundamentally contributes to establish the short-wavelength infrared detection by hyperdoped Si in the forefront of the state-of-the-art of short-IR Si photonics. PMID:28262746

  1. Room-temperature short-wavelength infrared Si photodetector

    NASA Astrophysics Data System (ADS)

    Berencén, Yonder; Prucnal, Slawomir; Liu, Fang; Skorupa, Ilona; Hübner, René; Rebohle, Lars; Zhou, Shengqiang; Schneider, Harald; Helm, Manfred; Skorupa, Wolfgang

    2017-03-01

    The optoelectronic applications of Si are restricted to the visible and near-infrared spectral range due to its 1.12 eV-indirect band gap. Sub-band gap light detection in Si, for instance, has been a long-standing scientific challenge for many decades since most photons with sub-band gap energies pass through Si unabsorbed. This fundamental shortcoming, however, can be overcome by introducing non-equilibrium deep-level dopant concentrations into Si, which results in the formation of an impurity band allowing for strong sub-band gap absorption. Here, we present steady-state room-temperature short-wavelength infrared p-n photodiodes from single-crystalline Si hyperdoped with Se concentrations as high as 9 × 1020 cm‑3, which are introduced by a robust and reliable non-equilibrium processing consisting of ion implantation followed by millisecond-range flash lamp annealing. We provide a detailed description of the material properties, working principle and performance of the photodiodes as well as the main features in the studied wavelength region. This work fundamentally contributes to establish the short-wavelength infrared detection by hyperdoped Si in the forefront of the state-of-the-art of short-IR Si photonics.

  2. FY 2008 Infrared Photonics Final Report

    SciTech Connect

    Anheier, Norman C.; Bernacki, Bruce E.; Carlie, Nathan A.; Gervais, Kevin L.; Hatchell, Brian K.; Johnson, Bradley R.; Krishnaswami, Kannan; McCloy, John S.; Phillips, Mark C.; Qiao, Hong

    2008-12-01

    Through the duration of the NNSA Office of Nuclear Nonproliferation Research and development (NA-22) ITAS lifecycle project, the Infrared Photonics research has been focused on developing integrated quantum cascade (QC) laser technology to enable next-generation remote sensing designs. Our team developed the concept of the integrated QC laser transmitter and originated and promoted the vision of mid-infrared (3–12 μm) wavelength photonics. Sustained NA-22 project funding produced the QC laser transmitter that is now deployed in follow-on projects. Our team produced nationally recognized cutting-edge research in the area of infrared transparent chalcogenide photonics. Three technical staff were recruited from outside PNNL and hired to support this research. This project also supported student research at the national laboratory, including high school, undergraduate, and graduate students. This provided a derivative benefit to NA-22, PNNL, and the educational institutions through training and mentoring next-generation students in science and technology. The student support was also the catalyst to develop research collaborations with two universities that are internationally recognized for their chalcogenide glass research.

  3. Mid-infrared nonlinear silicon photonics

    NASA Astrophysics Data System (ADS)

    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.

  4. Group IV mid-infrared photonics

    NASA Astrophysics Data System (ADS)

    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.

  5. Resolution in two-photon infrared vision (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Artal, Pablo; Komar, Katarzyna; Gambin, Adrian; Manzanera, Silvestre; Wojtkowski, Maciej

    2017-02-01

    Human subjects can detect infrared light at wavelengths over 1000 nm perceived as visible of the corresponding half wavelength. This is due to a two-photon process and requires the use of pulsed light sources well focused within the retina. We have developed an experimental system to measure, for the first time, the visual resolution of the eye when is stimulated with infrared (1043 nm) and compared with visible light (543 nm). Scanner mirrors were used to project letters of different sizes onto the retina in both wavelengths. Subjects performed a visual test to determine the smallest letter size that was distinguishable for each wavelength for a range of defocus values. An additional optical path was used to record the retinal images of the spot after reflection in the retina and double-pass through the optical media. The best visual acuity was obtained at different defocus locations corresponding to the chromatic difference between green and infrared. Although, there was some individual variability, visual acuity was found to be similar both in visible and infrared. The use of two-photon infrared vision may have some potential applications for vision in those cases were the optical media is opaque to visible wavelengths while keeping some transparency in the infrared.

  6. Wavelength shifting of intra-cavity photons: Adiabatic wavelength tuning in rapidly wavelength-swept lasers

    PubMed Central

    Jirauschek, Christian; Huber, Robert

    2015-01-01

    We analyze the physics behind the newest generation of rapidly wavelength tunable sources for optical coherence tomography (OCT), retaining a single longitudinal cavity mode during operation without repeated build up of lasing. In this context, we theoretically investigate the currently existing concepts of rapidly wavelength-swept lasers based on tuning of the cavity length or refractive index, leading to an altered optical path length inside the resonator. Specifically, we consider vertical-cavity surface-emitting lasers (VCSELs) with microelectromechanical system (MEMS) mirrors as well as Fourier domain mode-locked (FDML) and Vernier-tuned distributed Bragg reflector (VT-DBR) lasers. Based on heuristic arguments and exact analytical solutions of Maxwell’s equations for a fundamental laser resonator model, we show that adiabatic wavelength tuning is achieved, i.e., hopping between cavity modes associated with a repeated build up of lasing is avoided, and the photon number is conserved. As a consequence, no fundamental limit exists for the wavelength tuning speed, in principle enabling wide-range wavelength sweeps at arbitrary tuning speeds with narrow instantaneous linewidth. PMID:26203373

  7. Design and fabrication of rod-type two-dimensional photonic crystal slabs with large high-order bandgaps in near-infrared wavelengths.

    PubMed

    Jiang, Liyong; Jia, Wei; Zheng, Gaige; Li, Xiangyin

    2012-05-01

    We proposed a novel two-dimensional photonic crystal slab comprised of a number of silicon rods with different radii and locations in the square-lattice unit cell pattern. Such rod-type photonic crystal slabs were automatically optimized by the genetic algorithm and fabricated on the silicon-on-insulator wafer. In particular, the measured transmission spectra of the five-rods sample have shown a large accepted high-order bandgap between 1498 and 1648 nm (gap size is 9.54%). Based on the theories of multiple Bragg and Mie scattering effects, we have given a reasonable explanation to the large high-order bandgaps found in the present study.

  8. Short-Wavelength Infrared Views of Messier 81

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The magnificent spiral arms of the nearby galaxy Messier 81 are highlighted in this NASA Spitzer Space Telescope image. Located in the northern constellation of Ursa Major (which also includes the Big Dipper), this galaxy is easily visible through binoculars or a small telescope. M81 is located at a distance of 12 million light-years from Earth.

    Because of its proximity, M81 provides astronomers with an enticing opportunity to study the anatomy of a spiral galaxy in detail. The unprecedented spatial resolution and sensitivity of Spitzer at infrared wavelengths show a clear separation between the several key constituents of the galaxy: the old stars, the interstellar dust heated by star formation activity, and the embedded sites of massive star formation. The infrared images also permit quantitative measurements of the galaxy's overall dust content, as well as the rate at which new stars are being formed.

    The infrared image was obtained by Spitzer's infrared array camera. It is a four-color composite of invisible light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (yellow) and 8.0 microns (red). Winding outward from the bluish-white central bulge of the galaxy, where old stars predominate and there is little dust, the grand spiral arms are dominated by infrared emission from dust. Dust in the galaxy is bathed by ultraviolet and visible light from the surrounding stars. Upon absorbing an ultraviolet or visible-light photon, a dust grain is heated and re-emits the energy at longer infrared wavelengths. The dust particles, composed of silicates (which are chemically similar to beach sand) and polycyclic aromatic hydrocarbons, trace the gas distribution in the galaxy. The well-mixed gas (which is best detected at radio wavelengths) and dust provide a reservoir of raw materials for future star formation.

    The infrared-bright clumpy knots within the spiral arms denote where massive stars are being born in giant H

  9. Short-Wavelength Infrared Views of Messier 81

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The magnificent spiral arms of the nearby galaxy Messier 81 are highlighted in this NASA Spitzer Space Telescope image. Located in the northern constellation of Ursa Major (which also includes the Big Dipper), this galaxy is easily visible through binoculars or a small telescope. M81 is located at a distance of 12 million light-years from Earth.

    Because of its proximity, M81 provides astronomers with an enticing opportunity to study the anatomy of a spiral galaxy in detail. The unprecedented spatial resolution and sensitivity of Spitzer at infrared wavelengths show a clear separation between the several key constituents of the galaxy: the old stars, the interstellar dust heated by star formation activity, and the embedded sites of massive star formation. The infrared images also permit quantitative measurements of the galaxy's overall dust content, as well as the rate at which new stars are being formed.

    The infrared image was obtained by Spitzer's infrared array camera. It is a four-color composite of invisible light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (yellow) and 8.0 microns (red). Winding outward from the bluish-white central bulge of the galaxy, where old stars predominate and there is little dust, the grand spiral arms are dominated by infrared emission from dust. Dust in the galaxy is bathed by ultraviolet and visible light from the surrounding stars. Upon absorbing an ultraviolet or visible-light photon, a dust grain is heated and re-emits the energy at longer infrared wavelengths. The dust particles, composed of silicates (which are chemically similar to beach sand) and polycyclic aromatic hydrocarbons, trace the gas distribution in the galaxy. The well-mixed gas (which is best detected at radio wavelengths) and dust provide a reservoir of raw materials for future star formation.

    The infrared-bright clumpy knots within the spiral arms denote where massive stars are being born in giant H

  10. Multiple wavelength infrared cameras and their biomedical applications

    NASA Astrophysics Data System (ADS)

    Anbar, Michael

    1995-03-01

    There have been substantial advances in multiple wavelength infrared imaging systems that can measure emissivity and temperature of surfaces. Multiplewavelength measurements can be done (1) using an array of detectors, each sensitive to a different range of photon energies; (2) using a tunable filter in front of a broad-band infrared detector; or (3) by using a focal plane array of tunable detectors. In choosing a multiplewavelength infrared camera for biomedical research or for clinical practice, the parameters of importance include cost, spectral resolution, spatial resolution, and response time. For many biological systems the assessment of infrared emissivity and/or fluorescence must be done simultaneously with the temperature measurement, because these parameters may rapidly change independently from each other. In addition to providing accurate absolute temperature readings in any thermological study, the measurement of emissivity and fluorescence and the display of their spatial distribution can be especially helpful in dermatology, dermatological oncology, dermatological pharmacology (assessment of pharmacokinetics and of diaphoretic excretion of drug metabolites), skin toxicology, burns management, assessment of radiation overexposure and microtelecalorimetry of cells, micro-organisms and tissue cultures. The measurement of light induced cutaneous vasoconstriction pose novel biomedical research problems that require the use of multiplewavelength cameras. In addition to the use of more sophisticated cameras, precision clinical telethermometry requires a better controlled environment. One must take into account infrared fluorescence, photoreflectance and light induced vasoconstriction all of which are induced by environmental illumination.

  11. Innovative Long Wavelength Infrared Detector Workshop Proceedings

    NASA Technical Reports Server (NTRS)

    Grunthaner, Frank J.

    1990-01-01

    The focus of the workshop was on innovative long wavelength (lambda less than 17 microns) infrared (LWIR) detectors with the potential of meeting future NASA and DoD long-duration space application needs. Requirements are for focal plane arrays which operate near 65K using active refrigeration with mission lifetimes of five to ten years. The workshop addressed innovative concepts, new material systems, novel device physics, and current progress in relation to benchmark technology. It also provided a forum for discussion of performance characterization, producibility, reliability, and fundamental limitations of device physics. It covered the status of the incumbent HgCdTe technology, which shows encouraging progress towards LWIR arrays, and provided a snapshot of research and development in several new contender technologies.

  12. Development of Charge Sensitive Infrared Phototransistors for the Far-Infrared Wavelength

    NASA Astrophysics Data System (ADS)

    Nihei, R.; Komiyama, S.; Kawada, M.; Matsuura, S.; Doi, Y.; Satoh, T.; Nakagawa, T.

    2014-08-01

    Ultra-highly-sensitive far-infrared detectors are developed for potential application to astronomy. The detectors exploit a novel mechanism called Charge Sensitive Infrared Phototransistors (CSIPs), in which an upper quantum well (QW) in GaAs/AlGaAs double QW structures is positively charged up by photo-excitation via inter-subband transition. This causes the conductance of the lower QW channel to increase. The device is effectively a phototransistor, in which the upper QW serves as a photo-sensitive gate to the source-drain channel provided by the lower QW. Resultant extraordinary high photoconductive gain makes CSIPs so sensitive as to detect single photons. CSIPs are well established in the mid-infrared ( = 12-20 m), achieving noise equivalent power around 1.9 10 W/Hz with a quantum efficiency of 7 %. CSIPs have been demonstrated to work in longer wavelengths up to 45 m, but the sensitivity was not as high as in the shorter wavelengths, probably due to lower quantum efficiency. Reported here is a remarkable improvement in the performance of longer wavelength CSIPs (45 m), achieved primarily by optimizing the doping concentration in the upper QW. This work indicates that longer wavelength CSIPs are promising detectors for the astronomical application.

  13. Quantum-dot spin-photon entanglement via frequency downconversion to telecom wavelength.

    PubMed

    De Greve, Kristiaan; Yu, Leo; McMahon, Peter L; Pelc, Jason S; Natarajan, Chandra M; Kim, Na Young; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Kamp, Martin; Höfling, Sven; Hadfield, Robert H; Forchel, Alfred; Fejer, M M; Yamamoto, Yoshihisa

    2012-11-15

    Long-distance quantum teleportation and quantum repeater technologies require entanglement between a single matter quantum bit (qubit) and a telecommunications (telecom)-wavelength photonic qubit. Electron spins in III-V semiconductor quantum dots are among the matter qubits that allow for the fastest spin manipulation and photon emission, but entanglement between a single quantum-dot spin qubit and a flying (propagating) photonic qubit has yet to be demonstrated. Moreover, many quantum dots emit single photons at visible to near-infrared wavelengths, where silica fibre losses are so high that long-distance quantum communication protocols become difficult to implement. Here we demonstrate entanglement between an InAs quantum-dot electron spin qubit and a photonic qubit, by frequency downconversion of a spontaneously emitted photon from a singly charged quantum dot to a wavelength of 1,560 nanometres. The use of sub-10-picosecond pulses at a wavelength of 2.2 micrometres in the frequency downconversion process provides the necessary quantum erasure to eliminate which-path information in the photon energy. Together with previously demonstrated indistinguishable single-photon emission at high repetition rates, the present technique advances the III-V semiconductor quantum-dot spin system as a promising platform for long-distance quantum communication.

  14. FY 2006 Infrared Photonics Final Report

    SciTech Connect

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

    2006-12-28

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

  15. Coherent dynamics of a telecom-wavelength entangled photon source

    NASA Astrophysics Data System (ADS)

    Ward, M. B.; Dean, M. C.; Stevenson, R. M.; Bennett, A. J.; Ellis, D. J. P.; Cooper, K.; Farrer, I.; Nicoll, C. A.; Ritchie, D. A.; Shields, A. J.

    2014-02-01

    Quantum networks can interconnect remote quantum information processors, allowing interaction between different architectures and increasing net computational power. Fibre-optic telecommunications technology offers a practical platform for routing weakly interacting photonic qubits, allowing quantum correlations and entanglement to be established between distant nodes. Although entangled photons have been produced at telecommunications wavelengths using spontaneous parametric downconversion in nonlinear media, as system complexity increases their inherent excess photon generation will become limiting. Here we demonstrate entangled photon pair generation from a semiconductor quantum dot at a telecommunications wavelength. Emitted photons are intrinsically anti-bunched and violate Bell’s inequality by 17 standard deviations High-visibility oscillations of the biphoton polarization reveal the time evolution of the emitted state with exceptional clarity, exposing long coherence times. Furthermore, we introduce a method to evaluate the fidelity to a time-evolving Bell state, revealing entanglement between photons emitted up to 5 ns apart, exceeding the exciton lifetime.

  16. Coherent dynamics of a telecom-wavelength entangled photon source.

    PubMed

    Ward, M B; Dean, M C; Stevenson, R M; Bennett, A J; Ellis, D J P; Cooper, K; Farrer, I; Nicoll, C A; Ritchie, D A; Shields, A J

    2014-01-01

    Quantum networks can interconnect remote quantum information processors, allowing interaction between different architectures and increasing net computational power. Fibre-optic telecommunications technology offers a practical platform for routing weakly interacting photonic qubits, allowing quantum correlations and entanglement to be established between distant nodes. Although entangled photons have been produced at telecommunications wavelengths using spontaneous parametric downconversion in nonlinear media, as system complexity increases their inherent excess photon generation will become limiting. Here we demonstrate entangled photon pair generation from a semiconductor quantum dot at a telecommunications wavelength. Emitted photons are intrinsically anti-bunched and violate Bell's inequality by 17 standard deviations High-visibility oscillations of the biphoton polarization reveal the time evolution of the emitted state with exceptional clarity, exposing long coherence times. Furthermore, we introduce a method to evaluate the fidelity to a time-evolving Bell state, revealing entanglement between photons emitted up to 5 ns apart, exceeding the exciton lifetime.

  17. Wavelength Sensitive Photonic Modules for Signal Conditioning

    DTIC Science & Technology

    2000-04-18

    LaboratoryN. A. Riza Variable Photonic Delay Line using Small Tilt Digital Micromirror Mirror Mirror 2-D Binary DMD 2-D Binary DMD Mirror MirrorMirror...APPROVED FOR PUBLIC RELEASE, DISTRIBUTION UNLIMITED Photonic Information Processing Systems LaboratoryN. A. Riza Large micromirror sizes Non-Robust...Approaches to make a Variable Fiber-Optic Attenuator Big Translational Mirror Slow Response Speed Solution for Faster Speed Use One Small Micromirror Problems

  18. Applications of photonic crystal in wavelength multiplex visualization

    NASA Astrophysics Data System (ADS)

    Qian, Shi; Lei, Zhang

    2016-10-01

    The triple-channel photonic crystal filters are proposed designed. These devices have advantages of better filtering effect and high wavelength accuracy. In wavelength multiplex visualization, these filters can bring different wavelength of view entering into eyes so that stereo images are formed. we discuss the problem about minimization of the angle shift .The simulation shows that higher-index material and more high-index material in a basic period can decrease the angle shift.

  19. Compact wavelength demultiplexing using focusing negative index photonic crystal superprisms.

    PubMed

    Momeni, Babak; Huang, Jiandong; Soltani, Mohammad; Askari, Murtaza; Mohammadi, Saeed; Rakhshandehroo, Mohammad; Adibi, Ali

    2006-03-20

    Here, we demonstrate a compact photonic crystal wavelength demultiplexing device based on a diffraction compensation scheme with two orders of magnitude performance improvement over the conventional superprism structures reported to date. We show that the main problems of the conventional superprism-based wavelength demultiplexing devices can be overcome by combining the superprism effect with two other main properties of photonic crystals, i.e., negative diffraction and negative refraction. Here, a 4-channel optical demultiplexer with a channel spacing of 8 nm and cross-talk level of better than -6.5 dB is experimentally demonstrated using a 4500 microm(2) photonic crystal region.

  20. Infrared spectroscopy assisted by entangled photons

    NASA Astrophysics Data System (ADS)

    Paterova, Anna V.; Lung, Shaun; Kalashnikov, Dmitry A.; Kulik, Sergei P.; Krivitsky, Leonid A.

    2016-11-01

    We describe a proof-of-concept of a method for measurement of both real (refraction) and imaginary (absorption) part of the refractive index in the infrared (IR) range by measuring an interference pattern in the visible range without the need for any spectral and spatial selection. The concept is based on nonlinear interference of entangled photons, generated via Spontaneous Parametric Down Conversion (SPDC). In our interferometer, the phase of the signal photon in the visible range depends on the phase of an entangled IR photon. When the IR photon is traveling through the media of interest, its properties can be found from the observations of the visible photon.

  1. FY 2005 Infrared Photonics Final Report

    SciTech Connect

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

    2005-12-01

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

  2. AFRL Nanotechnology Initiative: Hybrid Nanomaterials in Photonic Crystal Cavities for Multi-Spectral Infrared Detector Arrays

    DTIC Science & Technology

    2010-03-31

    INITIATIVE) HYBRID NANOMATERIALS IN PHOTONIC CRYSTAL CAVITIES FOR MULTI -SPECTRAL INFRARED DETECTOR ARRAYS 5b. GRANT NUMBER F A9550-06-1-0482 5c...IR) photodetector using hybrid nanornaterials in photonic crystal (PC) cavities for enhanced absorption at selected wavelengths. The simultaneous...infrared photodetection, quantum dots, photonic crystal cavities, matrix-assisted pulsed laser evaporation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  3. Avalanche photodiodes for near-infrared photon counting

    NASA Astrophysics Data System (ADS)

    Cova, Sergio D.; Lacaita, Andrea L.; Zappa, Franco; Lovati, Piergiorgio G.

    1995-05-01

    We report the photon-counting and timing performance of various Single-Photon Avalanche Diodes (SPADs) employed to detect single photons in the near-infrared wavelength range. Suitable Silicon structures achieve high quantum efficiency (70% at 800 nm) and can work up to 1.1 micrometers . Ge SPADs and InGaAs devices are sensitive up to 1.4 micrometers and 1.6 micrometers , respectively, wit ha few percent-quantum efficiencies. We compare these results with the performance of state-of-the-art photomultiplier tubes with extended near-infrared sensitivity. We also report the first results obtained with a germanium quad-cell sensor, which may be considered the first step towards the development of SPAD arrays.

  4. 128 x 128 Pixel long wavelength infrared acquisition camera

    SciTech Connect

    LeVan, P.D.; Colucci, D.; Cowan, W.D.; Figie, B.D.; Stewart, E.J.

    1994-12-31

    This paper describes a Phillips Laboratory internal design for a high sensitivity, large field of view infrared acquisition camera. Currently, the acquisition of a satellite with the 1.5 meter telescope of the Starfire Optical Range typically requires a sunlit target and dark sky. However, the level of thermal radiation from such a satellite is often sufficiently high in the Long Wavelength Infrared (LWIR) to permit detection with ground based telescopes irrespective of target illumination. The drawbacks of LWIR acquisition include the high levels of thermal radiation from both the telescope and the atmosphere which pose two constraints: (1), the ``background signal`` usually exceeds the target signal and must be removed on time scales over which it is relatively constant, and (2), associated with the background signal is a noise level that dominates all system noise sources. The background signal level at the detector array for the application varies between 10{sup 15} to 10{sup 16} photons sec{sup {minus}1} cm{sup {minus}2}, depending on the infrared bandpass used. The optical design for the LWIR acquisition camera maps a 128 x 128 pixel detector array onto a two milliradian (mrad) scene. The optical design uses two aspheric lenses, one to re-image the field onto a cold field stop, and the telescope pupil onto a cryogenic chopping mirror and collocated radiation stop. The second lens re-images the field stop onto the detector array. Aberrations are designed to be better than diffraction limited over the entire two mrad field of view. The end product of the acquisition system is a video display of the infrared scene, with the background signal removed. A user then positions mouse-driven cross hairs over a target in the scene. The resulting position and time update is used to revise the target ephemeris, and to provide pointing information for target acquisition by other SOR tracking platforms.

  5. FY 2004 Infrared Photonics Final Report

    SciTech Connect

    Anheier, Norman C.; Allen, Paul J.; Keller, Paul E.; Bennett, Wendy D.; Martin, Peter M.; Johnson, Bradley R.; Sundaram, S. K.; Riley, Brian J.; Martinez, James E.; Qiao, Hong; Schultz, John F.

    2004-10-01

    Research done by the Infrared Photonics team at PNNL is focused on developing miniaturized integrated optics for the MWIR and LWIR by exploiting the unique optical and material properties of chalcogenide glass. PNNL has developed thin film deposition capabilities, direct-laser writing techniques, IR photonic device demonstration, holographic optical element design and fabrication, photonic device modeling, and advanced optical metrology - all specific to chalcogenide glass. Chalcogenide infrared photonics provides a pathway to Quantum Cascade Laser (QCL) transmitter miniaturization. QCLs provide a viable infrared laser source for a new class of laser transmitters capable of meeting the performance requirements for a variety of national security sensing applications. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors that are particularly useful for nuclear nonproliferation missions.

  6. Integrated photonics for infrared spectroscopic sensing

    NASA Astrophysics Data System (ADS)

    Lin, Hongtao; Kita, Derek; Han, Zhaohong; Su, Peter; Agarwal, Anu; Yadav, Anupama; Richardson, Kathleen; Gu, Tian; Hu, Juejun

    2017-05-01

    Infrared (IR) spectroscopy is widely recognized as a gold standard technique for chemical analysis. Traditional IR spectroscopy relies on fragile bench-top instruments located in dedicated laboratory settings, and is thus not suitable for emerging field-deployed applications such as in-line industrial process control, environmental monitoring, and point-ofcare diagnosis. Recent strides in photonic integration technologies provide a promising route towards enabling miniaturized, rugged platforms for IR spectroscopic analysis. Chalcogenide glasses, the amorphous compounds containing S, Se or Te, have stand out as a promising material for infrared photonic integration given their broadband infrared transparency and compatibility with silicon photonic integration. In this paper, we discuss our recent work exploring integrated chalcogenide glass based photonic devices for IR spectroscopic chemical analysis, including on-chip cavityenhanced chemical sensing and monolithic integration of mid-IR waveguides with photodetectors.

  7. Aluminum infrared plasmonic perfect absorbers for wavelength selective devices

    NASA Astrophysics Data System (ADS)

    Dao, Thang Duy; Ishii, Satoshi; Chen, Kai; Yokoyama, Takahiro; Nabatame, Toshihide; Nagao, Tadaaki

    2016-09-01

    We demonstrate the development of colloidal lithography technique to fabricate large-area plasmonic perfect absorbers using Al, which is an earth abundant low-cost plasmonic material in contrast to Au and Ag. Using numerical electromagnetic simulations, we optimize the geometrical parameters of Al perfect absorbers (AlPAs) with resonances at desired wavelengths depending on the applications. The fabricated AlPAs exhibit narrowband absorptions with high efficiency up to 98 %. By tuning AlPAs parameters, the resonance of AlPAs can be tuned from the visible to the middle infrared region. The AlPAs can be applied for spectrally selective infrared devices such as selective thermal emitters, selective surface-enhanced vibrational spectroscopy (SEIRA) for molecular sensing and selective IR detectors. In this report, we demonstrate applications of AlPAs for selective thermal emitters and SEIRA. The results obtained here reveal a simple technique to fabricate scalable plasmonic perfect absorbers as well as their potential applications in optoelectronic and photonic devices.

  8. Minority carrier lifetime in mid-wavelength infrared InAs/InAsSb superlattices: Photon recycling and the role of radiative and Shockley-Read-Hall recombination mechanisms

    SciTech Connect

    Höglund, L.; Ting, D. Z.; Soibel, A.; Fisher, A.; Khoshakhlagh, A.; Hill, C. J.; Keo, S.; Gunapala, S. D.

    2014-11-10

    The influence of radiative recombination on the minority carrier lifetime in mid-wavelength InAs/InAsSb superlattices was investigated. From the lifetime's dependence on temperature, photon recycling, and carrier concentration, it was demonstrated that radiative lifetime dominates for carrier concentrations >5 × 10{sup 14} cm{sup −3}, and Shockley-Read-Hall recombination starts to dominate the minority carrier lifetime for carrier concentrations <5 × 10{sup 14} cm{sup −3}. An observed increase of the minority carrier lifetime with increasing superlattice thickness was attributed to photon recycling, and good agreement between measured and theoretical values of the photon recycling factor was obtained.

  9. Photonic crystal slab quantum well infrared photodetector

    NASA Astrophysics Data System (ADS)

    Kalchmair, S.; Detz, H.; Cole, G. D.; Andrews, A. M.; Klang, P.; Nobile, M.; Gansch, R.; Ostermaier, C.; Schrenk, W.; Strasser, G.

    2011-01-01

    In this letter we present a quantum well infrared photodetector (QWIP), which is fabricated as a photonic crystal slab (PCS). With the PCS it is possible to enhance the absorption efficiency by increasing photon lifetime in the detector active region. To understand the optical properties of the device we simulate the PCS photonic band structure, which differs significantly from a real two-dimensional photonic crystal. By fabricating a PCS-QWIP with 100x less quantum well doping, compared to a standard QWIP, we are able to see strong absorption enhancement and sharp resonance peaks up to temperatures of 170 K.

  10. Photonic crystal enhancement of auger-suppressed infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Djurić, Zoran; Jakšić, Zoran; Ehrfeld, Wolfgang; Schmidt, Andreas; Matić, Milan; Popović, Mirjana

    2001-04-01

    We examine theoretically and experimentally the possibilities to reach room-temperature background-limited operation of narrow-bandgap compound semiconductor photodetectors in (3-14) micrometer infrared wavelength range. To this purpose we consider the combination of non-equilibrium Auger suppression with photonic crystal enhancement (PCE). This means that Auger generation-recombination processes are suppressed utilizing exclusion, extraction or magnetoconcentration effects or their combination. The residual radiative recombination is removed by immersing the detector active area into a photonic crystal and using the benefits of re-absorption (photon recycling) to effectively increase the radiative lifetime. In this manner the total generation-recombination noise is strongly quenched in sufficiently defect-free device materials. It is concluded that the operation of thus enhanced photonic detectors could even approach signal fluctuation limit.

  11. Infrared presensitization photography at deuterium fluoride laser wavelengths

    SciTech Connect

    Geary, J.M.; Ross, K.; Suter, K. )

    1989-09-01

    Near-field irradiance distributions of a deuterium flouride laser system are obtained using infrared presensitization photography. This represents the shortest wavelength region to employ this technique thus far.

  12. Photoluminescence Study of Long Wavelength Superlattice Infrared Detectors

    NASA Technical Reports Server (NTRS)

    Hoglund, Linda; Khoshakhlagh, Arezou; Soibel, Alexander; Ting, David Z.; Hill, Cory J.; Keo, Sam; Gunapala, Sarath D.

    2011-01-01

    In this paper, the relation between the photoluminescence (PL) intensity and the PL peak wavelength was studied. A linear decrease of the PL intensity with increasing cut-off wavelength of long wavelength infrared CBIRDs was observed at 77 K and the trend remained unchanged in the temperature range 10 - 77 K. This relation between the PL intensity and the peak wavelength can be favorably used for comparison of the optical quality of samples with different PL peak wavelengths. A strong increase of the width of the PL spectrum in the studied temperature interval was observed, which was attributed to thermal broadening.

  13. Mid-infrared supercontinuum generation in silica photonic crystal fibers.

    PubMed

    Bi, Wanjun; Gao, Juanjuan; Li, Xia; Xiong, Liangming; Liao, Meisong

    2016-08-10

    A mid-infrared supercontinuum (SC) light source, which has important applications in many fields, has been extensively investigated in soft glass fibers. However, the poor instinct properties of soft glass fibers and the development of ultrashort pulse lasers left an opportunity for mid-infrared SC generation in silica fiber. Until now, silica fiber has been the commonly used medium for SC generation due to its outstanding properties. In this paper, mid-infrared SC generation in short silica photonic crystal fibers (PCFs) is investigated theoretically and systematically. In the case of a 1550�nm pump, the soliton self-frequency shift effect is utilized to extend the long wavelength edge of SC. Adopting a fiber that has a zero dispersion wavelength away from the pump pulse is a benefit for the suppression of blue spectral component and energy distribution in the long wavelength band. In the case of a 1950�nm pump, the generation of a red-shifted dispersive wave is an efficient way to extend the long wavelength edge of SC. Additionally, the coherence for femtosecond pulse pumping is discussed in this paper. Finally, the long wavelength edge of SC is beyond 3000�nm when a 1950�nm femtosecond pump pulse propagates in a PCF with negative dispersive slope around the pump pulse.

  14. Using Guide Wavelengths to Assess Far-Infrared Laser Emissions

    NASA Astrophysics Data System (ADS)

    DeShano, B.; Olivier, K.; Cain, B.; Zink, L. R.; Jackson, M.

    2014-09-01

    An optically pumped molecular laser system with a transverse excitation scheme has been used to observe 77 guide wavelengths associated with the modes of an oversized waveguide laser resonator. These guide wavelengths, spanning from 102.6 to 990.6 μm, were generated by a variety of lasing media, including methanol along with several symmetric- and asymmetric-top molecules. The guide wavelengths displayed several consistent characteristics when compared with their respective fundamental laser emissions: their wavelengths were about 0.47 % larger and their relative powers were at least a factor of ten weaker. The properties of these guide wavelengths were used to assess frequency and wavelength measurements associated with known far-infrared laser emissions. For several of these laser emissions, this prompted a reinvestigation and subsequent revision of their measured values. Five far-infrared laser frequencies were also measured for the first time.

  15. Using Guide Wavelengths to Assess Far-Infrared Laser Emissions

    NASA Astrophysics Data System (ADS)

    DeShano, B.; Olivier, K.; Cain, B.; Zink, L. R.; Jackson, M.

    2015-01-01

    An optically pumped molecular laser system with a transverse excitation scheme has been used to observe 77 guide wavelengths associated with the modes of an oversized waveguide laser resonator. These guide wavelengths, spanning from 102.6 to 990.6 μm, were generated by a variety of lasing media, including methanol along with several symmetric- and asymmetric-top molecules. The guide wavelengths displayed several consistent characteristics when compared with their respective fundamental laser emissions: their wavelengths were about 0.47 % larger and their relative powers were at least a factor of ten weaker. The properties of these guide wavelengths were used to assess frequency and wavelength measurements associated with known far-infrared laser emissions. For several of these laser emissions, this prompted a reinvestigation and subsequent revision of their measured values. Five far-infrared laser frequencies were also measured for the first time.

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

    PubMed Central

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

    2017-01-01

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

  17. Extraordinary wavelength reduction in terahertz graphene-cladded photonic crystal slabs.

    PubMed

    Williamson, Ian A D; Mousavi, S Hossein; Wang, Zheng

    2016-05-04

    Photonic crystal slabs have been widely used in nanophotonics for light confinement, dispersion engineering, nonlinearity enhancement, and other unusual effects arising from their structural periodicity. Sub-micron device sizes and mode volumes are routine for silicon-based photonic crystal slabs, however spectrally they are limited to operate in the near infrared. Here, we show that two single-layer graphene sheets allow silicon photonic crystal slabs with submicron periodicity to operate in the terahertz regime, with an extreme 100× wavelength reduction from graphene's large kinetic inductance. The atomically thin graphene further leads to excellent out-of-plane confinement, and consequently photonic-crystal-slab band structures that closely resemble those of ideal two-dimensional photonic crystals, with broad band gaps even when the slab thickness approaches zero. The overall photonic band structure not only scales with the graphene Fermi level, but more importantly scales to lower frequencies with reduced slab thickness. Just like ideal 2D photonic crystals, graphene-cladded photonic crystal slabs confine light along line defects, forming waveguides with the propagation lengths on the order of tens of lattice constants. The proposed structure opens up the possibility to dramatically reduce the size of terahertz photonic systems by orders of magnitude.

  18. Extraordinary wavelength reduction in terahertz graphene-cladded photonic crystal slabs

    PubMed Central

    Williamson, Ian A. D.; Mousavi, S. Hossein; Wang, Zheng

    2016-01-01

    Photonic crystal slabs have been widely used in nanophotonics for light confinement, dispersion engineering, nonlinearity enhancement, and other unusual effects arising from their structural periodicity. Sub-micron device sizes and mode volumes are routine for silicon-based photonic crystal slabs, however spectrally they are limited to operate in the near infrared. Here, we show that two single-layer graphene sheets allow silicon photonic crystal slabs with submicron periodicity to operate in the terahertz regime, with an extreme 100× wavelength reduction from graphene’s large kinetic inductance. The atomically thin graphene further leads to excellent out-of-plane confinement, and consequently photonic-crystal-slab band structures that closely resemble those of ideal two-dimensional photonic crystals, with broad band gaps even when the slab thickness approaches zero. The overall photonic band structure not only scales with the graphene Fermi level, but more importantly scales to lower frequencies with reduced slab thickness. Just like ideal 2D photonic crystals, graphene-cladded photonic crystal slabs confine light along line defects, forming waveguides with the propagation lengths on the order of tens of lattice constants. The proposed structure opens up the possibility to dramatically reduce the size of terahertz photonic systems by orders of magnitude. PMID:27143314

  19. The Universe at Infrared and Submillimeter Wavelengths

    NASA Technical Reports Server (NTRS)

    Dwek, E.; Arendt, R. G.; Benford, D. J.; Mather, J. C.; Moseley, S. H.; Shafer, R. A.; Staguhn, J.

    2004-01-01

    Far infrared and submillimeter surveys offer unique information on the early stages of galaxy formation and evolution, and the cosmic history of star formation and metal enrichment. This paper presents various model results that can be used in the interpretation of far-IR and submm surveys with different diameter telescopes.

  20. Quantum photonics at telecom wavelengths based on lithium niobate waveguides

    NASA Astrophysics Data System (ADS)

    Alibart, Olivier; D'Auria, Virginia; De Micheli, Marc; Doutre, Florent; Kaiser, Florian; Labonté, Laurent; Lunghi, Tommaso; Picholle, Éric; Tanzilli, Sébastien

    2016-10-01

    Integrated optical components on lithium niobate play a major role in standard high-speed communication systems. Over the last two decades, after the birth and positioning of quantum information science, lithium niobate waveguide architectures have emerged as one of the key platforms for enabling photonics quantum technologies. Due to mature technological processes for waveguide structure integration, as well as inherent and efficient properties for nonlinear optical effects, lithium niobate devices are nowadays at the heart of many photon-pair or triplet sources, single-photon detectors, coherent wavelength-conversion interfaces, and quantum memories. Consequently, they find applications in advanced and complex quantum communication systems, where compactness, stability, efficiency, and interconnectability with other guided-wave technologies are required. In this review paper, we first introduce the material aspects of lithium niobate, and subsequently discuss all of the above mentioned quantum components, ranging from standard photon-pair sources to more complex and advanced circuits.

  1. New infrared photon absorption processes

    SciTech Connect

    Bayfield, J.E.

    1993-05-01

    The fast ionization of atoms by very short laser pulses, and its possible suppression at extreme pulse intensities, is an active new field of investigation at present. Described is an investigation of whether past techniques for infrared laser multiphoton ionization of excited hydrogen atoms and of one-dimensional microwave ionization of highly excited hydrogen atoms can be combined and extended to address the new issues. Although technically difficult and requiring further improvement of apparatus, intense-field infrared laser experiments on excited hydrogen atoms are possible and can directly test theoretical and numerical results.

  2. An 8-channel wavelength demultiplexer based on photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Malka, Dror

    2017-05-01

    We propose a novel 8-channel wavelength demultiplexer based on photonic crystal fiber (PCF) structures that operate at 1530nm, 1535nm, 1540nm, 1545nm, 1550nm, 1555nm, 1560nm and 1565nm wavelengths. The new design is based on replacing some air-holes zones with silicon nitride and lithium niobate materials along the PCF axis with optimization of the PCF size. The reason of using these materials is because that each wavelength has a different value of coupling length. Numerical investigations were carried out on the geometrical parameters by using a beam propagation method (BPM). Simulation results show that the proposed device can transmit 8-channel that works in the whole C-band (1530- 1565nm) with low crosstalk ((-16.88)-(-15.93) dB) and bandwidth (4.02-4.69nm). Thus, the device can be very useful in optical networking systems that work on dense wavelength division multiplexing (DWDM) technology.

  3. Superconducting single-photon detectors designed for operation at 1.55-µm telecommunication wavelength

    NASA Astrophysics Data System (ADS)

    Milostnaya, I.; Korneev, A.; Rubtsova, I.; Seleznev, V.; Minaeva, O.; Chulkova, G.; Okunev, O.; Voronov, B.; Smirnov, K.; Gol'Tsman, G.; Slysz, W.; Wegrzecki, M.; Guziewicz, M.; Bar, J.; Gorska, M.; Pearlman, A.; Kitaygorsky, J.; Cross, A.; Sobolewski, Roman

    2006-06-01

    We report on our progress in development of superconducting single-photon detectors (SSPDs), specifically designed for secure high-speed quantum communications. The SSPDs consist of NbN-based meander nanostructures and operate at liquid helium temperatures. In general, our devices are capable of GHz-rate photon counting in a spectral range from visible light to mid-infrared. The device jitter is 18 ps and dark counts can reach negligibly small levels. The quantum efficiency (QE) of our best SSPDs for visible-light photons approaches a saturation level of ~30-40%, which is limited by the NbN film absorption. For the infrared range (1.55µm), QE is ~6% at 4.2 K, but it can be significantly improved by reduction of the operation temperature to the 2-K level, when QE reaches ~20% for 1.55-µm photons. In order to further enhance the SSPD efficiency at the wavelength of 1.55 µm, we have integrated our detectors with optical cavities, aiming to increase the effective interaction of the photon with the superconducting meander and, therefore, increase the QE. A successful effort was made to fabricate an advanced SSPD structure with an optical microcavity optimized for absorption of 1.55 µm photons. The design consisted of a quarter-wave dielectric layer, combined with a metallic mirror. Early tests performed on relatively low-QE devices integrated with microcavities, showed that the QE value at the resonator maximum (1.55-µm wavelength) was of the factor 3-to-4 higher than that for a nonresonant SSPD. Independently, we have successfully coupled our SSPDs to single-mode optical fibers. The completed receivers, inserted into a liquid-helium transport dewar, reached ~1% system QE for 1.55 µm photons. The SSPD receivers that are fiber-coupled and, simultaneously, integrated with resonators are expected to be the ultimate photon counters for optical quantum communications.

  4. Photonic entanglement processing with a single sub-wavelength structure

    NASA Astrophysics Data System (ADS)

    Molina-Terriza, Gabriel; Buese, Alexander; Juan, Mathieu; Tischler, Nora

    2017-04-01

    A fundamental problem of using photonic states as carriers of quantum information is that they interact weakly with matter and that the interaction volume is typically limited by the wavelength of light. The use of metallic structures in quantum plasmonics has the potential to alleviate these problems. Here, we present the first results showing that a single subwavelength plasmonic nanoaperture can controllably modify the quantum state of light. We achieve this effect by using a specially engineered two photon state to match the properties of the nanoaperture.

  5. Innovative Long Wavelength Infrared Detector Workshop Proceedings

    DTIC Science & Technology

    2007-11-02

    AMMONIA ICE FILTER wN.EL B - FAR IP#RARED, I80 K SOLOMETRIC DETECTOR ARRAY, 64 x 64 PIXELS 8I 570 - 630 16.7 BANDPASS FILTER B2 470 - 510 20.4...34* IMPROVED COOLING IS EXPENSIVE IN MASS AND POWER "* IMPROVED DETECTOR PERFORMANCE IS EXPENSIVE IN UP FRONT DEVELOPMENT COSTS 27 • • a !I I I SAFIRE...range from short wavelengths out to 30 gtm. Large arrays are required, and producibility and cost are major factors. The SDIO is pursuing several

  6. Sulfonated aluminum phthalocyanines for two-photon photodynamic cancer therapy: the effect of the excitation wavelength

    NASA Astrophysics Data System (ADS)

    Wang, J.; Li, W.; Yu, H. B.; Cheung, N. H.; Chen, J. Y.

    2014-03-01

    Sulfonated aluminum phthalocyanine (AlPcS) is a well-studied photosensitizer which has been widely used in research and in clinical applications of the photodynamic therapy of cancers. Conventionally, one-photon excitation was used, but it was unknown whether two-photon excitation of AlPcS was equally effective. In this study, the two-photon absorption cross sections of AlPcS at near infrared wavelengths were deduced from femtosecond (fs) laser-induced fluorescence. We found that the two-photon absorption cross section of AlPcS was strongly dependent on the excitation wavelength. It was about 19 GM when excited at 800 nm, but grew to 855 GM when excited at 750 nm. The 750 nm fs-laser-induced fluorescence images of AlPcS in human nasopharyngeal carcinoma cells were clearly visible while the corresponding images were very dim when excited at 800 nm. Singlet oxygen production was 13 times higher when excited at 750 nm relative to 800 nm. Our subsequent in vitro experiments showed that 750 nm two-photon excitation with an unfocused fs laser beam damaged cancer cells in a light-dose-dependent manner typical of photodynamic therapy (PDT). The killing at 750 nm was about 9-10 times more efficient than at 800 nm. These results demonstrated for the first time that AlPcS has good potential for two-photon PDT of cancers.

  7. Multi-wavelength mid-infrared plasmonic antennas with single nanoscale focal point.

    PubMed

    Blanchard, Romain; Boriskina, Svetlana V; Genevet, Patrice; Kats, Mikhail A; Tetienne, Jean-Philippe; Yu, Nanfang; Scully, Marlan O; Dal Negro, Luca; Capasso, Federico

    2011-10-24

    We propose and demonstrate a novel photonic-plasmonic antenna capable of confining electromagnetic radiation at several mid-infrared wavelengths to a single sub-wavelength spot. The structure relies on the coupling between the localized surface plasmon resonance of a bow-tie nanoantenna with the photonic modes of surrounding multi-periodic particle arrays. Far-field measurements of the transmission through the central bow-tie demonstrate the presence of Fano-like interference effects resulting from the interaction of the bow-tie antenna with the surrounding nanoparticle arrays. The near-field of the multi-wavelength antenna is imaged using an aperture-less near-field scanning optical microscope. This antenna is relevant for the development of near-field probes for nanoimaging, spectroscopy and biosensing.

  8. Chalcogenide waveguide structure for dispersion in mid-infrared wavelength

    NASA Astrophysics Data System (ADS)

    Ashok, Nandam; Lak Lee, Yeung; Shin, WooJin

    2017-03-01

    We present a waveguide design with low dispersion in mid-infrared wavelengths. The design consists of slot-strip-slot structures horizontally, the strip structure is considered with high index and slot is considered with low index material. We show a dispersion of 0–350 ps/(km·nm) over a band width of 1375 nm, and the structure shows zero dispersions at 2512 and 3887 nm wavelength. The magnitude of dispersion can be fine-tuned by varying the waveguide parameters. Such a waveguide structure with low dispersion at mid-infrared wavelengths has a great potential for supercontinuum generation application. Apart this, we have also proposed dispersion compensation structure, the structure shows a high negative dispersion at 1510 nm wavelength. The structure should find application in the design of an integrated optic dispersion compensator for optical telecommunication and ultrafast waveguide lasers.

  9. Sub-wavelength energy concentration with electrically generated mid-infrared surface plasmons.

    PubMed

    Bousseksou, A; Babuty, A; Tetienne, J-P; Moldovan-Doyen, I; Braive, R; Beaudoin, G; Sagnes, I; De Wilde, Y; Colombelli, R

    2012-06-18

    While freely propagating photons cannot be focused below their diffraction limit, surface-plasmon polaritons follow the metallic surface to which they are bound, and can lead to extremely sub-wavelength energy volumes. These properties are lost at long mid-infrared and THz wavelengths where metals behave as quasi-perfect conductors, but can in principle be recovered by artificially tailoring the surface-plasmon dispersion. We demonstrate - in the important mid-infrared range of the electromagnetic spectrum - the generation onto a semiconductor chip of plasmonic excitations which can travel along long distances, on bent paths, to be finally focused into a sub-wavelength volume. The demonstration of these advanced functionalities is supported by full near-field characterizations of the electromagnetic field distribution on the surface of the active plasmonic device.

  10. Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength

    PubMed Central

    Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

    2014-01-01

    Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110 nm FWHM) squeezed state in the telecom band centred at 1535 nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology. PMID:24694515

  11. Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength.

    PubMed

    Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

    2014-04-03

    Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110 nm FWHM) squeezed state in the telecom band centred at 1535 nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology.

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

    PubMed

    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.

  13. Photonic digital-to-analog conversion based on wavelength multiplexing

    NASA Astrophysics Data System (ADS)

    Yang, Shuna; Hu, Miao; Chi, Hao; Li, Qiliang

    2017-10-01

    A novel photonic digital-to-analog conversion (PDAC) scheme, which is based on optical intensity weighting and multiplexing/summing of different wavelengths, is proposed. The employment of wavelength multiplexing in the system, which conducts the function of modulated light intensity summation, greatly simplifies the system complexity and improves the conversion speed/accuracy limited by large-area photo-detectors and associated electronics. A 4-bit PDAC with a conversion speed of 10 GS/s demonstrates the feasibility of the proposed scheme. In addition, the performance degradation induced by the limited extinction ratios of the applied electro-optic modulators, the synchronization errors among different wavelength channels, and the bit resolutions of the built system is also discussed.

  14. Backward Raman Amplification in the Long-wavelength Infrared

    DTIC Science & Technology

    2016-12-29

    mechanism for generating intense , broad bandwidth, long-wavelength infrared radiation . An electromagnetic finite-difference time-domain simulation...driven by strong- field science, including advanced proton acceleration [10], high harmonic genera- tion [11], mid-infrared supercontinuum generation...used to extract individual field envelopes and intensity profiles. Figure 3 shows the dependence of the amplified seed on pump intensity with and with

  15. Super sub-wavelength patterns in photon coincidence detection.

    PubMed

    Liu, Ruifeng; Zhang, Pei; Zhou, Yu; Gao, Hong; Li, Fuli

    2014-02-17

    High-precision measurements implemented with light are desired in all fields of science. However, light acts as a wave, and the Rayleigh criterion in classical optics yields a diffraction limit that prevents obtaining a resolution smaller than the wavelength. Sub-wavelength interference has potential application in lithography because it beats the classical Rayleigh resolution limit. Here, we carefully study second-order correlation theory to establish the physics behind sub-wavelength interference in photon coincidence detection. A Young's double slit experiment with pseudo-thermal light is performed to test the second-order correlation pattern. The results show that when two point detectors are scanned in different ways, super sub-wavelength interference patterns can be obtained. We then provide a theoretical explanation for this surprising result, and demonstrate that this explanation is also suitable for the results found for entangled light. Furthermore, we discuss the limitations of these types of super sub-wavelength interference patterns in quantum lithography.

  16. Super sub-wavelength patterns in photon coincidence detection

    NASA Astrophysics Data System (ADS)

    Liu, Ruifeng; Zhang, Pei; Zhou, Yu; Gao, Hong; Li, Fuli

    2014-02-01

    High-precision measurements implemented with light are desired in all fields of science. However, light acts as a wave, and the Rayleigh criterion in classical optics yields a diffraction limit that prevents obtaining a resolution smaller than the wavelength. Sub-wavelength interference has potential application in lithography because it beats the classical Rayleigh resolution limit. Here, we carefully study second-order correlation theory to establish the physics behind sub-wavelength interference in photon coincidence detection. A Young's double slit experiment with pseudo-thermal light is performed to test the second-order correlation pattern. The results show that when two point detectors are scanned in different ways, super sub-wavelength interference patterns can be obtained. We then provide a theoretical explanation for this surprising result, and demonstrate that this explanation is also suitable for the results found for entangled light. Furthermore, we discuss the limitations of these types of super sub-wavelength interference patterns in quantum lithography.

  17. Competitive technologies of third generation infrared photon detectors

    NASA Astrophysics Data System (ADS)

    Rogalski, A.

    2006-03-01

    Hitherto, two families of multielement infrared (IR) detectors are used for principal military and civilian infrared applications; one is used for scanning systems (first generation) and the other is used for staring systems (second generation). Third generation systems are being developed nowadays. In the common understanding, third generation IR systems provide enhanced capabilities like larger number of pixels, higher frame rates, better thermal resolution as well as multicolour functionality and other on-chip functions. In the paper, issues associated with the development and exploitation of materials used in fabrication of third generation infrared photon detectors are discussed. In this class of detectors two main competitors, HgCdTe photodiodes and quantum well IR photoconductors (QWIPs) are considered. The performance figures of merit of state-of-the-art HgCdTe and QWIP focal plane arrays (FPAs) are similar because the main limitations come from the readout circuits. However, the metallurgical issues of the epitaxial layers such as uniformity and number of defected elements are the serious problems in the case of long wavelength infrared (LWIR) and very LWIR (VLWIR) HgCdTe FPAs. It is predicted that superlattice based InAs/GaInSb system grown on GaSb substrate seems to be an attractive to HgCdTe with good spatial uniformity and an ability to span cutoff wavelength from 3 to 25 μm.

  18. Competitive technologies for third generation infrared photon detectors

    NASA Astrophysics Data System (ADS)

    Rogalski, A.

    2006-05-01

    Hitherto, two families of multielement infrared (IR) detectors are used for principal military and civilian infrared applications; one is used for scanning systems (first generation) and the other is used for staring systems (second generation). Third generation systems are being developed nowadays. In the common understanding, third generation IR systems provide enhanced capabilities like larger number of pixels, higher frame rates, better thermal resolution as well as multicolor functionality and other on-chip functions. In the paper, issues associated with the development and exploitation of materials used in fabrication of third generation infrared photon detectors are discussed. In this class of detectors two main competitors, HgCdTe photodiodes and quantum well photoconductors are considered. The performance figures of merit of state-of-the-art HgCdTe and QWIP focal plane arrays (FPAs) are similar because the main limitations come from the readout circuits. The metallurgical issues of the epitaxial layers such as uniformity and number of defected elements are the serious problems in the case of long wavelength infrared (LWIR) and very LWIR (VLWIR) HgCdTe FPAs. It is predicted that superlattice based InAs/GaInSb system grown on GaSb substrate seems to be an attractive to HgCdTe with good spatial uniformity and an ability to span cutoff wavelength from 3 to 25 μm. In this context the material properties of type II superlattices are considered more in detail.

  19. Long-wavelength photonic integrated circuits and avalanche photodetectors

    NASA Astrophysics Data System (ADS)

    Tsou, Yi-Jen D.; Zaytsev, Sergey; Pauchard, Alexandre; Hummel, Steve; Lo, Yu-Hwa

    2001-10-01

    Fast-growing internet traffic volume require high data communication bandwidth over longer distances. Access network bottlenecks put pressure on short-range (SR) telecommunication systems. To effectively address these datacom and telecom market needs, low-cost, high-speed laser modules at 1310 to 1550 nm wavelengths and avalanche photodetectors are required. The great success of GaAs 850nm VCSEls for Gb/s Ethernet has motivated efforts to extend VCSEL technology to longer wavelengths in the 1310 and 1550 nm regimes. However, the technological challenges associated with materials for long wavelength VCSELs are tremendous. Even with recent advances in this area, it is believed that significant additional development is necessary before long wavelength VCSELs that meet commercial specifications will be widely available. In addition, the more stringent OC192 and OC768 specifications for single-mode fiber (SMF) datacom may require more than just a long wavelength laser diode, VCSEL or not, to address numerous cost and performance issues. We believe that photonic integrated circuits (PICs), which compactly integrate surface-emitting lasers with additional active and passive optical components with extended functionality, will provide the best solutions to today's problems. Photonic integrated circuits have been investigated for more than a decade. However, they have produced limited commercial impact to date primarily because the highly complicated fabrication processes produce significant yield and device performance issues. In this presentation, we will discuss a new technology platform of InP-based PICs compatible with surface-emitting laser technology, as well as a high data rate externally modulated laser module. Avalanche photodetectors (APDs) are the key component in the receiver to achieve high data rate over long transmission distance because of their high sensitivity and large gain- bandwidth product. We have used wafer fusion technology to achieve In

  20. Stress induced long wavelength photoconductivity in doped silicon infrared detectors

    NASA Technical Reports Server (NTRS)

    Houck, J. R.

    1982-01-01

    The long wavelength cutoff of a Si:P detector was extended to 34 microns by the application of a uniaxial stress. An unstressed Si:P photoconductive detector responds to photons of up to 28 microns wavelength. By applying a uniaxial stress to a detector along the /100/ crystal axis, the response was extended to approximately 34 microns. The /100/ axis was chosen as the stress direction because theoretical calculations predicted that such a stress extends the wavelength response more than one along the /110/ axis. These theoretical calculations were based upon fits to experimental data obtained at stresses of up to approximately kbar, and indicated that the extension in wavelength response continues to increase at much larger stresses.

  1. Apparatus for generating coherent infrared energy of selected wavelength

    DOEpatents

    Stevens, C.G.

    A tunable source of coherent infrared energy includes a heat pipe having an intermediate region at which cesium is heated to vaporizing temperature and end regions at which the vapor is condensed and returned to the intermediate region for reheating and recirculation. Optical pumping light is directed along the axis of the heat pipe through a first end window to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window. A porous walled tubulation extends along the axis of the heat pipe and defines a region in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light. Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light.

  2. Apparatus for generating coherent infrared energy of selected wavelength

    DOEpatents

    Stevens, Charles G.

    1985-01-01

    A tunable source (11) of coherent infrared energy includes a heat pipe (12) having an intermediate region (24) at which cesium (22) is heated to vaporizing temperature and end regions (27, 28) at which the vapor is condensed and returned to the intermediate region (24) for reheating and recirculation. Optical pumping light (43) is directed along the axis of the heat pipe (12) through a first end window (17) to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window (18). A porous walled tubulation (44) extends along the axis of the heat pipe (12) and defines a region (46) in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light (43). Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light (43).

  3. Long-Wavelength Infrared (LWIR) Quantum Dot Infrared Photodetector (QDIP) Focal Plane Array

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath D.; Bandara, S. V.; Liu, J. K.; Hill, C. J.; Rafol, S. B.; Mumolo, J. M.; Shott, C. A.

    2006-01-01

    We have exploited the artificial atomlike properties of epitaxially self-assembled quantum dots for the development of high operating temperature long wavelength infrared (LWIR) focal plane arrays. Quantum dots are nanometer-scale islands that form spontaneously on a semiconductor substrate due to lattice mismatch. QDIPs are expected to outperform quantum well infrared detectors (QWIPs) and are expected to offer significant advantages over II-VI material based focal plane arrays. QDIPs are fabricated using robust wide bandgap III-V materials which are well suited to the production of highly uniform LWIR arrays. We have used molecular beam epitaxy (MBE) technology to grow multi-layer LWIR quantum dot structures based on the InAs/InGaAs/GaAs material system. JPL is building on its significant QWIP experience and is basically building a Dot-in-the-Well (DWELL) device design by embedding InAs quantum dots in a QWIP structure. This hybrid quantum dot/quantum well device offers additional control in wavelength tuning via control of dot-size and/or quantum well sizes. In addition the quantum wells can trap electrons and aide in ground state refilling. Recent measurements have shown a 10 times higher photoconductive gain than the typical QWIP device, which indirectly confirms the lower relaxation rate of excited electrons (photon bottleneck) in QDPs. Subsequent material and device improvements have demonstrated an absorption quantum efficiency (QE) of approx. 3%. Dot-in-the-well (DWELL) QDIPs were also experimentally shown to absorb both 45 deg. and normally incident light. Thus we have employed a reflection grating structure to further enhance the quantum efficiency. JPL has demonstrated wavelength control by progressively growing material and fabricating devices structures that have continuously increased in LWIR response. The most recent devices exhibit peak responsivity out to 8.1 microns. Peak detectivity of the 8.1 micrometer devices has reached approx. 1 x 10(exp 10

  4. Long-Wavelength Infrared (LWIR) Quantum Dot Infrared Photodetector (QDIP) Focal Plane Array

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath D.; Bandara, S. V.; Liu, J. K.; Hill, C. J.; Rafol, S. B.; Mumolo, J. M.; Shott, C. A.

    2006-01-01

    We have exploited the artificial atomlike properties of epitaxially self-assembled quantum dots for the development of high operating temperature long wavelength infrared (LWIR) focal plane arrays. Quantum dots are nanometer-scale islands that form spontaneously on a semiconductor substrate due to lattice mismatch. QDIPs are expected to outperform quantum well infrared detectors (QWIPs) and are expected to offer significant advantages over II-VI material based focal plane arrays. QDIPs are fabricated using robust wide bandgap III-V materials which are well suited to the production of highly uniform LWIR arrays. We have used molecular beam epitaxy (MBE) technology to grow multi-layer LWIR quantum dot structures based on the InAs/InGaAs/GaAs material system. JPL is building on its significant QWIP experience and is basically building a Dot-in-the-Well (DWELL) device design by embedding InAs quantum dots in a QWIP structure. This hybrid quantum dot/quantum well device offers additional control in wavelength tuning via control of dot-size and/or quantum well sizes. In addition the quantum wells can trap electrons and aide in ground state refilling. Recent measurements have shown a 10 times higher photoconductive gain than the typical QWIP device, which indirectly confirms the lower relaxation rate of excited electrons (photon bottleneck) in QDPs. Subsequent material and device improvements have demonstrated an absorption quantum efficiency (QE) of approx. 3%. Dot-in-the-well (DWELL) QDIPs were also experimentally shown to absorb both 45 deg. and normally incident light. Thus we have employed a reflection grating structure to further enhance the quantum efficiency. JPL has demonstrated wavelength control by progressively growing material and fabricating devices structures that have continuously increased in LWIR response. The most recent devices exhibit peak responsivity out to 8.1 microns. Peak detectivity of the 8.1 micrometer devices has reached approx. 1 x 10(exp 10

  5. Shifting wavelengths of ultraweak photon emissions from dying melanoma cells: their chemical enhancement and blocking are predicted by Cosic's theory of resonant recognition model for macromolecules

    NASA Astrophysics Data System (ADS)

    Dotta, Blake T.; Murugan, Nirosha J.; Karbowski, Lukasz M.; Lafrenie, Robert M.; Persinger, Michael A.

    2014-02-01

    During the first 24 h after removal from incubation, melanoma cells in culture displayed reliable increases in emissions of photons of specific wavelengths during discrete portions of this interval. Applications of specific filters revealed marked and protracted increases in infrared (950 nm) photons about 7 h after removal followed 3 h later by marked and protracted increases in near ultraviolet (370 nm) photon emissions. Specific wavelengths within the visible (400 to 800 nm) peaked 12 to 24 h later. Specific activators or inhibitors for specific wavelengths based upon Cosic's resonant recognition model elicited either enhancement or diminishment of photons at the specific wavelength as predicted. Inhibitors or activators predicted for other wavelengths, even within 10 nm, were less or not effective. There is now evidence for quantitative coupling between the wavelength of photon emissions and intrinsic cellular chemistry. The results are consistent with initial activation of signaling molecules associated with infrared followed about 3 h later by growth and protein-structural factors associated with ultraviolet. The greater-than-expected photon counts compared with raw measures through the various filters, which also function as reflective material to other photons, suggest that photons of different wavelengths might be self-stimulatory and could play a significant role in cell-to-cell communication.

  6. Shifting wavelengths of ultraweak photon emissions from dying melanoma cells: their chemical enhancement and blocking are predicted by Cosic's theory of resonant recognition model for macromolecules.

    PubMed

    Dotta, Blake T; Murugan, Nirosha J; Karbowski, Lukasz M; Lafrenie, Robert M; Persinger, Michael A

    2014-02-01

    During the first 24 h after removal from incubation, melanoma cells in culture displayed reliable increases in emissions of photons of specific wavelengths during discrete portions of this interval. Applications of specific filters revealed marked and protracted increases in infrared (950 nm) photons about 7 h after removal followed 3 h later by marked and protracted increases in near ultraviolet (370 nm) photon emissions. Specific wavelengths within the visible (400 to 800 nm) peaked 12 to 24 h later. Specific activators or inhibitors for specific wavelengths based upon Cosic's resonant recognition model elicited either enhancement or diminishment of photons at the specific wavelength as predicted. Inhibitors or activators predicted for other wavelengths, even within 10 nm, were less or not effective. There is now evidence for quantitative coupling between the wavelength of photon emissions and intrinsic cellular chemistry. The results are consistent with initial activation of signaling molecules associated with infrared followed about 3 h later by growth and protein-structural factors associated with ultraviolet. The greater-than-expected photon counts compared with raw measures through the various filters, which also function as reflective material to other photons, suggest that photons of different wavelengths might be self-stimulatory and could play a significant role in cell-to-cell communication.

  7. A single-photon detector in the far-infrared range

    PubMed

    Komiyama; Astafiev; Antonov; Kutsuwa; Hirai

    2000-01-27

    The far-infrared region (wavelengths in the range 10 microm-1 mm) is one of the richest areas of spectroscopic research, encompassing the rotational spectra of molecules and vibrational spectra of solids, liquids and gases. But studies in this spectral region are hampered by the absence of sensitive detectors--despite recent efforts to improve superconducting bolometers, attainable sensitivities are currently far below the level of single-photon detection. This is in marked contrast to the visible and near-infrared regions (wavelengths shorter than about 1.5 microm), in which single-photon counting is possible using photomultiplier tubes. Here we report the detection of single far-infrared photons in the wavelength range 175-210 microm (6.0-7.1 meV), using a single-electron transistor consisting of a semiconductor quantum dot in high magnetic field. We detect, with a time resolution of a millisecond, an incident flux of 0.1 photons per second on an effective detector area of 0.1 mm2--a sensitivity that exceeds previously reported values by a factor of more than 10(4). The sensitivity is a consequence of the unconventional detection mechanism, in which one absorbed photon leads to a current of 10(6)-10(12) electrons through the quantum dot. By contrast, mechanisms of conventional detectors or photon assisted tunnelling in single-electron transistors produce only a few electrons per incident photon.

  8. Backward Raman amplification in the long-wavelength infrared

    NASA Astrophysics Data System (ADS)

    Johnson, L. A.; Gordon, D. F.; Palastro, J. P.; Hafizi, B.

    2017-03-01

    The wealth of work in backward Raman amplification in plasma has focused on the extreme intensity limit; however, backward Raman amplification may also provide an effective and practical mechanism for generating intense, broad bandwidth, long-wavelength infrared radiation (LWIR). An electromagnetic simulation coupled with a relativistic cold fluid plasma model is used to demonstrate the generation of picosecond pulses at a wavelength of 10 μm with terawatt powers through backward Raman amplification. The effects of collisional damping, Landau damping, pump depletion, and wave breaking are examined, as well as the resulting design considerations for an LWIR Raman amplifier.

  9. Electrically tunable zero dispersion wavelengths in photonic crystal fibers filled with a dual frequency addressable liquid crystal

    SciTech Connect

    Wahle, Markus Kitzerow, Heinz-Siegfried

    2015-11-16

    We present a liquid crystal (LC) infiltrated photonic crystal fiber, which enables the electrical tuning of the position of zero dispersion wavelengths (ZDWs). A dual frequency addressable liquid crystal is aligned perpendicular on the inclusion walls of a photonic crystal fiber, which results in an escaped radial director field. The orientation of the LC is controlled by applying an external electric field. Due to the high index of the liquid crystal the fiber guides light by the photonic band gap effect. Multiple ZDWs exist in the visible and near infrared. The positions of the ZDWs can be either blue or red shifted depending on the frequency of the applied voltage.

  10. A compact time-resolved system for near infrared spectroscopy based on wavelength space multiplexing

    NASA Astrophysics Data System (ADS)

    Re, Rebecca; Contini, Davide; Caffini, Matteo; Cubeddu, Rinaldo; Spinelli, Lorenzo; Torricelli, Alessandro

    2010-11-01

    We designed and developed a compact dual-wavelength and dual-channel time-resolved system for near-infrared spectroscopy studies of muscle and brain. The system employs pulsed diode lasers as sources, compact photomultipliers, and time-correlated single photon counting boards for detection. To exploit the full temporal and dynamic range of the acquisition technique, we implemented an approach based on wavelength space multiplexing: laser pulses at the two wavelengths are alternatively injected into the two channels by means of an optical 2×2 switch. In each detection line (i.e., in each temporal window), the distribution of photon time-of-flights at one wavelength is acquired. The proposed approach increases the signal-to-noise ratio and avoids wavelength cross-talk with respect to the typical approach based on time multiplexing. The instrument was characterized on tissue phantoms to assess its properties in terms of linearity, stability, noise, and reproducibility. Finally, it was successfully tested in preliminary in vivo measurements on muscle during standard cuff occlusion and on the brain during a motor cortex response due to hand movements.

  11. Combined visible and near-infrared OPA for wavelength scaling experiments in strong-field physics

    NASA Astrophysics Data System (ADS)

    Lloyd, David T.; O'Keeffe, Kevin; Wyatt, Adam S.; Anderson, Patrick N.; Treacher, Daniel; Hooker, Simon M.

    2017-02-01

    We report the operation of an optical parametric amplifier (OPA) capable of producing gigawatt peak-power laser pulses with tunable wavelength in either the visible or near-infrared spectrum. The OPA has two distinct operation modes (i) generation of > 350 μJ, sub 100 fs pulses, tunable between 1250 - 1550 nm; (ii) generation of > 170 μJ, sub 150 fs pulses tunable between 490 - 530 nm. We have recorded high-order harmonic spectra over a wide range of driving wavelengths. This flexible source of femtosecond pulses presents a useful tool for exploring the wavelength-dependence of strong-field phenomena, in both the multi-photon and tunnel ionization regimes.

  12. Detection Wavelength Control of Uncooled Infrared Sensors Using Two-Dimensional Lattice Plasmonic Absorbers †

    PubMed Central

    Takagawa, Yousuke; Ogawa, Shinpei; Kimata, Masafumi

    2015-01-01

    Wavelength-selective uncooled infrared (IR) sensors are highly promising for a wide range of applications, such as fire detection, gas analysis and biomedical analysis. We have recently developed wavelength-selective uncooled IR sensors using square lattice two-dimensional plasmonic absorbers (2-D PLAs). The PLAs consist of a periodic 2-D lattice of Au-based dimples, which allow photons to be manipulated using surface plasmon modes. In the present study, a detailed investigation into control of the detection wavelength was conducted by varying the PLA lattice structure. A comparison was made between wavelength-selective uncooled IR sensors with triangular and square PLA lattices that were fabricated using complementary metal oxide semiconductor and micromachining techniques. Selective enhancement of the responsivity could be achieved, and the detection wavelength for the triangular lattice was shorter than that for the square lattice. The results indicate that the detection wavelength is determined by the reciprocal-lattice vector for the PLAs. The ability to control the detection wavelength in this manner enables the application of such PLAs to many types of thermal IR sensors. The results obtained here represent an important step towards multi-color imaging in the IR region. PMID:26067198

  13. Detection Wavelength Control of Uncooled Infrared Sensors Using Two-Dimensional Lattice Plasmonic Absorbers.

    PubMed

    Takagawa, Yousuke; Ogawa, Shinpei; Kimata, Masafumi

    2015-06-10

    Wavelength-selective uncooled infrared (IR) sensors are highly promising for a wide range of applications, such as fire detection, gas analysis and biomedical analysis. We have recently developed wavelength-selective uncooled IR sensors using square lattice two-dimensional plasmonic absorbers (2-D PLAs). The PLAs consist of a periodic 2-D lattice of Au-based dimples, which allow photons to be manipulated using surface plasmon modes. In the present study, a detailed investigation into control of the detection wavelength was conducted by varying the PLA lattice structure. A comparison was made between wavelength-selective uncooled IR sensors with triangular and square PLA lattices that were fabricated using complementary metal oxide semiconductor and micromachining techniques. Selective enhancement of the responsivity could be achieved, and the detection wavelength for the triangular lattice was shorter than that for the square lattice. The results indicate that the detection wavelength is determined by the reciprocal-lattice vector for the PLAs. The ability to control the detection wavelength in this manner enables the application of such PLAs to many types of thermal IR sensors. The results obtained here represent an important step towards multi-color imaging in the IR region.

  14. Promising new wavelengths for multi-photon microscopy: thinking outside the Ti:Sapphire box

    NASA Astrophysics Data System (ADS)

    Norris, Greg; Amor, Rumelo; Dempster, John; Amos, William B.; McConnell, Gail

    2013-02-01

    Multi-photon excitation (MPE) imaging is dominated by the Ti:Sapphire laser as the source for excitation. However, it is limited when considering 3PE of common fluorophores and efficient 2PE of UV dyes which require wavelengths beyond the range of the Ti:Sapphire. Two ultra-short pulsed sources are presented as alternatives: a novel optical parametric oscillator (OPO) geometry (1400-1600nm) and the sum-frequency mixing of an OPO and Yb-doped fibre laser, providing a tunable output (626-635nm). For long wavelengths, we report three-photon laser scanning microscopy (3PLSM) using a bi-directional pumped optical parametric oscillator (OPO) with signal wavelength output at 1500 nm. This novel laser was used to overcome the high optical loss in the infrared spectral region observed in laser scanning microscopes and objective lenses that renders them otherwise difficult to use for imaging. To test our system, we performed 3PLSM auto-fluorescence imaging of live plant cells at 1500 nm, specifically Spirogyra, and compared performance with two-photon excitation (2PLSM) imaging using a femtosecond pulsed Ti:Sapphire laser at 780 nm. Analysis of cell viability based on cytoplasmic organelle streaming and structural changes of cells revealed that at similar peak powers, 2PLSM caused gross cell damage after 5 minutes but 3PLSM showed little or no interference with cell function after 15 minutes. The 1500 nm OPO was thus shown to be a practical laser source for live cell imaging. For short wavelengths, we report the use of an all-solid-state ultra-short pulsed source specifically for two-photon microscopy at wavelengths shorter than those of the conventional Ti:Sapphire laser. Our approach involved sumfrequency mixing of the output from the long-wavelength OPO described above with residual pump radiation to generate fs-pulsed output in the red spectral region. We demonstrated the performance of our ultra-short pulsed system using fluorescently labelled and autofluorescent tissue

  15. Effect of graphene on plasmonic metasurfaces at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Ueno, Masashi

    2013-11-01

    Significant enhancement of infrared transmittance by the presence of a graphene layer on a plasmonic metasurface (PLM) has been demonstrated. PLMs with different configurations were fabricated, and their transmittance with and without graphene was compared. Selective enhancement by graphene occurred at the plasmon resonance wavelength. The degree of enhancement was found to depend on the width of the gap between the periodic metal regions in the PLM. A maximum enhancement of ˜210% was achieved at a wavelength of 10 μm. The ability to achieve such a drastic increase in transmittance at the plasmon resonant wavelength is expected to lead to improvements in the performance of energy collecting devices and optical sensors.

  16. Effect of graphene on plasmonic metasurfaces at infrared wavelengths

    SciTech Connect

    Ogawa, Shinpei Fujisawa, Daisuke; Ueno, Masashi

    2013-11-15

    Significant enhancement of infrared transmittance by the presence of a graphene layer on a plasmonic metasurface (PLM) has been demonstrated. PLMs with different configurations were fabricated, and their transmittance with and without graphene was compared. Selective enhancement by graphene occurred at the plasmon resonance wavelength. The degree of enhancement was found to depend on the width of the gap between the periodic metal regions in the PLM. A maximum enhancement of ∼210% was achieved at a wavelength of 10 μm. The ability to achieve such a drastic increase in transmittance at the plasmon resonant wavelength is expected to lead to improvements in the performance of energy collecting devices and optical sensors.

  17. Long-Wavelength Infrared Views of Messier 81

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The magnificent and dusty spiral arms of the nearby galaxy Messier 81 are highlighted in these NASA Spitzer Space Telescope images. Located in the northern constellation of Ursa Major (which also includes the Big Dipper), this galaxy is easily visible through binoculars or a small telescope. M81 is located at a distance of 12 million light-years.

    The three-panel mosaic is a series of images obtained with the multiband imaging photometer for Spitzer. Thermal infrared emission at 24 microns (top), 70 microns (center) and 160 microns (bottom) is shown in the images. Note that the effective spatial resolution degrades as ones moves to longer wavelengths.

    At these wavelengths, Spitzer sees the dust, rather than the stars, within the disc of silicates and carbonaceous grains. It is well-mixed with gas, which is best seen at radio wavelengths, to form the essential ingredients for future star formation.

  18. Group IV photonics for the mid infrared

    NASA Astrophysics Data System (ADS)

    Soref, Richard

    2013-02-01

    This paper outlines the challenges and benefits of applying silicon-based photonic techniques in the 2 to 5 μm midinfrared (MIR) wavelength range for chem.-bio-physical sensing, medical diagnostics, industrial process control, environmental monitoring, secure communications, Ladar, active imaging, and high-speed communications at 2 μm. Onchip passive and active components, mostly waveguided, will enable opto-electronic CMOS or BiCMOS integrated "circuits" for system-on-a-chip applications such as spectroscopy and lab-on-a-chip. Volume manufacture in a silicon foundry is expected to yield low-cost (or even disposable) chips with benefits in size-weight-power and ruggedness. This is "long-wavelength optoelectronic integration on silicon" which we call LIOS. Room temperature operation appears feasible, albeit with performance compromises at 4 to 5 μm. In addition to the electronics layer (which may include RF wireless), a 3-D LIOS chip can include several inter-communicating layers utilizing the photonic, plasmonic, photoniccrystal and opto-electro-mechanical technologies. The LIOS challenge can be met by (1) discovering new physics, (2) employing "new" IV and III-V alloys, (3) scaling-up and modifying telecom components, and (4) applying nonlinearoptical wavelength conversion in some cases. This paper presents proposals for MIR chip spectrometers employing frequency-comb and Ge blackbody sources. Active heterostructures employing Si, Ge, SiGe, GeSn and SiGeSn are key for laser diodes, photodetectors, LEDs, switches, amplifiers, and modulators that provide totally monolithic foundry integration, while numerous III-V semiconductor MIR devices within the InGaAsSb and InGaAsP families offer practical hybrid integration on Si PICs. Interband cascade and quantum cascade lasers on Ge waveguides are important in this context.

  19. Compact Broad-Band Wavelength-Agile Mid-Infrared Semiconductor Lasers for Spectroscopic Sensing

    DTIC Science & Technology

    2004-12-01

    IEEE Photon. Technol. Lett. Jan 2005). Yi Wang, Chuan Peng, HuanLin Zhang, and Han Q. Le, “Wavelength modulation imaging with tunable mid- infrared...Wen-Yen Hwang, Jae Um, Bujin Guo, Hao Lee, and Chih- Hsiang Lin, “Continuous-wave operation of a 5.2 µm quantum-cascade laser up to 210 K”, Appl. Phys...Lett. 79, 1745-1747, (2001). 2. Proceedings Yi Wang, Yang Wang, Chuan Peng, HuanLin Zhang, Anush Seetheraman, and Han Q. Le, “Concepts for Scalable

  20. Photonic crystal lasers using wavelength-scale embedded active region

    NASA Astrophysics Data System (ADS)

    Matsuo, Shinji; Sato, Tomonari; Takeda, Koji; Shinya, Akihiko; Nozaki, Kengo; Kuramochi, Eiichi; Taniyama, Hideaki; Notomi, Masaya; Fujii, Takuro; Hasebe, Koichi; Kakitsuka, Takaaki

    2014-01-01

    Lasers with ultra-low operating energy are desired for use in chip-to-chip and on-chip optical interconnects. If we are to reduce the operating energy, we must reduce the active volume. Therefore, a photonic crystal (PhC) laser with a wavelength-scale cavity has attracted a lot of attention because a PhC provides a large Q-factor with a small volume. To improve this device's performance, we employ an embedded active region structure in which the wavelength-scale active region is buried with an InP PhC slab. This structure enables us to achieve effective confinement of both carriers and photons, and to improve the thermal resistance of the device. Thus, we have obtained a large external differential quantum efficiency of 55% and an output power of -10 dBm by optical pumping. For electrical pumping, we use a lateral p-i-n structure that employs Zn diffusion and Si ion implantation for p-type and n-type doping, respectively. We have achieved room-temperature continuous-wave operation with a threshold current of 7.8 µA and a maximum 3 dB bandwidth of 16.2 GHz. The results of an experimental bit error rate measurement with a 10 Gbit s-1 NRZ signal reveal the minimum operating energy for transferring a single bit of 5.5 fJ. These results show the potential of this laser to be used for very short reach interconnects. We also describe the optimal design of cavity quality (Q) factor in terms of achieving a large output power with a low operating energy using a calculation based on rate equations. When we assume an internal absorption loss of 20 cm-1, the optimized coupling Q-factor is 2000.

  1. Sub-wavelength nanofluidics in photonic crystal sensors.

    PubMed

    Huang, Min; Yanik, Ahmet Ali; Chang, Tsung-Yao; Altug, Hatice

    2009-12-21

    We introduce a novel sensor scheme combining nano-photonics and nano-fluidics on a single platform through the use of free-standing photonic crystals. By harnessing nano-scale openings, we theoretically and experimentally demonstrate that both fluidics and light can be manipulated at sub-wavelength scales. Compared to the conventional fluidic channels, we actively steer the convective flow through the nanohole openings for effective delivery of the analytes to the sensor surface. We apply our method to detect refractive index changes in aqueous solutions. Bulk measurements indicate that active delivery of the convective flow results in better sensitivities. The sensitivity of the sensor reaches 510 nm/RIU for resonance located around 850 nm with a line-width of approximately 10 nm in solution. Experimental results are matched very well with numerical simulations. We also show that cross-polarization measurements can be employed to further improve the detection limit by increasing the signal-to-noise ratio.

  2. Bridging visible and telecom wavelengths with a single-mode broadband photon pair source

    SciTech Connect

    Soeller, C.; Brecht, B.; Mosley, P. J.; Zang, L. Y.; Podlipensky, A.; Joly, N. Y.; Russell, P. St. J.; Silberhorn, C.

    2010-03-15

    We present a spectrally decorrelated photon pair source bridging the visible and telecom wavelength regions. Tailored design and fabrication of a solid-core photonic crystal fiber (PCF) lead to the emission of signal and idler photons into only a single spectral and spatial mode. Thus no narrowband filtering is necessary and the heralded generation of pure photon number states in ultrafast wave packets at telecom wavelengths becomes possible.

  3. Dark current and photoresponse characteristics of extended wavelength infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Chauhan, D.; Perera, A. G. U.; Li, L. H.; Chen, L.; Linfield, E. H.

    2017-07-01

    The dark current and spectral photoresponse thresholds of a semiconductor photodetector are normally determined by the minimum energy gap (Δ) of the material, or the interfacial energy gap of the heterostructure. In this manuscript, we discuss the performance of an asymmetric p-GaAs/AlxGa1-xAs heterostructure-based infrared photodetector, which shows an extended wavelength threshold beyond the limit set by Δ. The measured dark current was found to agree well with fits obtained from a 3D carrier drift model using the designed value of Δ ˜ 0.40 eV (˜3.1 μm). In contrast, the spectral photoresponse showed extended wavelength thresholds of ˜68 μm, ˜45 μm, and ˜60 μm at positive, zero, and negative biases, respectively, at 5.3 K. For a reference (symmetric) photodetector, the dark current was fitted with the designed value of Δ ˜0.30 eV, and excellent agreement was obtained for both the measured dark current and spectral response. This underlies the advantage of using asymmetric infrared photo-detector designs, in which an extension to the detected wavelengths can be obtained with little compromise to the dark current characteristics.

  4. Multi-channel medical device for time domain functional near infrared spectroscopy based on wavelength space multiplexing

    PubMed Central

    Re, Rebecca; Contini, Davide; Turola, Massimo; Spinelli, Lorenzo; Zucchelli, Lucia; Caffini, Matteo; Cubeddu, Rinaldo; Torricelli, Alessandro

    2013-01-01

    We have designed a compact dual wavelength (687 nm, 826 nm) multi-channel (16 sources, 8 detectors) medical device for muscle and brain imaging based on time domain functional near infrared spectroscopy. The system employs the wavelength space multiplexing approach to reduce wavelength cross-talk and increase signal-to-noise ratio. System performances have been tested on homogeneous and heterogeneous tissue phantoms following specifically designed protocols for photon migration instruments. Preliminary in vivo measurements have been performed to validate the instrument capability to monitor hemodynamic parameters changes in the arm muscle during arterial occlusion and in the adult head during a motor task experiment. PMID:24156079

  5. Long wavelength photoconductive detectors for airborne and orbital infrared astronomy

    NASA Technical Reports Server (NTRS)

    Houck, J. R.

    1983-01-01

    Seven gallium doped germanium (Ge:Ga) photoconductive infrared detectors were fabricated and mounted in integrating cavities. In addition, a cold preamplifier package consisting of J230 junction field effect transistors (JFETs) was produced. Tests of the system under low photon background conditions indicated that sensitivity was limited by the Johnson noise of the load resistor. The detectors were mounted in the Ames cooled grating spectrometer, and flown on the Kuiper Airborne Observatory. Good quality astronomical data were obtained during the flight of 7 July 1983.

  6. Optically guided neuronal growth at near-infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Stevenson, D. J.; Lake, T. K.; Agate, B.; Garcés-Chávez, V.; Dholakia, K.; Gunn-Moore, F.

    2006-08-01

    Recent work has indicated the potential of light to guide the growth cones of neuronal cells using a Ti:Sapphire laser at 800 nm (Ehrlicher et al, PNAS, 2002). We have developed an optical set-up that has allowed, for the first time, the direct comparison of this process at near infrared wavelengths. A high number of growth cones were studied in order to provide a detailed statistical analysis. Actively extending growth cones of the neuroblastoma cell-line, NG108, can be guided at not only 780 nm, but also at 1064 nm. These wavelengths are an appropriate choice for guidance experiments, as wavelengths in the visible spectrum and UV are highly absorbing by cells and lead to death by phototoxicity and thermal stress. At 780 nm, 47% of actively extending growth cones were found to turn towards the focused incident light by at least 30° (n=32 growth cones). At 1064 nm, 61% of cells were successfully guided (n=31 growth cones). This suggests that the light detection mechanism within the cell is not due a single protein with a defined activity wavelength as occurs for example with the photoreceptor family of opsin proteins in the mammalian eye. We present two novel mechanisms of light induced neuronal guidance which are not related to temperature increases, or optical tweezing of the growth cone. We are also now identifying the signaling pathways that mediate this phenomenon.

  7. Interference with a quantum dot single-photon source and a laser at telecom wavelength

    SciTech Connect

    Felle, M.; Huwer, J. Stevenson, R. M.; Skiba-Szymanska, J.; Ward, M. B.; Shields, A. J.; Farrer, I.; Ritchie, D. A.; Penty, R. V.

    2015-09-28

    The interference of photons emitted by dissimilar sources is an essential requirement for a wide range of photonic quantum information applications. Many of these applications are in quantum communications and need to operate at standard telecommunication wavelengths to minimize the impact of photon losses and be compatible with existing infrastructure. Here, we demonstrate for the first time the quantum interference of telecom-wavelength photons from an InAs/GaAs quantum dot single-photon source and a laser; an important step towards such applications. The results are in good agreement with a theoretical model, indicating a high degree of indistinguishability for the interfering photons.

  8. Variable CO2 laser attenuator. [for infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Klein, B. J.; Degnan, J. J.; Walker, H. E.; Zagwodzki, T.

    1974-01-01

    An infrared wavelength variable attenuator based on contra-rotating germanium wedges is examined theoretically. The device redirects the paths of internal reflections associated with an optical flat to avoid closely spaced parallel beams at the output. Complementary wedges separated by an air gap compose an optical flat which, when combined with a masking arrangement, restricts unwanted reflections. A model of the device was built and experimentally evaluated. The results compare favorably with the dynamic range of attenuation of 2 to 50 db from theoretical calculations, and show a substantial reduction in the etalon effect associated with pairs of optical flats.

  9. Avalanche quantum dot-in-well long wavelength infrared photodetectors: Linear and Geiger mode operation

    NASA Astrophysics Data System (ADS)

    Zavvari, Mahdi; Ahmadi, Vahid

    2014-07-01

    Employment of additional multiplication region in the structure of quantum dots-in-well (DWELL) intersubband photodetectors can be a useful alternative for amplification of the photocurrent and giving higher gain to detected optical signal. For such detector the photocurrent of DWELL detector is increased by avalanche multiplication to achieve higher responsivity and resonant tunneling barriers are used in absorption region to reduce the dark current. In this paper the linear and Geiger mode operation of proposed detector is studied for operation at λ = 11 μm. In linear operation, the specific detectivity (D*) is increased about one order of magnitude in comparison to experimentally reported conventional DWELL detectors. We also report the single photon detection around mid and long infrared wavelength by gated mode operation of this detector with single photon quantum efficiency of about 3%.

  10. Multiple higher-order stop gaps in infrared polymer photonic crystals.

    PubMed

    Straub, M; Ventura, M; Gu, M

    2003-07-25

    Engineering of stop gaps between higher photonic bands provides an alternative to miniaturization of photonic crystals. Femtosecond laser microfabrication of highly correlated void channel polymer microstructures results in photonic crystals with large stop gaps and a multitude of higher-order gaps in the mid- and near-infrared spectral regions. The gap wavelengths obey Bragg's law. Consistent with theory, varying the woodpile structure unit cell allows for tuning the number of higher-order gaps, and transitions from mere resonant Bragg scattering to stop band total reflection are observed.

  11. High Operating Temperature Barrier Infrared Detector with Tailorable Cutoff Wavelength

    NASA Technical Reports Server (NTRS)

    Ting, David Z. (Inventor); Hill, Cory J. (Inventor); Seibel, Alexander (Inventor); Bandara, Sumith Y. (Inventor); Gunapala, Sarath D. (Inventor)

    2015-01-01

    A barrier infrared detector with absorber materials having selectable cutoff wavelengths and its method of manufacture is described. A GaInAsSb absorber layer may be grown on a GaSb substrate layer formed by mixing GaSb and InAsSb by an absorber mixing ratio. A GaAlAsSb barrier layer may then be grown on the barrier layer formed by mixing GaSb and AlSbAs by a barrier mixing ratio. The absorber mixing ratio may be selected to adjust a band gap of the absorber layer and thereby determine a cutoff wavelength for the barrier infrared detector. The absorber mixing ratio may vary along an absorber layer growth direction. Various contact layer architectures may be used. In addition, a top contact layer may be isolated into an array of elements electrically isolated as individual functional detectors that may be used in a detector array, imaging array, or focal plane array.

  12. Local density of optical states of an asymmetric waveguide grating at photonic band gap resonant wavelength

    NASA Astrophysics Data System (ADS)

    Alatas, Husin; Sumaryada, Tony I.; Ahmad, Faozan

    2015-01-01

    We have investigated the characteristics of local density of optical states (LDOS) at photonic band gap resonant wavelength of an asymmetric waveguide grating based on Green's function formulation. It is found that the LDOS of the considered structure exhibits different characteristics in its localization between the upper and lower resonant wavelengths of the corresponding photonic band gap edges.

  13. Continuous injection synthesis of indium arsenide quantum dots emissive in the short-wavelength infrared

    NASA Astrophysics Data System (ADS)

    Franke, Daniel; Harris, Daniel K.; Chen, Ou; Bruns, Oliver T.; Carr, Jessica A.; Wilson, Mark W. B.; Bawendi, Moungi G.

    2016-11-01

    With the emergence of applications based on short-wavelength infrared light, indium arsenide quantum dots are promising candidates to address existing shortcomings of other infrared-emissive nanomaterials. However, III-V quantum dots have historically struggled to match the high-quality optical properties of II-VI quantum dots. Here we present an extensive investigation of the kinetics that govern indium arsenide nanocrystal growth. Based on these insights, we design a synthesis of large indium arsenide quantum dots with narrow emission linewidths. We further synthesize indium arsenide-based core-shell-shell nanocrystals with quantum yields up to 82% and improved photo- and long-term storage stability. We then demonstrate non-invasive through-skull fluorescence imaging of the brain vasculature of murine models, and show that our probes exhibit 2-3 orders of magnitude higher quantum yields than commonly employed infrared emitters across the entire infrared camera sensitivity range. We anticipate that these probes will not only enable new biomedical imaging applications, but also improved infrared nanocrystal-LEDs and photon-upconversion technology.

  14. Continuous injection synthesis of indium arsenide quantum dots emissive in the short-wavelength infrared

    PubMed Central

    Franke, Daniel; Harris, Daniel K.; Chen, Ou; Bruns, Oliver T.; Carr, Jessica A.; Wilson, Mark W. B.; Bawendi, Moungi G.

    2016-01-01

    With the emergence of applications based on short-wavelength infrared light, indium arsenide quantum dots are promising candidates to address existing shortcomings of other infrared-emissive nanomaterials. However, III–V quantum dots have historically struggled to match the high-quality optical properties of II–VI quantum dots. Here we present an extensive investigation of the kinetics that govern indium arsenide nanocrystal growth. Based on these insights, we design a synthesis of large indium arsenide quantum dots with narrow emission linewidths. We further synthesize indium arsenide-based core-shell-shell nanocrystals with quantum yields up to 82% and improved photo- and long-term storage stability. We then demonstrate non-invasive through-skull fluorescence imaging of the brain vasculature of murine models, and show that our probes exhibit 2–3 orders of magnitude higher quantum yields than commonly employed infrared emitters across the entire infrared camera sensitivity range. We anticipate that these probes will not only enable new biomedical imaging applications, but also improved infrared nanocrystal-LEDs and photon-upconversion technology. PMID:27834371

  15. Experimental realization of optical lumped nanocircuits at infrared wavelengths

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

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

    PubMed

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

    2012-01-29

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

  17. III–V-on-Silicon Photonic Integrated Circuits for Spectroscopic Sensing in the 2–4 μm Wavelength Range

    PubMed Central

    Wang, Ruijun; Vasiliev, Anton; Muneeb, Muhammad; Malik, Aditya; Sprengel, Stephan; Boehm, Gerhard; Amann, Markus-Christian; Šimonytė, Ieva; Vizbaras, Augustinas; Vizbaras, Kristijonas; Baets, Roel; Roelkens, Gunther

    2017-01-01

    The availability of silicon photonic integrated circuits (ICs) in the 2–4 μm wavelength range enables miniature optical sensors for trace gas and bio-molecule detection. In this paper, we review our recent work on III–V-on-silicon waveguide circuits for spectroscopic sensing in this wavelength range. We first present results on the heterogeneous integration of 2.3 μm wavelength III–V laser sources and photodetectors on silicon photonic ICs for fully integrated optical sensors. Then a compact 2 μm wavelength widely tunable external cavity laser using a silicon photonic IC for the wavelength selective feedback is shown. High-performance silicon arrayed waveguide grating spectrometers are also presented. Further we show an on-chip photothermal transducer using a suspended silicon-on-insulator microring resonator used for mid-infrared photothermal spectroscopy. PMID:28777291

  18. Wavelength conversion of nanosecond pulses to the mid-IR in photonic crystal fibers.

    PubMed

    Herzog, Amir; Shamir, Avishay; Ishaaya, Amiel A

    2012-01-01

    We investigate degenerate four wave mixing with nanosecond pulses in fused silica photonic crystal fibers. Phase-matching curves are calculated taking into account the material and waveguide dispersion. Experiments with a nanosecond pulsed Nd:YAG pump laser and relatively short fiber lengths show more than an octave spanning conversion to idler and signal wavelengths at 3.105 μm and 0.642 μm, respectively. Conversion efficiency depends on the fiber length and pump intensity and is limited in our experiments by damage of the fiber input facet. Our results represent a new stretch towards the limit of the silica transmission window in the mid-infrared (IR).

  19. Infrared FEL photochemistry: Multiple-photon dissociation of Freon gas

    SciTech Connect

    Newnam, B.E.; Early, J.W.; Lyman, J.L.

    1993-10-01

    Wavelength tunability, synchrotron sidebands, and picosecond pulse structure are inherent FEL characteristics that should be advantageous for photochemistry involving infrared multiple-photon photodissociation. Tuned to an absorption resonance, the FEL sideband structure will overlap the broad, excited-state spectral absorption and should lead to enhanced dissociation. The Los Alamos APEX FEL was operated with and without sidebands to test this hypothesis on CFCl{sub 3} (Freon 11), an inert chlorofluorocarbon widely used in refrigeration systems and one of the gases implicated as depleting the ozone in the Earth`s stratospheric layer. The FEL wavelength was set at the C-Cl stretch absorption resonance at 11.8-{mu}m, the oscillator cavity length was detuned first to minimize and then to maximize the spectral bandwidth, and the beam was focused through a pair of test cells (1.0 Torr Freon+1.7 Torr air). Comparison of final and initial absorbance spectra indicated the CFCl{sub 3} photodissociation yield was 1.2% for the cell exposed with sideband spectra (3% FWHM) and 9-ns micropulse separation. Negligible effect was seen without sidebands, albeit at lower total beam fluence. Although the result of this single experiment is not large enough to be conclusive, it does provide a basis for optimizing the FEL temporal and spectral parameters to attain higher photodissociation yield in future tests.

  20. Infrared FEL photochemistry: Multiple-photon dissociation of freon gas

    NASA Astrophysics Data System (ADS)

    Newnam, B. E.; Early, J. W.; Lyman, J. L.

    Wavelength tunability, synchrotron sidebands, and picosecond pulse structure are inherent FEL characteristics that should be advantageous for photochemistry involving infrared multiple-photon photodissociation. Tuned to an absorption resonance, the FEL sideband structure will overlap the broad, excited-state spectral absorption and should lead to enhanced dissociation. The Los Alamos APEX FEL was operated with and without sidebands to test this hypothesis on CFCl3 (Freon 11), an inert chlorofluorocarbon widely used in refrigeration systems and one of the gases implicated as depleting the ozone in the Earth's stratospheric layer. The FEL wavelength was set at the C-Cl stretch absorption resonance at 11.8-microns, the oscillator cavity length was detuned first to minimize and then to maximize the spectral bandwidth, and the beam was focused through a pair of test cells (1.0 Torr Freon + 1.7 Torr air). Comparison of final and initial absorbance spectra indicated the CFCl3 photodissociation yield was 1.2% for the cell exposed with sideband spectra (3% FWHM) and 9-ns micropulse separation. Negligible effect was seen without sidebands, albeit at lower total beam fluence. Although the result of this single experiment is not large enough to be conclusive, it does provide a basis for optimizing the FEL temporal and spectral parameters to attain higher photodissociation yield in future tests.

  1. Infrared FEL photochemistry: multiple-photon dissociation of Freon gas

    NASA Astrophysics Data System (ADS)

    Newnam, Brian E.; Early, James W.; Lyman, John L.

    1994-03-01

    Wavelength tunability, synchrotron sidebands, and picosecond pulse structure are inherent characteristics of free-electron lasers (FELs) that should be advantageous for photochemistry involving infrared multiple-photon photodissociation. Tuned to an absorption resonance, the FEL sideband structure will overlap the broad, red-shifted, quasi-continuous excited-state absorption spectra and should lead to enhanced dissociation. The Los Alamos APEX FEL was operated with and without sidebands to test this hypothesis on CFCl 3 (Freon 11), one of the gases implicated as depleting the ozone in the Earth's stratospheric layer. The FEL wavelength was set at the CCl stretch absorption resonance at 11.8 μm, the oscillator cavity length was detuned first to minimize and then to maximize the spectral bandwidth, and the beam was focused through a pair of test cells. Comparison of final and initial absorbance spectra indicated the CFCl 3 photodissociation yield was 1.2% for the cell exposed with sideband spectra (3% FWHM) and 9-ns micropulse separation. Negligible effect was seen without sidebands, albeit at lower total beam fluence.

  2. Nonlinear refractive index on multiwavelength generation through mismatch photonic crystal fibre from transmission wavelength

    NASA Astrophysics Data System (ADS)

    Abdullah, Mohd Nizam; Shaari, Sahbudin; Ehsan, Abang Annuar; Menon, Susthitha; Zakaria, Osman; Marzuki, Nazri

    2014-05-01

    This paper proposes a measurement of nonlinear refractive index in the course of multi wavelength technique. We have generated a multi wavelengths formation by utilising a photonic crystal fibre (PCF) which mismatches zero dispersion wavelength from transmission wavelength at 1550 nm. We provide an experimental set-up in generating the multi wavelength phenomenon. A fibre ring laser configuration consists of erbium doped fibre amplifier (EDFA) set up and arrangement of FBGs is described. Encouraging results obtained from the set up proves the relations of signals generated through FBGs and new wavelengths. These findings shows, multi wavelengths able to present valuable inputs in determination of nonlinear refractive index parameter.

  3. Long wavelength infrared dual field-of-view optical system

    NASA Astrophysics Data System (ADS)

    Xiong, Tao; Yang, Chang-cheng

    2007-12-01

    For cooled 320×240 staring focal plane array (FPA), a novel long wavelength infrared dual field-of-view optical system is presented in the paper. The optical system is composed of re-imaging part and zooming part. The parameters of the system are 1.96 f/number, 100% cold shield efficiency, 180mm/60mm effective focal length (EFL) and 8-10 μm spectrum region. The optical system is analyzed from two modes of narrow field of view (NFOV) and wide field of view (WFOV). The system can be used in the temperature range from-30°Cand 60°C without significant degradation of optical performance. The final test results prove the designed performance is good..

  4. Pulsed source of spectrally uncorrelated and indistinguishable photons at telecom wavelengths.

    PubMed

    Bruno, N; Martin, A; Guerreiro, T; Sanguinetti, B; Thew, R T

    2014-07-14

    We report on the generation of indistinguishable photon pairs at telecom wavelengths based on a type-II parametric down conversion process in a periodically poled potassium titanyl phosphate (PPKTP) crystal. The phase matching, pump laser characteristics and coupling geometry are optimised to obtain spectrally uncorrelated photons with high coupling efficiencies. Four photons are generated by a counter-propagating pump in the same crystal and anlysed via two photon interference experiments between photons from each pair source as well as joint spectral and g((2)) measurements. We obtain a spectral purity of 0.91 and coupling efficiencies around 90% for all four photons without any filtering. These pure indistinguishable photon sources at telecom wavelengths are perfectly adapted for quantum network demonstrations and other multi-photon protocols.

  5. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

    PubMed Central

    Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

    2015-01-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances. PMID:26597223

  6. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

    PubMed

    Yu, Leo; Natarajan, Chandra M; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S; Tanner, Michael G; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H; Fejer, Martin M; Yamamoto, Yoshihisa

    2015-11-24

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

  7. Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

    NASA Astrophysics Data System (ADS)

    Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

    2015-11-01

    Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

  8. Tunable room-temperature single-photon emission at telecom wavelengths from sp3 defects in carbon nanotubes

    DOE PAGES

    He, Xiaowei; Hartmann, Nicolai F.; Ma, Xuedan; ...

    2017-07-31

    Generating quantum light emitters that operate at room temperature and at telecom wavelengths remains a significant materials challenge. To achieve this goal requires light sources that emit in the near-infrared wavelength region and that, ideally, are tunable to allow desired output wavelengths to be accessed in a controllable manner. Here, we show that exciton localization at covalently introduced aryl sp3 defect sites in single-walled carbon nanotubes provides a route to room-temperature single-photon emission with ultrahigh single-photon purity (99%) and enhanced emission stability approaching the shot-noise limit. Moreover, we demonstrate that the inherent optical tunability of single-walled carbon nanotubes, present inmore » their structural diversity, allows us to generate room-temperature single-photon emission spanning the entire telecom band. Furthermore, single-photon emission deep into the centre of the telecom C band (1.55 um) is achieved at the largest nanotube diameters we explore (0.936 nm).« less

  9. Uncooled infrared photon detector and multicolor infrared detection using microoptomechanical sensors

    DOEpatents

    Datskos, Panagiotis G.; Rajic, Solobodan; Datskou, Irene C.

    1999-01-01

    Systems and methods for infrared detection are described. An optomechanical photon detector includes a semiconductor material and is based on measurement of a photoinduced lattice strain. A multicolor infrared sensor includes a stack of frequency specific optomechanical detectors. The stack can include one, or more, of the optomechanical photon detectors that function based on the measurement of photoinduced lattice strain. The systems and methods provide advantages in that rapid, sensitive multicolor infrared imaging can be performed without the need for a cooling subsystem.

  10. Uncooled infrared photon detector and multicolor infrared detection using microoptomechanical sensors

    SciTech Connect

    Datskos, P.G.; Rajic, S.; Datskou, I.C.

    1999-11-02

    Systems and methods for infrared detection are described. An optomechanical photon detector includes a semiconductor material and is based on measurement of a photoinduced lattice strain. A multicolor infrared sensor includes a stack of frequency specific optomechanical detectors. The stack can include one, or more, of the optomechanical photon detectors that function based on the measurement of photoinduced lattice strain. The systems and methods provide advantages in that rapid, sensitive multicolor infrared imaging can be performed without the need for a cooling subsystem.

  11. Near-Infrared Photoluminescent Polymer-Carbon Nanodots with Two-Photon Fluorescence.

    PubMed

    Lu, Siyu; Sui, Laizhi; Liu, Junjun; Zhu, Shoujun; Chen, Anmin; Jin, Mingxing; Yang, Bai

    2017-02-13

    A facile, high-output strategy is developed for fabricating near-infrared-emissive polymer-carbon nanodots (PCNDs). The PCNDs emit at a wavelength of 710 nm with a QY of 26.28%, which is promising for deep biological imaging and luminescent devices. Moreover, the PCNDs possess two-photon fluorescence and. In vivo bioimaging and red light emitting diodes based on these PCNDs are demonstrated.

  12. Efficient generation of twin photons at telecom wavelengths with 2.5 GHz repetition-rate-tunable comb laser.

    PubMed

    Jin, Rui-Bo; Shimizu, Ryosuke; Morohashi, Isao; Wakui, Kentaro; Takeoka, Masahiro; Izumi, Shuro; Sakamoto, Takahide; Fujiwara, Mikio; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Wang, Zhen; Sasaki, Masahide

    2014-12-19

    Efficient generation and detection of indistinguishable twin photons are at the core of quantum information and communications technology (Q-ICT). These photons are conventionally generated by spontaneous parametric down conversion (SPDC), which is a probabilistic process, and hence occurs at a limited rate, which restricts wider applications of Q-ICT. To increase the rate, one had to excite SPDC by higher pump power, while it inevitably produced more unwanted multi-photon components, harmfully degrading quantum interference visibility. Here we solve this problem by using recently developed 10 GHz repetition-rate-tunable comb laser, combined with a group-velocity-matched nonlinear crystal, and superconducting nanowire single photon detectors. They operate at telecom wavelengths more efficiently with less noises than conventional schemes, those typically operate at visible and near infrared wavelengths generated by a 76 MHz Ti Sapphire laser and detected by Si detectors. We could show high interference visibilities, which are free from the pump-power induced degradation. Our laser, nonlinear crystal, and detectors constitute a powerful tool box, which will pave a way to implementing quantum photonics circuits with variety of good and low-cost telecom components, and will eventually realize scalable Q-ICT in optical infra-structures.

  13. Linkage and Anomeric Differentiation in Trisaccharides by Sequential Fragmentation and Variable-Wavelength Infrared Photodissociation

    NASA Astrophysics Data System (ADS)

    Tan, Yanglan; Polfer, Nicolas C.

    2015-02-01

    Carbohydrates and their derivatives play important roles in biological systems, but their isomeric heterogeneity also presents a considerable challenge for analytical techniques. Here, a stepwise approach using infrared multiple-photon dissociation (IRMPD) via a tunable CO2 laser (9.2-10.7 μm) was employed to characterize isomeric variants of glucose-based trisaccharides. After the deprotonated trisaccharides were trapped and fragmented to disaccharide C2 fragments in a Fourier transform ion cyclotron resonance (FTICR) cell, a further variable-wavelength infrared irradiation of the C2 ion produced wavelength-dependent dissociation patterns that are represented as heat maps. The photodissociation patterns of these C2 fragments are shown to be strikingly similar to the photodissociation patterns of disaccharides with identical glycosidic bonds. Conversely, the photodissociation patterns of different glycosidic linkages exhibit considerable differences. On the basis of these results, the linkage position and anomericity of glycosidic bonds of disaccharide units in trisaccharides can be systematically differentiated and identified, providing a promising approach to characterize the structures of isomeric oligosaccharides.

  14. Two-photon quantum well infrared photodetectors below 6 THz

    NASA Astrophysics Data System (ADS)

    Franke, Carsten; Walther, Martin; Helm, Manfred; Schneider, Harald

    2015-05-01

    Two-photon quantum well infrared photodetectors (QWIPs) are nonlinear detectors for the mid-infrared and terahertz regimes optimized for resonant two-photon absorption. Here we present first results on two-photon QWIP samples based on the GaAs/AlGaAs material system with intersubband energies between 25 and 12 meV (6-3 THz) confirmed by photocurrent spectra. The dark current showed large discontinuities, presumably caused by impact ionization. We performed interferometric autocorrelation experiments at the free-electron laser FELBE and observed nonlinear interferograms for all samples.

  15. Nonlinear silicon photonics from the near to mid infrared

    NASA Astrophysics Data System (ADS)

    Park, Jung Soo

    This dissertation presents experimental work investigating silicon-on-insulator (SOI) photonic waveguides for parametric nonlinear optic devices. An introduction is presented in Chapter 1, including background and motivation for exploring SOI as a platform for integrated photonics, as well as an overview of integrated nonlinear optic devices. Chapter 2 discusses on-chip slow light structures based on coupled-resonator optical waveguides (CROW), potentially useful for enhancing nonlinearities for efficient chip-scale nonlinear optics. Although slowing light is limited by fabrication tolerance-induced disorder, a fundamental phenomenon is observed: the Anderson localization of optical waves. Chapter 3 of the dissertation discusses four-wave mixing in SOI waveguides. SOI waveguide fabrication is described in detail, including achieving low fiber-to-chip coupling loss and waveguide propagation loss. Two approaches for dispersion engineering are presented: with the design of waveguide dimensions and with a thin-film cladding. Parametric wavelength conversion by degenerate (single-pump) FWM in these dispersion-engineered waveguides is demonstrated and discussed. Chapter 4 concerns FWM with two pumps, an approach that promises functionalities not possible with a single pump such as multiple sideband generation with self-seeded higher-order pumps. In addition to demonstrating the generation of up to ten sidebands with dual pumps and subsequent self-seeded higher order pumps, we characterize trade-offs in maximum conversion efficiency due to nondegenerate two-photon absorption (TPA). The work presented in Chapter 5 takes a novel approach to SOI parametric devices by exploring a new spectral range, toward the mid-infrared (mid-IR), near 2 mum and beyond. We measure FWM in silicon waveguides with a pump near 2 mum, which itself is generated by the parametric conversion of a 1300 nm seed by a 1589 nm pump in a highly-nonlinear fiber (HNLF). Fundamentally, our results show

  16. A promising new wavelength region for three-photon fluorescence microscopy of live cells.

    PubMed

    Norris, Greg; Amor, Rumelo; Dempster, John; Amos, William B; McConnell, Gail

    2012-06-01

    We report three-photon laser scanning microscopy (3PLSM) using a bi-directional pumped optical parametric oscillator (OPO) with signal wavelength output at λ= 1500 nm. This novel laser was used to overcome the high optical loss in the infrared spectral region observed in laser scanning microscopes and objective lenses that renders them otherwise difficult to use for imaging. To test our system, we performed 3PLSM auto-fluorescence imaging of live plant cells at λ= 1500 nm, specifically Spirogyra, and compared performance with two-photon excitation (2PLSM) imaging using a femtosecond pulsed Ti:Sapphire laser at λ= 780 nm. Analysis of cell viability based on cytoplasmic organelle streaming and structural changes of cells revealed that at similar peak powers, 2PLSM caused gross cell damage after 5 min but 3PLSM showed little or no interference with cell function after 15 min. The λ= 1500 nm OPO is thus shown to be a practical laser source for live cell imaging.

  17. Multiple plasmonic-photonic couplings in the Au nanobeaker arrays: enhanced robustness and wavelength tunability.

    PubMed

    Lin, Linhan; Zheng, Yuebing

    2015-05-01

    Diffractive coupling in the plasmonic nanoparticle arrays introduces the collective plasmon resonances with high scattering efficiency and narrow linewidth. However, the collective plasmon resonances can be suppressed when the arrays are supported on the solid-state substrates with different superstrates because of the different dispersion relations between the substrate and the superstrate. Herein, we develop a general concept which seeks to synergize the subnanoparticle engineering of "hot spots" with the far-field coupling behavior, for the versatile control of plasmonic-photonic couplings in an asymmetric environment. To demonstrate our concept, we choose as an example the Au nanobeaker arrays (NBAs), which are the conformally coated Au thin layers on the interior sidewalls and bottoms of nanohole arrays in SiO2 substrates. Using the finite-difference time-domain simulations, we show that engineering the plasmonic "hot spots" in the NBAs by simply controlling the depth-to-diameter aspect ratio of individual units enables multiple plasmonic-photonic couplings in an asymmetric environment. These couplings are robust with a wide range of resonance wavelengths from visible to infrared. Furthermore, the angle-dependent transmission spectra of the arrays reveal a transition from band-edge to propagating state for the orthogonal coupling and a splitting of diffraction waves in the parallel coupling. The proposed NBAs will find enhanced applications in plasmonic lasers and biosensing.

  18. The appearance of dusty H II blisters at radio and infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Icke, V.; Gatley, I.; Israel, F. P.

    1980-01-01

    Detailed calculations for the observational appearance of nonspherical Stromgren regions at radio and infrared wavelengths are presented. The computations are made feasible by two assumptions, namely (1) no stellar photon leaves the solid angle within which it was emitted, and (2) the radiation spectrum can be represented by three delta functions corresponding to Lyman continuum, Lyman alpha, and softer radiation. These calculations are used to develop models for the H II blisters M17 A and 30 Doradus, and also first order parameters for a sample of other well-studied galactic H II regions. It is concluded that the observations are well explained by an ionizing object in a density gradient, without the need for peculiar dust properties or distribution.

  19. The appearance of dusty H II blisters at radio and infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Icke, V.; Gatley, I.; Israel, F. P.

    1980-01-01

    Detailed calculations for the observational appearance of nonspherical Stromgren regions at radio and infrared wavelengths are presented. The computations are made feasible by two assumptions, namely (1) no stellar photon leaves the solid angle within which it was emitted, and (2) the radiation spectrum can be represented by three delta functions corresponding to Lyman continuum, Lyman alpha, and softer radiation. These calculations are used to develop models for the H II blisters M17 A and 30 Doradus, and also first order parameters for a sample of other well-studied galactic H II regions. It is concluded that the observations are well explained by an ionizing object in a density gradient, without the need for peculiar dust properties or distribution.

  20. Europa Composition Using Visible to Short Wavelength Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Blaney, Diana L.; Dalton, J. B.; Green, R. O.; Hibbits, K.; McCord, T.; Murchie, S.; Piccioni, G.; Tosi, F.

    2010-10-01

    One of the major goals of the Jupiter Europa Orbiter (JEO) is to understand the chemistry of Europa's inorganic and organic materials. Europa's surface material composition is controlled by the original materials forming Europa and by their differentiation and chemical alterations. Material is probably still being transported to the surface by active processes in the interior. At the surface, the material is exposed to the effects of vacuum and temperature, irradiated by solar UV, and bombarded by material entrained in Jupiter's magnetic field. The materials on the surface and their distributions are evidence of the processes operating, both endogenic and exogenic. These processes include effects of a subsurface liquid ocean and its chemistry; the mechanisms of material emplacement from below; and photolysis and radiolysis. Visible to Short Wavelength Infrared (VSWIR) spectroscopy is a well-understood technique for mapping key inorganic, organic, and volatile compositions on remote surfaces such as Europa. Key spectral absorption features have been detected in both the icy and the non-icy Europa materials and many important constituents of the surface have been identified or proposed (e.g. hydrated salts, sulfuric acid hydrate, organics, CO2, H2O2, SO2). The determination of planetary surface composition from remote infrared spectroscopy depends upon adequate signal-to-noise, spectral resolution, and spatial scale to distinguish the diagnostic spectral features of the compounds of interest. For icy satellites, laboratory reference spectra obtained at the temperatures of the target bodies are also required. We have compared diagnostic spectral features in cryogenic laboratory spectra of hydrated salts relevant to Europa in order to optimize detection of these materials under realistic mission conditions. Effects of spectral resolution, signal to noise ratio, and areal mixtures are explored to determine the impacts on detection. This work was carried out at the Jet

  1. Bragg-scattering conversion at telecom wavelengths towards the photon counting regime.

    PubMed

    Krupa, Katarzyna; Tonello, Alessandro; Kozlov, Victor V; Couderc, Vincent; Di Bin, Philippe; Wabnitz, Stefan; Barthélémy, Alain; Labonté, Laurent; Tanzilli, Sébastien

    2012-11-19

    We experimentally study Bragg-scattering four-wave mixing in a highly nonlinear fiber at telecom wavelengths using photon counters. We explore the polarization dependence of this process with a continuous wave signal in the macroscopic and attenuated regime, with a wavelength shift of 23 nm. Our measurements of mean photon numbers per second under various pump polarization configurations agree well with the theoretical and numerical predictions based on classical models. We discuss the impact of noise under these different polarization configurations.

  2. Improved performance of HgCdTe infrared detector focal plane arrays by modulating light field based on photonic crystal structure

    SciTech Connect

    Liang, Jian; Hu, Weida Ye, Zhenhua; Li, Zhifeng; Chen, Xiaoshuang Lu, Wei; Liao, Lei

    2014-05-14

    An HgCdTe long-wavelength infrared focal plane array photodetector is proposed by modulating light distributions based on the photonic crystal. It is shown that a promising prospect of improving performance is better light harvest and dark current limitation. To optimize the photon field distributions of the HgCdTe-based photonic crystal structure, a numerical method is built by combining the finite-element modeling and the finite-difference time-domain simulation. The optical and electrical characteristics of designed HgCdTe mid-wavelength and long-wavelength photon-trapping infrared detector focal plane arrays are obtained numerically. The results indicate that the photon crystal structure, which is entirely compatible with the large infrared focal plane arrays, can significantly reduce the dark current without degrading the quantum efficiency compared to the regular mesa or planar structure.

  3. Integration of both dense wavelength-division multiplexing and coarse wavelength-division multiplexing demultiplexer on one photonic crystal chip

    NASA Astrophysics Data System (ADS)

    Tian, Huiping; Shen, Guansheng; Liu, Weijia; Ji, Yuefeng

    2013-07-01

    An integrated model of photonic crystal (PC) demultiplexer that can be used to combine dense wavelength-division multiplexing (DWDM) and coarse wavelength-division multiplexing (CWDM) systems is first proposed. By applying the PC demultiplexer, dense channel spacing 0.8 nm and coarse channel spacing 20 nm are obtained at the same time. The transmission can be improved to nearly 90%, and the crosstalk can be decreased to less than -18 dB by enlarging the width of the bus waveguide. The total size of the device is 21×42 μm2. Four channels on one side of the demultiplexer can achieve DWDM in the wavelength range between 1575 and 1578 nm, and the other four channels on the other side can achieve CWDM in the wavelength range between 1490 and 1565 nm, respectively. The demonstrated demultiplexer can be applied in the future CWDM and DWDM system, and the architecture costs can be significantly reduced.

  4. Long-wavelength infrared hyperspectral data "mining" at Cuprite, NV

    NASA Astrophysics Data System (ADS)

    Sundberg, Robert; Adler-Golden, Steven; Conforti, Patrick

    2015-09-01

    In recent years long-wavelength infrared (LWIR) hyperspectral imagery has significantly improved in quality and become much more widely available, sparking interest in a variety of applications involving remote sensing of surface composition. This in turn has motivated the development and study of LWIR-focused algorithms for atmospheric retrieval, temperature-emissivity separation (TES) and material detection and identification. In this paper we evaluate some LWIR algorithms for atmospheric retrieval, TES, endmember-finding and rare material detection for their utility in characterizing mineral composition in SEBASS hyperspectral imagery taken near Cuprite, NV. Atmospheric correction results using the In-Scene Atmospheric Correction (ISAC) method are compared with those from the first-principles, MODTRAN©-based FLAASH-IR method. Covariance-whitened endmember-finding methods are observed to be sensitive to image artifacts. However, with clean data and all-natural terrain they can automatically locate and distinguish many minor mineral components, with especially high sensitivity to varieties of calcite. Not surprisingly, the major scene materials, including silicates, are best located using unwhitened techniques. Minerals that we identified in the data include calcite, quartz, alunite and (tentatively) kaolinite.

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

    NASA Astrophysics Data System (ADS)

    Lopez-Rodriguez, E.

    2016-01-01

    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 μm, and the edges 8-9 μm and/or 11-13 μm, of the wavelength range are recommended to optimally disentangle the polarization mechanisms.

  6. Extrasolar planet detection at infrared wavelengths from the Earth

    NASA Astrophysics Data System (ADS)

    Yu, Ka Chun; Bally, John

    We show that extrasolar planets in orbit around nearby stars can be detected from the ground or from a stratospheric telescope in the infrared region of the spectrum. We present calculations on the detectability of extrasolar planets, using Erich Grossman's Atmospheric Transmission (AT) code to compute atmospheric transmission at bands centered at 11 μm, 20 μm, 27 μm, 200 μm, 225 μm, 350 μm, 450 μm, 640 μm, 750 μm, and 870 μm. Detection limits for terrestrial and Jovian planets orbiting Sun-like stars are presented by assuming Planck emission. We consider several potential sites including the south pole, a 5000-m elevation site in the Atacama Desert in Chile, Mauna Kea in Hawaii, and an aerostat-borne telescope flown near the poles. We consider extrasolar planet detection with a 10-m class mid-IR telescope and a dilute aperture stratospheric telescope consisting of 4-m mirrors optimized for this task. Detection in the submillimeter, even with a 104 m2 collecting area array is extremely difficult because of low atmospheric transparency, and the decrease (~λ-2) in planet emission with increasing wavelength in the Rayleigh-Jeans limit. We discuss critical technologies needed for this undertaking, including tethered aerostats and balloon-borne telescopes, the development of mid-IR nulling interferometry, actively cooled optics operating in the atmosphere, and optimized filters that are matched to the atmospheric transmission windows.

  7. Efficient generation of indistinguishable single photons on-demand at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Kim, Jehyung; Cai, Tao; Richardson, Christopher; Leavitt, Richard; Waks, Edo

    Highly efficient single photon sources are important building blocks for optical quantum information processing. For practical use and long-distance quantum communication, single photons should have fiber-compatible telecom wavelengths. In addition, most quantum communication applications require high degree of indistinguishability of single photons, such that they exhibit interference on a beam splitter. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem in particular at telecom wavelengths. We demonstrate a telecom wavelength source of indistinguishable single photons using an InAs/InP quantum dot in a nanophotonic cavity. To obtain the efficient single quantum dot emission, we employ the higher order mode in L3 photonic crystal cavity that shows a nearly Gaussian transverse mode profile and results in out-coupling efficiency exceeding 46 % and unusual bright single quantum dot emission exceeding 1.5 million counts per second at a detector. We also observe Purcell enhanced spontaneous emission rate as large as 4 and high linear polarization ratio of 0.96 for the coupled dots. Using this source, we generate high purity single photons at 1.3 μm wavelength and demonstrate the indistinguishable nature of the emission using a two-photon interference measurement.

  8. Counting near infrared photons with microwave kinetic inductance detectors

    NASA Astrophysics Data System (ADS)

    Guo, W.; Liu, X.; Wang, Y.; Wei, Q.; Wei, L. F.; Hubmayr, J.; Fowler, J.; Ullom, J.; Vale, L.; Vissers, M. R.; Gao, J.

    2017-05-01

    We demonstrate photon counting at 1550 nm wavelength using microwave kinetic inductance detectors (MKIDs) made from TiN/Ti/TiN trilayer films with superconducting transition temperature T c ≈ 1.4 K. The detectors have a lumped-element design with a large interdigitated capacitor covered by aluminum and inductive photon absorbers whose volume ranges from 0.4 μm3 to 20 μm3. The energy resolution improves as the absorber volume is reduced. We achieved an energy resolution of 0.22 eV and resolved up to 7 photons per optical pulse, both greatly improved from previously reported results at 1550 nm wavelength using MKIDs. Further improvements are possible by optimizing the optical coupling to maximize photon absorption into the inductive absorber.

  9. Polymer lattices as mechanically tunable 3-dimensional photonic crystals operating in the infrared

    SciTech Connect

    Chernow, V. F.; Alaeian, H.; Dionne, J. A.; Greer, J. R.

    2015-09-07

    Broadly tunable photonic crystals in the near- to mid-infrared region could find use in spectroscopy, non-invasive medical diagnosis, chemical and biological sensing, and military applications, but so far have not been widely realized. We report the fabrication and characterization of three-dimensional tunable photonic crystals composed of polymer nanolattices with an octahedron unit-cell geometry. These photonic crystals exhibit a strong peak in reflection in the mid-infrared that shifts substantially and reversibly with application of compressive uniaxial strain. A strain of ∼40% results in a 2.2 μm wavelength shift in the pseudo-stop band, from 7.3 μm for the as-fabricated nanolattice to 5.1 μm when strained. We found a linear relationship between the overall compressive strain in the photonic crystal and the resulting stopband shift, with a ∼50 nm blueshift in the reflection peak position per percent increase in strain. These results suggest that architected nanolattices can serve as efficient three-dimensional mechanically tunable photonic crystals, providing a foundation for new opto-mechanical components and devices across infrared and possibly visible frequencies.

  10. Polymer lattices as mechanically tunable 3-dimensional photonic crystals operating in the infrared

    NASA Astrophysics Data System (ADS)

    Chernow, V. F.; Alaeian, H.; Dionne, J. A.; Greer, J. R.

    2015-09-01

    Broadly tunable photonic crystals in the near- to mid-infrared region could find use in spectroscopy, non-invasive medical diagnosis, chemical and biological sensing, and military applications, but so far have not been widely realized. We report the fabrication and characterization of three-dimensional tunable photonic crystals composed of polymer nanolattices with an octahedron unit-cell geometry. These photonic crystals exhibit a strong peak in reflection in the mid-infrared that shifts substantially and reversibly with application of compressive uniaxial strain. A strain of ˜40% results in a 2.2 μm wavelength shift in the pseudo-stop band, from 7.3 μm for the as-fabricated nanolattice to 5.1 μm when strained. We found a linear relationship between the overall compressive strain in the photonic crystal and the resulting stopband shift, with a ˜50 nm blueshift in the reflection peak position per percent increase in strain. These results suggest that architected nanolattices can serve as efficient three-dimensional mechanically tunable photonic crystals, providing a foundation for new opto-mechanical components and devices across infrared and possibly visible frequencies.

  11. Impedance match of long-wavelength electromagnetic waves incident into magnetic photonic crystals.

    PubMed

    Yang, S Y

    2007-06-11

    By utilizing an effective-medium method, the effective dielectric constant and effective magnetic permeability of magnetic photonic crystals at long-wavelength limits were calculated. We also examined the impedance ratio when a long-wavelength electromagnetic wave is incident to a magnetic photonic crystal. In this work, we focus on investigating the impact of the magnetic permeability of rods forming magnetic photonic crystals on the impedance ratio. Furthermore, we analyze the dependencies of the incident angle at impedance match on the magnetic permeability and filling factor of rods.

  12. Algol - CPNG: photon counting cameras for interferometry in visible wavelengths

    NASA Astrophysics Data System (ADS)

    Blazit, A.; Thiébaut, E.; Vakili, F.; Abe, L.; Spang, A.; Clausse, J.-M.; Mourard, D.; Foy, R.; Rondeau, X.

    Images in visible interferometry are characterised by their low coherence time, and except for brightest stars, the flux on the detector is much less than one photon per pixel per image. Algol and Comptage de Photons Nouvelle Génération (CPNG) are new photon counting cameras developed for high angular resolution in the visible. They are intensified CCDs built to benefit from improvements in photonic commercial components, and personal computer processing power. We present how we achieve optimal performances (sensitivity and spatiotemporal resolution) by the combination of proper optical and electronics design, and real-time elaborated data processing. The number of pixels is 532× 516 and 768× 640 read at a frame rate of 262 Hz and 50 Hz for CPNG and Algol respectively. The dark current is very low: 5×10-4 electron.pixel-1.s-1. Quantum efficiencies reach up to 36% in the visible with the GaAsP photocathodes and and 26% in the red with the GaAs ones, thanks to the sensitivity of the photocathodes and to the photon centroiding algorithm; they are likely the highest values reported for ICCDs.

  13. Micropolarizing device for long wavelength infrared polarization imaging.

    SciTech Connect

    Wendt, Joel Robert; Carter, Tony Ray; Samora, Sally; Cruz-Cabrera, Alvaro Augusto; Vawter, Gregory Allen; Kemme, Shanalyn A.; Alford, Charles Fred; Boye, Robert R.; Smith, Jody Lynn

    2006-11-01

    The goal of this project is to fabricate a four-state pixelated subwavelength optical device that enables mid-wave infrared (MWIR) or long-wave infrared (LWIR) snapshot polarimetric imaging. The polarization information can help to classify imaged materials and identify objects of interest for numerous remote sensing and military applications. While traditional, sequential polarimetric imaging produces scenes with polarization information through a series of assembled images, snapshot polarimetric imaging collects the spatial distribution of all four Stokes parameters simultaneously. In this way any noise due to scene movement from one frame to the next is eliminated. We fabricated several arrays of subwavelength components for MWIR polarization imaging applications. Each pixel unit of the array consists of four elements. These elements are micropolarizers with three or four different polarizing axis orientations. The fourth element sometimes has a micro birefringent waveplate on the top of one of the micropolarizers. The linear micropolarizers were fabricated by patterning nano-scale metallic grids on a transparent substrate. A large area birefringent waveplate was fabricated by deeply etching a subwavelength structure into a dielectric substrate. The principle of making linear micropolarizers for long wavelengths is based upon strong anisotropic absorption of light in the nano-metallic grid structures. The nano-metallic grid structures are patterned with different orientations; therefore, the micropolarizers have different polarization axes. The birefringent waveplate is a deeply etched dielectric one-dimensional subwavelength grating; therefore two orthogonally polarized waves have different phase delays. Finally, in this project, we investigated the near field and diffractive effects of the subwavelength element apertures upon detection. The fabricated pixelated polarizers had a measured extinction ratios larger than 100:1 for pixel sizes in the order of 15

  14. GaN photonic-crystal surface-emitting laser at blue-violet wavelengths.

    PubMed

    Matsubara, Hideki; Yoshimoto, Susumu; Saito, Hirohisa; Jianglin, Yue; Tanaka, Yoshinori; Noda, Susumu

    2008-01-25

    Shorter-wavelength surface-emitting laser sources are important for a variety of fields, including photonics, information processing, and biology. We report on the creation of a current-driven blue-violet photonic-crystal surface-emitting laser. We have developed a fabrication method, named "air holes retained over growth," in order to construct a two-dimensional gallium nitride (GaN)/air photonic-crystal structure. The resulting periodic structure has a photonic-crystal band-edge effect sufficient for the successful operation of a current-injection surface-emitting laser. This represents an important step in the development of laser sources that could be focused to a size much less than the wavelength and be integrated two-dimensionally at such short wavelengths.

  15. Pulsed Sagnac polarization-entangled photon source with a PPKTP crystal at telecom wavelength.

    PubMed

    Jin, Rui-Bo; Shimizu, Ryosuke; Wakui, Kentaro; Fujiwara, Mikio; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Wang, Zhen; Sasaki, Masahide

    2014-05-19

    We demonstrate pulsed polarization-entangled photons generated from a periodically poled KTiOPO(4) (PPKTP) crystal in a Sagnac interferometer configuration at telecom wavelength. Since the group-velocity-matching (GVM) condition is satisfied, the intrinsic spectral purity of the photons is much higher than in the previous scheme at around 800 nm wavelength. The combination of a Sagnac interferometer and the GVM-PPKTP crystal makes our entangled source compact, stable, highly entangled, spectrally pure and ultra-bright. The photons were detected by two superconducting nanowire single photon detectors (SNSPDs) with detection efficiencies of 70% and 68% at dark counts of less than 1 kcps. We achieved fidelities of 0.981 ± 0.0002 for |ψ(-)〉 and 0.980 ± 0.001 for |ψ(+)〉 respectively. This GVM-PPKTP-Sagnac scheme is directly applicable to quantum communication experiments at telecom wavelength, especially in free space.

  16. Short-wavelength infrared laser activates the auditory neurons: comparing the effect of 980 vs. 810 nm wavelength.

    PubMed

    Tian, Lan; Wang, Jingxuan; Wei, Ying; Lu, Jianren; Xu, Anting; Xia, Ming

    2017-02-01

    Research on auditory neural triggering by optical stimulus has been developed as an emerging technique to elicit the auditory neural response, which may provide an alternative method to the cochlear implants. However, most previous studies have been focused on using longer-wavelength near-infrared (>1800 nm) laser. The effect comparison of different laser wavelengths in short-wavelength infrared (SWIR) range on the auditory neural stimulation has not been previously explored. In this study, the pulsed 980- and 810-nm SWIR lasers were applied as optical stimuli to irradiate the auditory neurons in the cochlea of five deafened guinea pigs and the neural response under the two laser wavelengths was compared by recording the evoked optical auditory brainstem responses (OABRs). In addition, the effect of radiant exposure, laser pulse width, and threshold with the two laser wavelengths was further investigated and compared. The one-way analysis of variance (ANOVA) was used to analyze those data. Results showed that the OABR amplitude with the 980-nm laser is higher than the amplitude with the 810-nm laser under the same radiant exposure from 10 to 102 mJ/cm(2). And the laser stimulation of 980 nm wavelength has lower threshold radiant exposure than the 810 nm wavelength at varied pulse duration in 20-500 μs range. Moreover, the 810-nm laser has a wider optimized pulse duration range than the 980-nm laser for the auditory neural stimulation.

  17. Photonic band gaps of wurtzite GaN and AlN photonic crystals at short wavelengths

    NASA Astrophysics Data System (ADS)

    Melo, E. G.; Alayo, M. I.

    2015-04-01

    Group III-nitride materials such as GaN and AlN have attracted a great attention in researches on photonic devices that operate at short light wavelengths. The large band gaps of these materials turn them suitable for nanophotonic devices that operate in light ranges from visible to deep ultraviolet. The physical properties of wurtzite GaN and AlN such as their second and third order nonlinear susceptibilities, and their thermal and piezoelectric coefficients, also make them excellent candidates for integrate photonic devices with electronics, microelectromechanics, microfluidics and general sensing applications. Using a plane wave expansion method (PWE) the photonic band gap maps of 36 different two-dimensional photonic crystal lattices in wurtzite GaN and AlN were obtained and analyzed. The wavelength dependence and the effects of the material anisotropy on the position of the photonic band gaps are also discussed. The results show regions with slow group velocity at the edges of a complete photonic band gap in the M-K direction of the triangular lattices with circular, hexagonal, and rhombic air holes. Was also found a very interesting disposition of the photonic band gaps in the lattices composed of rhombic air holes.

  18. Topology optimized gold nanostrips for enhanced near-infrared photon upconversion

    NASA Astrophysics Data System (ADS)

    Vester-Petersen, Joakim; Christiansen, Rasmus E.; Julsgaard, Brian; Balling, Peter; Sigmund, Ole; Madsen, Søren P.

    2017-09-01

    This letter presents a topology optimization study of metal nanostructures optimized for electric-field enhancement in the infrared spectrum. Coupling of such nanostructures with suitable ions allows for an increased photon-upconversion yield, with one application being an increased solar-cell efficiency by exploiting the long-wavelength part of the solar spectrum. In this work, topology optimization is used to design a periodic array of two-dimensional gold nanostrips for electric-field enhancements in a thin film doped with upconverting erbium ions. The infrared absorption band of erbium is utilized by simultaneously optimizing for two polarizations, up to three wavelengths, and three incident angles. Geometric robustness towards manufacturing variations is implemented considering three different design realizations simultaneously in the optimization. The polarization-averaged field enhancement for each design is evaluated over an 80 nm wavelength range and a ±15-degree incident angle span. The highest polarization-averaged field enhancement is 42.2 varying by maximally 2% under ±5 nm near-uniform design perturbations at three different wavelengths (1480 nm, 1520 nm, and 1560 nm). The proposed method is generally applicable to many optical systems and is therefore not limited to enhancing photon upconversion.

  19. Infrared single-photon detection by two-photon absorption in silicon

    SciTech Connect

    Hayat, Alex; Ginzburg, Pavel; Orenstein, Meir

    2008-03-15

    We propose a scheme for infrared single-photon detection based on two-photon absorption at room temperature in Si avalanche photodiodes, where the detected photon's energy is lower than the band gap and the energy difference is complemented by a pump field. A quantum nonperturbative model is developed for nondegenerate two-photon absorption in direct and indirect semiconductors yielding proper nondivergent rates allowing device efficiency optimization. The proposed monolithic detector is simple, miniature, and integrable and does not require phase matching, while not compromising the performance and exhibiting even better efficiency than the competing up-conversion schemes ({approx}1 order of magnitude) for similar optical pump levels.

  20. Single photon ranging system using two wavelengths laser and analysis of precision

    NASA Astrophysics Data System (ADS)

    Chen, Yunfei; He, Weiji; Miao, Zhuang; Gu, Guohua; Chen, Qian

    2013-09-01

    The laser ranging system based on time correlation single photon counting technology and single photon detector has the feature of high precision and low emergent energy etc. In this paper, we established a single photon laser ranging system that use the supercontinuum laser as light source, and two wavelengths (532nm and 830nm) of echo signal as the stop signal. We propose a new method that is capable to improve the single photon ranging system performance. The method is implemented by using two single-photon detectors to receive respectively the two different wavelength signals at the same time. We extracted the firings of the two detectors triggered by the same laser pulse at the same time and then took mean time of the two firings as the combined detection time-of-flight. The detection by two channels using two wavelengths will effectively improve the detection precision and decrease the false alarm probability. Finally, an experimental single photon ranging system was established. Through a lot of experiments, we got the system precision using both single and two wavelengths and verified the effectiveness of the method.

  1. Heralded wave packet manipulation and storage of a frequency-converted pair photon at telecom wavelength

    NASA Astrophysics Data System (ADS)

    Kroh, Tim; Ahlrichs, Andreas; Sprenger, Benjamin; Benson, Oliver

    2017-09-01

    Future quantum networks require a hybrid platform of dissimilar quantum systems. Within the platform, joint quantum states have to be mediated either by single photons, photon pairs or entangled photon pairs. The photon wavelength has to lie within the telecommunication band to enable long-distance fibre transmission. In addition, the temporal shape of the photons needs to be tailored to efficiently match the involved quantum systems. Altogether, this requires the efficient coherent wavelength-conversion of arbitrarily shaped single-photon wave packets. Here, we demonstrate the heralded temporal filtering of single photons as well as the synchronisation of state manipulation and detection as key elements in a typical experiment, besides of delaying a photon in a long fibre. All three are realised by utilising commercial telecommunication fibre-optical components which will permit the transition of quantum networks from the lab to real-world applications. The combination of these renders a temporally filtering single-photon storage in a fast switchable fibre loop possible.

  2. 1024 x 1024 pixel mid-wavelength and long-wavelength infrared QWIP focal plane arrays for imaging applications

    NASA Technical Reports Server (NTRS)

    Gunapala, S. D.; Bandara, S. V.; Liu, J. K.; Hill, C. J.; Rafol, S. B.; Mumolo, J. M.; Trinh, J. T.; Tidrow, M. Z.; LeVan, P. D.

    2005-01-01

    Mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) 10(24) x 10(24) pixel quantum well infrared photodetector (QWIP) focal planes have been demonstrated with excellent imaging performance. The MWIR QWIP detector array has demonstrated a noise equivalent differential temperature (NEAT) of 17 mK at a 95 K operating temperature with f/2.5 optics at 300 K background and the LWIR detector array has demonstrated a NEAT of 13 mK at a 70 K operating temperature with the same optical and background conditions as the MWIR detector array after the subtraction of system noise. Both MWIR and LWIR focal planes have shown background limited performance (BLIP) at 90 K and 70 K operating temperatures respectively, with similar optical and background conditions. In this paper, we will discuss the performance in terms of quantum efficiency, NE(delta)T, uniformity, operability and modulation transfer functions.

  3. 1024 x 1024 pixel mid-wavelength and long-wavelength infrared QWIP focal plane arrays for imaging applications

    NASA Technical Reports Server (NTRS)

    Gunapala, S. D.; Bandara, S. V.; Liu, J. K.; Hill, C. J.; Rafol, S. B.; Mumolo, J. M.; Trinh, J. T.; Tidrow, M. Z.; LeVan, P. D.

    2005-01-01

    Mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) 10(24) x 10(24) pixel quantum well infrared photodetector (QWIP) focal planes have been demonstrated with excellent imaging performance. The MWIR QWIP detector array has demonstrated a noise equivalent differential temperature (NEAT) of 17 mK at a 95 K operating temperature with f/2.5 optics at 300 K background and the LWIR detector array has demonstrated a NEAT of 13 mK at a 70 K operating temperature with the same optical and background conditions as the MWIR detector array after the subtraction of system noise. Both MWIR and LWIR focal planes have shown background limited performance (BLIP) at 90 K and 70 K operating temperatures respectively, with similar optical and background conditions. In this paper, we will discuss the performance in terms of quantum efficiency, NE(delta)T, uniformity, operability and modulation transfer functions.

  4. Design, fabrication, and characterization of mid wavelength infrared avalanche photodiode

    NASA Astrophysics Data System (ADS)

    Mallick, Shubhrangshu

    Photodetectors with high bandwidth and internal gain are required to detect highly attenuated optical signals for defense applications and long distance communication. Modern laser detection and ranging (LADAR) systems as well as weapon systems, used for long range military and astronomical applications, need to detect, recognize and track a variety of targets under a wide spectrum of atmospheric conditions. A continually varying atmospheric conditions and optical absorption by carbon dioxide, carbon monoxide and water vapor pose severe threats for the proper recognition of the target. The choice of an additional amplification stage along with the detection stage becomes obvious to enhance the signal to noise ratio at the receiver. Avalanche Photodiode (APD) plays a unique role by combing the detection and amplification stage and hence reduces the complexity. But due to the probabilistic nature associated with the incident radiation absorption and multiplication of the photo-generated carriers, the noise level (known as excess noise) of an APD increases and might result in the deterioration of the signal to noise ratio at the detector output. Participation of both electrons and holes in the avalanche mechanism increases the probability, hence the excess noise at the detector output. So, the goal of the APD design lies in the fact of the minimization of the excess noise along with a reasonable multiplication gain. In this research, two material systems, II-VI based Hg1-xCd xTe on Si, and III-V based InAs/GaSb strained layer superlattice (SLS) was studied extensively to achieve the noiseless avalanche characteristics in the mid wavelength infrared region. The electronic bandstructure of the multiplication region of these APDs were designed with the help of 14 band k.p model. The doping and thickness of individual layers were designed with the help of Atlas and Sentaurus simulation platform. The devices were fabricated using standard UV Photo-lithography and wet

  5. Metal-assisted photonic mode for ultrasmall bending with long propagation length at visible wavelengths.

    PubMed

    Yang, Chengyuan; Teo, Ee Jin; Goh, Tian; Teo, Siew Lang; Teng, Jing Hua; Bettiol, Andrew A

    2012-10-08

    In this work, we investigate the use of metal-assisted photonic guiding in a polymer-metal waveguide as an alternative approach for high density photonic integration at visible wavelengths. We demonstrate high confinement and long propagation length in sub-wavelength dimensions down to 300nm × 200nm using leakage radiation microscopy at a wavelength of 632.8 nm. Simulations using the finite element method (FEM) show that the optimum dimension that gives good confinement and propagation length is similar to that of the predicted plasmonic mode supported in the same waveguide. Under such optimum conditions, the metal-assisted photonic mode shows a five times longer propagation length and higher transmission efficiency for all 90° bending radius down to 1 μm compared to the plasmonic mode.

  6. Mid-infrared coincidence measurements on twin photons at room temperature

    PubMed Central

    Mancinelli, M.; Trenti, A.; Piccione, S.; Fontana, G.; Dam, J. S.; Tidemand-Lichtenberg, P.; Pedersen, C.; Pavesi, L.

    2017-01-01

    Quantum measurements using single-photon detectors are opening interesting new perspectives in diverse fields such as remote sensing, quantum cryptography and quantum computing. A particularly demanding class of applications relies on the simultaneous detection of correlated single photons. In the visible and near infrared wavelength ranges suitable single-photon detectors do exist. However, low detector quantum efficiency or excessive noise has hampered their mid-infrared (MIR) counterpart. Fast and highly efficient single-photon detectors are thus highly sought after for MIR applications. Here we pave the way to quantum measurements in the MIR by the demonstration of a room temperature coincidence measurement with non-degenerate twin photons at about 3.1 μm. The experiment is based on the spectral translation of MIR radiation into the visible region, by means of efficient up-converter modules. The up-converted pairs are then detected with low-noise silicon avalanche photodiodes without the need for cryogenic cooling. PMID:28504244

  7. Mid-infrared coincidence measurements on twin photons at room temperature

    NASA Astrophysics Data System (ADS)

    Mancinelli, M.; Trenti, A.; Piccione, S.; Fontana, G.; Dam, J. S.; Tidemand-Lichtenberg, P.; Pedersen, C.; Pavesi, L.

    2017-05-01

    Quantum measurements using single-photon detectors are opening interesting new perspectives in diverse fields such as remote sensing, quantum cryptography and quantum computing. A particularly demanding class of applications relies on the simultaneous detection of correlated single photons. In the visible and near infrared wavelength ranges suitable single-photon detectors do exist. However, low detector quantum efficiency or excessive noise has hampered their mid-infrared (MIR) counterpart. Fast and highly efficient single-photon detectors are thus highly sought after for MIR applications. Here we pave the way to quantum measurements in the MIR by the demonstration of a room temperature coincidence measurement with non-degenerate twin photons at about 3.1 μm. The experiment is based on the spectral translation of MIR radiation into the visible region, by means of efficient up-converter modules. The up-converted pairs are then detected with low-noise silicon avalanche photodiodes without the need for cryogenic cooling.

  8. Terahertz two-photon quantum well infrared photodetector.

    PubMed

    Schneider, H; Liu, H C; Winnerl, S; Song, C Y; Walther, M; Helm, M

    2009-07-20

    A two-photon detector based on intersubband transitions in GaAs/AlGaAs quantum wells operating in the Terahertz regime below the Reststrahlenband is reported. Resonantly enhanced optical nonlinearities enables sensitive quadratic detection at pJ pulse energies. We demonstrate its use in a quadratic autocorrelator for far-infrared picosecond pulses at around 7 THz.

  9. Integrated photonic crystals and quantum well infrared photodetector

    NASA Astrophysics Data System (ADS)

    Zhou, T.; Tsui, D. C.; Choi, K. K.

    2004-03-01

    GaAs/AlGaAs based quantum well infrared photodetectors (QWIP) are becoming very reliable technologies that are widely used to detect mid-infrared light. Photonic crystals, on the other hand, are very powerful tools to manipulate light and thus are very crucial elements in future optical integration circuits. have fabricated a series of devices that incorporate QWIP and 2d photonic crystals together on a single GaAs based chip. These devices work at the 7-13 μ m range. Compared with the conventional photonic crystals designed for fiber communication, these devices have the advantage that they only require photolithography instead of e-beam lithography. The fabrication of such devices is thus far less costly and time-consuming.

  10. A femtosecond Raman generator for long wavelength two-photon and third harmonic generation imaging

    NASA Astrophysics Data System (ADS)

    Trägârdh, J.; Schniete, J.; Parsons, M.; McConnell, G.

    2016-12-01

    We demonstrate a femtosecond single pass Raman generator based on an YVO4 crystal pumped by a high energy fiber laser at a wavelength of 1064 nm and a repetition rate of 1 MHz. The Raman generator shifts the pump wavelength to 1175 nm, in a broadband spectrum, making it suitable for multi-photon microscopy. We use the Raman generator for third harmonic generation imaging of live plant specimens as well as for two-photon fluorescence imaging of red fluorescent protein expressing HeLa cells. We demonstrate that the photo-damage to a live specimen is low.

  11. Nonlinear wavelength conversion in photonic crystal fibers with three zero-dispersion points

    SciTech Connect

    Stark, S. P.; Biancalana, F.; Podlipensky, A.; St. J. Russell, P.

    2011-02-15

    In this theoretical study, we show that a simple endlessly single-mode photonic crystal fiber can be designed to yield, not just two, but three zero-dispersion wavelengths. The presence of a third dispersion zero creates a rich phase-matching topology, enabling enhanced control over the spectral locations of the four-wave-mixing and resonant-radiation bands emitted by solitons and short pulses. The greatly enhanced flexibility in the positioning of these bands has applications in wavelength conversion, supercontinuum generation, and pair-photon sources for quantum optics.

  12. Wavelength-tunable entangled photons from silicon-integrated III-V quantum dots.

    PubMed

    Chen, Yan; Zhang, Jiaxiang; Zopf, Michael; Jung, Kyubong; Zhang, Yang; Keil, Robert; Ding, Fei; Schmidt, Oliver G

    2016-01-27

    Many of the quantum information applications rely on indistinguishable sources of polarization-entangled photons. Semiconductor quantum dots are among the leading candidates for a deterministic entangled photon source; however, due to their random growth nature, it is impossible to find different quantum dots emitting entangled photons with identical wavelengths. The wavelength tunability has therefore become a fundamental requirement for a number of envisioned applications, for example, nesting different dots via the entanglement swapping and interfacing dots with cavities/atoms. Here we report the generation of wavelength-tunable entangled photons from on-chip integrated InAs/GaAs quantum dots. With a novel anisotropic strain engineering technique based on PMN-PT/silicon micro-electromechanical system, we can recover the quantum dot electronic symmetry at different exciton emission wavelengths. Together with a footprint of several hundred microns, our device facilitates the scalable integration of indistinguishable entangled photon sources on-chip, and therefore removes a major stumbling block to the quantum-dot-based solid-state quantum information platforms.

  13. Wavelength-tunable entangled photons from silicon-integrated III-V quantum dots

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Zhang, Jiaxiang; Zopf, Michael; Jung, Kyubong; Zhang, Yang; Keil, Robert; Ding, Fei; Schmidt, Oliver G.

    2016-01-01

    Many of the quantum information applications rely on indistinguishable sources of polarization-entangled photons. Semiconductor quantum dots are among the leading candidates for a deterministic entangled photon source; however, due to their random growth nature, it is impossible to find different quantum dots emitting entangled photons with identical wavelengths. The wavelength tunability has therefore become a fundamental requirement for a number of envisioned applications, for example, nesting different dots via the entanglement swapping and interfacing dots with cavities/atoms. Here we report the generation of wavelength-tunable entangled photons from on-chip integrated InAs/GaAs quantum dots. With a novel anisotropic strain engineering technique based on PMN-PT/silicon micro-electromechanical system, we can recover the quantum dot electronic symmetry at different exciton emission wavelengths. Together with a footprint of several hundred microns, our device facilitates the scalable integration of indistinguishable entangled photon sources on-chip, and therefore removes a major stumbling block to the quantum-dot-based solid-state quantum information platforms.

  14. Wavelength-tunable entangled photons from silicon-integrated III–V quantum dots

    PubMed Central

    Chen, Yan; Zhang, Jiaxiang; Zopf, Michael; Jung, Kyubong; Zhang, Yang; Keil, Robert; Ding, Fei; Schmidt, Oliver G.

    2016-01-01

    Many of the quantum information applications rely on indistinguishable sources of polarization-entangled photons. Semiconductor quantum dots are among the leading candidates for a deterministic entangled photon source; however, due to their random growth nature, it is impossible to find different quantum dots emitting entangled photons with identical wavelengths. The wavelength tunability has therefore become a fundamental requirement for a number of envisioned applications, for example, nesting different dots via the entanglement swapping and interfacing dots with cavities/atoms. Here we report the generation of wavelength-tunable entangled photons from on-chip integrated InAs/GaAs quantum dots. With a novel anisotropic strain engineering technique based on PMN-PT/silicon micro-electromechanical system, we can recover the quantum dot electronic symmetry at different exciton emission wavelengths. Together with a footprint of several hundred microns, our device facilitates the scalable integration of indistinguishable entangled photon sources on-chip, and therefore removes a major stumbling block to the quantum-dot-based solid-state quantum information platforms. PMID:26813326

  15. All-silicon photonic crystal photoconductor on silicon-on-insulator at telecom wavelength.

    PubMed

    Haret, Laurent-Daniel; Checoury, Xavier; Han, Zheng; Boucaud, Philippe; Combrié, Sylvain; De Rossi, Alfredo

    2010-11-08

    We demonstrate an all-silicon photodetector working at telecom wavelength. The device is a simple metal-semiconductor-metal detector fabricated on silicon-on-insulator. A two-dimensional photonic crystal nanocavity (Q=60,000) is used to increase the response that arises from the linear and two-photon absorption of silicon. The responsivity of the detector is about 20 mA/W and its bandwidth is larger than 1 GHz.

  16. Doping-Spike PtSi Schottky Infrared Detectors with Extended Cutoff Wavelengths

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Park, J. S.; Gunapala, S. D.; Jones, E. W.; Castillo, H. M. Del

    1994-01-01

    A technique incorporating a p+ doping spike at the silicide/Si interface to reduce the effective Schottky barrier of the silicide infrared detectors and thus extend the cutoff wavelength has been developed.

  17. Stacked silicide/silicon mid- to long-wavelength infrared detector

    NASA Technical Reports Server (NTRS)

    Maserjian, Joseph (Inventor)

    1990-01-01

    The use of stacked Schottky barriers (16) with epitaxially grown thin silicides (10) combined with selective doping (22) of the barriers provides high quantum efficiency infrared detectors (30) at longer wavelengths that is compatible with existing silicon VLSI technology.

  18. Stacked silicide/silicon mid- to long-wavelength infrared detector

    DOEpatents

    Maserjian, Joseph

    1990-03-13

    The use of stacked Schottky barriers (16) with epitaxially grown thin silicides (10) combined with selective doping (22) of the barriers provides high quantum efficiency infrared detectors (30) at longer wavelengths that is compatible with existing silicon VLSI technology.

  19. Doping-Spike PtSi Schottky Infrared Detectors with Extended Cutoff Wavelengths

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Park, J. S.; Gunapala, S. D.; Jones, E. W.; Castillo, H. M. Del

    1994-01-01

    A technique incorporating a p+ doping spike at the silicide/Si interface to reduce the effective Schottky barrier of the silicide infrared detectors and thus extend the cutoff wavelength has been developed.

  20. Advanced quantum cascade laser transmitter architectures and infrared photonics development

    SciTech Connect

    Anheier, Norman C.; Allen, Paul J.; Myers, Tanya L.

    2004-08-01

    Quantum cascade lasers (QCLs) provide a viable infrared laser source for a new class of laser transmitters capable of meeting the performance requirements for a variety of national security and civilian applications. The high output power, small size, and superb stability and modulation characteristics of QCLs make them amenable for integration as transmitters into ultra-sensitive, ultra-selective point sampling and remote short-range chemical sensors. This paper reports on the current development in infrared photonics that provides a pathway for QCL transmitter miniaturization. This research has produced infrared waveguide-based optical components in chalcogenide glass using both direct-laser writing and holographic exposure techniques. We discuss here the design and fabrication concepts and capabilities required to produce integrated waveguides, waveguide couplers, and other photonic devices.

  1. Methods and devices for maintaining a resonant wavelength of a photonic microresonator

    SciTech Connect

    Jones, Adam; Zortman, William A.

    2015-07-14

    A photonic microresonator incorporates a localized heater element within a section of an optical bus waveguide that is in proximity to the resonator structure. The application of an adjustable control voltage to the heater element provides a localized change in the refractive index value of the bus waveguide, compensating for temperature-induced wavelength drift and maintaining a stabilized value of the microresonator's resonant wavelength.

  2. Photonic Nonlinear Transient Computing with Multiple-Delay Wavelength Dynamics

    NASA Astrophysics Data System (ADS)

    Martinenghi, Romain; Rybalko, Sergei; Jacquot, Maxime; Chembo, Yanne K.; Larger, Laurent

    2012-06-01

    We report on the experimental demonstration of a hybrid optoelectronic neuromorphic computer based on a complex nonlinear wavelength dynamics including multiple delayed feedbacks with randomly defined weights. This neuromorphic approach is based on a new paradigm of a brain-inspired computational unit, intrinsically differing from Turing machines. This recent paradigm consists in expanding the input information to be processed into a higher dimensional phase space, through the nonlinear transient response of a complex dynamics excited by the input information. The computed output is then extracted via a linear separation of the transient trajectory in the complex phase space. The hyperplane separation is derived from a learning phase consisting of the resolution of a regression problem. The processing capability originates from the nonlinear transient, resulting in nonlinear transient computing. The computational performance is successfully evaluated on a standard benchmark test, namely, a spoken digit recognition task.

  3. New ATM photonic wavelength-division switching block with optical buffer

    NASA Astrophysics Data System (ADS)

    Wang, Chunshui; Chen, Wenlu; Zhang, Zhijian; Sun, Haifeng; Guo, Yili; Zhang, Hanyi; Zhou, BingKun

    1996-09-01

    A new 2 X 2 ATM photonic wavelength switching block has been presented. It is composed of wavelength beacon, wavelength filter and splitter, 2 X 2 LiNbO2 waveguide switches and optical buffer. Different input-line cells will be converted into the cells with the different wavelengths according to their destination address by the wavelength beacon. With the wavelength routing tag, the cell could be self-routed to the destination output-line. The routing path is both low loss and los noise. ATM cell contention is settled by an optical buffer in which the fiber delay-line, LiNbO3 waveguide switches and nonlinear semiconductor optical amplifiers are employed. Composed by various delay fibers and waveguide switches, the buffer can store 7 cells or more. This block can be easily reconfiguration and extended to the 4 X 4, 8 X 8 ATM photonic switching system. It can be used as ATM switching unit and optical cross connection component in the all optical networks. The ATM input line bit rate of our photonic switching block is 2 X 622 Mbit/s.

  4. Wavelength Shifting in InP based Ultra-thin Quantum Well Infrared Photodetectors

    NASA Technical Reports Server (NTRS)

    Sengupta, D. K.; Gunapala, S. D.; Bandara, S. V.; Pool, F.; Liu, J. K.; McKelvy, M.

    1998-01-01

    We have demonstrated red-shifting of the wavelength response of a bound-to-continuum p-type ultra-thin InGaAs/Inp quantum well infrared photodetector after growth via rapid thermal annealing. Compared to the as-grown detector, the peak spectral response of the annealed detector was shifted to longer wavelength without any major degradation in responsivity characteristics.

  5. On the Determination of the Emission Wavelength of an Infrared LED with Common Laboratory Instruments

    ERIC Educational Resources Information Center

    RayChaudhuri, Barun

    2011-01-01

    This work demonstrates an experiment on the optoelectronic properties of a p-n junction suitable for students of undergraduate physics. It investigates, from an educational point of view, the origin of the wavelength of radiation emitted by a light emitting diode (LED) and determines the emission wavelength of an infrared LED without using…

  6. On the Determination of the Emission Wavelength of an Infrared LED with Common Laboratory Instruments

    ERIC Educational Resources Information Center

    RayChaudhuri, Barun

    2011-01-01

    This work demonstrates an experiment on the optoelectronic properties of a p-n junction suitable for students of undergraduate physics. It investigates, from an educational point of view, the origin of the wavelength of radiation emitted by a light emitting diode (LED) and determines the emission wavelength of an infrared LED without using…

  7. Design on compatible stealth photonic crystal of nearmiddle infrared and 1.06 μm laser

    NASA Astrophysics Data System (ADS)

    Zhang, Ji-kui; Wang, Jia-Chun; Wang, Qi-Chao

    2016-01-01

    In the near and middle infrared atmospheric window, infrared stealth material require a low absorptivity (which means a low emissivity according to Kirchhoff's law of black body), at the same time, it also requires high absorptivity so as to decrease the reflectance at military laser wavelength of 1.06μm. Under this circumstances, compatible stealth of infrared and laser is an urgent demand, but the demand is ambivalent for conventional materials. Photonic crystal (PC), as a new type of artificial periodic structure function material, can realize broadband thermal infrared stealth based on its high-reflection photon forbidden band(also called photonic band gap). The high-reflection photon forbidden band of PC can be adjusted to near and middle infrared wave band through some rational methods. When a defect was added into the periodic structure of PC, a "hole-digging" reflection spectrum, which is high absorption at military laser wavelength of 1.06μm, can be achieved, so compatible stealth of near and middle infrared and military laser wavelength of 1.06μm can be achieved too. In this paper, we selected near and middle infrared-transparent materials, Te and MgF2 , as high refractive index and low refractive index material respectively, and designed a one-dimensional one-defect-mode PC whose photon forbidden band was broadened to 1-5μm by constructing two photonic crystals into one. The optical property of the PC was calculated by Transfer matrix method(TMM) of thin-film optical theory, and the results shows that the as-designed PC has a high spectral reflectance in the near and middle infrared band, among which the reflectivity in 1.68μm 5.26μm band reached more than 90%, and the 2.48 5.07μm band even reached 99.99%. The result also shows that between the band gap of 1-5μm, there are one defect mode locating in the wavelength of 1.06μm, whose reflectance is below 0.70%, which means its spectral absorptivity is greater than 99.30%. All the above we have

  8. Enhanced Plasmonic Wavelength Selective Infrared Emission Combined with Microheater.

    PubMed

    Ishihara, Hiroki; Masuno, Katsuya; Ishii, Makoto; Kumagai, Shinya; Sasaki, Minoru

    2017-09-14

    The indirect wavelength selective thermal emitter that we have proposed is constructed using a new microheater, demonstrating the enhancement of the emission peak generated by the surface plasmon polariton. The thermal isolation is improved using a 2 μm-thick Si membrane having 3.6 and 5.4 mm outer diameter. The emission at around the wavelength of the absorption band of CO₂ gas is enhanced. The absorption signal increases, confirming the suitability for gas sensing. Against input power, the intensity at the peak wavelength shows a steeper increasing ratio than the background intensity. The microheater with higher thermal isolation gives larger peak intensity and its increasing ratio against the input power.

  9. Silicon and germanium mid-infrared photonics

    NASA Astrophysics Data System (ADS)

    Mashanovich, G. Z.; Reed, G. T.; Nedeljkovic, M.; Soler Penades, J.; Mitchell, C. J.; Khokhar, A. Z.; Littlejohns, C. J.; Stankovic, S.; Chen, X.; Shen, L.; Healy, N.; Peacock, A. C.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Ackert, J. J.; Knights, A. P.; Gardes, F. Y.; Thomson, D. J.

    2016-02-01

    We present three main material platforms: SOI, suspended Si and Ge on Si. We report low loss SOI waveguides (rib, strip, slot) with losses of ~1dB/cm. We also show efficient modulators and detectors realized in SOI, as well as filters and multiplexers. To extend transparency of SOI waveguides, bottom oxide cladding can be removed. We have fabricated low loss passive devices in a suspended platform that employ subwavelength gratings. Ge on Si material can have larger transparency range than suspended Si. We have designed passive devices in this platform, demonstrated all optical modulation and carried out two photon absorption measurements. We have also investigated theoretically free carrier optical modulation in Ge.

  10. Ultra-low-power silicon photonics wavelength converter for phase-encoded telecommunication signals

    NASA Astrophysics Data System (ADS)

    Lacava, C.; Ettabib, M. A.; Cristiani, I.; Fedeli, J.-M.; Richardson, D. J.; Petropoulos, P.

    2016-03-01

    The development of compact, low power, silicon photonics CMOS compatible components for all-optical signal processing represents a key step towards the development of fully functional platforms for next generation all-optical communication networks. The wavelength conversion functionality at key nodes is highly desirable to achieve transparent interoperability and wavelength routing allowing efficient management of network resources operated with high speed, phase encoded signals. All optical wavelength conversion has already been demonstrated in Si-based devices, mainly utilizing the strong Kerr effect that silicon exhibits at telecommunication wavelengths. Unfortunately, Two Photon Absorption (TPA) and Free Carrier (FC) effects strongly limit their performance, even at moderate power levels, making them unsuitable for practical nonlinear applications. Amorphous silicon has recently emerged as a viable alternative to crystalline silicon (c-Si), showing both an enhanced Kerr as well as a reduced TPA coefficient at telecom wavelengths, with respect to its c-Si counterpart. Here we present an ultra-low power wavelength converter based on a passive, CMOS compatible, 1-mm long amorphous silicon waveguide operated at a maximum pump power level of only 70 mW. We demonstrate TPA-free Four Wave Mixing (FWM)-based wavelength conversion of Binary Phase Shift Keyed (BPSK) and Quadrature Phase Shift Keyed (QPSK) signals at 20 Gbit/s with <1 dB power penalty at BER = 10-5.

  11. Photon Counting Detectors for the 1.0 - 2.0 Micron Wavelength Range

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    2004-01-01

    We describe results on the development of greater than 200 micron diameter, single-element photon-counting detectors for the 1-2 micron wavelength range. The technical goals include quantum efficiency in the range 10-70%; detector diameter greater than 200 microns; dark count rate below 100 kilo counts-per-second (cps), and maximum count rate above 10 Mcps.

  12. Excited-state absorption of Tm3 + -doped single crystals at photon-avalanche wavelengths

    NASA Astrophysics Data System (ADS)

    Garnier, N.; Moncorgé, R.; Manaa, H.; Descroix, E.; Laporte, P.; Guyot, Y.

    1996-04-01

    Excited-state absorption (ESA) spectra calibrated in units of cross sections are reported in the case of Tm3+-doped YAG, YAP, and Y2O3 single crystals around wavelengths at which photon-avalanche absorptions were observed recently. The peak ESA cross sections are compared with those obtained theoretically by using the Judd-Ofelt approach.

  13. Centimeter- and millimeter-wavelength matched loads based on microwave photonic crystals

    NASA Astrophysics Data System (ADS)

    Usanov, D. A.; Meshchanov, V. P.; Skripal', A. V.; Popova, N. F.; Ponomarev, D. V.; Merdanov, M. K.

    2017-02-01

    Novel, small-sized broadband matched loads in the form of disordered photonic crystals containing nanometer metallic and insulating layers have been developed. It has been proposed to form insulating layers with different permittivities and low dissipation factors in both centimeter and millimeter wavelength ranges from the composites that consist of insulating matrices filled with air inclusions.

  14. Extinction by Dielectric Particles at Optical and Infrared Wavelength.

    DTIC Science & Technology

    1987-08-31

    particular interest. Specific problems which were studied included determining the scattering matrix for randomly oriented spheroidal particles ...block tnember) Light scattering calculations for spheroidal particles have determined a relationship between the scattering matrix and the physical...scattering features of dielectric particles . Calculations for nonspherical particles which are larger than the wavelength of the incident beam were of

  15. The Infrared Spectral Energy Distribution of Normal Star-forming Galaxies: Calibration at Far-Infrared and Submillimeter Wavelengths

    NASA Astrophysics Data System (ADS)

    Dale, Daniel A.; Helou, George

    2002-09-01

    New far-infrared and submillimeter data are used to solidify and to extend to long wavelengths the empirical calibration of the infrared spectral energy distribution (SED) of normal star-forming galaxies. As was found by Dale and coworkers in 2001, a single parameter family, characterized by fν(60μm)/fν(100μm), is adequate to describe the range of normal galaxy SEDs observed by the Infrared Astronomical Satellite and Infrared Space Observatory from 3 to 100 μm. However, predictions based on the first-generation models at longer wavelengths (122-850 μm) are increasingly overluminous compared to the data for smaller fν(60μm)/fν(100μm), or alternatively, for weaker global interstellar radiation fields. After slightly modifying the far-infrared/submillimeter dust emissivity in those models as a function of the radiation field intensity to better match the long-wavelength data, a suite of SEDs from 3 μm to 20 cm in wavelength is presented. Results from relevant applications are also discussed, including submillimeter-based photometric redshift indicators, the infrared energy budget and simple formulae for recovering the bolometric infrared luminosity, and dust mass estimates in galaxies. Regarding the latter, since galaxy infrared SEDs are not well described by single blackbody curves, the usual methods of estimating dust masses can be grossly inadequate. The improved model presented herein is used to provide a more accurate relation between infrared luminosity and dust mass.

  16. Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre

    NASA Astrophysics Data System (ADS)

    Saglamyurek, Erhan; Jin, Jeongwan; Verma, Varun B.; Shaw, Matthew D.; Marsili, Francesco; Nam, Sae Woo; Oblak, Daniel; Tittel, Wolfgang

    2015-02-01

    The realization of a future quantum Internet requires the processing and storage of quantum information at local nodes and interconnecting distant nodes using free-space and fibre-optic links. Quantum memories for light are key elements of such quantum networks. However, to date, neither an atomic quantum memory for non-classical states of light operating at a wavelength compatible with standard telecom fibre infrastructure, nor a fibre-based implementation of a quantum memory, has been reported. Here, we demonstrate the storage and faithful recall of the state of a 1,532 nm wavelength photon entangled with a 795 nm photon, in an ensemble of cryogenically cooled erbium ions doped into a 20-m-long silica fibre, using a photon-echo quantum memory protocol. Despite its currently limited efficiency and storage time, our broadband light-matter interface brings fibre-based quantum networks one step closer to reality.

  17. Detection range enhancement using circularly polarized light in scattering environments for infrared wavelengths

    SciTech Connect

    van der Laan, J. D.; Scrymgeour, D. A.; Kemme, S. A.; Dereniak, E. L.

    2015-03-13

    We find for infrared wavelengths there are broad ranges of particle sizes and refractive indices that represent fog and rain where the use of circular polarization can persist to longer ranges than linear polarization. Using polarization tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, we show that for specific scene parameters circular polarization outperforms linear polarization in maintaining the intended polarization state for large optical depths. This enhancement with circular polarization can be exploited to improve range and target detection in obscurant environments that are important in many critical sensing applications. Specifically, circular polarization persists better than linear for radiation fog in the short-wave infrared, for advection fog in the short-wave infrared and the long-wave infrared, and large particle sizes of Sahara dust around the 4 micron wavelength.

  18. Detection range enhancement using circularly polarized light in scattering environments for infrared wavelengths

    DOE PAGES

    van der Laan, J. D.; Sandia National Lab.; Scrymgeour, D. A.; ...

    2015-03-13

    We find for infrared wavelengths there are broad ranges of particle sizes and refractive indices that represent fog and rain where the use of circular polarization can persist to longer ranges than linear polarization. Using polarization tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, we show that for specific scene parameters circular polarization outperforms linear polarization in maintaining the intended polarization state for large optical depths. This enhancement with circular polarization can be exploited to improve range and target detection in obscurant environments that are important in many critical sensing applications. Specifically, circular polarization persists bettermore » than linear for radiation fog in the short-wave infrared, for advection fog in the short-wave infrared and the long-wave infrared, and large particle sizes of Sahara dust around the 4 micron wavelength.« less

  19. Current-matching versus non-current-matching in long wavelength interband cascade infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Huang, Wenxiang; Lei, Lin; Li, Lu; Massengale, Jeremy A.; Yang, Rui Q.; Mishima, Tetsuya D.; Santos, Michael B.

    2017-08-01

    We report on a comparative study of two sets of different long-wavelength (LW) interband cascade infrared photodetectors (ICIPs) based on a type-II InAs/GaSb superlattice. The devices in one set have a current-matched configuration while those in the other set are non-current-matched. It is shown that carrier transport in these LW ICIPs at high temperatures is diffusion limited and the diffusion length is estimated to be longer than or comparable to 0.5 μm at various temperatures. By comparing the two sets of devices, we demonstrate the necessity of current-matching to maximize utilization of absorbed photons for an optimal responsivity and the correlation of reduced responsivity with light attenuation in the optically deeper stages for non-current-matched ICIPs. However, the device performances for both sets are comparable in terms of detectivity. Electrical gain exceeding unity is observed, which is more significant in the last stage of non-current-matched ICIPs than in any other stages in order to obtain photocurrent continuity. The significant electrical gain enabled an appreciable responsivity in non-current-matched ICIPs and resulted in Johnson-noise limited detectivities as high as 2.4 × 108 Jones at 300 K, which substantially exceeds the reported value (e.g., 4.0 × 107 Jones) for commercial uncooled mercury cadmium telluride detectors.

  20. Calibration-Free Pulse Oximetry Based on Two Wavelengths in the Infrared — A Preliminary Study

    PubMed Central

    Nitzan, Meir; Noach, Salman; Tobal, Elias; Adar, Yair; Miller, Yaacov; Shalom, Eran; Engelberg, Shlomo

    2014-01-01

    The assessment of oxygen saturation in arterial blood by pulse oximetry (SpO2) is based on the different light absorption spectra for oxygenated and deoxygenated hemoglobin and the analysis of photoplethysmographic (PPG) signals acquired at two wavelengths. Commercial pulse oximeters use two wavelengths in the red and infrared regions which have different pathlengths and the relationship between the PPG-derived parameters and oxygen saturation in arterial blood is determined by means of an empirical calibration. This calibration results in an inherent error, and pulse oximetry thus has an error of about 4%, which is too high for some clinical problems. We present calibration-free pulse oximetry for measurement of SpO2, based on PPG pulses of two nearby wavelengths in the infrared. By neglecting the difference between the path-lengths of the two nearby wavelengths, SpO2 can be derived from the PPG parameters with no need for calibration. In the current study we used three laser diodes of wavelengths 780, 785 and 808 nm, with narrow spectral line-width. SaO2 was calculated by using each pair of PPG signals selected from the three wavelengths. In measurements on healthy subjects, SpO2 values, obtained by the 780–808 nm wavelength pair were found to be in the normal range. The measurement of SpO2 by two nearby wavelengths in the infrared with narrow line-width enables the assessment of SpO2 without calibration. PMID:24763216

  1. Two-Photon-Excited Fluorescence-Encoded Infrared Spectroscopy.

    PubMed

    Mastron, Joseph N; Tokmakoff, Andrei

    2016-11-23

    We report on a method for performing ultrafast infrared (IR) vibrational spectroscopy using fluorescence detection. Vibrational dynamics on the ground electronic state driven by femtosecond mid-infrared pulses are detected by changes in fluorescence amplitude resulting from modulation of a two-photon visible transition by nuclear motion. We examine a series of coumarin dyes and study the signals as a function of solvent and excitation pulse parameters. The measured signal characterizes the relaxation of vibrational populations and coherences but yields different information than conventional IR transient absorption measurements. These differences result from the manner in which the ground-state dynamics are projected by the two-photon detection step. Extensions of this method can be adapted for a variety of increased-sensitivity IR measurements.

  2. Photon statistics and polarization correlations at telecommunications wavelengths from a warm atomic ensemble.

    PubMed

    Willis, R T; Becerra, F E; Orozco, L A; Rolston, S L

    2011-07-18

    We present measurements of the polarization correlation and photon statistics of photon pairs that emerge from a laser-pumped warm rubidium vapor cell. The photon pairs occur at 780 nm and 1367 nm and are polarization entangled. We measure the autocorrelation of each of the generated fields as well as the cross-correlation function, and observe a strong violation of the two-beam Cauchy-Schwartz inequality. We evaluate the performance of the system as source of heralded single photons at a telecommunication wavelength. We measure the heralded autocorrelation and see that coincidences are suppressed by a factor of ≈ 20 from a Poissonian source at a generation rate of 1500 s(-1), a heralding efficiency of 10%, and a narrow spectral width.

  3. Design, fabrication, and characterization of quantum well infrared photoconductor in long-wavelength infrared

    NASA Astrophysics Data System (ADS)

    Jin, Ju-peng; Chen, Jian-xin; Lin, Chun

    2011-08-01

    Optimum quantum well infrared photodetectors (QWIP) structure parameters such as well width and barrier height for a given peak detection wavelength of 8 μm were designed, based on which GaAs/AlGaAs material with designed structure was grown and single element QWIP devices were fabricated. In order to accurately calculate the optimum QWIP structure parameters including well width, barrier height and doping density etc., we took into account higher order effects such as band nonparabolicity in our calculations. One band effective mass approximation was employed in modeling and shooting method was used in calculation. We fabricated three kinds of QWIP samples that have 20, 40 and 60 periods of quantum wells respectively. I-V characteristic curves and photoresponse at different temperature were measured to characterize the detectors. A peak detectivity of 8×1010 cmHz1/2/W was demonstrated by one of our QWIP devices. Besides, the varying performance of the three samples due to the different repeats of wells is discussed in this paper.

  4. Infrared Avionics Signal Distribution using Wavelength Division Multiplexing

    NASA Technical Reports Server (NTRS)

    Atiquzzaman, Mohammed; Sluss, Jim; Nguyen, Hung; Ngo, Duc

    2003-01-01

    Pilots in the cockpits of aircrafts currently communicate with ground stations using Radio Frequency (RF) signals. Antennas mounted outside the aircraft receive and transmit RF signals from and to the ground stations. The RF signals received at the antennas are sent to the cockpit using coaxial cables. As the number of antennas needed to provide more than one frequency band in aircrafts increases, RF distribution media (such as coaxial cable) adds to the complexity and weight of the cockpit wiring. Concomitantly, the safety and signal to noise ratio also decreases due to the use of RF signals. The University of Oklahoma is collaborating with the National Aeronautics and Space Administration to develop optical fiber based schemes to replace the coaxial cable used for RF signal distribution within an aircraft. The project aims at exploiting emerging Wavelength Division Multiplexing (WDM) techniques to reduce the weight of cabling, and increase the signal to noise ratio and reliability. This will be achieved by wavelength division multiplexing the signals from the various antennas and then demultiplexing the signals to recover the original signals at the cockpit. This paper will show that (i) RF signals can not only be wavelength multiplexed at the end of a fiber, but additional signals can be inserted into the middle of the fiber using WDM technology, and (ii) the signals can also be successfully extracted by tapping into the middle of the fiber. We are currently extending our previous laboratory prototype (which could multiplex signals only at the end of the fiber) to include additional multiplexing and demultiplexing of RF signals from the middle of the optical backbone with a view to validating the proof of concept, and carrying out measurements to determine the effectiveness of Wavelength Division Multiplexing for avionics applications. A test bed to perform measurements of several relevant parameters for various modulation schemes and frequencies (such as VHF

  5. Infrared Avionics Signal Distribution using Wavelength Division Multiplexing

    NASA Technical Reports Server (NTRS)

    Atiquzzaman, Mohammed; Sluss, Jim; Nguyen, Hung; Ngo, Duc

    2003-01-01

    Pilots in the cockpits of aircrafts currently communicate with ground stations using Radio Frequency (RF) signals. Antennas mounted outside the aircraft receive and transmit RF signals from and to the ground stations. The RF signals received at the antennas are sent to the cockpit using coaxial cables. As the number of antennas needed to provide more than one frequency band in aircrafts increases, RF distribution media (such as coaxial cable) adds to the complexity and weight of the cockpit wiring. Concomitantly, the safety and signal to noise ratio also decreases due to the use of RF signals. The University of Oklahoma is collaborating with the National Aeronautics and Space Administration to develop optical fiber based schemes to replace the coaxial cable used for RF signal distribution within an aircraft. The project aims at exploiting emerging Wavelength Division Multiplexing (WDM) techniques to reduce the weight of cabling, and increase the signal to noise ratio and reliability. This will be achieved by wavelength division multiplexing the signals from the various antennas and then demultiplexing the signals to recover the original signals at the cockpit. This paper will show that (i) RF signals can not only be wavelength multiplexed at the end of a fiber, but additional signals can be inserted into the middle of the fiber using WDM technology, and (ii) the signals can also be successfully extracted by tapping into the middle of the fiber. We are currently extending our previous laboratory prototype (which could multiplex signals only at the end of the fiber) to include additional multiplexing and demultiplexing of RF signals from the middle of the optical backbone with a view to validating the proof of concept, and carrying out measurements to determine the effectiveness of Wavelength Division Multiplexing for avionics applications. A test bed to perform measurements of several relevant parameters for various modulation schemes and frequencies (such as VHF

  6. Detection range enhancement using circularly polarized light in scattering environments for infrared wavelengths.

    PubMed

    van der Laan, J D; Scrymgeour, D A; Kemme, S A; Dereniak, E L

    2015-03-20

    We find for infrared wavelengths that there are broad ranges of particle sizes and refractive indices that represent fog and rain, where circular polarization can persist to longer ranges than linear polarization. Using polarization tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, we show that, for specific scene parameters, circular polarization outperforms linear polarization in maintaining the illuminating polarization state for large optical depths. This enhancement with circular polarization can be exploited to improve range and target detection in obscurant environments that are important in many critical sensing applications. Initially, researchers employed polarization-discriminating schemes, often using linearly polarized active illumination, to further distinguish target signals from the background noise. More recently, researchers have investigated circular polarization as a means to separate signal from noise even more. Specifically, we quantify both linearly and circularly polarized active illumination and show here that circular polarization persists better than linear for radiation fog in the short-wave infrared, for advection fog in the short-wave and long-wave infrared, and large particle sizes of Sahara dust around the 4 μm wavelength. Conversely, we quantify where linear polarization persists better than circular polarization for some limited particle sizes of radiation fog in the long-wave infrared, small particle sizes of Sahara dust for wavelengths of 9-10.5 μm, and large particle sizes of Sahara dust through the 8-11 μm wavelength range in the long-wave infrared.

  7. Polarization study of a supercontinuum light source for different wavelengths through a photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Valle-Atilano, F. J.; Estudillo-Ayala, J. M.; Filoteo-Razo, J. D.; Hernández-Garcia, J. C.; Lauterio-Cruz, J. P.; Jáuregui-Vázquez, D.; Ibarra-Escamilla, B.; Rojas-Laguna, R.; Pottiez, O.; Kuzin, E. A.

    2016-03-01

    In this work we show the changes of polarization at different wavelengths in the end of a photonic crystal fiber (PCF) by means bandpass filters in a supercontinuum light source. A linear and circular polarization was introduced in a piece of PCF, showing the changes of the polarization for each wavelength of each one of the filters from 450 to 700nm. We used a microchip laser as pumping source with wavelength of 532nm and short pulses of 650ps with repetition rate of 5kHz. We obtained a continuous spectrum in the visible spectral region, showing a comparison of the polarization state at the fiber input with respect to polarization state in the fiber output for different wavelengths by rotating the axes of the PCF.

  8. Broadband wavelength converter based on four-wave mixing in a highly nonlinear photonic crystal fiber.

    PubMed

    Zhang, Ailing; Demokan, M S

    2005-09-15

    We demonstrate a 10 Gbit/s nonreturn-to-zero wavelength converter based on four-wave mixing in a 20 m highly nonlinear photonic crystal fiber. The tunable wavelength conversion bandwidth (3 dB) is about 100 nm. The conversion efficiency is -16 dB when the pump power is 22.5 dBm. Phase modulation was not used to suppress the stimulated Brillouin scattering; thus the linewidth of the converted wavelength remained very narrow. The eye diagrams show that there is no additional noise during wavelength conversion. The measured power penalty at a 10(-9) bit-error-rate level is about 0.7 dB.

  9. Astronomical polarization studies at radio and infrared wavelengths. Part 2: Far infrared polarization of dust clouds

    NASA Technical Reports Server (NTRS)

    Dennison, B. K.

    1976-01-01

    Far infrared polarization of dust clouds is examined. The recently observed 10 micron polarization of the Orion Nebula and the Galactic Center suggests that far infrared polarization may be found in these objects. Estimates are made of the degree of far infrared polarization that may exist in the Orion Nebula. An attempt to observe far infrared polarization from the Orion Nebula was carried out.

  10. Theoretical investigation of all-metal-based mushroom plasmonic metamaterial absorbers at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Kimata, Masafumi

    2015-12-01

    High-performance wavelength-selective infrared (IR) sensors require small pixel structures, a low-thermal mass, and operation in the middle-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) regions for multicolor IR imaging. All-metal-based mushroom plasmonic metamaterial absorbers (MPMAs) were investigated theoretically and were designed to enhance the performance of wavelength-selective uncooled IR sensors. All components of the MPMAs are based on thin layers of metals such as Au without oxide insulators for increased absorption. The absorption properties of the MPMAs were investigated by rigorous coupled-wave analysis. Strong wavelength-selective absorption is realized over a wide range of MWIR and LWIR wavelengths by the plasmonic resonance of the micropatch and the narrow-gap resonance, without disturbance from the intrinsic absorption of oxide insulators. The absorption wavelength is defined mainly by the micropatch size and is longer than its period. The metal post width has less impact on the absorption properties and can maintain single-mode operation. Through-holes can be formed on the plate area to reduce the thermal mass. A small pixel size with reduced thermal mass and wideband single-mode operation can be realized using all-metal-based MPMAs.

  11. Wavelength tuning of planar photonic crystals by local processing of individual holes.

    PubMed

    Kicken, H H J E; Alkemade, P F A; van der Heijden, R W; Karouta, F; Nötzel, R; van der Drift, E; Salemink, H W M

    2009-11-23

    Tuning of the resonant wavelength of a single hole defect cavity in planar photonic crystals was demonstrated using transmission spectroscopy. Local post-production processing of single holes in a planar photonic crystal is carried out after selectively opening a masking layer by focused ion beam milling. The resonance was blue-shifted by enlargement of selected holes using local wet chemical etching and red-shifted by infiltration with liquid crystals. This method can be applied to precisely control the resonant frequency, and can also be used for mode selective tuning.

  12. Optical links for detector instrumentation: on-detector multi-wavelength silicon photonic transmitters

    NASA Astrophysics Data System (ADS)

    Karnick, D.; Skwierawski, P.; Schneider, M.; Eisenblätter, L.; Weber, M.

    2017-03-01

    We report on our recent progress in developing an optical transmission system based on wavelength division multiplexing (WDM) to enhance the read-out data rate of future particle detectors. The design and experimental results of the prototype of a monolithically integrated multi-wavelength transmitter are presented as well as temperature studies of electro-optic modulators. Furthermore, we show the successful permanent coupling of optical fibers to photonic chips, which is an essential step towards packaging of the opto-electronic components.

  13. Extension of long wavelength response by modulation doping in extrinsic germanium infrared detectors

    NASA Technical Reports Server (NTRS)

    Hadek, V.; Farhoomand, J.; Beichman, C. A.; Watson, D. M.; Jack, M. D.

    1985-01-01

    A new concept for infrared detectors based on multilayer epitaxy and modulation doping has been investigated. This permits a high doping concentration and lower excitation energy in the photodetecting layer as is necessary for longer wavelength response, without incurring the detrimental effects of increased dark current and noise as would be the case with conventional detector designs. Germanium photodetectors using conventional materials and designs have a long wavelength cutoff in the infrared at 138 microns, which can only be extended through the inconvenient application of mechanical stress or magnetic fields. As a result of this approach which was arrived at from theoretical considerations and subsequently demonstrated experimentally, the long wavelength cutoff for germanium extrinsic detectors was extended beyond 200 microns, as determined by direct infrared optical measurements.

  14. Silicon photonic time-wavelength pulse interleaver for photonic analog-to-digital converters.

    PubMed

    Gevorgyan, Hayk; Al Qubaisi, Kenaish; Dahlem, Marcus S; Khilo, Anatol

    2016-06-13

    A 4-channel time-wavelength optical pulse interleaver is implemented on a silicon chip. The interleaver forms a train of pulses with periodically changing wavelengths by demultiplexing the input pulse train into several wavelength components, delaying these components with respect to each other, and multiplexing them back into a single path. The interleaver is integrated on a silicon chip, with two arrays of microring resonator filters performing multiplexing and demultiplexing, and long sections of silicon waveguides acting as delay lines. The 4-channel interleaver is designed for an input pulse train with 1 GHz repetition rate, and is measured to have 0.35% RMS pulse timing error, insertion loss between 1.6 dB and 5.8 dB in different channels, crosstalk below -24 dB, and 52 nm free spectral range achieved using the Vernier effect.

  15. 640 x 512 Pixels Long-Wavelength Infrared (LWIR) Quantum-Dot Infrared Photodetector (QDIP) Imaging Focal Plane Array

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath D.; Bandara, Sumith V.; Hill, Cory J.; Ting, David Z.; Liu, John K.; Rafol, Sir B.; Blazejewski, Edward R.; Mumolo, Jason M.; Keo, Sam A.; Krishna, Sanjay; hide

    2007-01-01

    Epitaxially grown self-assembled. InAs-InGaAs-GaAs quantum dots (QDs) are exploited for the development of large-format long-wavelength infrared focal plane arrays (FPAs). The dot-in-a-well (DWELL) structures were experimentally shown to absorb both 45 degrees and normal incident light, therefore, a reflection grating structure was used to enhance the quantum efficiency. The devices exhibit peak responsivity out to 8.1 micrometers, with peak detectivity reaching approximately 1 X 10(exp 10) Jones at 77 K. The devices were fabricated into the first long-wavelength 640 x 512 pixel QD infrared photodetector imaging FPA, which has produced excellent infrared imagery with noise equivalent temperature difference of 40 mK at 60-K operating temperature.

  16. 640 x 512 Pixels Long-Wavelength Infrared (LWIR) Quantum-Dot Infrared Photodetector (QDIP) Imaging Focal Plane Array

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath D.; Bandara, Sumith V.; Hill, Cory J.; Ting, David Z.; Liu, John K.; Rafol, Sir B.; Blazejewski, Edward R.; Mumolo, Jason M.; Keo, Sam A.; Krishna, Sanjay; Chang, Y. -C.; Shott, Craig A.

    2007-01-01

    Epitaxially grown self-assembled. InAs-InGaAs-GaAs quantum dots (QDs) are exploited for the development of large-format long-wavelength infrared focal plane arrays (FPAs). The dot-in-a-well (DWELL) structures were experimentally shown to absorb both 45 degrees and normal incident light, therefore, a reflection grating structure was used to enhance the quantum efficiency. The devices exhibit peak responsivity out to 8.1 micrometers, with peak detectivity reaching approximately 1 X 10(exp 10) Jones at 77 K. The devices were fabricated into the first long-wavelength 640 x 512 pixel QD infrared photodetector imaging FPA, which has produced excellent infrared imagery with noise equivalent temperature difference of 40 mK at 60-K operating temperature.

  17. Generation of Multiple Mid Infrared Wavelengths Using PPLN and AgGaSe2

    DTIC Science & Technology

    1998-01-01

    Approved for public release; distribution is unlimited. Generation of Multiple Mid Infrared Wavelengths Using PPLN and AgGaSe2 Ti Chuang, Nigel...Martin and Ralph Burnham Fibertek, Inc. 510 Herndon Parkway, Herndon, VA 20170 ABSTRACT We report the demonstration of simultaneously generating two mid...noncritically phase matching (NCPM), to generate a wavelength at 1.54 µm. This 1.54 µm source becomes the pump for the second OPO that generates

  18. Post-process wavelength tuning of silicon photonic crystal slow-light waveguides.

    PubMed

    Awan, Kashif M; Schulz, Sebastian A; Liu, Dennis X; Dolgaleva, Ksenia; Upham, Jeremy; Boyd, Robert W

    2015-05-01

    Silicon photonic crystal waveguides have enabled a range of technologies, yet their fabrication continues to present challenges. Here, we report on a post-processing method that allows us to tune the operational wavelength of slow-light photonic crystal waveguides in concert with optical characterization, offsetting the effects of hole-radii and slab thickness variations. Our method consist of wet chemical surface oxidation, followed by oxide stripping. Theoretical modelling shows that the changes in optical behavior were predictable, and hence controlled tuning can be achieved by changing the number of processing cycles, where each cycle removes approximately 0.25 nm from all exposed surfaces, producing a blueshift of 1.6±0.1  nm in operating wavelength.

  19. Widely tunable single photon source with high purity at telecom wavelength.

    PubMed

    Jin, Rui-Bo; Shimizu, Ryosuke; Wakui, Kentaro; Benichi, Hugo; Sasaki, Masahide

    2013-05-06

    We theoretically and experimentally investigate the spectral tunability and purity of photon pairs generated from spontaneous parametric down conversion in periodically poled KTiOPO(4) crystal with group-velocity matching condition. The numerical simulation predicts that the spectral purity can be kept higher than 0.81 when the wavelength is tuned from 1460 nm to 1675 nm, which covers the S-, C-, L-, and U-band in telecommunication wavelengths. We also experimentally measured the joint spectral intensity at 1565 nm, 1584 nm and 1565 nm, yielding Schmidt numbers of 1.01, 1.02 and 1.04, respectively. Such a photon source is useful for quantum information and communication systems.

  20. Tantalum(V) nitride inverse opals as photonic structures for visible wavelengths.

    PubMed

    Rugge, Alessandro; Park, Jin-Seong; Gordon, Roy G; Tolbert, Sarah H

    2005-03-10

    The development of materials with a complete photonic band gap at visible wavelengths is believed to have the potential to lead to new control over long-lived emissive excited states, single molecule lasers, and nearly lossless nanoscale waveguides. In this work we move toward that goal with the synthesis of an inverse opal thin film of Ta3N5 produced through atomic layer deposition. The highly regular architecture achievable by atomic layer deposition is combined with an unusually high refractive index and transparency in at least part of the visible spectrum. The result is a material that represents the closest example to date of a photonic crystal with a band gap at optical wavelengths.

  1. Single frequency and wavelength stabilized near infrared laser source for water vapor DIAL remote sensing application

    NASA Astrophysics Data System (ADS)

    Chuang, Ti; Walters, Brooke; Shuman, Tim; Losee, Andrew; Schum, Tom; Puffenberger, Kent; Burnham, Ralph

    2015-02-01

    Fibertek has demonstrated a single frequency, wavelength stabilized near infrared laser transmitter for NASA airborne water vapor DIAL application. The application required a single-frequency laser transmitter operating at 935 nm near infrared (NIR) region of the water vapor absorption spectrum, capable of being wavelength seeded and locked to a reference laser source and being tuned at least 100 pm across the water absorption spectrum for DIAL on/off measurements. Fibertek is building a laser transmitter system based on the demonstrated results. The laser system will be deployed in a high altitude aircraft (ER-2 or UAV) to autonomously perform remote, long duration and high altitude water vapor measurements.

  2. Measurements of wavelength-dependent double photoelectron emission from single photons in VUV-sensitive photomultiplier tubes

    NASA Astrophysics Data System (ADS)

    Faham, C. H.; Gehman, V. M.; Currie, A.; Dobi, A.; Sorensen, P.; Gaitskell, R. J.

    2015-09-01

    Measurements of double photoelectron emission (DPE) probabilities as a function of wavelength are reported for Hamamatsu R8778, R8520, and R11410 VUV-sensitive photomultiplier tubes (PMTs). In DPE, a single photon strikes the PMT photocathode and produces two photoelectrons instead of a single one. It was found that the fraction of detected photons that result in DPE emission is a function of the incident photon wavelength, and manifests itself below ~250 nm. For the xenon scintillation wavelength of 175 nm, a DPE probability of 18-24% was measured depending on the tube and measurement method. This wavelength-dependent single photon response has implications for the energy calibration and photon counting of current and future liquid xenon detectors such as LUX, LZ, XENON100/1T, Panda-X and XMASS.

  3. At what wavelengths should we search for signals from extraterrestrial intelligence? (SETI/infrared communication/interstellar communication/extraterrestrial intelligence)

    NASA Technical Reports Server (NTRS)

    Townes, C. H.

    1979-01-01

    Searches for extraterrestrial intelligence concentrate on attempts to receive signals in the microwave region, the argument being given that communication occurs there at minimum broadcasted power. Such a conclusion is shown to result only under a restricted set of assumptions. If generalized types of detection are considered, in particular photon detection rather than linear detection alone, and if advantage is taken of the directivity of telescopes at short wavelengths, then somewhat less power is required for communication at infrared wavelengths than in the microwave region. Furthermore, a variety of parameters other than power alone can be chosen for optimization by an extraterrestrial civilization.

  4. Optimized photonic crystal design for quantum well infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Reininger, P.; Kalchmair, S.; Gansch, R.; Andrews, A. M.; Detz, H.; Zederbauer, T.; Ahn, S. I.; Schrenk, W.; Strasser, G.

    2012-06-01

    The performance of quantum well infrared photodetectors (QWIP) can be significantly enhanced combining it with a photonic crystal slab (PCS) resonator. In such a system the chosen PCS mode is designed to coincide with the absorption maximum of the photodetector by adjusting the lattice parameters. However there is a multitude of parameter sets that exhibit the same resonance frequency of the chosen PCS mode. We have investigated how the choice of the PC design can be exploited for a further enhancement of QWIPs. Several sets of lattice parameters that exhibit the chosen PCS mode at the same resonance frequency have been obtained and the finite difference time domain method was used to simulate the absorption spectra of the different PCS. A photonic crystal slab quantum well infrared photodetector with three different photonic crystal lattice designs that exhibit the same resonance frequency of the chosen PCS mode were designed, fabricated and measured. This work shows that the quality factor of a PCS-QWIP and therefore the absorption enhancement can be increased by an optimized PCS design. The improvement is a combined effect of a changed lattice constant, PC normalized radius and normalized slab thickness. An enhancement of the measured photocurrent of more than a factor of two was measured.

  5. GHz low noise short wavelength infrared (SWIR) photoreceivers

    NASA Astrophysics Data System (ADS)

    Bai, Xiaogang; Yuan, Ping; McDonald, Paul; Boisvert, Joseph; Chang, James; Woo, Robyn; Labios, Eduardo; Sudharsanan, Rengarajan; Krainak, Michael; Yang, Guangning; Sun, Xiaoli; Lu, Wei; McIntosh, Dion; Zhou, Qiugui; Campbell, Joe

    2011-06-01

    Next generation LIDAR mapping systems require multiple channels of sensitive photoreceivers that operate in the wavelength region of 1.06 to 1.55 microns, with GHz bandwidth and sensitivity less than 300 fW/√Hz. Spectrolab has been developing high sensitivity photoreceivers using InAlAs impact ionization engineering (I2E) avalanche photodiodes (APDs) structures for this application. APD structures were grown using metal organic vapor epitaxy (MOVPE) and mesa devices were fabricated using these structures. We have achieved low excess noise at high gain in these APD devices; an impact ionization parameter, k, of about 0.15 has been achieved at gains >20 using InAlAs/InGaAlAs as a multiplier layer. Electrical characterization data of these devices show dark current less than 2 nA at a gain of 20 at room temperature; and capacitance of 0.4 pF for a typical 75 micron diameter APD. Photoreceivers were built by integrating I2E APDs with a low noise GHz transimpedance amplifier (TIA). The photoreceivers showed a bandwidth of 1 GHz and a noise equivalent power (NEP) of 150 fW/rt(Hz) at room temperature.

  6. MHz rate and efficient synchronous heralding of single photons at telecom wavelengths.

    PubMed

    Pomarico, Enrico; Sanguinetti, Bruno; Guerreiro, Thiago; Thew, Rob; Zbinden, Hugo

    2012-10-08

    We report on the realization of a synchronous source of heralded single photons at telecom wavelengths with MHz heralding rates and high heralding efficiency. This source is based on the generation of photon pairs at 810 and 1550 nm via Spontaneous Parametric Down Conversion (SPDC) in a 1 cm periodically poled lithium niobate (PPLN) crystal pumped by a 532 nm pulsed laser. As high rates are fundamental for multi-photon experiments, we show that single telecom photons can be announced at 4.4 MHz rate with 45% heralding efficiency. When we focus only on the optimization of the coupling of the heralded photon, the heralding efficiency can be increased up to 80%. Furthermore, we experimentally observe that group velocity mismatch inside long crystals pumped in a pulsed mode affects the spectrum of the emitted photons and their fibre coupling efficiency. The length of the crystal in this source has been chosen as a trade off between high brightness and high coupling efficiency.

  7. Human infrared vision is triggered by two-photon chromophore isomerization

    PubMed Central

    Palczewska, Grazyna; Vinberg, Frans; Stremplewski, Patrycjusz; Bircher, Martin P.; Salom, David; Komar, Katarzyna; Zhang, Jianye; Cascella, Michele; Wojtkowski, Maciej; Kefalov, Vladimir J.; Palczewski, Krzysztof

    2014-01-01

    Vision relies on photoactivation of visual pigments in rod and cone photoreceptor cells of the retina. The human eye structure and the absorption spectra of pigments limit our visual perception of light. Our visual perception is most responsive to stimulating light in the 400- to 720-nm (visible) range. First, we demonstrate by psychophysical experiments that humans can perceive infrared laser emission as visible light. Moreover, we show that mammalian photoreceptors can be directly activated by near infrared light with a sensitivity that paradoxically increases at wavelengths above 900 nm, and display quadratic dependence on laser power, indicating a nonlinear optical process. Biochemical experiments with rhodopsin, cone visual pigments, and a chromophore model compound 11-cis-retinyl-propylamine Schiff base demonstrate the direct isomerization of visual chromophore by a two-photon chromophore isomerization. Indeed, quantum mechanics modeling indicates the feasibility of this mechanism. Together, these findings clearly show that human visual perception of near infrared light occurs by two-photon isomerization of visual pigments. PMID:25453064

  8. Human infrared vision is triggered by two-photon chromophore isomerization.

    PubMed

    Palczewska, Grazyna; Vinberg, Frans; Stremplewski, Patrycjusz; Bircher, Martin P; Salom, David; Komar, Katarzyna; Zhang, Jianye; Cascella, Michele; Wojtkowski, Maciej; Kefalov, Vladimir J; Palczewski, Krzysztof

    2014-12-16

    Vision relies on photoactivation of visual pigments in rod and cone photoreceptor cells of the retina. The human eye structure and the absorption spectra of pigments limit our visual perception of light. Our visual perception is most responsive to stimulating light in the 400- to 720-nm (visible) range. First, we demonstrate by psychophysical experiments that humans can perceive infrared laser emission as visible light. Moreover, we show that mammalian photoreceptors can be directly activated by near infrared light with a sensitivity that paradoxically increases at wavelengths above 900 nm, and display quadratic dependence on laser power, indicating a nonlinear optical process. Biochemical experiments with rhodopsin, cone visual pigments, and a chromophore model compound 11-cis-retinyl-propylamine Schiff base demonstrate the direct isomerization of visual chromophore by a two-photon chromophore isomerization. Indeed, quantum mechanics modeling indicates the feasibility of this mechanism. Together, these findings clearly show that human visual perception of near infrared light occurs by two-photon isomerization of visual pigments.

  9. Long Wavelength 256 X 256 Quantum Well Infrared Photodetector Portable Camera

    NASA Technical Reports Server (NTRS)

    Gunapala, S. D.; Liu, J. K.; Shott, C. A.; Hoelter, T.; Sundaram, M.; Park, J. S.; Laband, S.; James, J.

    1996-01-01

    In this paper, we discuss the development of very sensitive long wavelength infrared (LWIR) GaAs/AlGal-xAs Quantum well infrared photodetectors (QWIPS), fabrication of random reflectors for efficient light coupling, and the demonstration of a LWIR 256 X 256 focal plane array imaging camera. Excellent imagery, with a noise equivalent differential temperature (NE-delta-T) of 25 mK has been achieved.

  10. High Q micro-ring resonators fabricated from polycrystalline aluminum nitride films for near infrared and visible photonics.

    PubMed

    Pernice, Wolfram H P; Xiong, Chi; Tang, Hong X

    2012-05-21

    We demonstrate wideband integrated photonic circuits in sputter-deposited aluminum nitride (AlN) thin films. At both near-infrared and visible wavelengths, we achieve low propagation loss in integrated waveguides and realize high-quality optical resonators. In the telecoms C-band (1520-1580 nm), we obtain the highest optical Q factor of 440,000. Critical coupled devices show extinction ratio above 30 dB. For visible wavelengths (around 770 nm), intrinsic quality factors in excess of 30,000 is demonstrated. Our work illustrates the potential of AlN as a low loss material for wideband optical applications.

  11. Wavelength-Selective One- and Two-Photon Uncaging of GABA

    PubMed Central

    2013-01-01

    We have synthesized photolabile 7-diethylamino coumarin (DEAC) derivatives of γ-aminobutyric acid (GABA). These caged neurotransmitters efficiently release GABA using linear or nonlinear excitation. We used a new DEAC-based caging chromophore that has a vinyl acrylate substituent at the 3-position that shifts the absorption maximum of DEAC to about 450 nm and thus is named “DEAC450”. DEAC450-caged GABA is photolyzed with a quantum yield of 0.39 and is highly soluble and stable in physiological buffer. We found that DEAC450-caged GABA is relatively inactive toward two-photon excitation at 720 nm, so when paired with a nitroaromatic caged glutamate that is efficiently excited at such wavelengths, we could photorelease glutamate and GABA around single spine heads on neurons in brain slices with excellent wavelength selectivity using two- and one-photon photolysis, respectively. Furthermore, we found that DEAC450-caged GABA could be effectively released using two-photon excitation at 900 nm with spatial resolution of about 3 μm. Taken together, our experiments show that the DEAC450 caging chromophore holds great promise for the development of new caged compounds that will enable wavelength-selective, two-color interrogation of neuronal signaling with excellent subcellular resolution. PMID:24304264

  12. High numerical aperture large-core photonic crystal fiber for a broadband infrared transmission

    NASA Astrophysics Data System (ADS)

    Pniewski, J.; Stepniewski, G.; Kasztelanic, R.; Siwicki, B.; Pierscinska, D.; Pierscinski, K.; Pysz, D.; Borzycki, K.; Stepien, R.; Bugajski, M.; Buczynski, R.

    2016-11-01

    In this paper we present a large mode area photonic crystal fiber made of the heavy metal oxide glass CS-740, dedicated for a broadband light guidance in the visible, near- and mid-infrared regions of wavelengths from 0.4 to 4.7 μm. The fiber is effectively multi-mode in the considered wavelength range. It is composed of a ring of air-holes surrounding the core, with a high linear filling factor of 0.97. The fiber was made using a standard stack-and-draw technique. Each hole has a size of approx. 2.5 × 3.0 μm and diameter of core is 80 μm. Fiber attenuation is below 3 dB/m in the 0.9-1.7 μm wavelength range, while at 4.4 μm (mid-IR) it is approx. 5 dB/cm. Bending loss at the 1.55 μm wavelength is 0.45 dB per loop of 8 mm radius. Fiber numerical aperture is 0.53 at 1.55 μm. The effective mode area of the fundamental mode is approx. 2400 μm2 in the wavelength range of 0.8-1.7 μm. We present a proof-of-concept demonstration that our large core photonic crystal fiber is able to efficiently collect light directly from a mid-IR quantum cascade laser without use of additional optics and can be used for pigtailing mid-IR sources and detectors.

  13. Near infrared single photon avalanche detector with negative feedback and self quenching

    NASA Astrophysics Data System (ADS)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2009-08-01

    We present the design and development of a negative feedback devices using the internal discrete amplifier approach used for the development of a single photon avalanche photodetector in the near infrared wavelength region. This new family of photodetectors with negative feedback, requiring no quenching mechanism using Internal Discrete Amplification (IDA) mechanism for the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions, operates in the non-gated mode under a constant bias voltage. The demonstrated device performance far exceeds any available solid state Photodetectors in the near infrared wavelength range. The measured devices have Gain > 2×105, Excess noise factor < 1.05, Rise time < 350ps, Fall time < 500ps, Dark current < 2×106 cps at room temperature, and Operating Voltage < 60V. These devices are ideal for researchers in the field of Ladar/Lidar, free space optical communication, 3D imaging, industrial and scientific instrumentation, night vision, quantum cryptography, and other military, defence and aerospace applications.

  14. Broadband mid-infrared wavelength conversion laser based on Cr2+ doped ceramic materials

    NASA Astrophysics Data System (ADS)

    Shang, Yaping; Yin, Ke; Li, Xiao; Wang, Peng; Xu, Xiaojun

    2015-10-01

    Broadband mid-infrared lasers are desirable for pretty important applications in fields of environmental protection, medical treatment, military applications, scientific, and other domains. Recently, super-continuum laser sources have achieved striking development. However, limited by the substrate materials, the output power scaling of the broadband mid-infrared fiber laser sources could not be increased drastically, especially for the long wavelength region. In this paper, we reported an experimental study about the broadband mid-infrared lasers based on Cr2+ doped II-VI ceramic materials, by using of a super-continuum laser source developed by our groups operating at 1550~2130nm with 200mW output power. The result suggested that the near-infrared spectral component of the super-continuum source was deeply absorbed by transition metal doped zinc chalcogenides ceramic materials, meanwhile the mid-infrared part, however, had been enhanced significantly by this new "power amplifier." Actually single-pass amplification efficiency was very limited. The best way to solve this problem was multi-pass amplification systems. We had shown an initial proof of this assumption by a double-pass experiments, the result was consistent with expected effect. Above all, the spectrum shaping from short wavelength to long wavelength was obtained. The innovative discovery had laid a solid foundation for high power, high efficiency, broadly tunable mid-infrared solid state lasers.

  15. Potential of a superconducting photon counter for heterodyne detection at the telecommunication wavelength

    NASA Astrophysics Data System (ADS)

    Shcherbatenko, M.; Lobanov, Y.; Semenov, A.; Kovalyuk, V.; Korneev, A.; Ozhegov, R.; Kazakov, A.; Voronov, B. M.; Goltsman, G. N.

    2016-12-01

    Here, we report on successful operation of a NbN thin film superconducting nanowire single-photon detector (SNSPD) in a coherent mode (as a mixer) at the telecommunication wavelength of 1550 nm. Providing the Local Oscillator power of the order of a few picowatts, we were practically able to reach the quantum noise limited sensitivity. The intermediate frequency gain bandwidth was limited by the spectral band of single-photon response pulse of the detector, which is proportional to the detector size. We observed gain bandwidth of 65 MHz and 140 MHz for 7x7 um^2 and 3x3 um^2 devices respectively. Tiny amount of the required Local Oscillator power and wide gain and noise bandwidths along with the needless of any Low Noise Amplification opens possibility for a photon counting heterodyne-born megapixel array development.

  16. Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths

    PubMed Central

    Kahl, Oliver; Ferrari, Simone; Kovalyuk, Vadim; Goltsman, Gregory N.; Korneev, Alexander; Pernice, Wolfram H. P.

    2015-01-01

    Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10−19 W/Hz−1/2 range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms. PMID:26061283

  17. Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths.

    PubMed

    Kahl, Oliver; Ferrari, Simone; Kovalyuk, Vadim; Goltsman, Gregory N; Korneev, Alexander; Pernice, Wolfram H P

    2015-06-10

    Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10(-19) W/Hz(-1/2) range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms.

  18. Studies on output characteristics of stable dual-wavelength ytterbium-doped photonic crystal fiber laser

    NASA Astrophysics Data System (ADS)

    Tian, Hongchun; Zhang, Sa; Hou, Zhiyun; Xia, Changming; Zhou, Guiyao; Zhang, Wei; Liu, Jiantao; Wu, Jiale; Fu, Jian

    2016-06-01

    A stable dual-wavelength ytterbium-doped photonic crystal fiber laser pumped by a 976 nm laser diode has been demonstrated at room temperature. Single-wavelength, dual-wavelength laser oscillations are observed when the fiber laser operates under different pump power by using different length of fibers. Stable dual-wavelength radiation around 1045 nm and 1075 nm has been generated simultaneously at a high pump power directly from an ytterbium-doped fiber laser without using any spectral control mechanism. A small core ytterbium-doped PCF fabricated by the powder sinter direction drawn rod technology is used as gain medium. The pump power and fiber length which can affect the output characteristics of dual-wavelength fiber laser are analyzed in the experiment. Experiments confirm that higher pump power and longer fiber length favors 1075 nm output; lower pump power and shorter fiber length favors 1045 nm output. Those results have a good reference in multi-wavelength fiber laser.

  19. A hybrid multiplexer for wavelength/mode-division based on photonic crystals

    NASA Astrophysics Data System (ADS)

    Ji, Ke; Chen, Heming; Zhuang, Yuyang

    2016-01-01

    A hybrid multiplexer (HMUX) for wavelength/mode-division (WDM/MDM) based on photonic crystals (PCs) is proposed. The device can realize TE0 and TE1 modes multiplexing at wavelengths of 1550nm and 1570nm. According to quasi phase matching, a structure with an asymmetrical parallel waveguide (APW) was used to achieve mode conversion. The transmittance of the TE0 mode at wavelengths of 1550nm and 1570nm are 98.4% and 96.3%, the corresponding insertion loss are 0.07dB and 0.16dB respectively. The crosstalk of the TE0 mode at wavelengths of 1550nm and 1570nm are -27.66dB and -27.32dB respectively. The transmittance of the TE1 mode at wavelengths of 1550nm and 1570nm are 95.8% and 93.9%, the corresponding insertion loss are 0.19dB and 0.27dB respectively. The crosstalk of the TE1 mode at wavelengths of 1550nm and 1570nm are -38.73dB and -38.9dB respectively. The PC-based HMUX has great performance, and it will have great application potential in future ultrahigh-speed and large-capacity communication systems.

  20. Tunable multi-wavelength polymer laser based on a triangular-lattice photonic crystal structure

    NASA Astrophysics Data System (ADS)

    Huang, Wenbin; Pu, Donglin; Qiao, Wen; Wan, Wenqiang; Liu, Yanhua; Ye, Yan; Wu, Shaolong; Chen, Linsen

    2016-08-01

    A continuously tunable multi-wavelength polymer laser based on a triangular-lattice photonic crystal cavity is demonstrated. The triangular-lattice resonator was initially fabricated through multiple interference exposure and was then replicated into a low refractive index polymer via UV-nanoimprinting. The blend of a blue-emitting conjugated polymer and a red-emitting one was used as the gain medium. Three periods in the scalene triangular-lattice structure yield stable tri-wavelength laser emission (625.5 nm, 617.4 nm and 614.3 nm) in six different directions. A uniformly aligned liquid crystal (LC) layer was incorporated into the cavity as the top cladding layer. Upon heating, the orientation of LC molecules and thus the effective refractive index of the lasing mode changes which continuously shifts the lasing wavelength. A maximum tuning range of 12.2 nm was observed for the lasing mode at 625.5 nm. This tunable tri-wavelength polymer laser is simple constructed and cost-effective. It may find application in the fields of biosensors and photonic integrated circuits.

  1. Low work function surface layers produced by laser ablation using short-wavelength photons

    DOEpatents

    Balooch, Mehdi; Dinh, Long N.; Siekhaus, Wigbert J.

    2000-01-01

    Short-wavelength photons are used to ablate material from a low work function target onto a suitable substrate. The short-wavelength photons are at or below visible wavelength. The elemental composition of the deposit is controlled by the composition of the target and the gaseous environment in which the ablation process is performed. The process is carried out in a deposition chamber to which a short-wavelength laser is mounted and which includes a substrate holder which can be rotated, tilted, heated, or cooled. The target material is mounted onto a holder that spins the target during laser ablation. In addition, the deposition chamber is provided with a vacuum pump, an external gas supply with atomizer and radical generator, a gas generator for producing a flow of molecules on the substrate, and a substrate cleaning device, such as an ion gun. The substrate can be rotated and tilted, for example, whereby only the tip of an emitter can be coated with a low work function material.

  2. Soliton trapping of dispersive waves in photonic crystal fiber with two zero dispersive wavelengths.

    PubMed

    Wang, Weibin; Yang, Hua; Tang, Pinghua; Zhao, Chujun; Gao, Jing

    2013-05-06

    Based on the generalized nonlinear Schrödinger equation, we present a numerical study of trapping of dispersive waves by solitons during supercontinuum generation in photonic crystal fibers pumped with femtosecond pulses in the anomalous dispersion region. Numerical simulation results show that the generated supercontinuum is bounded by two branches of dispersive waves, namely blue-shifted dispersive waves (B-DWs) and red-shifted dispersive waves (R-DWs). We find a novel phenomenon that not only B-DWs but also R-DWs can be trapped by solitons across the zero-dispersion wavelength when the group-velocity matching between the soliton and the dispersive wave is satisfied, which may led to the generation of new spectral components via mixing of solitons and dispersive waves. Mixing of solitons with dispersive waves has been shown to play an important role in shaping not only the edge of the supercontinuum, but also its central part around the higher zero-dispersion wavelength. Further, we show that the phenomenon of soliton trapping of dispersive waves in photonic crystal fibers with two zero-dispersion wavelengths has a very close relationship with pumping power and the interval between two zero-dispersion wavelengths. In order to clearly display the evolution of soliton trapping of dispersive waves, the spectrogram of output pulses is observed using cross-correlation frequency-resolved optical gating technique (XFROG).

  3. Two dimensional tunable photonic crystal defect based drop filter at communication wavelength

    NASA Astrophysics Data System (ADS)

    D'souza, Nirmala Maria; Mathew, Vincent

    2017-07-01

    We propose a two dimensional photonic crystal (PhC) based drop filter, at communication wavelength with more than 90% transmission. The filtering is achieved by introducing two line defects and three point defects in a two dimensional triangular array of ferroelectric rods in air. Using the electro-optic property of the ferroelectric, about 32 nm tuning in the resonance wavelength is obtained. For the calculation of transmission, finite difference time domain (FDTD) simulations were performed. The operating frequency range is explored via the band structure which is obtained by the implementation of plane wave expansion (PWE) method. The influence of the radius of various rods on the filter wavelength as well as efficiency is also analyzed. The different possible configurations of this filter are also considered.

  4. Near infrared imaging of teeth at wavelengths between 1200 and 1600 nm

    NASA Astrophysics Data System (ADS)

    Chung, Soojeong; Fried, Daniel; Staninec, Michal; Darling, Cynthia L.

    2011-03-01

    Near-IR (NIR) imaging is a new technology that is currently being investigated for the detection and assessment of dental caries without the use of ionizing radiation. Several papers have been published on the use of transillumination and reflectance NIR imaging to detect early caries in enamel. The purpose of this study was to investigate alternative near infrared wavelengths besides 1300-nm in the range from 1200- 1600-nm to determine the wavelengths that yield the highest contrast in both transmission and reflectance imaging modes. Artificial lesions were created on thirty tooth sections of varying thickness for transillumination imaging. NIR images at wavelengths from the visible to 1600-nm were also acquired for fifty-four whole teeth with occlusal lesions using a tungsten halogen lamp with several spectral filters and a Ge-enhanced CMOS image sensor. Cavity preparations were also cut into whole teeth and Z250 composite was used as a restorative material to determine the contrast between composite and enamel at NIR wavelengths. Slightly longer NIR wavelengths are likely to have better performance for the transillumination of occlusal caries lesions while 1300-nm appears best for the transillumination of proximal surfaces. Significantly higher performance was attained at wavelengths that have higher water absorption, namely 1460-nm and wavelengths greater than 1500-nm and these wavelength regions are likely to be more effective for reflectance imaging. Wavelengths with higher water absorption also provided higher contrast of composite restorations.

  5. [Characteristic wavelength variable optimization of near-infrared spectroscopy based on Kalman filtering].

    PubMed

    Wang, Li-Qi; Ge, Hui-Fang; Li, Gui-Bin; Yu, Dian-Yu; Hu, Li-Zhi; Jiang, Lian-Zhou

    2014-04-01

    Combining classical Kalman filter with NIR analysis technology, a new method of characteristic wavelength variable selection, namely Kalman filtering method, is presented. The principle of Kalman filter for selecting optimal wavelength variable was analyzed. The wavelength selection algorithm was designed and applied to NIR detection of soybean oil acid value. First, the PLS (partial leastsquares) models were established by using different absorption bands of oil. The 4 472-5 000 cm(-1) characteristic band of oil acid value, including 132 wavelengths, was selected preliminarily. Then the Kalman filter was used to select characteristic wavelengths further. The PLS calibration model was established using selected 22 characteristic wavelength variables, the determination coefficient R2 of prediction set and RMSEP (root mean squared error of prediction) are 0.970 8 and 0.125 4 respectively, equivalent to that of 132 wavelengths, however, the number of wavelength variables was reduced to 16.67%. This algorithm is deterministic iteration, without complex parameters setting and randomicity of variable selection, and its physical significance was well defined. The modeling using a few selected characteristic wavelength variables which affected modeling effect heavily, instead of total spectrum, can make the complexity of model decreased, meanwhile the robustness of model improved. The research offered important reference for developing special oil near infrared spectroscopy analysis instruments on next step.

  6. Enhanced two-channel nonlinear imaging by a highly polarized supercontinuum light source generated from a nonlinear photonic crystal fiber with two zero-dispersion wavelengths

    NASA Astrophysics Data System (ADS)

    Tao, Wei; Bao, Hongchun; Gu, Min

    2011-05-01

    Real-time monitoring the variation of chlorophyll distributions and cellular structures in leaves during plant growth provides important information for understanding the physiological statuses of plants. Two-photon-excited autofluorescence imaging and second harmonic generation imaging of leaves can be used for monitoring the nature intrinsic fluorophores distribution and cellular structures of leaves by the use of the near-infrared region of light which has minimal light absorption by endogenous molecules and thus increases tissue penetration. However, the two-photon absorption peak of intrinsic fluorophores of a ficus benjamina leaf is 50 nm away from the second harmonic generation excitation wavelength, which cannot be effectively excited by a femtosecond laser beam with one central wavelength. This paper shows that a highly polarized supercontinuum light generated from a birefringent nonlinear photonic crystal fiber with two zero-dispersion wavelengths can effectively excite two-photon autofluorescence as well as second harmonic generation signals for simultaneously monitoring intrinsic fluorophore distributions and non-centrosymmetric structures of leaves.

  7. Enhanced two-channel nonlinear imaging by a highly polarized supercontinuum light source generated from a nonlinear photonic crystal fiber with two zero-dispersion wavelengths.

    PubMed

    Tao, Wei; Bao, Hongchun; Gu, Min

    2011-05-01

    Real-time monitoring the variation of chlorophyll distributions and cellular structures in leaves during plant growth provides important information for understanding the physiological statuses of plants. Two-photon-excited autofluorescence imaging and second harmonic generation imaging of leaves can be used for monitoring the nature intrinsic fluorophores distribution and cellular structures of leaves by the use of the near-infrared region of light which has minimal light absorption by endogenous molecules and thus increases tissue penetration. However, the two-photon absorption peak of intrinsic fluorophores of a ficus benjamina leaf is 50 nm away from the second harmonic generation excitation wavelength, which cannot be effectively excited by a femtosecond laser beam with one central wavelength. This paper shows that a highly polarized supercontinuum light generated from a birefringent nonlinear photonic crystal fiber with two zero-dispersion wavelengths can effectively excite two-photon autofluorescence as well as second harmonic generation signals for simultaneously monitoring intrinsic fluorophore distributions and non-centrosymmetric structures of leaves.

  8. Quantum detector tomography of a time-multiplexed superconducting nanowire single-photon detector at telecom wavelengths.

    PubMed

    Natarajan, Chandra M; Zhang, Lijian; Coldenstrodt-Ronge, Hendrik; Donati, Gaia; Dorenbos, Sander N; Zwiller, Val; Walmsley, Ian A; Hadfield, Robert H

    2013-01-14

    Superconducting nanowire single-photon detectors (SNSPDs) are widely used in telecom wavelength optical quantum information science applications. Quantum detector tomography allows the positive-operator-valued measure (POVM) of a single-photon detector to be determined. We use an all-fiber telecom wavelength detector tomography test bed to measure detector characteristics with respect to photon flux and polarization, and hence determine the POVM. We study the SNSPD both as a binary detector and in an 8-bin, fiber based, Time-Multiplexed (TM) configuration at repetition rates up to 4 MHz. The corresponding POVMs provide an accurate picture of the photon number resolving capability of the TM-SNSPD.

  9. Endoscopically compatible near-infrared photon migration probe

    NASA Astrophysics Data System (ADS)

    Lubawy, Carmalyn; Ramanujam, Nirmala

    2004-09-01

    We have developed a 2.3-mm-diameter fiber-optic probe for near-infrared photon migration spectroscopy that can be inserted into the body through an endoscope or biopsy needle. This probe is specifically designed to be inserted into a core biopsy needle to facilitate optical sampling of lesions during breast needle biopsy. This probe was tested on tissue phantoms containing heterogeneities (to stimulate breast lesions) of various sizes and optical properties. Under the conditions tested, the probe can measure the absorption coefficient to within 30% for heterogeneities with radii as small as 10 mm.

  10. Massive Photons: An Infrared Regularization Scheme for Lattice QCD +QED

    NASA Astrophysics Data System (ADS)

    Endres, Michael G.; Shindler, Andrea; Tiburzi, Brian C.; Walker-Loud, André

    2016-08-01

    Standard methods for including electromagnetic interactions in lattice quantum chromodynamics calculations result in power-law finite-volume corrections to physical quantities. Removing these by extrapolation requires costly computations at multiple volumes. We introduce a photon mass to alternatively regulate the infrared, and rely on effective field theory to remove its unphysical effects. Electromagnetic modifications to the hadron spectrum are reliably estimated with a precision and cost comparable to conventional approaches that utilize multiple larger volumes. A significant overall cost advantage emerges when accounting for ensemble generation. The proposed method may benefit lattice calculations involving multiple charged hadrons, as well as quantum many-body computations with long-range Coulomb interactions.

  11. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    ERIC Educational Resources Information Center

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  12. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    ERIC Educational Resources Information Center

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  13. Skin hydration imaging using a long-wavelength near-infrared digital camera

    NASA Astrophysics Data System (ADS)

    Attas, E. Michael; Posthumus, Trevor B.; Schattka, Bernhard J.; Sowa, Michael G.; Mantsch, Henry H.; Zhang, Shuliang L.

    2001-07-01

    Skin hydration is a key factor in skin health. Hydration measurements can provide diagnostic information on the condition of skin and can indicate the integrity of the skin barrier function. Near-infrared spectroscopy measures the water content of living tissue by its effect on tissue reflectance at a particular wavelength. Imaging has the important advantage of showing the degree of hydration as a function of location. Short-wavelength (650-1050 nm) near infrared spectroscopic reflectance imaging has previously been used in-vivo to determine the relative water content of skin under carefully controlled laboratory conditions. We have recently developed a novel spectroscopic imaging system to acquire image sets in the long-wavelength region of the near infrared (960 to 1700 nm), where the water absorption bands are more intense. The LW-NIR systems uses a liquid- crystal tunable filter in front of the objective lens and incorporates a 12-bit digital camera with a 320-by-240-pixel indium-gallium arsenide array sensor. Custom software controls the camera and tunable filter, allowing image sets to be acquired and displayed in near-real time. Forearm skin hydration was measured in a clinical context using the long- wavelength imaging system, a short-wavelength imaging system, and non-imaging instrumentation. Among these, the LW-NIR system appears to be the most sensitive at measuring dehydration of skin.

  14. Ocular aberrations as a function of wavelength in the near infrared measured with a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Fernández, Enrique J.; Unterhuber, Angelika; Prieto, Pedro M.; Hermann, Boris; Drexler, Wolfgang; Artal, Pablo

    2005-01-01

    A compact mode-locked Ti:sapphire laser, emitting a broad spectrum of 277 nm bandwidth, centered at 790 nm, was used to measure the dependence of the aberrations of the human eye with wavelength in the near infrared region. The aberrations were systematically measured with a Hartmann-Shack wave-front sensor at the following wavelengths: 700, 730, 750, 780, 800, 850, 870 and 900 nm, in four normal subjects. During the measurements, the wavelengths were selected by using 10 nm band-pass filters. We found that monochromatic high order aberrations, beyond defocus, were nearly constant across 700 to 900 nm wavelength in the four subjects. The average chromatic difference in defocus was 0.4 diopters in the considered wavelength band. The predictions of a simple water-eye model were compared with the experimental results in the near infrared. These results have potential applications in those situations where defocus or higher order aberration correction in the near infrared is required. This is the case of many imaging techniques: scanning laser ophthalmoscope, flood illumination fundus camera, or optical coherence tomography.

  15. Hyperspectral imaging sensor array based on diffractively driving infrared beams with chosen wavelength into designated subsensors

    NASA Astrophysics Data System (ADS)

    Qu, Yong; Zhang, Xinyu; Sang, Hongshi; Zhang, Tianxu; Xie, Changsheng

    2013-10-01

    In this paper, an integrated hyperspectral imaging sensor array technology by using arrayed diffractive micro-optics elements for driving infrared beams with chosen wavelength into designated subsensors is proposed. The diffractive optical element, which can be treated as a functioned microlens here, collect the incident Gaussian beam or other types of infrared beams out-from targets and then concentrate the incident light into desired monochromatic point pattern or arbitrary distinct hyperspectral image at the imaging plane based on phase transformation and diffraction propagation process. For the incident infrared beams with different wavelengths, the arrayed diffractive micro-optics elements is designed based on the diffractive integral theory, and the weighted iterative phase retrieval algorithm is modeled so as to obtain the needed phase distribution, and therefore the frequency spectrum of the incident beams can be separated locally in different locations over the focal plane according to designated wavelength. We can then achieve beam-splitting imaging by placing sensor array (4×4 pixels per subsensor) on the focal plane at locations that correspond to different wavelengths. Simulation results demonstrate that the designed elements can successfully implement both the functions of demultiplexing different wavelength beams and focusing each component at a pre-designated position simultaneously.

  16. Efficient generation of twin photons at telecom wavelengths with 2.5 GHz repetition-rate-tunable comb laser

    PubMed Central

    Jin, Rui-Bo; Shimizu, Ryosuke; Morohashi, Isao; Wakui, Kentaro; Takeoka, Masahiro; Izumi, Shuro; Sakamoto, Takahide; Fujiwara, Mikio; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Wang, Zhen; Sasaki, Masahide

    2014-01-01

    Efficient generation and detection of indistinguishable twin photons are at the core of quantum information and communications technology (Q-ICT). These photons are conventionally generated by spontaneous parametric down conversion (SPDC), which is a probabilistic process, and hence occurs at a limited rate, which restricts wider applications of Q-ICT. To increase the rate, one had to excite SPDC by higher pump power, while it inevitably produced more unwanted multi-photon components, harmfully degrading quantum interference visibility. Here we solve this problem by using recently developed 10 GHz repetition-rate-tunable comb laser, combined with a group-velocity-matched nonlinear crystal, and superconducting nanowire single photon detectors. They operate at telecom wavelengths more efficiently with less noises than conventional schemes, those typically operate at visible and near infrared wavelengths generated by a 76 MHz Ti Sapphire laser and detected by Si detectors. We could show high interference visibilities, which are free from the pump-power induced degradation. Our laser, nonlinear crystal, and detectors constitute a powerful tool box, which will pave a way to implementing quantum photonics circuits with variety of good and low-cost telecom components, and will eventually realize scalable Q-ICT in optical infra-structures. PMID:25524646

  17. Stellar Multi-Photon Absorption Materials: Beyond the Telecommunication Wavelength Band.

    PubMed

    Schwich, Torsten; Barlow, Adam; Cifuentes, Marie P; Szeremeta, Janusz; Samoc, Marek; Humphrey, Mark G

    2017-06-22

    Very large molecular two- and three-photon absorption cross-sections are achieved by appending ligated bis(diphosphine)ruthenium units to oligo(p-phenyleneethynylene) (OPE)-based "stars" with arms up to 7 phenyleneethynylene (PE) units in length. Extremely large three- and four-photon absorption cross-sections, through the telecommunications wavelengths range and beyond, are obtained for these complexes upon optimizing OPE length and the ruthenium-coordinated peripheral ligand. Multi-photon absorption (MPA) cross-sections are optimized with stars possessing arms 2 PE units in length. Peripheral ligand variation modifies MPA merit and, in particular, 4-nitrophenylethynyl ligand incorporation enhances maximal MPA values and "switches on" four-photon absorption (4PA) in these low molecular-weight complexes. The 4-nitrophenylethynyl-ligated 2PE-armed star possesses a maximal four-photon absorption cross-section of 1.8×10(-108)  cm(8)  s(3) at 1750 nm, and significant MPA activity extending beyond 2000 nm. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Long wavelength infrared camera (LWIRC): a 10 micron camera for the Keck Telescope

    SciTech Connect

    Wishnow, E.H.; Danchi, W.C.; Tuthill, P.; Wurtz, R.; Jernigan, J.G.; Arens, J.F.

    1998-05-01

    The Long Wavelength Infrared Camera (LWIRC) is a facility instrument for the Keck Observatory designed to operate at the f/25 forward Cassegrain focus of the Keck I telescope. The camera operates over the wavelength band 7-13 {micro}m using ZnSe transmissive optics. A set of filters, a circular variable filter (CVF), and a mid-infrared polarizer are available, as are three plate scales: 0.05``, 0.10``, 0.21`` per pixel. The camera focal plane array and optics are cooled using liquid helium. The system has been refurbished with a 128 x 128 pixel Si:As detector array. The electronics readout system used to clock the array is compatible with both the hardware and software of the other Keck infrared instruments NIRC and LWS. A new pre-amplifier/A-D converter has been designed and constructed which decreases greatly the system susceptibility to noise.

  19. Exploration of the two-photon excitation spectrum of fluorescent dyes at wavelengths below the range of the Ti:Sapphire laser

    PubMed Central

    Trägårdh, J; Robb, G; Amor, R; Amos, WB; Dempster, J; McConnell, G

    2015-01-01

    We have studied the wavelength dependence of the two-photon excitation efficiency for a number of common UV excitable fluorescent dyes; the nuclear stains DAPI, Hoechst and SYTOX Green, chitin- and cellulose-staining dye Calcofluor White and Alexa Fluor 350, in the visible and near-infrared wavelength range (540–800 nm). For several of the dyes, we observe a substantial increase in the fluorescence emission intensity for shorter excitation wavelengths than the 680 nm which is the shortest wavelength usually available for two-photon microscopy. We also find that although the rate of photo-bleaching increases at shorter wavelengths, it is still possible to acquire many images with higher fluorescence intensity. This is particularly useful for applications where the aim is to image the structure, rather than monitoring changes in emission intensity over extended periods of time. We measure the excitation spectrum when the dyes are used to stain biological specimens to get a more accurate representation of the spectrum of the dye in a cell environment as compared to solution-based measurements. PMID:25946127

  20. Multi-photon ionization of atoms in intense short-wavelength radiation fields

    NASA Astrophysics Data System (ADS)

    Meyer, Michael

    2015-05-01

    The unprecedented characteristics of XUV and X-ray Free Electron Lasers (FELs) have stimulated numerous investigations focusing on the detailed understanding of fundamental photon-matter interactions in atoms and molecules. In particular, the high intensities (up to 106 W/cm2) giving rise to non-linear phenomena in the short wavelength regime. The basic phenomenology involves the production of highly charged ions via electron emission to which both sequential and direct multi-photon absorption processes contribute. The detailed investigation of the role and relative weight of these processes under different conditions (wavelength, pulse duration, intensity) is the key element for a comprehensive understanding of the ionization dynamics. Here the results of recent investigations are presented, performed at the FELs in Hamburg (FLASH) and Trieste (FERMI) on atomic systems with electronic structures of increasing complexity (Ar, Ne and Xe). Mainly, electron spectroscopy is used to obtain quantitative information about the relevance of various multi-photon ionization processes. For the case of Ar, a variety of processes including above threshold ionization (ATI) from 3p and 3s valence shells, direct 2p two-photon ionization and resonant 2p-4p two-photon excitations were observed and their role was quantitatively determined comparing the experimental ionization yields to ab-initio calculations of the cross sections for the multi-photon processes. Using Ar as a benchmark to prove the reliability of the combined experimental and theoretical approach, the more complex and intriguing case of Xe was studied. Especially, the analysis of the two-photon ATI from the Xe 4d shell reveals new insight into the character of the 4d giant resonance, which was unresolved in the linear one-photon regime. Finally, the influence of intense XUV radiation to the relaxation dynamics of the Ne 2s-3p resonance was investigated by angle-resolved electron spectroscopy, especially be observing

  1. Quantum teleportation from a telecom-wavelength photon to a solid-state quantum memory

    NASA Astrophysics Data System (ADS)

    Bussières, Félix; Clausen, Christoph; Tiranov, Alexey; Korzh, Boris; Verma, Varun B.; Nam, Sae Woo; Marsili, Francesco; Ferrier, Alban; Goldner, Philippe; Herrmann, Harald; Silberhorn, Christine; Sohler, Wolfgang; Afzelius, Mikael; Gisin, Nicolas

    2014-10-01

    Quantum teleportation is a cornerstone of quantum information science due to its essential role in important tasks such as the long-distance transmission of quantum information using quantum repeaters. This requires the efficient distribution of entanglement between remote nodes of a network. Here, we demonstrate quantum teleportation of the polarization state of a telecom-wavelength photon onto the state of a solid-state quantum memory. Entanglement is established between a rare-earth-ion-doped crystal storing a single photon that is polarization-entangled with a flying telecom-wavelength photon. The latter is jointly measured with another flying polarization qubit to be teleported, which heralds the teleportation. The fidelity of the qubit retrieved from the memory is shown to be greater than the maximum fidelity achievable without entanglement, even when the combined distances travelled by the two flying qubits is 25 km of standard optical fibre. Our results demonstrate the possibility of long-distance quantum networks with solid-state resources.

  2. Long wavelength infrared radiation thermometry for non-contact temperature measurements in gas turbines

    NASA Astrophysics Data System (ADS)

    Manara, J.; Zipf, M.; Stark, T.; Arduini, M.; Ebert, H.-P.; Tutschke, A.; Hallam, A.; Hanspal, J.; Langley, M.; Hodge, D.; Hartmann, J.

    2017-01-01

    The objective of the EU project "Sensors Towards Advanced Monitoring and Control of Gas Turbine Engines (acronym STARGATE)" is the development of a suite of advanced sensors, instrumentation and related systems in order to contribute to the developing of the next generation of green and efficient gas turbine engines. One work package of the project deals with the design and development of a long wavelength infrared (LWIR) radiation thermometer for the non-contact measurement of the surface temperature of thermal barrier coatings (TBCs) during the operation of gas turbine engines. For opaque surfaces (e.g. metals or superalloys) radiation thermometers which are sensitive in the near or short wavelength infrared are used as state-of-the-art method for non-contact temperature measurements. But this is not suitable for oxide ceramic based TBCs (e.g. partially yttria stabilized zirconia) as oxide ceramics are semi-transparent in the near and short wavelength infrared spectral region. Fortunately the applied ceramic materials are non-transparent in the long wavelength infrared and additionally exhibit a high emittance in this wavelength region. Therefore, a LWIR pyrometer can be used for non-contact temperature measurements of the surfaces of TBCs as such pyrometers overcome the described limitation of existing techniques. For performing non-contact temperature measurements in gas turbines one has to know the infrared-optical properties of the applied TBCs as well as of the hot combustion gas in order to properly analyse the measurement data. For reaching a low uncertainty on the one hand the emittance of the TBC should be high (>0.9) in order to reduce reflections from the hot surrounding and on the other hand the absorbance of the hot combustion gas should be low (<0.1) in order to decrease the influence of the gas on the measured signal. This paper presents the results of the work performed by the authors with focus on the implementation of the LWIR pyrometer and the

  3. Enhancement of negligible transmission band using hybrid periodic/Fibonacci photonic crystal in near infrared and microwave domains

    NASA Astrophysics Data System (ADS)

    Mouldi, Abir; Kanzari, Mounir

    2012-06-01

    A hybrid structure of the type Bragg mirror-(Fibonacci)S is proposed to enhance the zero transmission band through the one dimensional photonic crystal in microwave domain and in the infrared. The efficiency of the configuration is proved in microwave domain for angles below 57°. In the infrared, the use of the configuration exhibits a large photonic band gap at any angle of incidence and for both polarizations. The proposed structure is a quarter wavelength omnidirectional mirror of 37 layers with a bandwidth larger than that of the periodic structure with an increasing ratio 3.7 and it covers all the optical telecommunication wavelengths 0.85, 1.3 and 1.55 μm. Unlike the previous devices, the structure is simple to fabricate and it shows interesting optical properties. The configuration Bragg mirror-(Fibonacci)S-Bragg mirror is also investigated to more extend the photonic band gap. Since different physical phenomena have their own appropriate physical scales, we exploited the physical properties of the proposed hybrid structure in different wavelength domains.

  4. High-Operating-Temperature Barrier Infrared Detector with Tailorable Cutoff Wavelength

    NASA Technical Reports Server (NTRS)

    Ting, David Z.; Hill, Cory, J.; Soibel, Alexander; Bandara, Sumith V.; Gunapala, Sarath D.

    2011-01-01

    A mid-wavelength infrared (MWIR) barrier photodetector is capable of operating at higher temperature than the prevailing MWIR detectors based on InSb. The standard high-operating-temperature barrier infrared detector (HOT-BIRD) is made with an InAsSb infrared absorber that is lattice-matched to a GaSb substrate, and has a cutoff wavelength of approximately 4 microns. To increase the versatility and utility of the HOT-BIRD, it is implemented with IR absorber materials with customizable cutoff wavelengths. The HOT-BIRD can be built with the quaternary alloy GaInAsSb as the absorber, GaAlSbAs as the barrier, on a lattice-matching GaSb substrate. The cutoff wavelength of the GaInAsSb can be tailored by adjusting the alloy composition. To build a HOT-BIRD requires a matching pair of absorber and barrier materials with the following properties: (1) their valence band edges must be approximately the same to allow unimpeded hole flow, while their conduction band edges should have a large difference to form an electron barrier; and (2) the absorber and the barrier must be respectively lattice-matched and closely lattice-matched to the substrate to ensure high material quality and low defect density. To make a HOT-BIRD with cutoff wavelength shorter than 4 microns, a GaInAsSb quaternary alloy was used as the absorber, and a matching GaAlSbAs quaternary alloy as the barrier. By changing the alloy composition, the band gap of the quaternary alloy absorber can be continuously adjusted with cutoff wavelength ranging from 4 microns down to the short wavelength infrared (SWIR). By carefully choosing the alloy composition of the barrier, a HOT-BIRD structure can be formed. With this method, a HOT-BIRD can be made with continuously tailorable cutoff wavelengths from 4 microns down to the SWIR. The HOT-BIRD detector technology is suitable for making very-large-format MWIR/SWIR focal plane arrays that can be operated by passive cooling from low Earth orbit. High-operating temperature

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

    PubMed

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

    2015-08-10

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

  6. Revised wavelength and spectral response calibrations for AKARI near-infrared grism spectroscopy: Cryogenic phase

    NASA Astrophysics Data System (ADS)

    Baba, Shunsuke; Nakagawa, Takao; Shirahata, Mai; Isobe, Naoki; Usui, Fumihiko; Ohyama, Youichi; Onaka, Takashi; Yano, Kenichi; Kochi, Chihiro

    2016-04-01

    We perform revised spectral calibrations for the AKARI near-infrared grism to correct quantitatively for the effect of the wavelength-dependent refractive index. The near-infrared grism covering the wavelength range of 2.5-5.0 μm, with a spectral resolving power of 120 at 3.6 μm, is found to be contaminated by second-order light at wavelengths longer than 4.9 μm, which is especially serious for red objects. First, we present the wavelength calibration considering the refractive index of the grism as a function of the wavelength for the first time. We find that the previous solution is positively shifted by up to 0.01 μm compared with the revised wavelengths at 2.5-5.0 μm. In addition, we demonstrate that second-order contamination occurs even with a perfect order-sorting filter owing to the wavelength dependence of the refractive index. Secondly, the spectral responses of the system from the first- and second-order light are simultaneously obtained from two types of standard objects with different colors. The response from the second-order light suggests leakage of the order-sorting filter below 2.5 μm. The relations between the output of the detector and the intensities of the first- and second-order light are formalized by a matrix equation that combines the two orders. The removal of the contaminating second-order light can be achieved by solving the matrix equation. The new calibration extends the available spectral coverage of the grism mode from 4.9 μm up to 5.0 μm. The revision can be used to study spectral features falling in these extended wavelengths, e.g., the carbon monoxide fundamental ro-vibrational absorption within nearby active galactic nuclei.

  7. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): High Angular Resolution Astronomy at Far-Infrared Wavelengths

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.

    2008-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and observations with Spitzer, the upcoming Herschel mission. and SOFIA will continue to provide exciting new discoveries. The comparatively low spatial resolution of these missions, however. is insufficient to resolve the physical scales on which mid- to far-infrared emission arises, resulting in source and structure ambiguities that limit our ability to answer key science questions. Interferometry enables high angular resolution at these wavelengths. We have proposed a new high altitude balloon experiment, the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). High altitude operation makes far-infrared (30- 300micron) observations possible, and BETTII's 8-meter baseline provides unprecedented angular resolution (-0.5 arcsec) in this band. BETTII will use a double- Fourier instrument to simultaneously obtain both spatial and spectral informatioT. he spatially resolved spectroscopy provided by BETTII will address key questions about the nature of disks in young cluster stars and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the groundwork for future space interferometers.

  8. The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): High Angular Resolution Astronomy at Far-Infrared Wavelengths

    NASA Technical Reports Server (NTRS)

    Rinehart, Stephen A.

    2008-01-01

    Astronomical studies at infrared wavelengths have dramatically improved our understanding of the universe, and observations with Spitzer, the upcoming Herschel mission. and SOFIA will continue to provide exciting new discoveries. The comparatively low spatial resolution of these missions, however. is insufficient to resolve the physical scales on which mid- to far-infrared emission arises, resulting in source and structure ambiguities that limit our ability to answer key science questions. Interferometry enables high angular resolution at these wavelengths. We have proposed a new high altitude balloon experiment, the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII). High altitude operation makes far-infrared (30- 300micron) observations possible, and BETTII's 8-meter baseline provides unprecedented angular resolution (-0.5 arcsec) in this band. BETTII will use a double- Fourier instrument to simultaneously obtain both spatial and spectral informatioT. he spatially resolved spectroscopy provided by BETTII will address key questions about the nature of disks in young cluster stars and active galactic nuclei and the envelopes of evolved stars. BETTII will also lay the groundwork for future space interferometers.

  9. Infrared Multiple Photon Dissociation Spectroscopy Of Metal Cluster-Adducts

    NASA Astrophysics Data System (ADS)

    Cox, D. M.; Kaldor, A.; Zakin, M. R.

    1987-01-01

    Recent development of the laser vaporization technique combined with mass-selective detection has made possible new studies of the fundamental chemical and physical properties of unsupported transition metal clusters as a function of the number of constituent atoms. A variety of experimental techniques have been developed in our laboratory to measure ionization threshold energies, magnetic moments, and gas phase reactivity of clusters. However, studies have so far been unable to determine the cluster structure or the chemical state of chemisorbed species on gas phase clusters. The application of infrared multiple photon dissociation IRMPD to obtain the IR absorption properties of metal cluster-adsorbate species in a molecular beam is described here. Specifically using a high power, pulsed CO2 laser as the infrared source, the IRMPD spectrum for methanol chemisorbed on small iron clusters is measured as a function of the number of both iron atoms and methanols in the complex for different methanol isotopes. Both the feasibility and potential utility of IRMPD for characterizing metal cluster-adsorbate interactions are demonstrated. The method is generally applicable to any cluster or cluster-adsorbate system dependent only upon the availability of appropriate high power infrared sources.

  10. The analysis of photon pair source at telecom wavelength based on the BBO crystal (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Gajewski, Andrzej; Kolenderski, Piotr L.

    2016-10-01

    There are several problems that must be solved in order to increase the distance of quantum communication protocols based on photons as an information carriers. One of them is the dispersion, whose effects can be minimized by engineering spectral properties of transmitted photons. In particular, it is expected that positively correlated photon pairs can be very useful. We present the full characterization of a source of single photon pairs at a telecom wavelength based on type II spontaneous parametric down conversion (SPDC) process in a beta-barium borate (BBO) crystal. In the type II process, a pump photon, which is polarized extraordinarily, splits in a nonlinear medium into signal and idler photons, which are polarized perpendicularly to each other. In order for the process to be efficient a phase matching condition must be fulfilled. These conditions originate from momentum and energy conservation rules and put severe restrictions on source parameters. Seemingly, these conditions force the photon pair to be negatively correlated in their spectral domain. However, it is possible to achieve positive correlation for pulsed pumping. The experimentally available degrees of freedom of a source are the width of the pumping beam, the collected modes' widths, the length of the nonlinear crystal and the duration of the pumping pulse. In our numerical model we use the following figures of merit: the pair production rate, the efficiency of photon coupling into a single mode fiber, the spectral correlation of the coupled photon pair. The last one is defined as the Pearson correlation parameter for a joint spectral distribution. The aim here is to find the largest positive spectral correlation and the highest coupling efficiency. By resorting to the numerical model Ref. [1] we showed in Ref. [2], that by careful adjustment of the pump's and the collected modes' characteristics, one can optimize any of the source's parameters. Our numerical outcomes conform to the

  11. Colloidal PbS nanocrystals integrated to Si-based photonics for applications at telecom wavelengths

    NASA Astrophysics Data System (ADS)

    Humer, M.; Guider, R.; Jantsch, W.; Fromherz, T.

    2013-05-01

    In the last decade, Si based photonics has made major advances in terms of design, fabrication, and device implementation. But due to Silicon's indirect bandgap, it still remains a challenge to create efficient Si-based light emitting devices. In order to overcome this problem, an approach is to develop hybrid systems integrating light-emitting materials into Si. A promising class of materials for this purpose is the class of semiconducting nanocrystal quantum dots (NCs) that are synthesized by colloidal chemistry. As their absorption and emission wavelength depends on the dot size, which can easily be controlled during synthesis, they are extremely attractive as building blocks for nanophotonic applications. For applications in telecom wavelength, Lead chalcogenide colloidal NCs are optimum materials due to their unique optical, electronic and nonlinear properties. In this work, we experimentally demonstrate the integration of PbS nanocrystals into Si-based photonic structures like slot waveguides and ring resonators as optically pumped emitters for room temperature applications. In order to create such hybrid structures, the NCs were dissolved into polymer resists and drop cast on top of the device. Upon optical pumping, intense photoluminescence emission from the resonating modes is recorded at the output of the waveguide with transmission quality factors up to 14000. The polymer host material was investigated with respect to its ability to stabilize the NC's photoluminescence emission against degradation under ambient conditions. The waveguide-ring coupling efficiency was also investigated as function of the NCs concentrations blended into the polymer matrix. The integration of colloidal quantum dots into Silicon photonic structures as demonstrated in this work is a very versatile technique and thus opens a large range of applications utilizing the linear and nonlinear optical properties of PbS NCs at telecom wavelengths.

  12. 128 × 128 long-wavelength/mid-wavelength two-color HgCdTe infrared focal plane array detector with ultralow spectral cross talk.

    PubMed

    Hu, Weida; Ye, Zhenhua; Liao, Lei; Chen, Honglei; Chen, Lu; Ding, Ruijun; He, Li; Chen, Xiaoshuang; Lu, Wei

    2014-09-01

    High temporal and spatial coherent simultaneous long-wavelength/mid-wavelength (LW/MW) two-color focal plane array (FPA) infrared detection is the cutting-edge technique for third-generation infrared remote sensing. In this Letter, HgCdTe LW/MW two-color infrared detectors were designed and fabricated. The top long-wavelength and bottom mid-wavelength infrared planar photodiodes were processed by selective B(+)-implantation after etching the long-wavelength epilayer into a curvature and exposing the mid-wavelength layers for the implantation of the n region of the MW photodiode by a micro-mesa array technique. A 128×128  MW/LW HgCdTe infrared FPA detector is fabricated photo-lithographically by simultaneous nonplanar B(+)-implantation of the LW and MW photodiodes, passivation and metallization of the sidewalls, mesa isolation, and flip-chip hybridization with a read-out integrated circuit. The inner mechanisms for suppressing the cross talk and improving photoresponse have been carried out by combining experimental work with numerical simulations.

  13. Beam-bending in spatially variant photonic crystals at telecommunications wavelengths

    NASA Astrophysics Data System (ADS)

    Digaum, Jennefir L.; Sharma, Rashi; Batista, Daniel; Pazos, Javier J.; Rumpf, Raymond C.; Kuebler, Stephen M.

    2016-03-01

    This work reports the fabrication of micron-scale spatially variant photonic crystals (SVPCs) and their use for steering light beams through turns with bending radius Rbend on the order of ten times the optical wavelength λ0. Devices based on conventional photonic crystals, metamaterials, plasmonics and transformation optics have all been explored for controlling light beams and steering them through tight turns. These devices offer promise for photonic interconnects, but they are based on exotic materials, including metals, that make them impractically lossy or difficult to fabricate. Waveguides can also be used to steer light using total internal reflection; however, Rbend of a waveguide must be hundreds of times λ0 to guide light efficiently, which limits their use in optical circuits. SVPCs are spatially variant 3D lattices which can be created in transparent, low-refractive-index media and used to control the propagation of light through the self-collimation effect. SVPCs were fabricated by multi-photon lithography using the commercially available photo-polymer IP-DIP. The SVPCs were structurally and optically characterized and found to be capable of bending light having λ0 = 1.55 μm through a 90-degree turn with Rbend = 10 μm. Curved waveguides with Rbend = 15 μm and 35 μm were also fabricated using IP-DIP and optically characterized. The SVPCs were able to steer the light beams through tighter turns than either waveguide and with higher efficiency.

  14. Observation of enhanced visible and infrared emissions in photonic crystal thin-film light-emitting diodes

    SciTech Connect

    Cheung, Y. F.; Li, K. H.; Hui, R. S. Y.; Choi, H. W.

    2014-08-18

    Photonic crystals, in the form of closed-packed nano-pillar arrays patterned by nanosphere lithography, have been formed on the n-faces of InGaN thin-film vertical light-emitting diodes (LEDs). Through laser lift-off of the sapphire substrate, the thin-film LEDs conduct vertically with reduced dynamic resistances, as well as reduced thermal resistances. The photonic crystal plays a role in enhancing light extraction, not only at visible wavelengths but also at infrared wavelengths boosting heat radiation at high currents, so that heat-induced effects on internal quantum efficiencies are minimized. The observations are consistent with predictions from finite-difference time-domain simulations.

  15. Observation of enhanced visible and infrared emissions in photonic crystal thin-film light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Cheung, Y. F.; Li, K. H.; Hui, R. S. Y.; Choi, H. W.

    2014-08-01

    Photonic crystals, in the form of closed-packed nano-pillar arrays patterned by nanosphere lithography, have been formed on the n-faces of InGaN thin-film vertical light-emitting diodes (LEDs). Through laser lift-off of the sapphire substrate, the thin-film LEDs conduct vertically with reduced dynamic resistances, as well as reduced thermal resistances. The photonic crystal plays a role in enhancing light extraction, not only at visible wavelengths but also at infrared wavelengths boosting heat radiation at high currents, so that heat-induced effects on internal quantum efficiencies are minimized. The observations are consistent with predictions from finite-difference time-domain simulations.

  16. Long-term evolution of FU Orionis objects at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Ábrahám, P.; Kóspál, Á.; Csizmadia, Sz.; Kun, M.; Moór, A.; Prusti, T.

    2004-12-01

    We investigate the brightness evolution of seven FU Orionis systems in the 1-100 μm wavelength range using data from the Infrared Space Observatory (ISO). The ISO measurements were supplemented by 2MASS and MSX observations performed in the same years as the ISO mission (1995-98). The spectral energy distributions (SEDs) based on these data points were compared with earlier ones derived from the IRAS photometry as well as from ground-based observations carried out around the epoch 1983. In three cases (Z CMa, Parsamian 21, V1331 Cyg) no difference between the two epochs was seen within the measurement uncertainties. V1057 Cyg, V1515 Cyg and V1735 Cyg have become fainter at near-infrared wavelengths while V346 Nor has become slightly brighter. V1057 Cyg exhibits a similar flux change in the mid-infrared. At λ≥ 60 μm most of the sources remained constant; only V346 Nor seems to fade. Our data on the long-term evolution of V1057 Cyg agree with the model predictions of Kenyon & Hartmann (\\cite{Kenyonh91}) and Turner et al. (\\cite{Turner97}) at near- and mid-infrared wavelengths, but disagree at λ>25 μm. We discuss if this observational result at far-infrared wavelengths could be understood in the framework of the existing models. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries France, Germany, the Netherlands and the United Kingdom) with participation of ISAS and NASA.

  17. Numerical calculation of phase-matching properties in photonic crystal fibers with three and four zero-dispersion wavelengths.

    PubMed

    Zhao, Xingtao; Liu, Xiaoxu; Wang, Shutao; Wang, Wei; Han, Ying; Liu, Zhaolun; Li, Shuguang; Hou, Lantian

    2015-10-19

    Photonic crystal fibers with three and four zero-dispersion wavelengths are presented through special design of the structural parameters, in which the closing to zero and ultra-flattened dispersion can be obtained. The unique phase-matching properties of the fibers with three and four zero-dispersion wavelengths are analyzed. Variation of the phase-matching wavelengths with the pump wavelengths, pump powers, dispersion properties, and fiber structural parameters is analyzed. The presence of three and four zero-dispersion wavelengths can realize wavelength conversion of optical soliton between two anomalous dispersion regions, generate six phase-matching sidebands through four-wave mixing and create more new photon pairs, which can be used for the study of supercontinuum generation, optical switches and quantum optics.

  18. Polarization maintaining highly nonlinear photonic crystal fiber with closely lying two zero dispersion wavelengths

    NASA Astrophysics Data System (ADS)

    Hasan, Md. Rabiul; Anower, Md. Shamim; Hasan, Md. Imran

    2016-05-01

    A simple hexagonal photonic crystal fiber is proposed to simultaneously achieve ultrahigh birefringence, large nonlinear coefficient, and two zero dispersion wavelengths (ZDWs). The finite element method with circular perfectly matched layer boundary condition is used to simulate the designed structure. Simulation results show that it is possible to achieve two closely lying ZDWs of 1.08 and 1.29 μm for x-polarization with 0.88 and 1.20 μm for y-polarization modes, respectively. In addition, an ultrahigh birefringence of 3.15×10-2 and a high nonlinear coefficient of 58 W-1 km-1 are also obtained at the excitation wavelength of 1.55 μm. The proposed fiber can have important applications in supercontinuum generation, parametric amplification, four-wave mixing, and optical sensors design.

  19. Photon antibunching in single-walled carbon nanotubes at telecommunication wavelengths and room temperature

    SciTech Connect

    Endo, Takumi Ishi-Hayase, Junko; Maki, Hideyuki

    2015-03-16

    We investigated the photoluminescence of individual air-suspended single-walled carbon nanotubes (SWNTs) from 6 to 300 K. Time-resolved and antibunching measurements over the telecommunication wavelength range were performed using a superconducting single-photon detector. We detected moderate temperature independent antibunching behavior over the whole temperature range studied. To investigate the exciton dynamics, which is responsible for the antibunching behavior, we measured excitation-power and temperature dependence of the photoluminescence spectra and lifetime decay curves. These measurements suggested an exciton confinement effect that is likely caused by high-dielectric amorphous carbon surrounding the SWNTs. These results indicate that SWNTs are good candidates for light sources in quantum communication technologies operating in the telecommunication wavelength range and at room temperature.

  20. Telecom wavelength emitting single quantum dots coupled to InP-based photonic crystal microcavities

    NASA Astrophysics Data System (ADS)

    Kors, A.; Fuchs, K.; Yacob, M.; Reithmaier, J. P.; Benyoucef, M.

    2017-01-01

    Here we report on the fabrication and optical characterization of InP-based L3 photonic crystal (PhC) microcavities embedded with a medium density InAs/InP quantum dots (QDs) emitting at telecom wavelengths. The QDs are grown by solid source molecular beam epitaxy using a ripening technique. Micro-photoluminescence (μ-PL) measurements of PhC samples reveal sharp cavity modes with quality factors exceeding 8500. QDs emit highly linear-polarized light at telecom wavelengths with resolution-limited spectral linewidth below 50 μeV. Enhanced PL intensity of QDs in PhC is observed in comparison to the PL intensity of QDs in bulk semiconductors. The combination of excitation power-dependent and polarization-resolved μ-PL measurements reveal the existence of an exciton-biexciton system with a small fine-structure splitting.

  1. A silicon photonic wavelength division multiplex system for high-speed data transmission in detector instrumentation

    NASA Astrophysics Data System (ADS)

    Skwierawski, P.; Schneider, M.; Karnick, D.; Eisenblätter, L.; Weber, M.

    2016-01-01

    We propose a new silicon photonics-based optical transmission system utilizing wavelength division multiplexing (WDM) . This technology has the possibility of reading out all raw data from a detector even without massive local data reduction. The transmitter in the detector volume consists of multiple integrated Mach-Zehnder modulators monolithically integrated with wavelength (de-)multiplexers. The first demonstrator currently under development aims for a data rate of 160 Gbit/s per fiber, scalable to 5 Tbit/s and beyond. We report on our recently developed Echelle grating WDM multiplexers with up to 45 channels on an area of 0.5 mm2 and electro-optic modulators providing a bandwidth of 18 GHz.

  2. Novel Si(1-x)Ge(x)/Si heterojunction internal photoemission long wavelength infrared detectors

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Maserjian, Joseph; Ksendzov, A.; Huberman, Mark L.; Terhune, R.; Krabach, T. N.

    1990-01-01

    There is a major need for long-wavelength-infrared (LWIR) detector arrays in the range of 8 to 16 microns which operate with close-cycle cryocoolers above 65 K. In addition, it would be very attractive to have Si-based infrared (IR) detectors that can be easily integrated with Si readout circuitry and have good pixel-to-pixel uniformity, which is critical for focal plane array (FPA) applications. Here, researchers report a novel Si(1-x)Ge(x)/Si heterojunction internal photoemission (HIP) detector approach with a tailorable long wavelength infrared cutoff wavelength, based on internal photoemission over the Si(1-x)Ge(x)/Si heterojunction. The HIP detectors were grown by molecular beam epitaxy (MBE), which allows one to optimize the device structure with precise control of doping profiles, layer thickness and composition. The feasibility of a novel Si(1-x)Ge(x)/Si HIP detector has been demonstrated with tailorable cutoff wavelength in the LWIR region. Photoresponse at wavelengths 2 to 10 microns are obtained with quantum efficiency (QE) above approx. 1 percent in these non-optimized device structures. It should be possible to significantly improve the QE of the HIP detectors by optimizing the thickness, composition, and doping concentration of the Si(1-x)Ge(x) layers and by configuring the detector for maximum absorption such as the use of a cavity structure. With optimization of the QE and by matching the barrier energy to the desired wavelength cutoff to minimize the thermionic current, researchers predict near background limited performance in the LWIR region with operating temperatures above 65K. Finally, with mature Si processing, the relatively simple device structure offers potential for low-cost producible arrays with excellent uniformity.

  3. Novel Si(1-x)Ge(x)/Si heterojunction internal photoemission long wavelength infrared detectors

    NASA Astrophysics Data System (ADS)

    Lin, T. L.; Maserjian, Joseph; Ksendzov, A.; Huberman, Mark L.; Terhune, R.; Krabach, T. N.

    1990-07-01

    There is a major need for long-wavelength-infrared (LWIR) detector arrays in the range of 8 to 16 microns which operate with close-cycle cryocoolers above 65 K. In addition, it would be very attractive to have Si-based infrared (IR) detectors that can be easily integrated with Si readout circuitry and have good pixel-to-pixel uniformity, which is critical for focal plane array (FPA) applications. Here, researchers report a novel Si(1-x)Ge(x)/Si heterojunction internal photoemission (HIP) detector approach with a tailorable long wavelength infrared cutoff wavelength, based on internal photoemission over the Si(1-x)Ge(x)/Si heterojunction. The HIP detectors were grown by molecular beam epitaxy (MBE), which allows one to optimize the device structure with precise control of doping profiles, layer thickness and composition. The feasibility of a novel Si(1-x)Ge(x)/Si HIP detector has been demonstrated with tailorable cutoff wavelength in the LWIR region. Photoresponse at wavelengths 2 to 10 microns are obtained with quantum efficiency (QE) above approx. 1 percent in these non-optimized device structures. It should be possible to significantly improve the QE of the HIP detectors by optimizing the thickness, composition, and doping concentration of the Si(1-x)Ge(x) layers and by configuring the detector for maximum absorption such as the use of a cavity structure. With optimization of the QE and by matching the barrier energy to the desired wavelength cutoff to minimize the thermionic current, researchers predict near background limited performance in the LWIR region with operating temperatures above 65K. Finally, with mature Si processing, the relatively simple device structure offers potential for low-cost producible arrays with excellent uniformity.

  4. Integrated photonic switches for nanosecond packet-switched optical wavelength conversion

    NASA Astrophysics Data System (ADS)

    Fidaner, Onur; Demir, Hilmi Volkan; Sabnis, Vijit A.; Zheng, Jun-Fei; Harris, James S., Jr.; Miller, David A. B.

    2006-01-01

    We present a multifunctional photonic switch that monolithically integrates an InGaAsP/InP quantum well electroabsorption modulator and an InGaAs photodiode as a part of an on-chip, InP optoelectronic circuit. The optical multifunctionality of the switch offers many configurations to allow for different optical network functions on a single chip. Here we experimentally demonstrate GHz-range optical wavelength-converting switching with only ~10 mW of absorbed input optical power, electronically controlled packet switching with a reconfiguration time of <2.5 ns, and optically controlled packet switching in <300 ps.

  5. Hybrid Ytterbium-doped large-mode-area photonic crystal fiber amplifier for long wavelengths.

    PubMed

    Petersen, Sidsel R; Alkeskjold, Thomas T; Poli, Federica; Coscelli, Enrico; Jørgensen, Mette M; Laurila, Marko; Lægsgaard, Jesper; Broeng, Jes

    2012-03-12

    A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with build-in gain shaping is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes define the large-mode-area core. Light confinement is achieved by combined index and bandgap guiding, which allows for single-mode operation and gain shaping through distributed spectral filtering of amplified spontaneous emission. The fiber properties are ideal for amplification in the long wavelength regime of the Ytterbium gain spectrum above 1100 nm, and red shifting of the maximum gain to 1130 nm is demonstrated.

  6. Zero-dispersion wavelength decreasing photonic crystal fibers for ultraviolet-extended supercontinuum generation.

    PubMed

    Kudlinski, A; George, A K; Knight, J C; Travers, J C; Rulkov, A B; Popov, S V; Taylor, J R

    2006-06-12

    We report the fabrication of photonic crystal fibers with a continuously-decreasing zero-dispersion wavelength along their length. These tapered fibers are designed to extend the generation of supercontinuum spectra from the visible into the ultraviolet. We report on their performance when pumped with both nanosecond and picosecond sources at 1.064 microm. The supercontinuum spectra have a spectral width (measured at the 10 dB points) extending from 0.372 microm to beyond 1.75 microm. In an optimal configuration a flat (3 dB) spectrum from 395 to 850 nm, with a minimum spectral power density of 2 mW/nm was achieved, with a total continuum output power of 3.5 W. We believe that the shortest wavelengths were generated by cascaded four-wave mixing: the continuous decrease of the zero dispersion wavelength along the fiber length enables the phase-matching condition to be satisfied for a wide range of wavelengths into the ultraviolet, while simultaneously increasing the nonlinear coefficient of the fiber.

  7. Mid-Infrared and multi-wavelength monitoring of the microquasar GRS 1915+105.

    NASA Astrophysics Data System (ADS)

    Fuchs, Yael; Chaty, Sylvain; Dhawan, Vivek; Diana, Hannikainen; Mirabel, Felix; Pooley, Guy; Ribo, Marc; Rodriguez, Jerome; Rupen, Michael

    2005-06-01

    We propose to continue mid-infrared photometric and spectroscopic observations of the microquasar GRS 1915+105 in the context of a campaign of multi-wavelength observations of the source. GRS 1915+105 is used as a laboratory to understand the accretion / ejection phenomena occurring in stellar-mass accreting black hole (microquasars) and by analogy in supermassive black holes (AGNs). A key question is the nature of the time-variable infrared emission in this system. Depending on the state of the source, we wish to know what is the contribution in the mid-infrared of the different possible emission mechanisms: the thermal emission from the K-M giant donor star, the synchrotron emission from the compact relativistic jets, X-ray reprocessing in the accretion disc and free-free emission from a possible disc-wind. The continuum in a wavelength range as large as possible and the possible emission lines observed thanks to the Infrared Array Camera (IRAC) and the Infrared Spectrograph (IRS) are important clues to achieve this study. These mid-infrared observations will be combined with observations with the RXTE and INTEGRAL satellites in the X-rays and gamma-rays, the ESO/NTT in near-infrared and the VLA/VLBA and Ryle Telescopes in radio. Thanks to these simultaneous multiwavelength observations we will identify the accretion state of the source and determine the contribution of each emission component of the system. As GRS 1915+105 had been rarely observed in the mid-infrared range in the past, the Spitzer Space Telescope brings the unique opportunity to do so, shedding light on the physical mechanisms occurring in this particular binary system and which could apply to the other black hole binaries.

  8. Fast hyper-spectral imaging of cytological samples in the mid-infrared wavelength region

    NASA Astrophysics Data System (ADS)

    Farries, Mark; Ward, Jon; Lindsay, Ian; Nallala, Jayakrupakar; Moselund, Peter

    2017-02-01

    A prototype mid-infrared spectral imaging system for rapid assessment of cells for cytological diagnosis is reported. Based on a fibre optic super-continuum source that has large spectral brightness and is coupled in to an acousto-optic tuneable filter that can rapidly scan over a set of wavelengths that are chosen to give a high level of selectivity for a specific skin disease. The system has the potential to collect an image cube of 100 wavelengths and 300k pixels in 2 seconds so that cells on living people could be analysed. The system has been evaluated with colon cells over 2700- 3100 cm-1.

  9. Germanium-on-silicon Vernier-effect photonic microcavities for the mid-infrared.

    PubMed

    Troia, Benedetto; Penades, Jordi Soler; Khokhar, Ali Z; Nedeljkovic, Milos; Alonso-Ramos, Carlos; Passaro, Vittorio M N; Mashanovich, Goran Z

    2016-02-01

    We present Vernier-effect photonic microcavities based on a germanium-on-silicon technology platform, operating around the mid-infrared wavelength of 3.8 μm. Cascaded racetrack resonators have been designed to operate in the second regime of the Vernier effect, and typical Vernier comb-like spectra have been successfully demonstrated with insertion losses of ∼5  dB, maximum extinction ratios of ∼23  dB, and loaded quality factors higher than 5000. Furthermore, an add-drop racetrack resonator designed for a Vernier device has been characterized, exhibiting average insertion losses of 1 dB, extinction ratios of up to 18 dB, and a quality factor of ∼1700.

  10. Mid-infrared wavelength conversion in silicon waveguides using ultracompact telecom-band-derived pump source

    NASA Astrophysics Data System (ADS)

    Zlatanovic, Sanja; Park, Jung S.; Moro, Slaven; Boggio, Jose M. Chavez; Divliansky, Ivan B.; Alic, Nikola; Mookherjea, Shayan; Radic, Stojan

    2010-08-01

    Mid-infrared light sources are essential for applications that include free-space communication, chemical and biomolecular sensing and infrared spectroscopy, but no devices comparable to those in the near-infrared regime have emerged to date. Indeed, sources operating above 1.8 µm, including optical parametric oscillators and thulium-doped fibre lasers, do not combine a large tunable range and narrow linewidth, and generally cannot be modulated to support advanced applications. Widely tunable mid-infrared quantum cascade lasers are available; however, room-temperature operation in the 3-4 µm range still presents a challenge because of material limitations. Wavelength conversion in silicon offers promise for the development of an ultracompact mid-infrared source that combines wide wavelength tuning, narrow linewidth and arbitrarily complex modulation rivalling those in the telecom window. Here, we report four-wave mixing in silicon waveguides in the spectral region beyond 2 µm, using probe and pump waves derived from ultracompact telecom fibre-optic sources, achieving generation of 2,388 nm light.

  11. Spiral superconducting nanowire single-photon detector with efficiency over 50% at 1550 nm wavelength

    NASA Astrophysics Data System (ADS)

    Huang, J.; Zhang, W. J.; You, L. X.; Liu, X. Y.; Guo, Q.; Wang, Y.; Zhang, L.; Yang, X. Y.; Li, H.; Wang, Z.; Xie, X. M.

    2017-07-01

    Superconducting nanowire single-photon detectors (SNSPDs) are widely used for the detection of visible and near-infrared single photons. Due to the nature of the polarization sensitive absorption of the nanowire, the detection efficiency (DE) of the meander SNSPD is polarization sensitive. In order to obtain a polarization-insensitive device with high DE, we fabricated NbN SNSPDs with spiral structure, which were embedded into an optical cavity. No meaningful current crowding effect was observed in the spiral SNSPDs. The spiral SNSPD showed a maximal system detection efficiency of 52.5% at 1550 nm with a dark count rate of 100 Hz and a polarization extinction ratio of 1.04, due to the combination of a spiral geometry and an optical cavity.

  12. Wavelength-selective and diffuse infrared thermal emission mediated by magnetic polaritons from silicon carbide metasurfaces

    NASA Astrophysics Data System (ADS)

    Yang, Yue; Taylor, Sydney; Alshehri, Hassan; Wang, Liping

    2017-07-01

    In the present study, we experimentally demonstrate the spectrally coherent and diffuse thermal emission by exciting magnetic polaritons in SiC metasurfaces fabricated by the focused ion beam technique. Spectral emittance characterized by using an infrared microscope coupled to a Fourier transform spectrometer clearly shows a wavelength-selective emission peak as high as 0.8. Numerical simulations including emittance spectra and contour plot of electromagnetic field distribution were carried out to verify and understand the underlying mechanism of magnetic polaritons. The metasurfaces were further shown to be direction and polarization independent. The results would facilitate metasurfaces for applications like radiative thermal management and infrared sensing.

  13. An ultra low noise telecom wavelength free running single photon detector using negative feedback avalanche diode.

    PubMed

    Yan, Zhizhong; Hamel, Deny R; Heinrichs, Aimee K; Jiang, Xudong; Itzler, Mark A; Jennewein, Thomas

    2012-07-01

    It is challenging to implement genuine free running single-photon detectors for the 1550 nm wavelength range with simultaneously high detection efficiency (DE), low dark noise, and good time resolution. We report a novel read out system for the signals from a negative feedback avalanche diode (NFAD) [M. A. Itzler, X. Jiang, B. Nyman, and K. Slomkowski, "Quantum sensing and nanophotonic devices VI," Proc. SPIE 7222, 72221K (2009); X. Jiang, M. A. Itzler, K. ODonnell, M. Entwistle, and K. Slomkowski, "Advanced photon counting techniques V," Proc. SPIE 8033, 80330K (2011); M. A. Itzler, X. Jiang, B. M. Onat, and K. Slomkowski, "Quantum sensing and nanophotonic devices VII," Proc. SPIE 7608, 760829 (2010)], which allows useful operation of these devices at a temperature of 193 K and results in very low darkcounts (∼100 counts per second (CPS)), good time jitter (∼30 ps), and good DE (∼10%). We characterized two NFADs with a time-correlation method using photons generated from weak coherent pulses and photon pairs produced by spontaneous parametric down conversion. The inferred detector efficiencies for both types of photon sources agree with each other. The best noise equivalent power of the device is estimated to be 8.1 × 10(-18) W Hz(-1/2), more than 10 times better than typical InP/InGaAs single photon avalanche diodes (SPADs) show in free running mode. The afterpulsing probability was found to be less than 0.1% per ns at the optimized operating point. In addition, we studied the performance of an entanglement-based quantum key distribution (QKD) using these detectors and develop a model for the quantum bit error rate that incorporates the afterpulsing coefficients. We verified experimentally that using these NFADs it is feasible to implement QKD over 400 km of telecom fiber. Our NFAD photon detector system is very simple, and is well suited for single-photon applications where ultra-low noise and free-running operation is required, and some afterpulsing

  14. Photonic crystal-enhanced quantum dot infrared photodetectors

    NASA Astrophysics Data System (ADS)

    McKerracher, I. R.; Hattori, H. T.; Fu, L.; Tan, H. H.; Jagadish, C.

    2008-08-01

    Quantum dot infrared photodetectors (QDIPs) promise improved performance over existing technologies in the form of higher temperature operation and normal-incidence detection. Variation in the size of self-assembled quantum dots leads to a broadened spectral response, which is undesirable for multi-color detection. Photonic crystal slabs can filter the transmission of normally-incident light using Fano resonances, and thus may be integrated with QDIPs to create a narrowband detector. Finite-difference time-domain simulations were used to optimize such a filter for QDIPs grown by metal-organic chemical vapor deposition. The simulations predict that the integrated detector could show up to 76% decrease in the detector linewidth, with a tunable peak location. These devices were then fabricated by standard optical lithography, however the spectral width of the integrated device was similar to that of the unfiltered QDIP. This is attributed to imperfections in the filter, so alternative fabrication methods are discussed for future processing.

  15. A passive long-wavelength infrared microscope with a highly sensitive phototransistor

    NASA Astrophysics Data System (ADS)

    Kajihara, Yusuke; Komiyama, Susumu; Nickels, Patrick; Ueda, Takeji

    2009-06-01

    A passive scanning confocal microscope in the long-wavelength infrared (LWIR) region has been developed for sensitive imaging of spontaneous LWIR radiation by utilizing an ultrahighly sensitive detector, called the charge-sensitive infrared phototransistor (CSIP). The microscope consisted of room-temperature components including a Ge objective lens and liquid helium temperature components including a confocal pinhole, Ge relay lenses, and CSIP detector. With the microscope, thermal radiation (wavelength of 14.7 μm) spontaneously emitted by the object was studied with a spatial resolution of 25 μm. Clear passive LWIR imaging pictures were obtained by scanning a sample consisting of glass, Al foil, Ag paste, and Au. Clear passive LWIR image was also obtained even when the sample surface was covered by a GaAs or Si plate. This work suggests usefulness of CSIP detectors for application of passive LWIR microscopy.

  16. A passive long-wavelength infrared microscope with a highly sensitive phototransistor.

    PubMed

    Kajihara, Yusuke; Komiyama, Susumu; Nickels, Patrick; Ueda, Takeji

    2009-06-01

    A passive scanning confocal microscope in the long-wavelength infrared (LWIR) region has been developed for sensitive imaging of spontaneous LWIR radiation by utilizing an ultrahighly sensitive detector, called the charge-sensitive infrared phototransistor (CSIP). The microscope consisted of room-temperature components including a Ge objective lens and liquid helium temperature components including a confocal pinhole, Ge relay lenses, and CSIP detector. With the microscope, thermal radiation (wavelength of 14.7 microm) spontaneously emitted by the object was studied with a spatial resolution of 25 microm. Clear passive LWIR imaging pictures were obtained by scanning a sample consisting of glass, Al foil, Ag paste, and Au. Clear passive LWIR image was also obtained even when the sample surface was covered by a GaAs or Si plate. This work suggests usefulness of CSIP detectors for application of passive LWIR microscopy.

  17. On the conversion of infrared radiation from fission reactor-based photon engine into parallel beam

    NASA Astrophysics Data System (ADS)

    Gulevich, Andrey V.; Levchenko, Vladislav E.; Loginov, Nicolay I.; Kukharchuk, Oleg F.; Evtodiev, Denis A.; Zrodnikov, Anatoly V.

    2002-01-01

    The efficiency of infrared radiation conversion from photon engine based on fission reactor into parallel photon beam is discussed. Two different ways of doing that are considered. One of them is to use the parabolic mirror to convert of infrared radiation into parallel photon beam. The another one is based on the use of special lattice consisting of numerous light conductors. The experimental facility and some results are described. .

  18. Novel Wavelength Shifting Collection Systems for Vacuum Ultraviolet Scintillation Photons in in Noble Gas Detectors

    NASA Astrophysics Data System (ADS)

    Gehman, Victor

    2013-04-01

    Detection of vacuum ultraviolet (VUV) photons presents a challenge because this band of the electromagnetic spectrum has a short enough wavelength to scatter off of most (though not all) materials, but is not energetic enough to penetrate into the bulk of a detector (so cannot be treated calorimetrically like x rays or γ rays). This is exactly the band in which noble gasses (which make excellent media for radiation detectors) scintillate. VUV photon detection usually involves shifting them to visible wavelengths with a fluorescent molecule deposited on an optically clear surface viewed by a photosensor. Such techniques, while comparatively efficient and simple to fabricate, have high cost and complexity per unit coverage area making them prohibitively expensive and complicated to scale up to the very large sizes necessary for the next generation of neutrino, dark matter, and other rare event search experiments. We present several lines of inquiry attempting to address this problem, focusing on solutions that are directly applicable to a variety of current or next generation noble gas detectors. This line of R&D is a potentially fruitful avenue capable of furthering the goals of many experiments with a broad portfolio of fundamental and applied research.

  19. Optically Tunable Long Wavelength Infrared Quantum Cascade Laser Operated at Room Temperature

    DTIC Science & Technology

    2013-01-09

    dx.doi.org/10.1063/1.4774267] Rapidly tunable quantum cascade lasers ( QCLs ) is a key element for the recently proposed long-wavelength infrared (LWIR...is the signal data bandwidth.1,2 QCLs are the only semiconductor lasers that can operate continuous-wave (CW) at room temperature in LWIR. Cur- rently...frequency-tuning of the distributed feedback (DFB) QCLs is typically achieved by temperature control over effective refractive index using pump

  20. Infrared images of jupiter at 5-micrometer wavelength during the voyager 1 encounter.

    PubMed

    Terrile, R J; Capps, R W; Backman, D E; Becklin, E E; Cruikshank, D P; Beichman, C A; Brown, R H; Westphal, J A

    1979-06-01

    A coordinated program to observe Jupiter at high spatial resolution in the 5-micrometer wavelength region was undertaken to support Voyager 1 imaging and infrared radiation experiment targeting. Jupiter was observed over a 5-month period from Palomar and Mauna Kea observatories. The frequency of observations allowed the selection of interesting areas for closer Voyager examination and also provided good short-term monitoring of variations in cloud morphology. Significant global changes in the 5-micrometer distribution are seen over this time period.

  1. Infrared images of Jupiter at 5-micrometer wavelength during the Voyager 1 encounter

    NASA Technical Reports Server (NTRS)

    Terrile, R. J.; Capps, R. W.; Backman, D. E.; Becklin, E. E.; Cruikshank, D. P.; Beichman, C. A.; Brown, R. H.; Westphal, J. A.

    1979-01-01

    A coordinated program to observe Jupiter at high spatial resolution in the 5-micrometer wavelength region was undertaken to support Voyager 1 imaging and infrared radiation experiment targeting. Jupiter was observed over a 5-month period from Palomar and Mauna Kea observatories. The frequency of observations allowed the selection of interesting areas for closer Voyager examination and also provided good short-term monitoring of variations in cloud morphology. Significant global changes in the 5-micrometer distribution are seen over this time period.

  2. Black Silicon Germanium (SiGe) for Extended Wavelength Near Infrared Electro-optical Applications

    DTIC Science & Technology

    2010-05-01

    BLISS ATTN RDRL SE E T BOWER ATTN RDRL SED E M LITZ ATTN RDRL SED P A LELIS ATTN RDRL SED P B MORGAN ATTN RDRL SED P K JONES...Meissner, and Priyalal Wijewarnasuriya ARL -TR-5202 May 2010 Approved for public release...Research Laboratory Adelphi, MD 20783-1197 ARL -TR-5202 May 2010 Black Silicon Germanium (SiGe) for Extended Wavelength Near Infrared

  3. Fourier transform infrared transmission microspectroscopy of photonic crystal structures.

    PubMed

    Kilby, Gregory R; Gaylord, Thomas K

    2009-07-01

    The detailed microscopic characterization of photonic crystal (PC) structures is challenging due to their small sizes. Generally, only the gross macroscopic behavior can be determined. This leaves in question the performance at the basic structure level. The single-incident-angle plane-wave transmittances of one-dimensional photonic crystal (PC) structures are extracted from multiple-incident-angle, focused-beam measurements. In the experimental apparatus, an infrared beam is focused by a reflecting microscope objective to produce an incident beam. This beam can be modeled as multiple, variable-intensity plane waves incident on the PC structure. The transmittance of the structure in response to a multiple-incident-angle composite beam is measured. The composite beam measurement is repeated at various incident angle orientations with respect to the sample normal so that, at each angular orientation, the included set of single-angle plane-wave components is unique. A set of measurements recorded over a range of angular orientations results in an underspecified matrix algebra problem. Regularization techniques can be applied to the problem to extract the single-angle plane-wave response of the structure from the composite measurements. Experimental results show very good agreement between the measured and theoretical single-angle plane-wave transmittances.

  4. Short-wavelength infrared defect emission as probe for degradation effects in diode lasers

    NASA Astrophysics Data System (ADS)

    Hempel, Martin; Tomm, Jens W.; Yue, Fangyu; Bettiati, Mauro; Elsaesser, Thomas

    2015-03-01

    The infrared emission from 980-nm single-mode high power diode lasers is analyzed in the wavelength range from 0.8 to 7.0 μm. A pronounced short-wavelength infrared (SWIR) emission band with a maximum at 1.3 μm is found to originate from defect states located within the waveguide of the devices. The SWIR intensity is verified to represent a measure of the non-equilibrium carrier concentration in the waveguide, allowing for non-destructive waveguide mapping in spatially resolved detection schemes. The potential of this approach is demonstrated by measuring spatially resolved profiles of SWIR emission and correlating them with mid-wavelength infrared thermal emission along the cavity of devices undergoing repeated catastrophic optical damage. The enhancement of SWIR emission in the damaged parts of the cavity is due to a locally enhanced carrier density in the waveguide and allows for in situ analysis of the damage patterns. Moreover, spatial resolved SWIR measurements are a promising tool for device inspecting even in low-power operation regimes.

  5. Spectroscopic technique with wide range of wavelength information improves near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Eda, Hideo; Aoki, Hiromichi; Eura, Shigeru; Ebe, Kazutoshi

    2009-02-01

    Near-infrared spectroscopy (NIRS) calculates hemoglobin parameters, such as oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) using the near-infrared light around the wavelength of 800nm. This is based on the modified-Lambert-Beer's law that changes in absorbance are proportional to changes in hemoglobin parameters. Many conventional measurement methods uses only a few wavelengths, however, in this research, basic examination of NIRS measurement was approached by acquiring wide range of wavelength information. Venous occlusion test was performed by using the blood pressure cuff around the upper arm. Pressure of 100mmHg was then applied for about 3 minutes. During the venous occlusion, the spectrum of the lower arm muscles was measured every 15 seconds, within the range of 600 to 1100nm. It was found that other wavelength bands hold information correlating to this venous occlusion task. Technique of improving the performance of NIRS measurement using the Spectroscopic Method is very important for Brain science.

  6. Short-wavelength infrared photodetector on Si employing strain-induced growth of very tall InAs nanowire arrays

    PubMed Central

    Wook Shin, Hyun; Jun Lee, Sang; Gun Kim, Doo; Bae, Myung-Ho; Heo, Jaeyeong; Jin Choi, Kyoung; Jun Choi, Won; Choe, Jeong-woo; Cheol Shin, Jae

    2015-01-01

    One-dimensional crystal growth enables the epitaxial integration of III-V compound semiconductors onto a silicon (Si) substrate despite significant lattice mismatch. Here, we report a short-wavelength infrared (SWIR, 1.4–3 μm) photodetector that employs InAs nanowires (NWs) grown on Si. The wafer-scale epitaxial InAs NWs form on the Si substrate without a metal catalyst or pattern assistance; thus, the growth is free of metal-atom-induced contaminations, and is also cost-effective. InAs NW arrays with an average height of 50 μm provide excellent anti-reflective and light trapping properties over a wide wavelength range. The photodetector exhibits a peak detectivity of 1.9 × 108  cm·Hz1/2/W for the SWIR band at 77 K and operates at temperatures as high as 220 K. The SWIR photodetector on the Si platform demonstrated in this study is promising for future low-cost optical sensors and Si photonics. PMID:26035286

  7. Short-wavelength infrared photodetector on Si employing strain-induced growth of very tall InAs nanowire arrays.

    PubMed

    Shin, Hyun Wook; Lee, Sang Jun; Kim, Doo Gun; Bae, Myung-Ho; Heo, Jaeyeong; Choi, Kyoung Jin; Choi, Won Jun; Choe, Jeong-woo; Shin, Jae Cheol

    2015-06-02

    One-dimensional crystal growth enables the epitaxial integration of III-V compound semiconductors onto a silicon (Si) substrate despite significant lattice mismatch. Here, we report a short-wavelength infrared (SWIR, 1.4-3 μm) photodetector that employs InAs nanowires (NWs) grown on Si. The wafer-scale epitaxial InAs NWs form on the Si substrate without a metal catalyst or pattern assistance; thus, the growth is free of metal-atom-induced contaminations, and is also cost-effective. InAs NW arrays with an average height of 50 μm provide excellent anti-reflective and light trapping properties over a wide wavelength range. The photodetector exhibits a peak detectivity of 1.9 × 10(8) cm · Hz(1/2)/W for the SWIR band at 77 K and operates at temperatures as high as 220 K. The SWIR photodetector on the Si platform demonstrated in this study is promising for future low-cost optical sensors and Si photonics.

  8. Potential of a superconducting photon counter for heterodyne detection at the telecommunication wavelength.

    PubMed

    Shcherbatenko, M; Lobanov, Y; Semenov, A; Kovalyuk, V; Korneev, A; Ozhegov, R; Kazakov, A; Voronov, B M; Goltsman, G N

    2016-12-26

    Here, we report on the successful operation of a NbN thin film superconducting nanowire single-photon detector (SNSPD) in a coherent mode (as a mixer) at the telecommunication wavelength of 1550 nm. Providing the local oscillator power of the order of a few picowatts, we were practically able to reach the quantum noise limited sensitivity. The intermediate frequency gain bandwidth (also referred to as response or conversion bandwidth) was limited by the spectral band of a single-photon response pulse of the detector, which is proportional to the detector size. We observed a gain bandwidth of 65 MHz and 140 MHz for 7 × 7 µm2 and 3 × 3 µm2 devices, respectively. A tiny amount of the required local oscillator power and wide gain and noise bandwidths, along with unnecessary low noise amplification, make this technology prominent for various applications, with the possibility for future development of a photon counting heterodyne-born large-scale array.

  9. Coherent detection of weak signals with superconducting nanowire single photon detector at the telecommunication wavelength

    NASA Astrophysics Data System (ADS)

    Shcherbatenko, M.; Lobanov, Y.; Semenov, A.; Kovalyuk, V.; Korneev, A.; Ozhegov, R.; Kaurova, N.; Voronov, B.; Goltsman, G.

    2017-05-01

    Achievement of the ultimate sensitivity along with a high spectral resolution is one of the frequently addressed problems, as the complication of the applied and fundamental scientific tasks being explored is growing up gradually. In our work, we have investigated performance of a superconducting nanowire photon-counting detector operating in the coherent mode for detection of weak signals at the telecommunication wavelength. Quantum-noise limited sensitivity of the detector was ensured by the nature of the photon-counting detection and restricted by the quantum efficiency of the detector only. Spectral resolution given by the heterodyne technique and was defined by the linewidth and stability of the Local Oscillator (LO). Response bandwidth was found to coincide with the detector's pulse width, which, in turn, could be controlled by the nanowire length. In addition, the system noise bandwidth was shown to be governed by the electronics/lab equipment, and the detector noise bandwidth is predicted to depend on its jitter. As have been demonstrated, a very small amount of the LO power (of the order of a few picowatts down to hundreds of femtowatts) was required for sufficient detection of the test signal, and eventual optimization could lead to further reduction of the LO power required, which would perfectly suit for the foreseen development of receiver matrices and the need for detection of ultra-low signals at a level of less-than-one-photon per second.

  10. Two Fabry-Perot interferometers for high precision wavelength calibration in the near-infrared

    NASA Astrophysics Data System (ADS)

    Schäfer, Sebastian; Reiners, Ansgar

    2012-09-01

    The most frequently used standard light sources for spectroscopic high precision wavelength calibration are hollow cathode lamps. These lamps, however, do not provide homogeneous line distribution and intensities. Particularly in the infrared, the number of useful lines is severely limited and the spectrum is contaminated by lines of the filler gas. With the goal of achieving sub m/s stability in the infrared, as required for detecting earthlike extra-solar planets, we are developing two passively stabilized Fabry-Perot interferometers for the red visible (600-1050nm) and near infrared wavelength regions (900-1350nm). Each of the two interferometers can produce ~15,000 lines of nearly constant brightness. The Fabry-Perot interferometers aim at a RV calibration precision of 10cm/s and are optimized in line shape and spacing for the infrared planet hunting CARMENES spectrograph that is currently being built for the Calar Alto 3.5m telescope. Here we present the first results of our work.

  11. An efficient technique for the reduction of wavelength noise in resonance-based integrated photonic sensors.

    PubMed

    Ghasemi, Farshid; Chamanzar, Maysamreza; Eftekhar, Ali A; Adibi, Ali

    2014-11-21

    A systematic study of the limit of detection (LOD) in resonance-based silicon photonic lab-on-chip sensors is presented. The effects of the noise, temperature fluctuations, and the fundamental thermodynamic limit of the resonator are studied. Wavelength noise is identified as the dominant source of noise, and an efficient technique for suppressing this noise is presented. A large ensemble of statistical data from the transmission measurements in a laser-scanning configuration on five silicon nitride (SiN) microrings is collected to discuss and identify the sources of noise. The experimental results show that the LOD is limited by a 3σ wavelength noise of ∼1.8 pm. We present a sub-periodic interferometric technique, relying on an inverse algorithm, to suppress this noise. Our technique reduces the wavelength noise by more than one order of magnitude to an ensemble average of 3σ = 120 fm, for a resonator quality factor (Q) of about 5 × 10(4) without any temperature stabilization or cooling. This technique is readily amenable to on-chip integration to realize highly accurate and low-cost lab-on-chip sensors.

  12. Noninvasive red and near-infrared wavelength-induced photobiomodulation: promoting impaired cutaneous wound healing.

    PubMed

    Yadav, Anju; Gupta, Asheesh

    2017-01-01

    The innumerable intricacies associated with chronic wounds have made the development of new painless, noninvasive, biophysical therapeutic interventions as the focus of current biomedical research. Red and near-infrared light-induced photobiomodulation therapy appears to emerge as a promising drug-free approach for promoting wound healing, reduction in inflammation, pain and restoration of function owing to penetration power in conjunction with their ability to positively modulate the biochemical and molecular responses. This review will describe the physical properties of red and near-infrared light and their interaction with skin and highlight their efficacy of wound repair and regeneration. Near-infrared (800-830 nm) was found to be the most effective and widely studied wavelength range followed by red (630-680 nm) and 904 nm superpulsed light exhibiting beneficial photobiomodulatory effects on impaired dermal wound healing.

  13. Switchable multi-wavelength fiber ring laser using a side-leakage photonic crystal fiber based filter

    NASA Astrophysics Data System (ADS)

    Chen, Weiguo; Lou, Shuqin; Wang, Liwen; Zou, Hui; Lu, Wenliang; Jian, Shuisheng

    2012-04-01

    A switchable multi-wavelength fiber ring laser is proposed and experimentally demonstrated with a novel side-leakage photonic crystal fiber (SLPCF) based filter incorporated into the ring cavity at room temperature. Stable multi-wavelength laser operations can be achieved due to the spatial mode beating, polarization hole burning and spectral hole burning effects. By adjusting the polarization controller appropriately, the laser can be switched among the single-, dual- and triple-wavelength lasing oscillations whose signal-to-noise ratio is up to 50 dB. In addition, the lasing wavelength can be also tuned and switched by applying the strain to the filter.

  14. Adaptive gain, equalization, and wavelength stabilization techniques for silicon photonic microring resonator-based optical receivers

    NASA Astrophysics Data System (ADS)

    Palermo, Samuel; Chiang, Patrick; Yu, Kunzhi; Bai, Rui; Li, Cheng; Chen, Chin-Hui; Fiorentino, Marco; Beausoleil, Ray; Li, Hao; Shafik, Ayman; Titriku, Alex

    2016-03-01

    Interconnect architectures based on high-Q silicon photonic microring resonator devices offer a promising solution to address the dramatic increase in datacenter I/O bandwidth demands due to their ability to realize wavelength-division multiplexing (WDM) in a compact and energy efficient manner. However, challenges exist in realizing efficient receivers for these systems due to varying per-channel link budgets, sensitivity requirements, and ring resonance wavelength shifts. This paper reports on adaptive optical receiver design techniques which address these issues and have been demonstrated in two hybrid-integrated prototypes based on microring drop filters and waveguide photodetectors implemented in a 130nm SOI process and high-speed optical front-ends designed in 65nm CMOS. A 10Gb/s powerscalable architecture employs supply voltage scaling of a three inverter-stage transimpedance amplifier (TIA) that is adapted with an eye-monitor control loop to yield the necessary sensitivity for a given channel. As reduction of TIA input-referred noise is more critical at higher data rates, a 25Gb/s design utilizes a large input-stage feedback resistor TIA cascaded with a continuous-time linear equalizer (CTLE) that compensates for the increased input pole. When tested with a waveguide Ge PD with 0.45A/W responsivity, this topology achieves 25Gb/s operation with -8.2dBm sensitivity at a BER=10-12. In order to address microring drop filters sensitivity to fabrication tolerances and thermal variations, efficient wavelength-stabilization control loops are necessary. A peak-power-based monitoring loop which locks the drop filter to the input wavelength, while achieving compatibility with the high-speed TIA offset-correction feedback loop is implemented with a 0.7nm tuning range at 43μW/GHz efficiency.

  15. Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

    NASA Astrophysics Data System (ADS)

    Zhang, Hairong; Salo, Daniel; Kim, David M.; Komarov, Sergey; Tai, Yuan-Chuan; Berezin, Mikhail Y.

    2016-12-01

    Measurement of photon penetration in biological tissues is a central theme in optical imaging. A great number of endogenous tissue factors such as absorption, scattering, and anisotropy affect the path of photons in tissue, making it difficult to predict the penetration depth at different wavelengths. Traditional studies evaluating photon penetration at different wavelengths are focused on tissue spectroscopy that does not take into account the heterogeneity within the sample. This is especially critical in shortwave infrared where the individual vibration-based absorption properties of the tissue molecules are affected by nearby tissue components. We have explored the depth penetration in biological tissues from 900 to 1650 nm using Monte-Carlo simulation and a hyperspectral imaging system with Michelson spatial contrast as a metric of light penetration. Chromatic aberration-free hyperspectral images in transmission and reflection geometries were collected with a spectral resolution of 5.27 nm and a total acquisition time of 3 min. Relatively short recording time minimized artifacts from sample drying. Results from both transmission and reflection geometries consistently revealed that the highest spatial contrast in the wavelength range for deep tissue lies within 1300 to 1375 nm however, in heavily pigmented tissue such as the liver, the range 1550 to 1600 nm is also prominent.

  16. Design and characterization of one-dimensional photonic crystals based on ZnS/Ge for infrared-visible compatible stealth applications

    NASA Astrophysics Data System (ADS)

    Qi, Dong; Wang, Xian; Cheng, Yongzhi; Gong, Rongzhou; Li, Bowen

    2016-12-01

    One-dimensional photonic crystals (1DPCs) based on ZnS/Ge for compatible stealth of infrared and visible were firstly proposed theoretically and investigated experimentally. Owing to the equal inclination interference, the designed 1DPCs structure can be fabricated with a certain color corresponding to the different responded wavelength. In addition, the average emissivity of the proposed structure can reach as low as 0.054 at infrared atmosphere window of 3-5 μm. The as-prepared structure indicates that it is feasible for 1DPC to achieve infrared-visible compatible stealth.

  17. Enhancement of the infrared detection efficiency of silicon photon-counting avalanche photodiodes by use of silicon germanium absorbing layers.

    PubMed

    Loudon, Alison Y; Hiskett, Philip A; Buller, Gerald S; Carline, Roger T; Herbert, Dave C; Leong, W Y; Rarity, John G

    2002-02-15

    An enhancement of the infrared detection efficiency of Si photon-counting detectors by inclusion of SiGe absorbing layers has been demonstrated for what is believed to be the first time. An improvement of 30 times in detection efficiency at a wavelength of 1210 nm compared with that of an all-Si structure operated under identical conditions has been measured. The Si/Si(0.7)Ge(0.3) device is capable of room-temperature operation and has a response time of less than 300 ps.

  18. Comparative morphological analysis of Puppis A at radio, infrared, optical, and X-ray wavelengths

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Dwek, Eli; Petre, Robert; Dickel, John R.; Roger, Robert S.

    1990-01-01

    This paper presents a new radio image of the supernova remnant Puppis A obtained with the Molonglo Observatory synthesis telescope (MOST) and the Parkes telescope, and infrared images of Puppis A and its surrounding medium obtained with the IRAS, and compares the remnant morphologies at radio, infrared, optical, and X-ray wavelengths. The radio image, which includes large-scale emission, shows a clumpy shell of emission with moderate central brightness. The infrared observations have the advantage of offering a detailed look at the medium into which the remnant is expanding. From the IR data, evidence is found of the remnant's expansion into a strong density gradient (distinct from the more gentle gradient of the Galactic plane). A strong isolated knot of enhanced X-ray and radio emission is a region of enhanced infrared emission as well. Detailed correlative analysis of the infrared, radio, and X-ray emission shows that the IR emission correlates very well with the X-ray emission, confirming the idea that the IR emission arises from dust that is collisionally heated by the shocked gas.

  19. Review on short-wavelength infrared laser gated-viewing at Fraunhofer IOSB

    NASA Astrophysics Data System (ADS)

    Göhler, Benjamin; Lutzmann, Peter

    2017-03-01

    This paper reviews the work that has been done at Fraunhofer IOSB (and its predecessor institutes) in the past ten years in the area of laser gated-viewing (GV) in the short-wavelength infrared (SWIR) band. Experimental system demonstrators in various configurations have been built up to show the potential for different applications and to investigate specific topics. The wavelength of the pulsed illumination laser is 1.57 μm and lies in the invisible, retina-safe region allowing much higher pulse energies than for wavelengths in the visible or near-infrared band concerning eye safety. All systems built up, consist of gated Intevac LIVAR® cameras based on EBCCD/EBCMOS detectors sensitive in the SWIR band. This review comprises military and civilian applications in maritime and land domain-in particular vision enhancement in bad visibility, long-range applications, silhouette imaging, 3-D imaging by sliding gates and slope method, bistatic GV imaging, and looking through windows. In addition, theoretical studies that were conducted-e.g., estimating 3-D accuracy or modeling range performance-are presented. Finally, an outlook for future work in the area of SWIR laser GV at Fraunhofer IOSB is given.

  20. Active plasmonic switching at mid-infrared wavelengths with graphene ribbon arrays

    NASA Astrophysics Data System (ADS)

    Chu, Hong-Son; How Gan, Choon

    2013-06-01

    An active plasmonic switch based on single- and few-layer doped graphene ribbon array operating in the mid-infrared spectrum is investigated with theoretical and numerical calculations. It is shown that significant resonance wavelength shifts and modulation depths can be achieved with a slight variation of the doping concentration of the graphene ribbon. The few-layer graphene ribbon array device outperforms the single-layer one in terms of the achievable modulation depth. Our simulations reveal that, by modulating the Fermi-energy level between 0.2 eV and 0.25 eV, a four-layer graphene ribbon array device can achieve a modulation depth and resonance wavelength shift of ˜13 dB and 0.94 μm, respectively, compared to ˜2.8 dB and 1.85 μm for a single-layer device. Additionally, simple fitting models to predict the modulation depth and the resonance wavelength shift are proposed. These prospects pave the way towards ultrafast active graphene-based plasmonic devices for infrared and THz applications.

  1. Method of single expression: an exact solution for wavelength scale 1D photonic structure computer modeling

    NASA Astrophysics Data System (ADS)

    Baghdasaryan, Hovik V.; Knyazyan, Tamara M.

    2003-12-01

    The principles of the method of single expression (MSE) for boundary problems solution in classical electrodynamics are presented. In the MSE the solution of the Helmholtz's equation is presented in the special form of a single expression describing resultant amplitude and phase distributions in the medium. This form of solution presenation permits to pass over the restrictions of the superposition principle and to solve both linear and nonlinear problems with ths same ease. In the MSE the Helmholtz's equation is reformulated to the set of first order differential equations and the boundary problem is solved numerically. No approximations are implied either in Helmholtz's equation or in boundary conditions. Using the MSE steady-state boundary problems are modeled for wavelength scale multilayer and modulated 1D photonic structures including amplification and nonuniformity evoked by intense electromagnetic field.

  2. Silicon nitride CMOS-compatible platform for integrated photonics applications at visible wavelengths.

    PubMed

    Romero-García, Sebastian; Merget, Florian; Zhong, Frank; Finkelstein, Hod; Witzens, Jeremy

    2013-06-17

    Silicon nitride is demonstrated as a high performance and cost-effective solution for dense integrated photonic circuits in the visible spectrum. Experimental results for nanophotonic waveguides fabricated in a standard CMOS pilot line with losses below 0.71dB/cm in an aqueous environment and 0.51dB/cm with silicon dioxide cladding are reported. Design and characterization of waveguide bends, grating couplers and multimode interference couplers (MMI) at a wavelength of 660 nm are presented. The index contrast of this technology enables high integration densities with insertion losses below 0.05 dB per 90° bend for radii as small as 35 µm. By a proper design of the buried oxide layer thickness, grating couplers with efficiencies above 38% for the TE polarization have been obtained.

  3. Comptonization of X-rays by low-temperature electrons. [photon wavelength redistribution in cosmic sources

    NASA Technical Reports Server (NTRS)

    Illarionov, A.; Kallman, T.; Mccray, R.; Ross, R.

    1979-01-01

    A method is described for calculating the spectrum that results from the Compton scattering of a monochromatic source of X-rays by low-temperature electrons, both for initial-value relaxation problems and for steady-state spatial diffusion problems. The method gives an exact solution of the inital-value problem for evolution of the spectrum in an infinite homogeneous medium if Klein-Nishina corrections to the Thomson cross section are neglected. This, together with approximate solutions for problems in which Klein-Nishina corrections are significant and/or spatial diffusion occurs, shows spectral structure near the original photon wavelength that may be used to infer physical conditions in cosmic X-ray sources. Explicit results, shown for examples of time relaxation in an infinite medium and spatial diffusion through a uniform sphere, are compared with results obtained by Monte Carlo calculations and by solving the appropriate Fokker-Planck equation.

  4. GeSn/SiGeSn photonic devices for mid-infrared applications: experiments and calculations

    NASA Astrophysics Data System (ADS)

    Han, Genquan; Zhang, Qingfang; Liu, Yan; Zhang, Chunfu; Hao, Yue

    2016-11-01

    In this work, a fully strained GeSn photodetector with Sn atom percent of 8% is fabricated on Ge buffer on Si(001) substrate. The wavelength λ of light signals with obvious optical response for Ge0.92Sn0.08 photodetector is extended to 2 μm. The impacts of compressive strain introduced during the epitaxial growth of GeSn on Ge/Si are studied by simulation. Besides, the tensile strain engineering of GeSn photonic devices is also investigated. Lattice-matched GeSn/SiGeSn double heterostructure light emitting diodes (LEDs) with Si3N4 tensile liner stressor are designed to promote the further mid-infrared applications of GeSn photonic devices. With the releasing of the residual stress in Si3N4 liner, a large biaxial tensile strain is induced in GeSn active layer. Under biaxial tensile strain, the spontaneous emission rate rsp and internal quantum efficiency ηIQE for GeSn/SiGeSn LED are significantly improved.

  5. Free-space-coupled superconducting nanowire single-photon detectors for infrared optical communications

    NASA Astrophysics Data System (ADS)

    Bellei, Francesco; Cartwright, Alyssa P.; McCaughan, Adam N.; Dane, Andrew E.; Najafi, Faraz; Zhao, Qingyuan; Berggren, Karl K.

    2016-02-01

    This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% +/- 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 +/- 0.11 {\\mu}m starting from a fiber source at wavelength, {\\lambda} = 1.55 {\\mu}m. We demonstrated efficient photon counting on a detector with an 8 x 7.3 {\\mu}m^2 area. We measured a dark count rate of 95 +/- 3.35 kcps and a system detection efficiency of 1.64% +/- 0.13%. We explain the key steps that are required to further improve the coupling efficiency.

  6. Mid-Infrared and multi-wavelength monitoring of the microquasar GRS 1915+105.

    NASA Astrophysics Data System (ADS)

    Fuchs, Yael; Chaty, Sylvain; Diana, Hannikainen; Mirabel, Felix; Rodriguez, Jerome

    2004-09-01

    We propose mid-infrared photometric and spectroscopic observations of the microquasar GRS 1915+105 in the context of a multi-wavelength follow-up campaign of the source. GRS 1915+105 is used as a laboratory to understand the accretion / ejection phenomena occurring in stellar-mass accreting black hole (microquasars) and by analogy in supermassive black holes (AGNs). A key question is the nature of the time-variable infrared emission in this system. Depending on the state of the source, we wish to know what is the contribution in the mid-infrared of the different possible emission mechanisms: the thermal emission from the K-M giant donor star, the synchrotron emission from the compact relativistic jets, X-ray reprocessing in the accretion disc and free-free emission from a dense wind. A particular contribution of the Spitzer Telescope will be the observation of this dense wind in GRS 1915+105, which is very difficult to detect in X-ray spectra due to pile-up phenomena in X-ray detectors. The continuum in a wavelength range as large as possible and the possible emission lines observed thanks to the Infrared Array Camera (IRAC) and the Infrared Spectrograph (IRS) are important clues to achieve this study. These mid-infrared observations will be combined with observations with the RXTE and INTEGRAL satellites in the X-rays and gamma-rays, the ESO/NTT in near-infrared and the Ryle Telescope in radio. Thanks to these simultaneous multiwavelength observations we will identify the accretion state of the source and determine the contribution of each emission component of the system. As GRS 1915+105 had been rarely observed in the mid-infrared range in the past, the Spitzer Space Telescope will bring the unique opportunity to do so, shedding light on the physical mechanisms occurring in this particular binary system and which could apply to the other black hole binaries.

  7. THE SPECTRAL ENERGY DISTRIBUTION OF THE CARINA NEBULA FROM FAR-INFRARED TO RADIO WAVELENGTHS

    SciTech Connect

    Salatino, M.; De Bernardis, P.; Masi, S.; Polenta, G.

    2012-03-20

    Multi-wavelength observations are necessary for understanding the physical properties of astrophysical sources. In this paper, we use observations in the far-infrared to radio range to derive the spectral energy distribution (SED) of the Carina nebula. To do this, we carefully subtract the irregularly varying diffuse emission from the Galactic plane, which can be of the order of 10% of the nebula flux at these wavelengths. We find that the far-infrared SED can be modeled as emission from a dust population with a single temperature T{sub d} = (34.5{sup +2.0}{sub -1.8}) K and with a spectral index of emissivity {alpha} = -1.37{sup +0.09}{sub -0.08}. We also find a total infrared luminosity of the nebula of (7.4{sup +2.5}{sub -1.4}) Multiplication-Sign 10{sup 6} L{sub Sun} and, assuming a single temperature of the dust, a mass of the dust of (9500{sup +4600}{sub -3500}) M{sub Sun }.

  8. Analysis of the resolution-bandwidth-noise trade-off in wavelength-based photonic analog-to-digital converters.

    PubMed

    Stigwall, Johan; Galt, Sheila

    2006-06-20

    The performance of wavelength-based photonic analog-to-digital converters (ADCs) is theoretically analyzed in terms of resolution and bandwidth as well as of noise tolerance. The analysis applies to any photonic ADC in which the analog input signal is converted into the wavelength of an optical carrier, but special emphasis is put on the spectrometerlike setup in which the wavelength is mapped to a spatial spot position. The binary output signals are then retrieved by an array of fan-out diffractive optical elements that redirect the beam onto the correct detectors. In particular, the case when the input signal controls the wavelength directly such that it will chirp in frequency during each sampling pulse or interval is studied. This chirping obviously broadens the spot on the diffractive optical element array; the effect of this broadening on noise tolerance and comparator accuracy is analytically analyzed, and accurate numerical calculations of the probability of error are presented.

  9. Single-wavelength two-photon excitation–stimulated emission depletion (SW2PE-STED) superresolution imaging

    PubMed Central

    Bianchini, Paolo; Harke, Benjamin; Galiani, Silvia; Vicidomini, Giuseppe; Diaspro, Alberto

    2012-01-01

    We developed a new class of two-photon excitation–stimulated emission depletion (2PE-STED) optical microscope. In this work, we show the opportunity to perform superresolved fluorescence imaging, exciting and stimulating the emission of a fluorophore by means of a single wavelength. We show that a widely used red-emitting fluorophore, ATTO647N, can be two-photon excited at a wavelength allowing both 2PE and STED using the very same laser source. This fact opens the possibility to perform 2PE microscopy at four to five times STED-improved resolution, while exploiting the intrinsic advantages of nonlinear excitation. PMID:22493221

  10. Two-color two-photon excited fluorescence of indole: determination of wavelength-dependent molecular parameters.

    PubMed

    Herbrich, Sebastian; Al-Hadhuri, Tawfik; Gericke, Karl-Heinz; Shternin, Peter S; Smolin, Andrey G; Vasyutinskii, Oleg S

    2015-01-14

    We present a detailed study of two-color two-photon excited fluorescence in indole dissolved in propylene glycol. Femtosecond excitation pulses at effective wavelengths from 268 to 293.33 nm were used to populate the two lowest indole excited states (1)La and (1)Lb and polarized fluorescence was then detected. All seven molecular parameters and the two-photon polarization ratio Ω containing information on two-photon absorption dynamics, molecular lifetime τf, and rotation correlation time τrot have been determined from experiment and analyzed as a function of the excitation wavelength. The analysis of the experimental data has shown that (1)Lb-(1)La inversion occurred under the conditions of our experiment. The two-photon absorption predominantly populated the (1)La state at all excitation wavelengths but in the 287-289 nm area which contained an absorption hump of the (1)Lb state 0-0 origin. The components of the two-photon excitation tensor S were analyzed giving important information on the principal tensor axes and absorption symmetry. The results obtained are in a good agreement with the results reported by other groups. The lifetime τf and the rotation correlation time τrot showed no explicit dependence on the effective excitation wavelength. Their calculated weighted average values were found to be τf = 3.83 ± 0.14 ns and τrot = 0.74 ± 0.06 ns.

  11. Two-color two-photon excited fluorescence of indole: Determination of wavelength-dependent molecular parameters

    NASA Astrophysics Data System (ADS)

    Herbrich, Sebastian; Al-Hadhuri, Tawfik; Gericke, Karl-Heinz; Shternin, Peter S.; Smolin, Andrey G.; Vasyutinskii, Oleg S.

    2015-01-01

    We present a detailed study of two-color two-photon excited fluorescence in indole dissolved in propylene glycol. Femtosecond excitation pulses at effective wavelengths from 268 to 293.33 nm were used to populate the two lowest indole excited states 1La and 1Lb and polarized fluorescence was then detected. All seven molecular parameters and the two-photon polarization ratio Ω containing information on two-photon absorption dynamics, molecular lifetime τf, and rotation correlation time τrot have been determined from experiment and analyzed as a function of the excitation wavelength. The analysis of the experimental data has shown that 1Lb-1La inversion occurred under the conditions of our experiment. The two-photon absorption predominantly populated the 1La state at all excitation wavelengths but in the 287-289 nm area which contained an absorption hump of the 1Lb state 0-0 origin. The components of the two-photon excitation tensor S were analyzed giving important information on the principal tensor axes and absorption symmetry. The results obtained are in a good agreement with the results reported by other groups. The lifetime τf and the rotation correlation time τrot showed no explicit dependence on the effective excitation wavelength. Their calculated weighted average values were found to be τf = 3.83 ± 0.14 ns and τrot = 0.74 ± 0.06 ns.

  12. Study of silicon strip waveguides with diffraction gratings and photonic crystals tuned to a wavelength of 1.5 µm

    SciTech Connect

    Barabanenkov, M. Yu. Vyatkin, A. F.; Volkov, V. T.; Gruzintsev, A. N.; Il’in, A. I.; Trofimov, O. V.

    2015-12-15

    Single-mode submicrometer-thick strip waveguides on silicon-on-insulator substrates, fabricated by silicon-planar-technology methods are considered. To solve the problem of 1.5-µm wavelength radiation input-output and its frequency filtering, strip diffraction gratings and two-dimensional photonic crystals are integrated into waveguides. The reflection and transmission spectra of gratings and photonic crystals are calculated. The waveguide-mode-attenuation coefficient for a polycrystalline silicon waveguide is experimentally estimated.

  13. Monolithic photonic integration technology platform and devices at wavelengths beyond 2μm for gas spectroscopy applications

    NASA Astrophysics Data System (ADS)

    Latkowski, S.; van Veldhoven, P. J.; Hänsel, A.; D'Agostino, D.; Rabbani-Haghighi, H.; Docter, B.; Bhattacharya, N.; Thijs, P. J. A.; Ambrosius, H. P. M. M.; Smit, M. K.; Williams, K. A.; Bente, E. A. J. M.

    2017-02-01

    In this paper a generic monolithic photonic integration technology platform and tunable laser devices for gas sensing applications at 2 μm will be presented. The basic set of long wavelength optical functions which is fundamental for a generic photonic integration approach is realized using planar, but-joint, active-passive integration on indium phosphide substrate with active components based on strained InGaAs quantum wells. Using this limited set of basic building blocks a novel geometry, widely tunable laser source was designed and fabricated within the first long wavelength multiproject wafer run. The fabricated laser operates around 2027 nm, covers a record tuning range of 31 nm and is successfully employed in absorption measurements of carbon dioxide. These results demonstrate a fully functional long wavelength photonic integrated circuit that operates at these wavelengths. Moreover, the process steps and material system used for the long wavelength technology are almost identical to the ones which are used in the technology process at 1.5μm which makes it straightforward and hassle-free to transfer to the photonic foundries with existing fabrication lines. The changes from the 1550 nm technology and the trade-offs made in the building block design and layer stack will be discussed.

  14. Stable and uniform dual-wavelength erbium-doped fiber laser based on fiber Bragg gratings and photonic crystal fiber.

    PubMed

    Liu, Xueming; Yang, Xiufeng; Lu, Fuyun; Ng, Junhong; Zhou, Xiaoqun; Lu, Chao

    2005-01-10

    Based on the fiber Bragg gratings (FBGs) and high nonlinear photonic crystal fiber (HN-PCF), a novel dual-wavelength erbium-doped fiber (EDF) laser is proposed and demonstrated. The experimental results show that, owing to the contributions of two degenerate four-wave mixings in the HN-PCF, the proposed fiber laser is great stable and two output signals are uniform at room temperature. With adjustment of the attenuator, our fiber laser can selectively realize one wavelength lasing.

  15. Experimental confirmation at visible light wavelengths of the backscattering enhancement phenomenon of the photonic nanojet

    PubMed Central

    Yang, Seungmoo; Taflove, Allen; Backman, Vadim

    2011-01-01

    We report what we believe is the first experimental confirmation at visible light wavelengths of the backscattering enhancement phenomenon of the photonic nanojet. A specially designed sample stage consisting of a multilayered sandwich of glass, solid polydimethylsiloxane (PDMS), and liquid PDMS, permitted the precise positioning of a gold nanoparticle of diameter between 50 and 100 nm within the nanojet emitted by a 4.4 μm diameter BaTiO3 microsphere embedded within the PDMS. We determined that, when the gold nanoparticle is optimally positioned within the nanojet, the backscattering of the microsphere can greatly increase: for example, by 3:1 (200%) for the 50 nm gold nanoparticle. The increased backscattering is strongly dependent upon the illumination wavelength and the numerical aperture of the imaging system, and occurs for nonresonant illuminations of the isolated microsphere. Low objective numerical apertures of approximately 0.075 yield the maximum observed increases in backscattering. The measured data agree well with numerical calculations incorporating Mie-based theory and Fourier optics. PMID:21503021

  16. Experimental confirmation at visible light wavelengths of the backscattering enhancement phenomenon of the photonic nanojet.

    PubMed

    Yang, Seungmoo; Taflove, Allen; Backman, Vadim

    2011-04-11

    We report what we believe is the first experimental confirmation at visible light wavelengths of the backscattering enhancement phenomenon of the photonic nanojet. A specially designed sample stage consisting of a multilayered sandwich of glass, solid polydimethylsiloxane (PDMS), and liquid PDMS, permitted the precise positioning of a gold nanoparticle of diameter between 50 and 100 nm within the nanojet emitted by a 4.4 μm diameter BaTiO(3) microsphere embedded within the PDMS. We determined that, when the gold nanoparticle is optimally positioned within the nanojet, the backscattering of the microsphere can greatly increase: for example, by 3:1 (200%) for the 50 nm gold nanoparticle. The increased backscattering is strongly dependent upon the illumination wavelength and the numerical aperture of the imaging system, and occurs for nonresonant illuminations of the isolated microsphere. Low objective numerical apertures of approximately 0.075 yield the maximum observed increases in backscattering. The measured data agree well with numerical calculations incorporating Mie-based theory and Fourier optics.

  17. Single meson production in photon-photon collisions and infrared renormalons

    SciTech Connect

    Ahmadov, A. I.; Aydin, Coskun; Dadashov, E. A.; Nagiyev, Sh. M.

    2010-03-01

    In this article, we investigate the contribution of the higher-twist Feynman diagrams to the large-p{sub T} inclusive single meson production cross section in photon-photon collisions and present the general formulas for the higher-twist differential cross sections in case of the running coupling and frozen coupling approaches. The structure of infrared renormalon singularities of the higher-twist subprocess cross section and the resummed expression (the Borel sum) for it are found. We compared the resummed higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. We obtain, that ratio R=({Sigma}{sub M}{sup +HT}){sup res}/({Sigma}{sub M}{sup +HT}){sup 0}, for all values of the transverse momentum p{sub T} of the meson identically equivalent to ratio r=({Delta}{sub M}{sup HT}){sup res}/({Delta}{sub M}{sup HT}){sup 0}. It is shown that the resummed result depends on the choice of the meson wave functions used in calculation. Phenomenological effects of the obtained results are discussed.

  18. HgCdTe avalanche photodiode detectors for airborne and spaceborne lidar at infrared wavelengths.

    PubMed

    Sun, Xiaoli; Abshire, James B; Beck, Jeffrey D; Mitra, Pradip; Reiff, Kirk; Yang, Guangning

    2017-07-10

    We report results from characterizing the HgCdTe avalanche photodiode (APD) arrays developed for lidar at infrared wavelengths by using the high density vertically integrated photodiodes (HDVIP(®)) technique. The results show >90% quantum efficiencies between 0.8 μm and the cut-off wavelength, >600 APD gain, near unity excess noise factor, 6-10 MHz electrical bandwidth and <0.5 fW/Hz(1/2) noise equivalent power (NEP). The detectors provide linear analog output with a dynamic range of 2-3 orders of magnitude at a fixed APD gain without averaging, and over 5 orders of magnitude by adjusting the APD gain settings. They have been used successfully in airborne CO2 and CH4 integrated path differential absorption (IPDA) lidar as precursors for use in space lidar.

  19. These images show thermal infrared radiation from Jupiter at different wavelengths which are diagnos

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These images show thermal infrared radiation from Jupiter at different wavelengths which are diagnostic of physical phenomena The 7.85-micron image in the upper left shows stratospheric temperatures which are elevated in the region of the A fragment impact (to the left of bottom). Temperatures deeper in the atmosphere near 150-mbar are shown by the 17.2-micron image in the upper right. There is a small elevation of temperatures at this depth, indicated by the arrow, and confirmed by other measurements near this wavelength. This indicates that the influence of the impact of fragment A on the troposphere has been minimal. The two images in the bottom row show no readily apparent perturbation of the ammmonia condensate cloud field near 600 mbar, as diagnosed by 8.57-micron radiation, and deeper cloud layers which are diagnosed by 5-micron radiation.

  20. Mid-infrared Raman amplification and wavelength conversion in dispersion engineered silicon-on-sapphire waveguides

    NASA Astrophysics Data System (ADS)

    Wang, Zhaolu; Liu, Hongjun; Huang, Nan; Sun, Qibing; Li, Xuefeng

    2014-01-01

    Raman amplification based on stimulated Stokes Raman scattering (SSRS) and wavelength conversion based on coherent anti-Stokes Raman scattering (CARS) are theoretically investigated in silicon-on-sapphire (SOS) waveguides in the mid-infrared (IR) region. When the linear phase mismatch Δk is close to zero, the Stokes gain and conversion efficiency drop down quickly due to the effect of parametric gain suppression when the Stokes-pump input ratio is sufficiently large. The Stokes gain increases with the increase of Δk, whereas efficient wavelength conversion needs appropriate Δk under different pump intensities. The conversion efficiency at exact linear phase matching (Δk = 0) is smaller than that at optimal linear phase mismatch by a factor of about 28 dB when the pump intensity is 2 GW cm-2.

  1. Laser Welding of Copper Using Multi Mode Fiber Lasers at Near Infrared Wavelength

    NASA Astrophysics Data System (ADS)

    Liebl, S.; Wiedenmann, R.; Ganser, A.; Schmitz, P.; Zaeh, M. F.

    Due to the increasing electrification of automotive drives and the expansion of decentralized renewable energygeneration, the consumption of copper for the fabrication of electrical components such as electric motors or conducting paths increases. To jointhese components, laser welding is more frequently used since it represents a flexible and fully automatable joining process. Because of the high thermal conductivity, the low absorption coefficient forinfrared wavelength of common laser beam sources and the resulting limited process efficiency, welding of copper alloys represents a major challenge for laser assisted processes. In this paper, experimental investigationsare presented to identify arising process limits during laser welding of pure copper materials with multi-mode fiber lasers at near infrared wavelength depending on the applied laser power and welding velocity. In addition, a potential stabilization of the welding process by shielding gas support was examined. Further investigations were focused on the influence of shielding gas on the molten pool geometry.

  2. A high-speed, eight-wavelength visible light-infrared pyrometer for shock physics experiments

    NASA Astrophysics Data System (ADS)

    Wang, Rongbo; Li, Shengfu; Zhou, Weijun; Luo, Zhen-Xiong; Meng, Jianhua; Tian, Jianhua; He, Lihua; Cheng, Xianchao

    2017-09-01

    An eight-channel, high speed pyrometer for precise temperature measurement is designed and realized in this work. The addition of longer-wavelength channels sensitive at lower temperatures highly expands the measured temperature range, which covers the temperature of interest in shock physics from 1500K-10000K. The working wavelength range is 400-1700nm from visible light to near-infrared (NIR). Semiconductor detectors of Si and InGaAs are used as photoelectric devices, whose bandwidths are 50MHz and 150MHz respectively. Benefitting from the high responsivity and high speed of detectors, the time resolution of the pyrometer can be smaller than 10ns. By combining the high-transmittance beam-splitters and narrow-bandwidth filters, the peak spectrum transmissivity of each channel can be higher than 60%. The gray-body temperatures of NaI crystal under shock-loading are successfully measured by this pyrometer.

  3. HgCdTe Avalanche Photodiode Detectors for Airborne and Spaceborne Lidar at Infrared Wavelengths

    NASA Technical Reports Server (NTRS)

    Sun, Xiaoli; Abshire, James B.; Beck, Jeffrey D.; Mitra, Pradip; Reiff, Kirk; Yang, Guangning

    2017-01-01

    We report results from characterizing the HgCdTe avalanche photodiode (APD) sensorchip assemblies (SCA) developed for lidar at infrared wavelength using the high density vertically integrated photodiodes (HDVIP) technique. These devices demonstrated high quantum efficiency, typically greater than 90 between 0.8 micrometers and the cut-off wavelength, greater than 600 APD gain, near unity excess noise factor, 6-10 MHz electrical bandwidth and less than 0.5 fW/Hz(exp.1/2) noise equivalent power (NEP). The detectors provide linear analog output with a dynamic range of 2-3 orders of magnitude at a fixed APD gain without averaging, and over 5 orders of magnitude by adjusting the APD and preamplifier gain settings. They have been successfully used in airborne CO2 and CH4 integrated path differential absorption (IPDA) lidar as a precursor for space lidar applications.

  4. Extended short wavelength infrared HgCdTe detectors on silicon substrates

    NASA Astrophysics Data System (ADS)

    Park, J. H.; Hansel, D.; Mukhortova, A.; Chang, Y.; Kodama, R.; Zhao, J.; Velicu, S.; Aqariden, F.

    2016-09-01

    We report high-quality n-type extended short wavelength infrared (eSWIR) HgCdTe (cutoff wavelength 2.59 μm at 77 K) layers grown on three-inch diameter CdTe/Si substrates by molecular beam epitaxy (MBE). This material is used to fabricate test diodes and arrays with a planar device architecture using arsenic implantation to achieve p-type doping. We use different variations of a test structure with a guarded design to compensate for the lateral leakage current of traditional test diodes. These test diodes with guarded arrays characterize the electrical performance of the active 640 × 512 format, 15 μm pitch detector array.

  5. Infrared transmission at the 3.39 micron helium-neon laser wavelength in liquid-core quartz fibers

    NASA Technical Reports Server (NTRS)

    Majumdar, A. K.; Hinkley, E. D.; Menzies, R. T.

    1979-01-01

    Infrared transmission at the 3.39 micron helium-neon laser wavelength has been measured in a tetrachloroethylene-filled fused-quartz fiber. The loss measurements were taken for three different settings of laser light intensity using a series of neutral density filters. The average value of transmission loss at this wavelength was found to be 56 dB/km.

  6. Novel Infrared Phototransistors for Atmospheric CO2 Profiling at 2 Micron Wavelength

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Abedin, M. Nurul; Sulima, Oleg V.; Singh, Upendra N.; Ismail, Syed

    2004-01-01

    Two-micron detectors are critical for atmospheric carbon dioxide profiling using the lidar technique. The characterization results of a novel infrared AlGaAsSb/ InGaAsSb phototransistor are reported. Emitter dark current variation with the collector-emitter voltage at different temperatures is acquired to examine the gain mechanism. Spectral response measurements resulted in responsivity as high as 2650 A/W at 2.05 m wavelength. Bias voltage and temperature effects on the device responsivity are presented. The detectivity of this device is compared to InGaAs and HgCdTe devices.

  7. Novel Infrared Phototransistors for Atmospheric CO2 Profiling at 2 microns Wavelength

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Abedin, M. Nurul; Sulima, Oleg V.; Singh, Upendra N.; Ismail, Syed

    2004-01-01

    Two-micron detectors are critical for atmospheric carbon dioxide profiling using the lidar technique. The characterization results of a novel infrared AlGaAsSb/ InGaAsSb phototransistor are reported. Emitter dark current variation with the collector-emitter voltage at different temperatures is acquired to examine the gain mechanism. Spectral response measurements resulted in responsivity as high as 2650 A/W at 2.05 microns wavelength. Bias voltage and temperature effects on the device responsivity are presented. The detectivity of this device is compared to InGaAs and HgCdTe devices.

  8. Optical nanoantennas as on-chip spectrometer: Discriminating the wavelength of infrared light

    NASA Astrophysics Data System (ADS)

    Lin, Zhongjin; Lin, Jie

    2015-08-01

    Based on the size-dependent resonant property of optical nanoantennas, we propose and theoretically verify that the optical detector element, which is composed of three different-size dipole nanoantennas (these antennas arrayed in the same plane look like a Yagi-Uda antenna), can discriminate the wavelength of the detected infrared light. As it behaves like a spectrometer that just needs to be laid on a micro-chip, we can refer to it as on-chip spectrometer. Such optical detector element also can be well extended to the visible-light region, and especially it can capture colour information by itself without Bayer filter.

  9. Solar limb theoretical tomography at millimeter, sub-millimeter, and infrared wavelengths

    NASA Astrophysics Data System (ADS)

    De la Luz, Victor; Gonzalez-Esparza, J. A.; Corona-Romero, P.; Mejia-Ambriz, J.

    2016-11-01

    Semi-empirical models of the solar Chromosphere show, in their emission spectrum, tomography property at millimeter, sub-millimeter, and infrared wavelengths for the center of the solar disk. In this work, we studied this property in the solar limb using our numerical code PakalMPI, focusing in the region where the solar atmosphere becomes optically thick. Individual contribution of Bremsstrahlung and H- opacities was take into account in the radiative transfer process. We found that the tomography property remains in all the spectrum region under study at limb altitudes. For frequencies between 2 GHz and 5 THz the contribution of Bremsstrahlung is the dominant process above the solar limb.

  10. Announcement - Scientific Importance of High Angular Resolution at Infrared and Optical Wavelengths - ESO Conference

    NASA Astrophysics Data System (ADS)

    1981-03-01

    The European Southern Observatory is organizing an international conference on the subject "SCIENTIFIC IMPORTANCE OF HIGH ANGULAR RESOLUTION AT INFRARED AND OPTICAL WAVELENGTHS", to be held in the ESO building at Garching bei München during the period of 24-27 March 1981. The purpose of this conference is to discuss, on the one hand, the systems in use or under construction and possible future developments to achieve high angular resolution and, on the other hand, to discuss the areas of astrophysics which, in the next decades, will most benefit from observations at high angular resolution.

  11. Long-wavelength quantum well infrared photodetector (QWIP) research at Jet Propulsion Laboratory

    NASA Astrophysics Data System (ADS)

    Gunapala, Sarath D.; Liu, John K.; Sundaram, Mani; Bandara, Sumith V.; Shott, C. A.; Hoelter, Theodore R.; Maker, Paul D.; Muller, Richard E.

    1996-06-01

    One of the simplest device realizations of the classic particle-in-a-box problem of basic quantum mechanics is the quantum well infrared photodetector (QWIP). Optimization of the detector design and material growth and processing have culminated in the realization of a 15 micrometer cutoff 128 by 128 focal plane array camera and a camera with large (256 by 256 pixel) focal plane array of QWIPs which can see at 8.5 micrometer, holding forth great promise for a variety of applications in the 6 - 25 micrometer wavelength range. This paper discusses the physics of the QWIP and QWIP technology development at Jet Propulsion Laboratory.

  12. Space-exposure effects on optical-baffle coatings at far-infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Blue, M. D.; Perkowitz, S.

    1992-01-01

    Reflectance of six optical-black coatings was remeasured over the near-infrared to the far-infrared region after nearly six years in space aboard the Long Duration Exposure Facility satellite. Measurements were made at room temperature and at cryogenic temperatures. The most notable effect was a general decrease in reflectance for typical samples at all wavelengths. Analysis indicates that this decrease is caused by an increase in absorption resulting from an increase in the imaginary part of the index of refraction, and not by a change in thickness, or increased surface roughness giving rise to increased scattering. These results suggest that such optical-baffle materials will provide enhanced performance as a result of aging in the space environment.

  13. Emissivity measurements on historic building materials using dual-wavelength infrared thermography

    NASA Astrophysics Data System (ADS)

    Moropoulou, Antonia; Avdelidis, Nicolas P.

    2001-03-01

    The most reliable method to obtain correct emissivity values for the infrared thermographic systems and applications is to determine the emissivity of the targets to be tested. Although this approach is not possible during in situ applications, samples of the targets can be collected and measured, as in this work, in the laboratory. In the present work, the emissivity values of selected historic building materials were measured at a variety of temperatures, in the 3-5.4 micrometers and 8-12 micrometers regions of the infrared spectrum. Porous stones from the Mediterranean area and marbles, used as historic building materials, were investigated. The examined materials presented different emissivity values, caused by their surface state and microstructure. In addition, the effect of temperature and wavelength on the emissivity values of such historic building materials was also considered.

  14. Space-exposure effects on optical-baffle coatings at far-infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Blue, M. D.; Perkowitz, S.

    1992-01-01

    Reflectance of six optical-black coatings was remeasured over the near-infrared to the far-infrared region after nearly six years in space aboard the Long Duration Exposure Facility satellite. Measurements were made at room temperature and at cryogenic temperatures. The most notable effect was a general decrease in reflectance for typical samples at all wavelengths. Analysis indicates that this decrease is caused by an increase in absorption resulting from an increase in the imaginary part of the index of refraction, and not by a change in thickness, or increased surface roughness giving rise to increased scattering. These results suggest that such optical-baffle materials will provide enhanced performance as a result of aging in the space environment.

  15. [Study of near infrared spectral preprocessing and wavelength selection methods for endometrial cancer tissue].

    PubMed

    Zhao, Li-Ting; Xiang, Yu-Hong; Dai, Yin-Mei; Zhang, Zhuo-Yong

    2010-04-01

    Near infrared spectroscopy was applied to measure the tissue slice of endometrial tissues for collecting the spectra. A total of 154 spectra were obtained from 154 samples. The number of normal, hyperplasia, and malignant samples was 36, 60, and 58, respectively. Original near infrared spectra are composed of many variables, for example, interference information including instrument errors and physical effects such as particle size and light scatter. In order to reduce these influences, original spectra data should be performed with different spectral preprocessing methods to compress variables and extract useful information. So the methods of spectral preprocessing and wavelength selection have played an important role in near infrared spectroscopy technique. In the present paper the raw spectra were processed using various preprocessing methods including first derivative, multiplication scatter correction, Savitzky-Golay first derivative algorithm, standard normal variate, smoothing, and moving-window median. Standard deviation was used to select the optimal spectral region of 4 000-6 000 cm(-1). Then principal component analysis was used for classification. Principal component analysis results showed that three types of samples could be discriminated completely and the accuracy almost achieved 100%. This study demonstrated that near infrared spectroscopy technology and chemometrics method could be a fast, efficient, and novel means to diagnose cancer. The proposed methods would be a promising and significant diagnosis technique of early stage cancer.

  16. A broadband LED source in visible to short-wave-infrared wavelengths for spectral tumor diagnostics

    NASA Astrophysics Data System (ADS)

    Hayashi, Daiyu; van Dongen, Anne Marie; Boerekamp, Jack; Spoor, Sandra; Lucassen, Gerald; Schleipen, Jean

    2017-06-01

    Various tumor types exhibit the spectral fingerprints in the absorption and reflection spectra in visible and especially in near- to short-wave-infrared wavelength ranges. For the purpose of spectral tumor diagnostics by means of diffuse reflectance spectroscopy, we developed a broadband light emitting diode (LED) source consisting of a blue LED for optical excitation, Lu3Al5O12:Ce3+,Cr3+ luminescent garnet for visible to near infrared emissions, and Bismuth doped GeO2 luminescent glass for near-infrared to short-wave infrared emissions. It emits broad-band light emissions continuously in 470-1600 nm with a spectral gap at 900-1000 nm. In comparison to the currently available broadband light sources like halogen lamps, high-pressure discharge lamps and super continuum lasers, the light sources of this paper has significant advantages for spectral tissue diagnostics in high-spectral stability, improved light coupling to optical fibers, potential in low light source cost and enabling battery-drive.

  17. Bandwidth control of wavelength-selective uncooled infrared sensors using two-dimensional plasmonic absorbers

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Kimata, Masafumi

    2016-05-01

    Although standard uncooled infrared (IR) sensors can be used to record information such as the shape, position, and average radiant intensity of objects, these devices cannot capture color (that is, wavelength) data. Achieving wavelength selectivity would pave the way for the development of advanced uncooled IR sensors capable of providing color information as well as multi-color image sensors that would have significant advantages in applications such as fire detection, gas analysis, hazardous material recognition, and biological analysis. We have previously demonstrated an uncooled IR sensor incorporating a two-dimensional plasmonic absorber (2D PLA) that exhibits wavelength selectivity over a wide range in the mid- and long-IR regions. This PLA has a 2D Au-based periodic array of dimples, in which surface plasmon modes are induced and wavelength-selective absorption occurs. However, the dependence of the absorption bandwidth on certain structural parameters has yet to be clarified. The bandwidth of such devices is a vital factor when considering the practical application of these sensors to tasks such as gas detection. In the present study, control of the bandwidth was theoretically investigated using a rigorous coupled wave analysis approach. It is demonstrated that the dimple sidewall structure has a significant impact on the bandwidth and can be used to control both narrow- and broadband absorption. Increasing the sidewall slope was found to decrease the bandwidth due to suppression of cavity-mode resonance in the depth direction of the dimples. These results will contribute to the development of high-resolution, wavelength-selective uncooled IR sensors.

  18. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): A Wavelength-Tunable Fiber-Coupled Narrow-Band Twin-Photon Source

    NASA Astrophysics Data System (ADS)

    Huang, Jian-Fa; Liu, Bi-Heng; Fang, Bin; Huang, Yun-Feng; Guo, Guang-Can

    2009-07-01

    We present a wavelength-tunable narrow-band fiber-coupled source to generate correlated photon pairs at 539nm and 1550nm. Using a 10-mm PPLN crystal, we obtain more than 50mm tunable range near 1550nm. This source, given its spectral property and tunable property, is well suited for tasks in fiber-optic quantum communication and cryptography networks.

  19. Photoelectronic studies of an asymmetric step quantum-well middle wavelength infrared detector

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Gang; Chen, Zhibin

    2001-10-01

    Photoelectronic characteristics of the fabricated InxGa1-xAs/AlyGa1- yAs/AlzGa1-zAs asymmetric step quantum-well middle wavelength (3 to approximately 5 micrometers ) infrared detectors are studied. The components display photovoltaic-type photocurrent response as well as the bias- controlled modulation of the peak wavelength of the main response, which is ascribed to the Stark shifts of the intersubband transitions from the local ground states to the extended first excited states in the quantum wells, at the 3 to approximately 5.3 micrometers infrared atmospheric transmission window. The blackbody detectivity (Dbb*) of the detectors reaches to about 1.0 X 1010 cm(DOT)Hz1/2/W at 77 K under bias of +/- 7 V. By expanding the electron wave function in terms of normalized plane wave basis withn the framwork of the effective-mass envelope-function theory, the linear Stark effects of the intersubband tansitions between the ground and first excited states in the asymmetric step well are calculated. The obtained results agree well with the corresponding experimental measurements.

  20. Optically efficient InAsSb nanowires for silicon-based mid-wavelength infrared optoelectronics.

    PubMed

    Zhuang, Q D; Alradhi, H; Jin, Z M; Chen, X R; Shao, J; Chen, X; Sanchez, Ana M; Cao, Y C; Liu, J Y; Yates, P; Durose, K; Jin, C J

    2017-03-10

    InAsSb nanowires (NWs) with a high Sb content have potential in the fabrication of advanced silicon-based optoelectronics such as infrared photondetectors/emitters and highly sensitive phototransistors, as well as in the generation of renewable electricity. However, producing optically efficient InAsSb NWs with a high Sb content remains a challenge, and optical emission is limited to 4.0 μm due to the quality of the nanowires. Here, we report, for the first time, the success of high-quality and optically efficient InAsSb NWs enabling silicon-based optoelectronics operating in entirely mid-wavelength infrared. Pure zinc-blende InAsSb NWs were realized with efficient photoluminescence emission. We obtained room-temperature photoluminescence emission in InAs NWs and successfully extended the emission wavelength in InAsSb NWs to 5.1 μm. The realization of this optically efficient InAsSb NW material paves the way to realizing next-generation devices, combining advances in III-V semiconductors and silicon.

  1. Mid- to long-wavelength infrared surface plasmon properties in doped zinc oxides

    NASA Astrophysics Data System (ADS)

    Cleary, Justin W.; Snure, Michael; Leedy, Kevin D.; Look, David C.; Eyink, Kurt; Tiwari, Ashutosh

    2012-09-01

    This work investigates properties of surface plasmons on doped metal oxides in the 2-20 μm wavelength regime. By varying the stoichiometry in pulse laser deposited Ga and Al doped ZnO, the plasmonic properties can be controlled via a fluctuating free carrier concentration. This deterministic approach may enable one to develop the most appropriate stoichometry of ZnAlO and ZnGaO in regards to specific plasmonic applications for particular IR wavelengths. Presented are theoretical and experimental investigations pertaining to ZnAlO and ZnGaO as surface plasmon host materials. Samples are fabricated via pulsed laser deposition and characterized by infrared ellipsometry and Hall-effect measurements. Complex permittivity spectra are presented, as well as plasmon properties such as the field propagation lengths and penetration depths, in the infrared range of interest. Drude considerations are utilized to determine how the optical properties may change with doping. Finite element simulations verify these plasmonic properties. These materials not only offer potential use as IR plasmon hosts for sensor applications, but also offer new integrated device possibilities due to stoichiometric control of electrical and optical properties.

  2. Optically efficient InAsSb nanowires for silicon-based mid-wavelength infrared optoelectronics

    NASA Astrophysics Data System (ADS)

    Zhuang, Q. D.; Alradhi, H.; Jin, Z. M.; Chen, X. R.; Shao, J.; Chen, X.; Sanchez, Ana M.; Cao, Y. C.; Liu, J. Y.; Yates, P.; Durose, K.; Jin, C. J.

    2017-03-01

    InAsSb nanowires (NWs) with a high Sb content have potential in the fabrication of advanced silicon-based optoelectronics such as infrared photondetectors/emitters and highly sensitive phototransistors, as well as in the generation of renewable electricity. However, producing optically efficient InAsSb NWs with a high Sb content remains a challenge, and optical emission is limited to 4.0 μm due to the quality of the nanowires. Here, we report, for the first time, the success of high-quality and optically efficient InAsSb NWs enabling silicon-based optoelectronics operating in entirely mid-wavelength infrared. Pure zinc-blende InAsSb NWs were realized with efficient photoluminescence emission. We obtained room-temperature photoluminescence emission in InAs NWs and successfully extended the emission wavelength in InAsSb NWs to 5.1 μm. The realization of this optically efficient InAsSb NW material paves the way to realizing next-generation devices, combining advances in III-V semiconductors and silicon.

  3. Wavelength and time-resolved imaging of material ejection in infrared matrix-assisted laser desorption.

    PubMed

    Fan, Xing; Murray, Kermit K

    2010-01-28

    The dynamics of glycerol ablation at atmospheric pressure was studied using fast photography. A mid-infrared optical parametric oscillator was used to irradiate a droplet of glycerol at normal incidence. The wavelength of the infrared source was tunable and was varied between 2.7 and 3.5 microm for the studies. After an adjustable delay, an excimer pumped dye laser was used to illuminate the expanding plume, and the 90 degrees scattered light was imaged with a high-speed CMOS camera. The time delay between the IR and UV lasers was varied up to 1 ms with a particular emphasis in the early stages of plume evolution below 1 micros. The threshold fluence for plume formation varied between 1000 and 6000 J/m(2), and the minimum fluence corresponded to the OH stretch absorption of glycerol near 3.0 microm, which also corresponded to the greatest scattered light signal and duration of material emission. The velocity of the expanding plume was measured and ranged from >300 m/s near the OH stretch absorption to <100 m/s near the 3.4 microm CH stretch. Plume modeling calculations suggest that material removal is driven by phase explosion in the stress confinement regime that is at a maximum near the wavelength of the OH stretch absorption.

  4. The development of InGaAs short wavelength infrared focal plane arrays with high performance

    NASA Astrophysics Data System (ADS)

    Li, Xue; Gong, Haimei; Fang, Jiaxiong; shao, Xiumei; Tang, Hengjing; Huang, Songlei; Li, Tao; Huang, Zhangcheng

    2017-01-01

    High performance, various specifications InGaAs focal plane arrays(FPAs) were studied in Shanghai Institute of Technical Physics (SITP). On the one hand, the typical linear 256 × 1, 512 × 1 and 1024 × 1 FPAs were obtained for response wavelengths from 0.9 μm to 1.7 μm. The typical 320 × 256 FPAs and special sizes 512 × 128, 512 × 256 FPAs for the near infrared multi-spectral imaging were studied. The performance of InGaAs FPAs from 0.9 μm to 1.7 μm has improved enormously. The average peak detectivity, the response non-uniformity and non-operable pixel of the FPAs are superior to 3 × 1012 cm Hz1/2/W, 5% and 1% at the room temperature. On the other hand, the development of the extended InGaAs FPAs was also focused in SITP. The dark current of InGaAs detectors with the response wavelength from 1.0 μm to 2.5 μm decreases to about 10 nA/cm2 at 200 K. The dark current mechanisms for extended InGaAs detectors were studied by P/A photodiodes. The special sizes 512 × 256 FPAs has been fabricated since 2011. The average peak detectivity, the response non-uniformity and non-operable pixel of the FPAs are superior to 5 × 1011 cm Hz1/2/W, 8% and 2% at 200 K. In order to verify the performance of FPAs, the short wavelength infrared lens was used to form optical imaging system. The buildings, water, trees are sharply imaged by 320 × 256 FPAs with 0.9-1.7 μm wavelength and 512 × 1 FPAs with 0.9-2.5 μm wavelength at about hundreds of meters distance as target at daylight.

  5. Hot spot generation in energetic materials created by long-wavelength infrared radiation

    SciTech Connect

    Chen, Ming-Wei; You, Sizhu; Suslick, Kenneth S.; Dlott, Dana D.

    2014-02-10

    Hot spots produced by long-wavelength infrared (LWIR) radiation in an energetic material, crystalline RDX (1,3,5-trinitroperhydro-1,3,5-triazine), were studied by thermal-imaging microscopy. The LWIR source was a CO{sub 2} laser operating in the 28-30 THz range. Hot spot generation was studied using relatively low intensity (∼100 W cm{sup −2}), long-duration (450 ms) LWIR pulses. The hot spots could be produced repeatedly in individual RDX crystals, to investigate the fundamental mechanisms of hot spot generation by LWIR, since the peak hot-spot temperatures were kept to ∼30 K above ambient. Hot spots were generated preferentially beneath RDX crystal planes making oblique angles with the LWIR beam. Surprisingly, hot spots were more prominent when the LWIR wavelength was tuned to be weakly absorbed (absorption depth ∼30 μm) than when the LWIR wavelength was strongly absorbed (absorption depth ∼5 μm). This unexpected effect was explained using a model that accounts for LWIR refraction and RDX thermal conduction. The weakly absorbed LWIR is slightly focused underneath the oblique crystal planes, and it penetrates the RDX crystals more deeply, increasing the likelihood of irradiating RDX defect inclusions that are able to strongly absorb or internally focus the LWIR beam.

  6. High-accuracy reference standards for two-photon absorption in the 680–1050 nm wavelength range

    PubMed Central

    de Reguardati, Sophie; Pahapill, Juri; Mikhailov, Alexander; Stepanenko, Yuriy; Rebane, Aleksander

    2016-01-01

    Degenerate two-photon absorption (2PA) of a series of organic fluorophores is measured using femtosecond fluorescence excitation method in the wavelength range, λ2PA = 680–1050 nm, and ~100 MHz pulse repetition rate. The function of relative 2PA spectral shape is obtained with estimated accuracy 5%, and the absolute 2PA cross section is measured at selected wavelengths with the accuracy 8%. Significant improvement of the accuracy is achieved by means of rigorous evaluation of the quadratic dependence of the fluorescence signal on the incident photon flux in the whole wavelength range, by comparing results obtained from two independent experiments, as well as due to meticulous evaluation of critical experimental parameters, including the excitation spatial- and temporal pulse shape, laser power and sample geometry. Application of the reference standards in nonlinear transmittance measurements is discussed. PMID:27137334

  7. Improved dropping efficiency in two-dimensional photonic crystal-based channel drop filter for coarse wavelength division multiplexing application

    NASA Astrophysics Data System (ADS)

    Chhipa, Mayur Kumar; Radhouene, Massoudi; Robinson, Savarimuthu; Suthar, Bhuvneshwer

    2017-01-01

    We study the two-dimensional photonic crystal (PC) square lattice structure to design a channel drop filter. The channel drop filter (CDF) is designed using a PC ring resonator structure because of its better response. The variation in the shape of scatterer rods causes the shift in resonant wavelength and also shows an improvement in quality factor as well as dropping efficiency. The dropping efficiency is improved from 92.7% to 99.5% for a particular wavelength at 1531 nm, which is especially used in telecommunication. The designed CDF structure is useful for coarse wavelength division multiplexer. The size of the device is very small, so these devices can play an important role in optical communication networks and photonic integrated circuits.

  8. Wavelength-selective coupling of dual-core photonic crystal fiber with a hybrid light-guiding mechanism.

    PubMed

    Sun, Xiwen

    2007-09-01

    A novel class of wavelength-selective coupling photonic crystal fiber (PCF) that operates by a hybrid light-guiding mechanism has been proposed. Different from the traditional PCF coupler operating principle, this fiber coupler shares properties of both the total internal reflection index-guided and the photonic bandgap mechanism. This coupler allows highly accurate control of the filtering wavelength; both bandstop and bandpass filters can be easily implemented. The spectral transmission results demonstrate that the bandpass characteristic of the coupler is very narrow and free of sidelobes. Moreover, the operating wavelength and the coupling length can be continuously tuned by changing the refractive index of the filling material. This research gives a physical insight into the propagation mechanism in the PCF coupler and is crucial for future applications of the proposed device.

  9. High-accuracy reference standards for two-photon absorption in the 680-1050 nm wavelength range.

    PubMed

    de Reguardati, Sophie; Pahapill, Juri; Mikhailov, Alexander; Stepanenko, Yuriy; Rebane, Aleksander

    2016-04-18

    Degenerate two-photon absorption (2PA) of a series of organic fluorophores is measured using femtosecond fluorescence excitation method in the wavelength range, λ2PA = 680-1050 nm, and ~100 MHz pulse repetition rate. The function of relative 2PA spectral shape is obtained with estimated accuracy 5%, and the absolute 2PA cross section is measured at selected wavelengths with the accuracy 8%. Significant improvement of the accuracy is achieved by means of rigorous evaluation of the quadratic dependence of the fluorescence signal on the incident photon flux in the whole wavelength range, by comparing results obtained from two independent experiments, as well as due to meticulous evaluation of critical experimental parameters, including the excitation spatial- and temporal pulse shape, laser power and sample geometry. Application of the reference standards in nonlinear transmittance measurements is discussed.

  10. Limiting dark current mechanisms in antimony-based superlattice infrared detectors for the long-wavelength infrared regime

    NASA Astrophysics Data System (ADS)

    Rehm, Robert; Lemke, Florian; Schmitz, Johannes; Wauro, Matthias; Walther, Martin

    2015-06-01

    A detailed understanding of limiting dark current mechanisms in InAs/GaSb type-II superlattice (T2SL) infrared detectors is key to improve the electrooptical performance of these devices. We present a six-component dark current analysis which, for the first time, takes account of sidewall-related dark current contributions in mesa-etched T2SL photodiodes. In a wide temperature range from 30K to 130K, the paper compares limiting mechanisms in two homojunction T2SL photodiode wafers for the long-wavelength infrared regime. While the two epi wafers were fabricated with nominally the same frontside process they were grown on different molecular beam epitaxy systems. In the available literature a limitation by Shockley-Read-Hall processes in the space charge region giving rise to generation-recombination (GR) dark current is the prevailing verdict on the bulk dark current mechanism in T2SL homojunction photodiodes around 77K. In contrast, we find that investigated photodiode wafers are instead limited by the diffusion mechanism and the ohmic shunt component, respectively. Furthermore, our in-depth analysis of the various dark current components has led to an interesting observation on the temperature dependence of the shunt resistance in T2SL homojunction photodiodes. Our results indicate that the GR and the shunt mechanism share the same dependence on bandgap and temperature, i.e., a proportionality to exp(-Eg/2kT).

  11. Selective excavation of decalcified dentin using a mid-infrared tunable nanosecond pulsed laser: wavelength dependency in the 6 μm wavelength range

    NASA Astrophysics Data System (ADS)

    Ishii, Katsunori; Saiki, Masayuki; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    2011-07-01

    Selective caries treatment has been anticipated as an essential application of dentistry. In clinic, some lasers have already realized the optical drilling of dental hard tissue. However, conventional lasers lack the selectivity, and still depend on the dentist's ability. Based on the absorption property of carious dentin, 6 μm wavelength range shows specific absorptions and promising characteristics for excavation. The objective of this study is to develop a selective excavation of carious dentin by using the laser ablation with 6 μm wavelength range. A mid-infrared tunable pulsed laser was obtained by difference-frequency generation technique. The wavelength was tuned around the absorption bands called amide 1 and amide 2. In the wavelength range from 5.75 to 6.60 μm, the difference of ablation depth between demineralized and normal dentin was observed. The wavelength at 6.02 μm and the average power density of 15 W/cm2, demineralized dentin was removed selectively with less-invasive effect on normal dentin. The wavelength at 6.42 μm required the increase of average power density, but also showed the possibility of selective ablation. This study provided a valuable insight into a wavelength choice for a novel dental laser device under development for minimal intervention dentistry.

  12. Fast path and polarization manipulation of telecom wavelength single photons in lithium niobate waveguide devices.

    PubMed

    Bonneau, Damien; Lobino, Mirko; Jiang, Pisu; Natarajan, Chandra M; Tanner, Michael G; Hadfield, Robert H; Dorenbos, Sanders N; Zwiller, Val; Thompson, Mark G; O'Brien, Jeremy L

    2012-02-03

    We demonstrate fast polarization and path control of photons at 1550 nm in lithium niobate waveguide devices using the electro-optic effect. We show heralded single photon state engineering, quantum interference, fast state preparation of two entangled photons, and feedback control of quantum interference. These results point the way to a single platform that will enable the integration of nonlinear single photon sources and fast reconfigurable circuits for future photonic quantum information science and technology.

  13. High-gain and low-excess noise near-infrared single-photon avalanche detector arrays

    NASA Astrophysics Data System (ADS)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2010-04-01

    We have designed and developed a new family of photodetectors and arrays with Internal Discrete Amplification (IDA) mechanism for the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions. These devices surpass many limitations of the Single Photon Avalanche Photodetectors such as ultra low excess noise factor, very high gain, lower reset time (< 200 ns). These devices are very simple to operate in the non-gated mode under a constant dc bias voltage. Because of its unique characteristics of self-quenching and self-recovery, no external quenching circuit is needed. This unique feature of self quenching and self-recovery makes it simple to less complex readout integrated circuit to realize large format detector arrays. In this paper, we present the discrete amplification design approach used for the development of self reset, high gain photodetector arrays in the near infrared wavelength region. The demonstrated device performance far exceeds any available solid state Photodetectors in the near infrared wavelength range. These devices are ideal for researchers in the field of spectroscopy, industrial and scientific instrumentation, Ladar, quantum cryptography, night vision and other military, defense and aerospace applications.

  14. Multi-Wavelength Observations of Asteroid 2100 Ra-Shalom: Visible, Infrared, and Thermal Spectroscopy Results

    NASA Technical Reports Server (NTRS)

    Clark, Beth Ellen; Shepard, M.; Bus, S. J.; Vilas, F.; Rivkin, A. S.; Lim, L.; Lederer, S.; Jarvis, K.; Shah, S.; McConnochie, T.

    2004-01-01

    The August 2003 apparition of asteroid 2100 Ra-Shalom brought together a collaboration of observers with the goal of obtaining rotationally resolved multiwavelength spectra at each of 5 facilities: infrared spectra at the NASA Infrared Telescope Facility (Clark and Shepard), radar images at Arecibo (Shepard and Clark), thermal infrared spectra at Palomar (Lim, McConnochie and Bell), visible spectra at McDonald Observatory (Vilas, Lederer and Jarvis), and visible lightcurves at Ondrojev Observatory (Pravec). The radar data was to be used to develop a high spatial resolution physical model to be used in conjunction with spectral data to investigate compositional and textural properties on the near surface of Ra Shalom as a function of rotation phase. This was the first coordinated multi-wavelength investigation of any Aten asteroid. There are many reasons to study near-Earth asteroid (NEA) 2100 Ra-Shalom: 1) It has a controversial classification (is it a C- or K-type object)? 2) There would be interesting dynamical ramifications if Ra-Shalom is a K-type because most K-types come from the Eos family and there are no known dynamical pathways from Eos to the Aten population. 3) The best available spectra obtained previously may indicate a heterogeneous surface (most asteroids appear to be fairly homogeneous). 4) Ra-Shalom thermal observations obtained previously indicated a lack of regolith, minimizing the worry of space weathering effects in the spectra. 5) Radar observations obtained previously hinted at interesting surface structures. 6) Ra-Shalom is one of the largest Aten objects. And 7) Ra-Shalom is on a short list of proposed NEAs for spacecraft encounters and possible sample returns. Preliminary results from the visible, infrared, and thermal spectroscopy measurements will be presented here.

  15. Wavelength division multiplexed and double-port pumped time-bin entangled photon pair generation using Si ring resonator.

    PubMed

    Fujiwara, Mikio; Wakabayashi, Ryota; Sasaki, Masahide; Takeoka, Masahiro

    2017-02-20

    We report a wavelength division multiplexed time-bin entangled photon pair source in telecom wavelength using a 10 μm radius Si ring resonator. This compact resonator has two add ports and two drop ports. By pumping one add port by a continuous laser, we demonstrate an efficient generation of two-wavelength division multiplexed time-bin entangled photon pairs in the telecom C-band, which come out of one drop port, and are then split into the signal and idler photons via a wavelength filter. The resonator structure enhances four-wave mixing for pair generation. Moreover, we demonstrate the double-port pumping where two counter propagating pump lights are injected to generate entanglement from the two drop ports simultaneously. We successfully observe the highly entangled outputs from both two drop ports. Surprisingly, the count rate at each drop port is even increased by twice that of the single-port pumping. Possible mechanisms of this observation are discussed. Our technique allows for the efficient use of the Si ring resonator and widens its functionality for variety of applications.

  16. Simple approach to three-color two-photon microscopy by a fiber-optic wavelength convertor

    PubMed Central

    Li, Kuen-Che; Huang, Lynn L. H.; Liang, Jhih-Hao; Chan, Ming-Che

    2016-01-01

    A simple approach to multi-color two-photon microscopy of the red, green, and blue fluorescent indicators was reported based on an ultra-compact 1.03-μm femtosecond laser and a nonlinear fiber. Inside the nonlinear fiber, the 1.03-μm laser pulses were simultaneously blue-shifted to 0.6~0.8 μm and red-shifted to 1.2~1.4 μm region by the Cherenkov radiation and fiber Raman gain effects. The wavelength-shifted 0.6~0.8 μm and 1.2~1.4 μm radiations were co-propagated with the residual non-converted 1.03-μm pulses inside the same nonlinear fiber to form a fiber-output three-color femtosecond source. The application of the multi-wavelength sources on multi-color two-photon fluorescence microscopy were also demonstrated. Overall, due to simple system configuration, convenient wavelength conversion, easy wavelength tunability within the entire 0.7~1.35 μm bio-penetration window and less requirement for high power and bulky light sources, the simple approach to multi-color two-photon microscopy could be widely applicable as an easily implemented and excellent research tool for future biomedical and possibly even clinical applications. PMID:27896017

  17. Simple approach to three-color two-photon microscopy by a fiber-optic wavelength convertor.

    PubMed

    Li, Kuen-Che; Huang, Lynn L H; Liang, Jhih-Hao; Chan, Ming-Che

    2016-11-01

    A simple approach to multi-color two-photon microscopy of the red, green, and blue fluorescent indicators was reported based on an ultra-compact 1.03-μm femtosecond laser and a nonlinear fiber. Inside the nonlinear fiber, the 1.03-μm laser pulses were simultaneously blue-shifted to 0.6~0.8 μm and red-shifted to 1.2~1.4 μm region by the Cherenkov radiation and fiber Raman gain effects. The wavelength-shifted 0.6~0.8 μm and 1.2~1.4 μm radiations were co-propagated with the residual non-converted 1.03-μm pulses inside the same nonlinear fiber to form a fiber-output three-color femtosecond source. The application of the multi-wavelength sources on multi-color two-photon fluorescence microscopy were also demonstrated. Overall, due to simple system configuration, convenient wavelength conversion, easy wavelength tunability within the entire 0.7~1.35 μm bio-penetration window and less requirement for high power and bulky light sources, the simple approach to multi-color two-photon microscopy could be widely applicable as an easily implemented and excellent research tool for future biomedical and possibly even clinical applications.

  18. Photon-counting array detectors for space and ground-based studies at ultraviolet and vacuum ultraviolet /VUV/ wavelengths

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Bybee, R. L.

    1981-01-01

    The Multi-Anode Microchannel Arrays (MAMAs) are a family of photoelectric photon-counting array detectors, with formats as large as (256 x 1024)-pixels that can be operated in a windowless configuration at vacuum ultraviolet (VUV) and soft X-ray wavelengths or in a sealed configuration at ultraviolet and visible wavelengths. This paper describes the construction and modes of operation of (1 x 1024)-pixel and (24 x 1024)-pixel MAMA detector systems that are being built and qualified for use in sounding-rocket spectrometers for solar and stellar observations at wavelengths below 1300 A. The performance characteristics of the MAMA detectors at ultraviolet and VUV wavelengths are also described.

  19. A high-speed, tunable silicon photonic ring modulator integrated with ultra-efficient active wavelength control.

    PubMed

    Zheng, Xuezhe; Chang, Eric; Amberg, Philip; Shubin, Ivan; Lexau, Jon; Liu, Frankie; Thacker, Hiren; Djordjevic, Stevan S; Lin, Shiyun; Luo, Ying; Yao, Jin; Lee, Jin-Hyoung; Raj, Kannan; Ho, Ron; Cunningham, John E; Krishnamoorthy, Ashok V

    2014-05-19

    We report the first complete 10G silicon photonic ring modulator with integrated ultra-efficient CMOS driver and closed-loop wavelength control. A selective substrate removal technique was used to improve the ring tuning efficiency. Limited by the thermal tuner driver output power, a maximum open-loop tuning range of about 4.5nm was measured with about 14mW of total tuning power including the heater driver circuit power consumption. Stable wavelength locking was achieved with a low-power mixed-signal closed-loop wavelength controller. An active wavelength tracking range of > 500GHz was demonstrated with controller energy cost of only 20fJ/bit.

  20. Photon-phonon-enhanced infrared rectification in a two-dimensional nanoantenna-coupled tunnel diode

    SciTech Connect

    Kadlec, Emil A.; Jarecki, Robert L.; Starbuck, Andrew; Peters, David W.; Davids, Paul S.

    2016-12-28

    The interplay of strong infrared photon-phonon coupling with electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast photon-assisted tunneling in metal-oxide-semiconductor (MOS) structures. Infrared active optical phonon modes in polar oxides lead to strong dispersion and enhanced electric fields at material interfaces. We find that the infrared dispersion of SiO2 near a longitudinal optical phonon mode can effectively impedance match a photonic surface mode into a nanoscale tunnel gap that results in large transverse-field confinement. An integrated 2D nanoantenna structure on a distributed large-area MOS tunnel-diode rectifier is designed and built to resonantly excite infrared surface modes and is shown to efficiently channel infrared radiation into nanometer-scale gaps in these MOS devices. This enhanced-gap transverse-electric field is converted to a rectified tunneling displacement current resulting in a dc photocurrent. We examine the angular and polarization-dependent spectral photocurrent response of these 2D nanoantenna-coupled tunnel diodes in the photon-enhanced tunneling spectral region. Lastly, our 2D nanoantenna-coupled infrared tunnel-diode rectifier promises to impact large-area thermal energy harvesting and infrared direct detectors.

  1. Photon-Phonon-Enhanced Infrared Rectification in a Two-Dimensional Nanoantenna-Coupled Tunnel Diode

    NASA Astrophysics Data System (ADS)

    Kadlec, Emil A.; Jarecki, Robert L.; Starbuck, Andrew; Peters, David W.; Davids, Paul S.

    2016-12-01

    The interplay of strong infrared photon-phonon coupling with electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast photon-assisted tunneling in metal-oxide-semiconductor (MOS) structures. Infrared active optical phonon modes in polar oxides lead to strong dispersion and enhanced electric fields at material interfaces. We find that the infrared dispersion of SiO2 near a longitudinal optical phonon mode can effectively impedance match a photonic surface mode into a nanoscale tunnel gap that results in large transverse-field confinement. An integrated 2D nanoantenna structure on a distributed large-area MOS tunnel-diode rectifier is designed and built to resonantly excite infrared surface modes and is shown to efficiently channel infrared radiation into nanometer-scale gaps in these MOS devices. This enhanced-gap transverse-electric field is converted to a rectified tunneling displacement current resulting in a dc photocurrent. We examine the angular and polarization-dependent spectral photocurrent response of these 2D nanoantenna-coupled tunnel diodes in the photon-enhanced tunneling spectral region. Our 2D nanoantenna-coupled infrared tunnel-diode rectifier promises to impact large-area thermal energy harvesting and infrared direct detectors.

  2. Two-color two-photon excited fluorescence of indole: Determination of wavelength-dependent molecular parameters

    SciTech Connect

    Herbrich, Sebastian; Al-Hadhuri, Tawfik; Gericke, Karl-Heinz; Shternin, Peter S. Vasyutinskii, Oleg S.; Smolin, Andrey G.

    2015-01-14

    We present a detailed study of two-color two-photon excited fluorescence in indole dissolved in propylene glycol. Femtosecond excitation pulses at effective wavelengths from 268 to 293.33 nm were used to populate the two lowest indole excited states {sup 1}L{sub a} and {sup 1}L{sub b} and polarized fluorescence was then detected. All seven molecular parameters and the two-photon polarization ratio Ω containing information on two-photon absorption dynamics, molecular lifetime τ{sub f}, and rotation correlation time τ{sub rot} have been determined from experiment and analyzed as a function of the excitation wavelength. The analysis of the experimental data has shown that {sup 1}L{sub b}–{sup 1}L{sub a} inversion occurred under the conditions of our experiment. The two-photon absorption predominantly populated the {sup 1}L{sub a} state at all excitation wavelengths but in the 287–289 nm area which contained an absorption hump of the {sup 1}L{sub b} state 0-0 origin. The components of the two-photon excitation tensor S were analyzed giving important information on the principal tensor axes and absorption symmetry. The results obtained are in a good agreement with the results reported by other groups. The lifetime τ{sub f} and the rotation correlation time τ{sub rot} showed no explicit dependence on the effective excitation wavelength. Their calculated weighted average values were found to be τ{sub f} = 3.83 ± 0.14 ns and τ{sub rot} = 0.74 ± 0.06 ns.

  3. Broadband three-photon near-infrared quantum cutting in Tm{sup 3+} singly doped YVO{sub 4}

    SciTech Connect

    Wang, Y. Z.; Yu, D. C.; Lin, H. H.; Ye, S.; Peng, M. Y.; Zhang, Q. Y.

    2013-11-28

    An efficient three-photon near-infrared (NIR) quantum cutting (QC) is reported in Tm{sup 3+} singly doped YVO{sub 4} polycrystalline phosphors, where an optimized content of Tm{sup 3+} is determined to be 1.0 mol. %. Upon the absorption of a visible photon around 473 nm, three NIR photons emitting at 1180, 1479, and 1800 nm can be obtained efficiently by the sequential three-step radiative transitions of Tm{sup 3+}. The underlying mechanisms are analyzed in terms of the steady and dynamic fluorescence spectra measurements. Internal quantum yield is calculated to be 161.8% as a theoretical value when luminescence quenching due to defect species can be overcome. In addition, the broadband ultraviolet (UV)-excited [VO{sub 4}]{sup 3−} can strongly sensitize the {sup 1}G{sub 4} level of Tm{sup 3+} in the wavelength range likely from 250 to 360 nm, greatly increasing the UV photo-response and NIR fluorescent intensity of Tm{sup 3+}. The further development of this broadband three-photon NIR QC material would explore the new route to improve the photo-response of novel photoelectronic devices, particularly in 250–360 nm.

  4. Atomic layer deposition of absorbing thin films on nanostructured electrodes for short-wavelength infrared photosensing

    NASA Astrophysics Data System (ADS)

    Xu, Jixian; Sutherland, Brandon R.; Hoogland, Sjoerd; Fan, Fengjia; Kinge, Sachin; Sargent, Edward H.

    2015-10-01

    Atomic layer deposition (ALD), prized for its high-quality thin-film formation in the absence of high temperature or high vacuum, has become an industry standard for the large-area deposition of a wide array of oxide materials. Recently, it has shown promise in the formation of nanocrystalline sulfide films. Here, we demonstrate the viability of ALD lead sulfide for photodetection. Leveraging the conformal capabilities of ALD, we enhance the absorption without compromising the extraction efficiency in the absorbing layer by utilizing a ZnO nanowire electrode. The nanowires are first coated with a thin shunt-preventing TiO2 layer, followed by an infrared-active ALD PbS layer for photosensing. The ALD PbS photodetector exhibits a peak responsivity of 10-2 A W-1 and a shot-derived specific detectivity of 3 × 109 Jones at 1530 nm wavelength.

  5. Emitted short wavelength infrared radiation for detection and monitoring of volcanic activity

    NASA Technical Reports Server (NTRS)

    Rothery, D. A.; Francis, P. W.; Wood, C. A.

    1988-01-01

    Thematic Mapper images from LANDSAT were used to monitor volcanoes. Achievements include: (1) the discovery of a magmatic precursor to the 16 Sept. 1986 eruption of Lascar, northern Chile, on images from Mar. and July 1985 and of continuing fumarolic activity after the eruption; (2) the detection of unreported major changes in the distribution of lava lakes on Erta'Ale, Ethiopia; and (3) the mapping of a halo of still-hot spatter surrounding a vent on Mount Erebus, Antarctica, on an image acquired 5 min after a minor eruption otherwise known only from seismic records. A spaceborne short wavelength infrared sensor for observing hot phenomena of volcanoes is proposed. A polar orbit is suggested.

  6. Emitted short wavelength infrared radiation for detection and monitoring of volcanic activity

    NASA Technical Reports Server (NTRS)

    Rothery, D. A.; Francis, P. W.; Wood, C. A.

    1988-01-01

    Thematic Mapper images from LANDSAT were used to monitor volcanoes. Achievements include: (1) the discovery of a magmatic precursor to the 16 Sept. 1986 eruption of Lascar, northern Chile, on images from Mar. and July 1985 and of continuing fumarolic activity after the eruption; (2) the detection of unreported major changes in the distribution of lava lakes on Erta'Ale, Ethiopia; and (3) the mapping of a halo of still-hot spatter surrounding a vent on Mount Erebus, Antarctica, on an image acquired 5 min after a minor eruption otherwise known only from seismic records. A spaceborne short wavelength infrared sensor for observing hot phenomena of volcanoes is proposed. A polar orbit is suggested.

  7. InTlSb for long-wavelength infrared photodetectors and arrays

    NASA Astrophysics Data System (ADS)

    Razeghi, Manijeh

    The heteorepitaxial narrow-gap semiconductors on Si or GaAs substrates offer the possibility of monolithic integration of detectors and readout circuits in the infrared focal plane arrays (IRFPA's). This structure can avoid the problems of a complicated etch-thinning process and indium bump displace in the hybrid case. This structure permits the production of a large-area FPA's with high reliability and low cost. The purpose of this project is to develop III-V IRFPA on InSb, GaAs, Si substrates, special detectors made from In(1-x)Tl(x)Sb material system. The devices are of potential in the long wavelength (8-14 micrometers), particularly in the application of thermal imaging, as MCT materials suffer from poor composition uniform over large areas and thermal stability. As a preliminary step towards InTlSb photovoltaic detectors, it is necessary to establish a reliable procedure to fabricate InSb photovoltaic detectors.

  8. Wavelength-independent anti-interference coating for the far-infrared

    NASA Technical Reports Server (NTRS)

    Mcknight, S. W.; Stewart, K. P.; Drew, H. D.; Moorjani, K.

    1987-01-01

    The transmission and reflection of radiation at an interface between two dielectrics with a thin conducting film is analyzed under conditions appropriate to the far-infrared. When the transmission is from a more dense to a less dense optical medium it is demonstrated that the reflectivity can be made arbitrarily small for a wide range of wavelengths by selecting the appropriate sheet resistance for the conducting film. This property can be exploited to produce a coating that drastically reduces the interference fringes in a flat plane-parallel dielectric substrate or window. The condition depends only on the film resistance which can be monitored precisely during deposition. This effect is demonstrated by evaporating films of nichrome on silicon substrates, which reduce the interference fringe contrast to less than 1 percent transmittance from 10-100/cm. Near the antiinterference condition the fringe contrast is shown to be a sensitive probe of the film conductivity.

  9. Spectral properties of hydrogen, helium, methane, and ammonia at thermal infrared wavelengths. [for Jupiter atmosphere

    NASA Technical Reports Server (NTRS)

    Taylor, F. W.; Jones, A. D., III

    1976-01-01

    The paper presents some results of a theoretical and laboratory program to determine the thermal infrared spectral properties of the principal gaseous constituents of the atmosphere of Jupiter. Birnbaum (1975) has measured laboratory spectra in the 16- to 1000-micron wavelength range for hydrogen and hydrogen-helium mixtures at Jovian temperatures. These are compared with theoretically computed spectra in order to determine the temperature dependence of the line strengths in the pressure-induced rotational band and the overlap parameters from the translational band. Existing spectral data for methane do not agree well with measurements of the nu 4 band at room temperature. A revised allocation of line intensities is proposed. Existing data for the nu 2 (10-micron) band of ammonia agree reasonably well with measurements at room temperature and at -77 C, but there are some important discrepancies which remain to be explained.

  10. Note: Three wavelengths near-infrared spectroscopy system for compensating the light absorbance by water

    NASA Astrophysics Data System (ADS)

    Bhutta, M. Raheel; Hong, Keum-Shik; Kim, Beop-Min; Hong, Melissa Jiyoun; Kim, Yun-Hee; Lee, Se-Ho

    2014-02-01

    Given that approximately 80% of blood is water, we develop a wireless functional near-infrared spectroscopy system that detects not only the concentration changes of oxy- and deoxy-hemoglobin (HbO and HbR) during mental activity but also that of water (H2O). Additionally, it implements a water-absorption correction algorithm that improves the HbO and HbR signal strengths during an arithmetic task. The system comprises a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a WiFi communication module, and a battery. System functionality was tested by means of arithmetic-task experiments performed by healthy male subjects.

  11. Wavelength-independent anti-interference coating for the far-infrared

    NASA Technical Reports Server (NTRS)

    Mcknight, S. W.; Stewart, K. P.; Drew, H. D.; Moorjani, K.

    1987-01-01

    The transmission and reflection of radiation at an interface between two dielectrics with a thin conducting film is analyzed under conditions appropriate to the far-infrared. When the transmission is from a more dense to a less dense optical medium it is demonstrated that the reflectivity can be made arbitrarily small for a wide range of wavelengths by selecting the appropriate sheet resistance for the conducting film. This property can be exploited to produce a coating that drastically reduces the interference fringes in a flat plane-parallel dielectric substrate or window. The condition depends only on the film resistance which can be monitored precisely during deposition. This effect is demonstrated by evaporating films of nichrome on silicon substrates, which reduce the interference fringe contrast to less than 1 percent transmittance from 10-100/cm. Near the antiinterference condition the fringe contrast is shown to be a sensitive probe of the film conductivity.

  12. Multi-wavelength Observations of Fast Infrared Flares from V404 Cygni in 2015

    NASA Astrophysics Data System (ADS)

    Dallilar, Yigit; Casella, Piergiorgio; Marsh, Tom; Gandhi, Poshak; Fender, Rob; Littlefair, Stuart; Eikenberry, Steve; Garner, Alan; Stelter, Deno; Dhillon, Vik; Mooley, Kunal

    2016-07-01

    We used the fast photometry mode of our new Canarias InfraRed Camera Experiment (CIRCE) on the 10.4-meter Gran Telescopio Canarias to observe V404 Cyg, a stellar mass black hole binary, on June 25, 2015 during its 2015 outburst. CIRCE provided 10Hz sampling in the Ks-band (2.2 microns) In addition, we obtained simultaneous multi wavelength data from our collaborators: three GHz radio bands from the AMI telescope and three optical/UV bands (u', g', r') from ULTRACAM on the William Herschel 4.2-meter telescope. We identify fast (1-second) IR flares with optical counterparts of varying strength/color, which we argue arise from a relativistic jet outflow. These observations provide important constraints on the emission processes and physical conditions in the jet forming region in V404 Cygni. We will discuss these results as well as their implications for relativistic jet formation around stellar-mass black holes.

  13. Multi-wavelength Observations of Fast Infrared Flares from V404 Cygni in 2015

    NASA Astrophysics Data System (ADS)

    Eikenberry, Stephen S.; Dallilar, Yigit; Garner, Alan; Deno Stelter, R.; Gandhi, Poshak; Dhillon, Vik; Littlefair, Stuart; Marsh, Thomas; Fender, Rob P.; Mooley, Kunal

    2016-04-01

    We used the fast photometry mode of our new Canarias InfraRed Camera Experiment (CIRCE) on the 10.4-meter Gran Telescopio Canarias to observe V404 Cyg, a stellar mass black hole binary, on June 25, 2015 during its 2015 outburst. CIRCE provided 10Hz sampling in the Ks-band (2.2 microns) In addition, we obtained simultaneous multi wavelength data from our collaborators: three GHz radio bands from the AMI telescope and three optical/UV bands (u', g', r') from ULTRACAM on the William Herschel 4.2-meter telescope. We identify fast (1-second) IR flares with optical counterparts of varying strength/color, which we argue arise from a relativistic jet outflow. These observations provide important constraints on the emission processes and physical conditions in the jet forming region in V404 Cygni. We will discuss these results as well as their implications for relativistic jet formation around stellar-mass black holes.

  14. Dark current reduction in a long wavelength quantum well infrared photodetector operating at low temperature

    NASA Astrophysics Data System (ADS)

    Lhuillier, Emmanuel; Péré-Laperne, Nicolas; Rosencher, Emmanuel; Ribet-Mohamed, Isabelle; Nedelcu, Alexandru; Doyennette, Laetitia; Berger, Vincent

    2011-05-01

    Defence and astronomy are particularly demanding applications of infrared focal plane arrays in the 8-20 μm range of wavelength. QWIP is a good candidate for the low flux applications. Dark current is clearly a limiting parameter for it. Therefore, we have studied the dark current at very low operating temperature where the electronic transport is in the tunneling regime. We have developed a model of transport based on hopping between localized states. In the tunneling regime of transport, we have identified the main role played by the interaction between electron and ionized impurities. Thus the dark current in the structure is sensitive to the doping profile (magnitude and shape). This paper is suggesting a new way of reduction of the dark current while keeping a constant absorption. A decrease of 50% of the dark current has already been achieved for specially designed components. An extra structure is presented and is leading to an even lower dark current.

  15. Three-dimensional facial recognition using passive long-wavelength infrared polarimetric imaging.

    PubMed

    Yuffa, Alex J; Gurton, Kristan P; Videen, Gorden

    2014-12-20

    We use a polarimetric camera to record the Stokes parameters and the degree of linear polarization of long-wavelength infrared radiation emitted by human faces. These Stokes images are combined with Fresnel relations to extract the surface normal at each pixel. Integrating over these surface normals yields a three-dimensional facial image. One major difficulty of this technique is that the normal vectors determined from the polarizations are not unique. We overcome this problem by introducing an additional boundary condition on the subject. The major sources of error in producing inversions are noise in the images caused by scattering of the background signal and the ambiguity in determining the surface normals from the Fresnel coefficients.

  16. Note: three wavelengths near-infrared spectroscopy system for compensating the light absorbance by water.

    PubMed

    Bhutta, M Raheel; Hong, Keum-Shik; Kim, Beop-Min; Hong, Melissa Jiyoun; Kim, Yun-Hee; Lee, Se-Ho

    2014-02-01

    Given that approximately 80% of blood is water, we develop a wireless functional near-infrared spectroscopy system that detects not only the concentration changes of oxy- and deoxy-hemoglobin (HbO and HbR) during mental activity but also that of water (H2O). Additionally, it implements a water-absorption correction algorithm that improves the HbO and HbR signal strengths during an arithmetic task. The system comprises a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a WiFi communication module, and a battery. System functionality was tested by means of arithmetic-task experiments performed by healthy male subjects.

  17. Electronic transport in a long wavelength infrared quantum cascade detector under dark condition

    NASA Astrophysics Data System (ADS)

    Li, L.; Zhou, X. H.; Lin, T.; Li, N.; Zhu, Z. Q.; Liu, F. Q.

    2016-09-01

    We present a joint experimental and theoretical investigation on a long wavelength infrared quantum cascade detector to reveal its dark current paths. The temperature dependence of the dark current is measured. It is shown that there are two different transport mechanisms, namely resonant tunneling at low temperatures and thermal excitation at higher temperature, dominate the carrier flow, respectively. Moreover, the experimental intersubband transition energies obtained by the magneto-transport measurements matches the theoretical predictions well. With the aid of the calculated band structures, we can explain the observed oscillation phenomena of the dark current under the magnetic field very well. The obtained results provide insight into the transport properties of quantum cascade detectors thus providing a useful tool for device optimization.

  18. Cooling of isolated anthracene cations probed with photons of different wavelengths in the Mini-Ring

    NASA Astrophysics Data System (ADS)

    Ji, M.; Bernard, J.; Chen, L.; Brédy, R.; Ortéga, C.; Joblin, C.; Cassimi, A.; Martin, S.

    2017-01-01

    We report on a direct measurement of the Internal Energy Distribution (IED) shift rate of an initially hot polycyclic aromatic hydrocarbon (PAH) molecular ensemble, anthracene cations (C14H10 +) . The ions were produced in an electron cyclotron resonance (ECR) ion source and stored in an electrostatic ion storage ring, the Mini-Ring. Laser pulses of two wavelengths were sent successively to merge the stored ion bunch at different storage times to enhance the neutral fragment yield due to fast laser induced dissociation. Using this technique, we have been able to determine directly the energy shift rate of the IED, without involving any theoretical simulation or any assumption on dissociation rates, cooling rates, or the initial IED. Theoretical energy shift rates have been estimated from the evolution of simulated IEDs by taking into account the effects of the unimolecular dissociation and two radiative decay mechanisms: the Poincaré fluorescence and the infrared vibrational emission. The comparison between the experimental results and the model provides new evidence of the important role of the Poincaré fluorescence in the overall cooling process of anthracene cations. Although in the short time range the commonly accepted intuition says that the cooling would result mostly from the dissociation of the hottest ions (depletion cooling), we demonstrate that the Poincaré fluorescence is the dominant contribution (about 85%) to the net cooling effect.

  19. Multi-Wavelength Near Infrared Observations of Marum and Yasur Volcanoes, Vanuatu

    NASA Astrophysics Data System (ADS)

    Howell, Robert R.; Radebaugh, Jani; Lopes, Rosaly M.; Lorenz, Ralph D.; Turtle, Elizabeth P.

    2014-11-01

    To help understand and test models of thermal emission from planetary volcanoes, we obtained in May 2014 a variety of near-infrared observations of the very active Marum lava lake on Ambrym, Vanuatu, as well as the Strombolian activity at Yasur on Tanna. Our observations include high resolution images and movies made with standard and modified cameras and camcorders. In addition, to test the planetary emission models, which typically rely on multi-wavelength observations, we developed a small inexpensive prototype imager named "Kerby", which consists of three simultaneously active near-infrared cameras operating at 0.860, 0.775, and 0.675 microns, as well as a fourth visible wavelength RGB camera. This prototype is based on the Raspberry Pi and Pi-NoIR cameras. It can record full high definition video, and is light enough to be carried by backpack and run from batteries. To date we have concentrated on the analysis of the Marum data. During our observations of the 40 m diameter lava lake, convection was so vigorous that areas of thin crust formed only intermittently and persisted for tens of seconds to a few minutes at most. The convection pattern primarily consisted of two upwelling centers located about 8 m in from the margins on opposite sides of the lake. Horizontal velocities away from the upwelling centers were approximately 4 m/s. A hot bright margin roughly 0.4 m wide frequently formed around parts of the lake perimeter. We are in the process of establishing the absolute photometry calibration to obtain temperatures, temperature distributions, and magma cooling rates.

  20. The Chromospheric Solar Limb Brightening at Radio, Millimeter, Sub-millimeter, and Infrared Wavelengths

    NASA Astrophysics Data System (ADS)

    De la Luz, V.

    2016-07-01

    Observations of the emission at radio, millimeter, sub-millimeter, and infrared wavelengths in the center of the solar disk validate the autoconsistence of semi-empirical models of the chromosphere. Theoretically, these models must reproduce the emission at the solar limb. In this work, we tested both the VALC and C7 semi-empirical models by computing their emission spectrum in the frequency range from 2 GHz to 10 THz at solar limb altitudes. We calculate the Sun's theoretical radii as well as their limb brightening. Non-local thermodynamic equilibrium was computed for hydrogen, electron density, and H-. In order to solve the radiative transfer equation, a three-dimensional (3D) geometry was employed to determine the ray paths, and Bremsstrahlung, H-, and inverse Bremsstrahlung opacity sources were integrated in the optical depth. We compared the computed solar radii with high-resolution observations at the limb obtained by Clark. We found that there are differences between the observed and computed solar radii of 12,000 km at 20 GHz, 5000 km at 100 GHz, and 1000 km at 3 THz for both semi-empirical models. A difference of 8000 km in the solar radii was found when comparing our results against the heights obtained from Hα observations of spicules-off at the solar limb. We conclude that the solar radii cannot be reproduced by VALC and C7 semi-empirical models at radio—infrared wavelengths. Therefore, the structures in the high chromosphere provide a better measurement of the solar radii and their limb brightening as shown in previous investigations.

  1. Mid-infrared quantum dot emitters utilizing planar photonic crystal technology.

    SciTech Connect

    Subramania,Ganapathi Subramanian; Lyo, Sungkwun Kenneth; Cederberg, Jeffrey George; Passmore, Brandon Scott; El-Kady, Ihab Fathy; Shaner, Eric Arthur

    2008-09-01

    The three-dimensional confinement inherent in InAs self-assembled quantum dots (SAQDs) yields vastly different optical properties compared to one-dimensionally confined quantum well systems. Intersubband transitions in quantum dots can emit light normal to the growth surface, whereas transitions in quantum wells emit only parallel to the surface. This is a key difference that can be exploited to create a variety of quantum dot devices that have no quantum well analog. Two significant problems limit the utilization of the beneficial features of SAQDs as mid-infrared emitters. One is the lack of understanding concerning how to electrically inject carriers into electronic states that allow optical transitions to occur efficiently. Engineering of an injector stage leading into the dot can provide current injection into an upper dot state; however, to increase the likelihood of an optical transition, the lower dot states must be emptied faster than upper states are occupied. The second issue is that SAQDs have significant inhomogeneous broadening due to the random size distribution. While this may not be a problem in the long term, this issue can be circumvented by using planar photonic crystal or plasmonic approaches to provide wavelength selectivity or other useful functionality.

  2. Multiplexing photonic devices integrated on a silicon/germanium platform for the mid-infrared

    NASA Astrophysics Data System (ADS)

    Labeye, P.; Koshkinbayeva, A.; Dupoy, M.; Barritault, P.; Lartigue, O.; Fournier, M.; Fedeli, J.-M.; Boutami, S.; Garcia, S.; Nicoletti, S.; Duraffourg, L.

    2017-02-01

    With the recent progress in integrated silicon photonics technology and the recent development of efficient quantum cascade laser technology (QCL), there is now a very good opportunity to investigate new gas sensors offering both very high sensitivity, high selectivity (multi-gas sensing, atmosphere analysis) and low cost thanks to the integration on planar substrate. In this context, we have developed singlemode optical waveguides in the mid-infrared based on Silicon/Germanium alloy integrated on silicon. These waveguides, compatible with standard microelectronic technologies present very low loss in the 3300 - 1300 cm-1 range. This paper presents the design, technological realization, and characterization of array waveguide grating devices specifically developed for the simultaneous detection of several gas using arrays of QCL sources. Gas sensing generally requires a tunable source continuously covering the whole operational range of the QCL stack. With this objective, specific design has been adopted to flatten the optical transfer function of the whole multiplexers. Samples devices around 2235cm-1 were realized and tested and showed results in good agreement with the modeling, flat transmission over a full 100 cm-1 operational range were obtained with a peak-to-valley modulation of -5dB were experimentally measured. These devices will be soon associated with QCL arrays in order to provide integrated, powerful, multi wavelength, laser sources in the 2235 cm-1 region applicable to NO, CO, and CO2 multi-gas sensor.

  3. Expanding two-photon intravital microscopy to the infrared by means of optical parametric oscillator.

    PubMed

    Herz, Josephine; Siffrin, Volker; Hauser, Anja E; Brandt, Alexander U; Leuenberger, Tina; Radbruch, Helena; Zipp, Frauke; Niesner, Raluca A

    2010-02-17

    Chronic inflammation in various organs, such as the brain, implies that different subpopulations of immune cells interact with the cells of the target organ. To monitor this cellular communication both morphologically and functionally, the ability to visualize more than two colors in deep tissue is indispensable. Here, we demonstrate the pronounced power of optical parametric oscillator (OPO)-based two-photon laser scanning microscopy for dynamic intravital imaging in hardly accessible organs of the central nervous and of the immune system, with particular relevance for long-term investigations of pathological mechanisms (e.g., chronic neuroinflammation) necessitating the use of fluorescent proteins. Expanding the wavelength excitation farther to the infrared overcomes the current limitations of standard Titanium:Sapphire laser excitation, leading to 1), simultaneous imaging of fluorophores with largely different excitation and emission spectra (e.g., GFP-derivatives and RFP-derivatives); and 2), higher penetration depths in tissue (up to 80%) at higher resolution and with reduced photobleaching and phototoxicity. This tool opens up new opportunities for deep-tissue imaging and will have a tremendous impact on the choice of protein fluorophores for intravital applications in bioscience and biomedicine, as we demonstrate in this work.

  4. Long-wavelength PtSi infrared detectors fabricated by incorporating a p(+) doping spike grown by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Park, J. S.; George, T.; Jones, E. W.; Fathauer, R. W.; Maserjian, J.

    1993-01-01

    By incorporating a 1-nm-thick p(+) doping spike at the PtSi/Si interface, we have successfully demonstrated extended cutoff wavelengths of PtSi Schottky infrared detectors in the long wavelength infrared (LWIR) regime for the first time. The extended cutoff wavelengths resulted from the combined effects of an increased electric field near the silicide/Si interface due to the p(+) doping spike and the Schottky image force. The p(+) doping spikes were grown by molecular beam epitaxy at 450 C, using elemental boron as the dopant source, with doping concentrations ranging from 5 x 10 exp 19 to 2 x 10 exp 20/cu cm. Transmission electron microscopy indicated good crystalline quality of the doping spikes. The cutoff wavelengths were shown to increase with increasing doping concentrations of the p(+) spikes. Thermionic emission dark current characteristics were observed and photoresponses in the LWIR regime were demonstrated.

  5. Long-wavelength PtSi infrared detectors fabricated by incorporating a p(+) doping spike grown by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Lin, T. L.; Park, J. S.; George, T.; Jones, E. W.; Fathauer, R. W.; Maserjian, J.

    1993-01-01

    By incorporating a 1-nm-thick p(+) doping spike at the PtSi/Si interface, we have successfully demonstrated extended cutoff wavelengths of PtSi Schottky infrared detectors in the long wavelength infrared (LWIR) regime for the first time. The extended cutoff wavelengths resulted from the combined effects of an increased electric field near the silicide/Si interface due to the p(+) doping spike and the Schottky image force. The p(+) doping spikes were grown by molecular beam epitaxy at 450 C, using elemental boron as the dopant source, with doping concentrations ranging from 5 x 10 exp 19 to 2 x 10 exp 20/cu cm. Transmission electron microscopy indicated good crystalline quality of the doping spikes. The cutoff wavelengths were shown to increase with increasing doping concentrations of the p(+) spikes. Thermionic emission dark current characteristics were observed and photoresponses in the LWIR regime were demonstrated.

  6. SOA-based fiber ring laser with seed of DFB wavelength scanning for relative humidity measurement using an air-guided photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Mohd Noor, M. Y.; Khalili, N.; Peng, G. D.

    2013-08-01

    We propose a novel ring laser for non-hygroscopic coating relative humidity (RH) fiber sensor by means of infrared absorption spectroscopy. A semiconductor optical amplifier (SOA)-based fiber ring laser is used in this scheme. No tunable optical filter is required for the ring laser scheme as wavelength scanning is introduced in the ring using a distributed feedback (DFB) laser. An air-guided photonic crystal fiber (AGPCF) is included in the ring cavity that acts as a sensing head. The detection of gas humidity inside the air holes of AGPCF is determined by DFB wavelength scanning around 1368.59 nm water vapor absorption peak with SOA as a gain medium in the ring. We have experimentally implemented the wavelength scanning of SOA-based fiber ring laser scheme with an AGPCF sensing head of 5 cm and a small gap between single mode fiber and AGPCF to allow air diffusion in and out of the air holes inside the AGPCF. The sensitivity of the sensor is increased from 2.47 to 10.93 mV/1% RH over the range from 0 to 90% RH when the non-lasing mode (single-pass absorption spectroscopy) of the sensor is changed into the lasing mode (multi-pass absorption spectroscopy).

  7. A reference-wavelength-based method for improved analysis of near-infrared spectroscopy.

    PubMed

    Chen, Yun; Chen, Wenliang; Shi, Zhenzhi; Yang, Yue; Xu, Kexin

    2009-05-01

    Near-infrared (NIR) spectroscopy has been widely used in many industrial applications. It also has tremendous potential for trace element detection and noninvasive human physiological measurements. In NIR spectroscopy, however, the measurement precision is often dependent on temperature, measurement position, and sample status. In order to improve measurement precision, a method using spectral information at a reference wavelength is developed in this paper. Based on the displacement effect between solvent and solute molecules in a solution, the signal at the reference wavelength is used as an internal reference to correct the spectrum of the sample under test. As an example, the spectra of glucose aqueous solutions under different temperatures are measured, and our method for eliminating the temperature disturbance is evaluated. The experimental results obtained show that the relative error of glucose concentration prediction is 330% per degree before the spectrum correction. After the correction, the relative error is reduced to 5.12%, and the error is no longer dependent on temperature. As the displacement effect can be found commonly in various solutions, the method described in this work may be used to improve the accuracy of spectral analysis of many other solutions.

  8. Room temperature and high responsivity short wavelength II-VI quantum well infrared photodetector

    NASA Astrophysics Data System (ADS)

    Ravikumar, Arvind P.; Chen, Guopeng; Zhao, Kuaile; Tian, Yue; Prucnal, Paul; Tamargo, Maria C.; Gmachl, Claire F.; Shen, Aidong

    2013-04-01

    We report the experimental demonstration of a room temperature, high responsivity, short wavelength II-VI Zn0.51Cd0.49Se/Zn0.29Cd0.26Mg0.45Se based quantum well infrared photodetector operating between 3 and 5 μm. Spectral response was observed up to room temperature with a cut off wavelength of 5 μm at 280 K. Measurements with a calibrated blackbody source yielded a peak responsivity of over 30 A/W at 280 K and an applied bias of -3 V. The dark current limited peak detectivity at 80 K and 280 K were measured to be 2 × 109 cm √Hz/W and 4 × 107 cm √Hz/W, respectively. These results are consistent with theoretical calculations that predict a maximum detectivity of the order of 107 cm √Hz/W at room temperature for typical carrier lifetimes and optimized doping levels.

  9. Intersubband absorption in Si(1-x)Ge(x/Si superlattices for long wavelength infrared detectors

    NASA Technical Reports Server (NTRS)

    Rajakarunanayake, Yasantha; Mcgill, Tom C.

    1990-01-01

    Researchers calculated the absorption strengths for intersubband transitions in n-type Si(1-x)Ge(x)/Si superlattices. These transitions can be used for the detection of long-wavelength infrared radiation. A significant advantage in Si(1-x)Ge(x)/Si supperlattice detectors is the ability to detect normally incident light; in Ga(1-x)Al(x)As/GaAs superlattices, intersubband absorption is possible only if the incident light contains a polarization component in the growth direction of the superlattice. Researchers present detailed calculation of absorption coefficients, and peak absorption wavelengths for (100), (111) and (110) Si(1-x)Ge(x)/Si superlattices. Peak absorption strengths of about 2000 to 6000 cm(exp -1) were obtained for typical sheet doping concentrations (approx. equals 10(exp 12)cm(exp -2)). Absorption comparable to that in Ga(1-x)Al(x)As/GaAs superlattice detectors, compatibility with existing Si technology, and the ability to detect normally incident light make these devices promising for future applications.

  10. Multi-wavelength mid-infrared micro-spectral imaging using semiconductor lasers.

    PubMed

    Guo, B; Wang, Y; Peng, C; Luo, G P; Le, H Q

    2003-07-01

    Infrared (IR, 3-12-microm) microscopic spectral imaging is an important analytical technique. Many current instruments employ thermal IR light sources, which suffer the problem of low brightness and high noise. This paper evaluates the system engineering merit in using semiconductor lasers, which offer orders-of-magnitude-higher power, brightness, and lower noise. A microscopic spectral imaging system using semiconductor lasers (quantum cascade) as illuminators, and focal plane array detectors demonstrated a high signal-to-noise ratio (> 20 dB) at video frame rate for a large illuminated area. The comparative advantages of laser vs. thermal light source are analyzed and demonstrated. Microscopic spectral imaging with fixed-wavelength and tunable lasers of 4.6-, 5.1-, 6-, and 9.3-microm wavelength was applied to a number of representative samples that consist of biological tissues (plant and animal), solid material (a stack of laminated polymers), and liquid chemical (benzene). Transmission spectral images with approximately 30-dB dynamic range were obtained with clear evidence of spectral features for different samples. The potential of more advanced systems with a wide coverage of spectral bands is discussed.

  11. Room temperature performance of mid-wavelength infrared InAsSb nBn detectors

    SciTech Connect

    Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Hoglund, Linda; Rosenberg, Robert; Kowalczyk, Robert; Khoshakhlagh, Arezou; Fisher, Anita; Ting, David Z.-Y.; Gunapala, Sarath D.

    2014-07-14

    In this work, we investigate the high temperature performance of mid-wavelength infrared InAsSb-AlAsSb nBn detectors with cut-off wavelengths near 4.5 μm. The quantum efficiency of these devices is 35% without antireflection coatings and does not change with temperature in the 77–325 K temperature range, indicating potential for room temperature operation. The current generation of nBn detectors shows an increase of operational bias with temperature, which is attributed to a shift in the Fermi energy level in the absorber. Analysis of the device performance shows that operational bias and quantum efficiency of these detectors can be further improved. The device dark current stays diffusion limited in the 150 K–325 K temperature range and becomes dominated by generation-recombination processes at lower temperatures. Detector detectivities are D*(λ) = 1 × 10{sup 9} (cm Hz{sup 0.5}/W) at T = 300 K and D*(λ) = 5 × 10{sup 9} (cm Hz{sup 0.5}/W) at T = 250 K, which is easily achievable with a one stage TE cooler.

  12. Quantitative evaluation of atherosclerotic plaque phantom by near-infrared multispectral imaging with three wavelengths

    NASA Astrophysics Data System (ADS)

    Nagao, Ryo; Ishii, Katsunori; Awazu, Kunio

    2014-03-01

    Atherosclerosis is a primary cause of critical ischemic disease. The risk of critical event is involved the content of lipid in unstable plaque. Near-infrared (NIR) range is effective for diagnosis of atherosclerotic plaque because of the absorption peaks of lipid. NIR multispectral imaging (NIR-MSI) is suitable for the evaluation of plaque because it can provide spectroscopic information and spatial image quickly with a simple measurement system. The purpose of this study is to evaluate the lipid concentrations in plaque phantoms quantitatively with a NIR-MSI system. A NIR-MSI system was constructed with a supercontinuum light, a grating spectrometer and a MCT camera. Plaque phantoms with different concentrations of lipid were prepared by mixing bovine fat and a biological soft tissue model to mimic the different stages of unstable plaque. We evaluated the phantoms by the NIR-MSI system with three wavelengths in the band at 1200 nm. Multispectral images were processed by spectral angle mapper method. As a result, the lipid areas of phantoms were effectively highlighted by using three wavelengths. In addition, the concentrations of lipid areas were classified according to the similarity between measured spectra and a reference spectrum. These results suggested the possibility of image enhancement and quantitative evaluation of lipid in unstable plaque with a NIR-MSI.

  13. Short-wavelength interband cascade infrared photodetectors operating above room temperature

    SciTech Connect

    Lotfi, Hossein; Li, Lu; Lei, Lin; Jiang, Yuchao; Yang, Rui Q.; Klem, John F.; Johnson, Matthew B.

    2016-01-13

    High temperature operation (250–340 K) of short-wavelength interband cascade infrared photodetectors (ICIPs) with InAs/GaSb/Al0.2In0.8Sb/GaSb superlattice absorbers has been demonstrated with a 50% cutoff wavelength of 2.9 μm at 300 K. Two ICIP structures, one with two and the other with three stages, were designed and grown to explore this multiple-stage architecture. At λ = 2.1 μm, the two- and three-stage ICIPs had Johnson-noise-limited detectivities of 5.1 × 109 and 5.8 ×109 cm Hz1/2/W, respectively, at 300 K. The better device performance of the three-stage ICIP over the two-stage ICIP confirmed the advantage of more stages for this cascade architecture. Furthermore, an Arrhenius activation energy of 450 meV is extracted for the bulk resistance-area product, which indicates the dominance of the diffusion current at these high temperatures.

  14. Short-wavelength interband cascade infrared photodetectors operating above room temperature

    DOE PAGES

    Lotfi, Hossein; Li, Lu; Lei, Lin; ...

    2016-01-13

    High temperature operation (250–340 K) of short-wavelength interband cascade infrared photodetectors (ICIPs) with InAs/GaSb/Al0.2In0.8Sb/GaSb superlattice absorbers has been demonstrated with a 50% cutoff wavelength of 2.9 μm at 300 K. Two ICIP structures, one with two and the other with three stages, were designed and grown to explore this multiple-stage architecture. At λ = 2.1 μm, the two- and three-stage ICIPs had Johnson-noise-limited detectivities of 5.1 × 109 and 5.8 ×109 cm Hz1/2/W, respectively, at 300 K. The better device performance of the three-stage ICIP over the two-stage ICIP confirmed the advantage of more stages for this cascade architecture. Furthermore,more » an Arrhenius activation energy of 450 meV is extracted for the bulk resistance-area product, which indicates the dominance of the diffusion current at these high temperatures.« less

  15. Experimental investigation on supercontinuum generation by single, dual, and triple wavelength pumping in a silica photonic crystal fiber.

    PubMed

    Gao, Weiqing; Xu, Qiang; Li, Xue; Zhang, Wei; Hu, Jigang; Li, Yuan; Chen, Xiangdong; Yuan, Zijun; Liao, Meisong; Cheng, Tonglei; Xue, Xiaojie; Suzuki, Takenobu; Ohishi, Yasutake

    2016-11-20

    We investigate the supercontinuum (SC) generation in an 1 cm long silica photonic crystal fiber (PCF) pumped by the pulse sources with single, dual, and triple wavelengths, respectively. The silica PCF has two zero-dispersion wavelengths at 900 and 2620 nm, respectively. When pumped by a single wavelength, the SC spectral range covers about 1000 nm. When pumped by dual and triple wavelengths, the SC spectral range covers wider than 2000 nm. Both the SC spectral range and the flatness are improved obviously when pumped by triple wavelengths. The maximum SC spectral range is obtained when the silica PCF is pumped by the triple wavelengths at 800, 1450, and 1785 nm. The SC spectral range covers 2810 nm from 350 to 3160 nm wider than three octaves. The 10 dB bandwidth covers 2280 nm from 450 to 2730 nm wider than two octaves. This is the first investigation on comparison of the SCs generated by different pump wavelengths up to three experimentally. The generated SC spectra have covered the full transmission window of silica fiber.

  16. DBR, Sub-wavelength grating, and Photonic crystal slab Fabry-Perot cavity design using phase analysis by FDTD.

    PubMed

    Kim, Jae Hwan Eric; Chrostowski, Lukas; Bisaillon, Eric; Plant, David V

    2007-08-06

    We demonstrate a Finite-Difference Time-Domain (FDTD) phase methodology to estimate resonant wavelengths in Fabry-Perot (FP) cavity structures. We validate the phase method in a conventional Vertical-Cavity Surface-Emitting Laser (VCSEL) structure using a transfer-matrix method, and compare results with a FDTD reflectance method. We extend this approach to a Sub-Wavelength Grating (SWG) and a Photonic Crystal (Phc) slab, either of which may replace one of the Distributed Bragg Reflectors (DBRs) in the VCSEL, and predict resonant conditions with varying lithographic parameters. Finally, we compare the resonant tunabilities of three different VCSEL structures, taking quality factors into account.

  17. Narrow-spectral-linewidth silicon photonic wavelength-tunable laser with highly asymmetric Mach-Zehnder interferometer.

    PubMed

    Tang, Rui; Kita, Tomohiro; Yamada, Hirohito

    2015-04-01

    We propose a narrow-spectral-linewidth silicon photonic wavelength-tunable laser with a novel external wavelength-tunable filter, which consists of two silicon ring resonators with different circumferences and a highly asymmetric Mach-Zehnder interferometer (MZI), the two optical paths of which have significantly different lengths. Calculations and experimental results indicated that the gain difference between longitudinal modes was increased by the highly asymmetric MZI. Consequently, a narrow spectral linewidth of 12 kHz and a stable single-mode oscillation were obtained.

  18. Extracting an entangled photon pair from collectively decohered pairs at a telecommunication wavelength.

    PubMed

    Tsujimoto, Yoshiaki; Sugiura, Yukihiro; Ando, Makoto; Katsuse, Daisuke; Ikuta, Rikizo; Yamamoto, Takashi; Koashi, Masato; Imoto, Nobuyuki

    2015-05-18

    We experimentally demonstrated entanglement extraction scheme by using photons at the telecommunication band for optical-fiber-based quantum communications. We generated two pairs of non-degenerate polarization entangled photons at 780 nm and 1551 nm by spontaneous parametric down-conversion and distributed the two photons at 1551 nm through a collective phase damping channel which gives the same amount of random phase shift on the two photons. Through local operation and classical communication, we extracted an entangled photon pair from two phase-disturbed photon pairs. An observed fidelity of the extracted photon pair to a maximally entangled photon pair was 0.73 ± 0.07 which clearly shows the recovery of entanglement.

  19. Parameterization of Photon Tunneling with Application to Ice Cloud Optical Properties at Terrestrial Wavelengths

    NASA Astrophysics Data System (ADS)

    Mitchell, D. L.

    2006-12-01

    Sometimes deep physical insights can be gained through the comparison of two theories of light scattering. Comparing van de Hulst's anomalous diffraction approximation (ADA) with Mie theory yielded insights on the behavior of the photon tunneling process that resulted in the modified anomalous diffraction approximation (MADA). (Tunneling is the process by which radiation just beyond a particle's physical cross-section may undergo large angle diffraction or absorption, contributing up to 40% of the absorption when wavelength and particle size are comparable.) Although this provided a means of parameterizing the tunneling process in terms of the real index of refraction and size parameter, it did not predict the efficiency of the tunneling process, where an efficiency of 100% is predicted for spheres by Mie theory. This tunneling efficiency, Tf, depends on particle shape and ranges from 0 to 1.0, with 1.0 corresponding to spheres. Similarly, by comparing absorption efficiencies predicted by the Finite Difference Time Domain Method (FDTD) with efficiencies predicted by MADA, Tf was determined for nine different ice particle shapes, including aggregates. This comparison confirmed that Tf is a strong function of ice crystal shape, including the aspect ratio when applicable. Tf was lowest (< 0.36) for aggregates and plates, and largest (> 0.9) for quasi- spherical shapes. A parameterization of Tf was developed in terms of (1) ice particle shape and (2) mean particle size regarding the large mode (D > 70 mm) of the ice particle size distribution. For the small mode, Tf is only a function of ice particle shape. When this Tf parameterization is used in MADA, absorption and extinction efficiency differences between MADA and FDTD are within 14% over the terrestrial wavelength range 3-100 mm for all size distributions and most crystal shapes likely to be found in cirrus clouds. Using hyperspectral radiances, it is demonstrated that Tf can be retrieved from ice clouds. Since Tf

  20. This image combines data from the DIRBE obtained at infrared wavelengths of 100, 140 and 240 Aum

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image combines data from the DIRBE obtained at infrared wavelengths of 100, 140 and 240 Aum - the longest wavelengths measured by this instrument. The sky brightness at these wavelengths is represented respectively by blue, green, and red colors in the image. This image shows where there is more material (appears brighter) and where this material is coldest (appears redder). The plane of the Milky Way Galaxy lies horizontally across the middle of the image with the Galactic center at the center. Most of the infrared radiation seen in this image originates from cold dust (approximately 20 K, or 20 degrees Centigrade above absolute zero) located in clouds of gas and dust between the stars in the Milky Way Galaxy. The wispy-looking dust features are called 'infrared cirrus.' The region of the Orion Nebula with active star formation - approximately 1,500 light years distance from the Sun - appears on the right of the image below the plane of the Milky Way. Neighboring galaxies, the Large and Small Magellanic Clouds, appear as faint 'blobs' below and slightly to the right of the Galactic center. Much of the picture appears to be the same color, indicating that there is not a large variation in the dust temperature. Because the brightness of the Solar System and Galaxy tends to decrease with increasing wavelength, these long wavelength DIRBE measurements are particularly valuable for searching for the cosmic infrared background.

  1. Short wavelength infrared optical windows for evaluation of benign and malignant tissues

    NASA Astrophysics Data System (ADS)

    Sordillo, Diana C.; Sordillo, Laura A.; Sordillo, Peter P.; Shi, Lingyan; Alfano, Robert R.

    2017-04-01

    There are three short wavelength infrared (SWIR) optical windows outside the conventionally used first near-infrared (NIR) window (650 to 950 nm). They occur in the 1000- to 2500-nm range and may be considered second, third, and fourth NIR windows. The second (1100 to 1350 nm) and third windows (1600 to 1870 nm) are now being explored through label-free linear and multiphoton imaging. The fourth window (2100 to 2350 nm) has been mostly ignored because of water absorption and the absence of sensitive detectors and ultrafast lasers. With the advent of new technology, use of window IV is now possible. Absorption and scattering properties of light through breast and prostate cancer, bone, lipids, and intralipid solutions at these windows were investigated. We found that breast and prostate cancer and bone have longer total attenuation lengths at NIR windows III and IV, whereas fatty tissues and intralipid have longest lengths at windows II and III. Since collagen is the major chromophore at 2100 and 2350 nm, window IV could be especially valuable in evaluating cancers and boney tissues, whereas windows II and III may be more useful for tissues with high lipid content. SWIR windows may be utilized as additional optical tools for the evaluation of collagen in tissues.

  2. High operation temperature mid-wavelength interband cascade infrared photodetectors grown on InAs substrate

    NASA Astrophysics Data System (ADS)

    Zhou, Yi; Chen, Jianxin; Xu, Zhicheng; He, Li

    2016-05-01

    In recent years, interband cascade detectors (ICIP) based on typer-II superlattice have shown great performance potential at high operation temperature. In this paper, we report our studies on mid-infrared interband cascade photodetectors first grown on InAs substrate. We examined the photo-generated carriers' transport in ICIP structures by comparing three detectors grown on InAs substrate. The 2-stages ICIP device has demonstrated a high quantum efficiency around 20% at room temperature. The dark current density of the 2-stages ICIP device at -0.05V is as low as 1 nA at 80K, 1 mA at 150K, which is comparable to the state of art PIN superlattice photodetectors with similar cutoff wavelength. The Johnson-noise limited D* reaches 1.64×1014cm.Hz1/2/W at 3.65 μm and 80K, and 4.1×1010cm.Hz1/2/W at 3.8 μm and 200K. The 300 K background limited infrared performance (BLIP) operation temperature is estimated to be over 140 K.

  3. Temporal and spatial multiplexed infrared single-photon counter based on high-speed avalanche photodiode

    PubMed Central

    Chen, Xiuliang; Ding, Chengjie; Pan, Haifeng; Huang, Kun; Laurat, Julien; Wu, Guang; Wu, E

    2017-01-01

    We report on a high-speed temporal and spatial multiplexed single-photon counter with photon-number-resolving capability up to four photons. The infrared detector combines a fiber loop to split, delay and recombine optical pulses and a 200 MHz dual-channel single-photon detector based on InGaAs/InP avalanche photodiode. To fully characterize the photon-number-resolving capability, we perform quantum detector tomography and then reconstruct its positive-operator-valued measure and the associated Wigner functions. The result shows that, despite of the afterpulsing noise and limited system detection efficiency, this temporal and spatial multiplexed single-photon counter can already find applications for large repetition rate quantum information schemes. PMID:28294155

  4. Temporal and spatial multiplexed infrared single-photon counter based on high-speed avalanche photodiode

    NASA Astrophysics Data System (ADS)

    Chen, Xiuliang; Ding, Chengjie; Pan, Haifeng; Huang, Kun; Laurat, Julien; Wu, Guang; Wu, E.

    2017-03-01

    We report on a high-speed temporal and spatial multiplexed single-photon counter with photon-number-resolving capability up to four photons. The infrared detector combines a fiber loop to split, delay and recombine optical pulses and a 200 MHz dual-channel single-photon detector based on InGaAs/InP avalanche photodiode. To fully characterize the photon-number-resolving capability, we perform quantum detector tomography and then reconstruct its positive-operator-valued measure and the associated Wigner functions. The result shows that, despite of the afterpulsing noise and limited system detection efficiency, this temporal and spatial multiplexed single-photon counter can already find applications for large repetition rate quantum information schemes.

  5. Long-wavelength infrared photoconductor technology based on epitaxially grown Hg1-xCdxTe

    NASA Astrophysics Data System (ADS)

    Siliquini, John F.; Fynn, Kevin A.; Musca, Charles A.; Nener, Brett D.; Dell, John M.; Faraone, Lorenzo

    1995-09-01

    The performance of Hg1-xCdxTe long wavelength infrared (LWIR) photoconductors is strongly dependent on the semiconductor surface conditions and contact characteristics. In this paper we review these effects in relation to obtaining an optimum device technology suitable for use in two-dimensional infrared focal plane arrays (IRFPAs) based on the fabrication of high performance LWIR photoconductors on epitaxially grown Hg1-xCdxTe. Although the proposed design can be applied to a variety of epitaxially grown Hg1-xCdxTe material, for optimum performance the starting Hg1-xCdxTe semiconductor consists of epitaxially grown heterostructure layers in which a two-dimensional mosaic of lateral design photoconductors are fabricated. The heterostructure layer provides high performance devices at greatly reduced power dissipation levels, while the unique design allows for the high density integration of photoconductors in a two-dimensional array geometry with high fill factor. The proposed photoconductor array with n+ blocking contacts has been experimentally verified in a 3 X 3 array format with all elements in the array exhibiting background limited infrared photodetector (BLIP) performance at 80 K. Performance issues such as response uniformity, pixel yield, fill factor, crosstalk, power dissipation, detector impedance, array architecture, and maximum array size are discussed in relation to the suitability of the proposed photoconductor structure for use in IRFPA modules. It is found that in many cases the proposed photoconductor technology has the potential to deliver significant advantages, such as higher yield, higher fill factor, better uniformity, less crosstalk, and larger potential array size, in comparison to an IRFPA design based on photovoltaic technology.

  6. Photon-phonon-enhanced infrared rectification in a two-dimensional nanoantenna-coupled tunnel diode

    DOE PAGES

    Kadlec, Emil A.; Jarecki, Robert L.; Starbuck, Andrew; ...

    2016-12-28

    The interplay of strong infrared photon-phonon coupling with electromagnetic confinement in nanoscale devices is demonstrated to have a large impact on ultrafast photon-assisted tunneling in metal-oxide-semiconductor (MOS) structures. Infrared active optical phonon modes in polar oxides lead to strong dispersion and enhanced electric fields at material interfaces. We find that the infrared dispersion of SiO2 near a longitudinal optical phonon mode can effectively impedance match a photonic surface mode into a nanoscale tunnel gap that results in large transverse-field confinement. An integrated 2D nanoantenna structure on a distributed large-area MOS tunnel-diode rectifier is designed and built to resonantly excite infraredmore » surface modes and is shown to efficiently channel infrared radiation into nanometer-scale gaps in these MOS devices. This enhanced-gap transverse-electric field is converted to a rectified tunneling displacement current resulting in a dc photocurrent. We examine the angular and polarization-dependent spectral photocurrent response of these 2D nanoantenna-coupled tunnel diodes in the photon-enhanced tunneling spectral region. Lastly, our 2D nanoantenna-coupled infrared tunnel-diode rectifier promises to impact large-area thermal energy harvesting and infrared direct detectors.« less

  7. Compact, lower-power-consumption wavelength tunable laser fabricated with silicon photonic-wire waveguide micro-ring resonators.

    PubMed

    Chu, Tao; Fujioka, Nobuhide; Ishizaka, Masashige

    2009-08-03

    A wavelength tunable laser with an SOA and external double micro-ring resonator, which is fabricated with silicon photonic-wire waveguides, is demonstrated. To date, it is the first wavelength tunable laser fabricated with silicon photonic technology. The device is ultra compact, and its external resonator footprint is 700 x 450 microm, which is about 1/25 that of conventional tunable lasers fabricated with SiON waveguides. The silicon resonator shows a wide tuning range covering the C or L bands for DWDM optical communication. We obtained a maximum tuning span of 38 nm at a tuning power consumption of 26 mW, which is about 1/8 that of SiON-type resonators.

  8. Broadband source of telecom-band polarization-entangled photon-pairs for wavelength-multiplexed entanglement distribution.

    PubMed

    Lim, Han Chuen; Yoshizawa, Akio; Tsuchida, Hidemi; Kikuchi, Kazuro

    2008-09-29

    Studies on telecom-band entangled photon-pair sources for entanglement distribution have so far focused on their narrowband operations. Fiber-based sources are seriously limited by spontaneous Raman scattering while sources based on quasi-phase-matched crystals or waveguides are usually narrowband because of long device lengths and/or operations far from degeneracy. An entanglement distributor would have to multiplex many such narrowband sources before entanglement distribution to fully utilize the available fiber transmission bandwidth. In this work, we demonstrate a broadband source of polarization-entangled photon-pairs suitable for wavelength-multiplexed entanglement distribution over optical fiber. We show that our source is potentially capable of simultaneously supporting up to forty-four independent wavelength channels.

  9. Single photon transport by a moving atom through sub-wavelength hole

    NASA Astrophysics Data System (ADS)

    Afanasiev, A. E.; Melentiev, P. N.; Kuzin, A. A.; Kalatskiy, A. Yu.; Balykin, V. I.

    2016-12-01

    The results of investigation of photon transport through the subwavelength hole in the opaque screen by using single neutral atom are represented. The basis of the proposed and implemented method is the absorption of a photon by a neutral atom immediately before the subwavelength aperture, traveling of the atoms through the hole and emission of a photon on the other side of the screen. Realized method is the alternative approach to existing for photon transport through a subwavelength aperture: 1) self-sustained transmittance of a photon through the aperture according to the Bethe's model; 2) extra ordinary transmission because of surface-plasmon excitation.

  10. Software-defined control-plane for wavelength selective unicast and multicast of optical data in a silicon photonic platform.

    PubMed

    Gazman, Alexander; Browning, Colm; Bahadori, Meisam; Zhu, Ziyi; Samadi, Payman; Rumley, Sébastien; Vujicic, Vidak; Barry, Liam P; Bergman, Keren

    2017-01-09

    We demonstrate a programmable control-plane based on field programmable gate array (FPGA) with a power-efficient algorithm for optical unicast, multicast, and broadcast functionalities in a silicon photonic platform. The platform includes a silicon photonic 1×8 microring array chip which in conjunction with a fast tunable laser over the C-band is capable of delivering software controlled wavelength selective functionality on top of spatial switching. We characterize the thermo-optic response of microring resonators and extract key parameters necessary for the development of the control-plane. The performance of the proposed architecture is tested with 10 Gb/s on-off keying (OOK) optical data and error-free operation is verified for various wavelength and spatial switching scenarios. Lastly, we evaluate electrical power and energy consumption required to reconfigure the silicon photonic device for all possible wavelength operations and output ports combinations and show that unicast, multicast of two, three, four, five, six, seven, and broadcast functions are achieved with energy overheads of 0.02, 0.07, 0.18, 0.49, 0.76, 1.01, 1.3, and 1.55 pJ/bit, respectively.

  11. Photonic crystal wave guide for non-cryogenic cooled carbon nanotube based middle wave infrared sensors

    NASA Astrophysics Data System (ADS)

    Fung, Carmen Kar Man; Xi, Ning; Lou, Jianyong; Lai, King Wai Chiu; Chen, Hongzhi

    2010-10-01

    We report high sensitivity carbon nanotube (CNT) based middle wave infrared (MWIR) sensors with a two-dimensional photonic crystal waveguide. MWIR sensors are of great importance in a variety of current military applications including ballistic missile defense, surveillance and target detection. Unlike other existing MWIR sensing materials, CNTs exhibit low noise level and can be used as new nano sensing materials for MWIR detection where cryogenic cooling is not required. However, the quantum efficiency of the CNT based infrared sensor is still limited by the small sensing area and low incoming electric field. Here, a photonic nanostructure is used as a resonant cavity for boosting the electric field intensity at the position of the CNT sensing element. A two-dimensional photonic crystal with periodic holes in a polymer thin film is fabricated and a resonant cavity is formed by removing holes from the array of the photonic crystal. Based on the design of the photonic crystal topologies, we theoretically study the electric field distribution to predict the resonant behavior of the structure. Numerical simulations reveal the field is enhanced and almost fully confined to the defect region of the photonic crystal. To verify the electric field enhancement effect, experiments are also performed to measure the photocurrent response of the sensor with and without the photonic crystal resonant cavity. Experimental results show that the photocurrent increases ~3 times after adding the photonic crystal resonant cavity.

  12. Photon sorting in the near field using subwavelength cavity arrays in the near-infrared

    SciTech Connect

    Mandel, Isroel M. Lansey, Eli; Gollub, Jonah N.; Sarantos, Chris H.; Akhmechet, Roman; Golovin, Andrii B.; Crouse, David T.

    2013-12-16

    A frequency selective metasurface capable of sorting photons in the near-infrared spectral range is designed, fabricated, and characterized. The metasurface, a periodic array of dielectric cylindrical cavities in a gold film, localizes and transmits light of two spectral frequency bands into spatially separated cavities, resulting in near-field light splitting. The design and fabrication methodologies of the metasurface are discussed. The transmittance and photon sorting properties of the designed structure is simulated numerically and the measured transmission is presented.

  13. Compact Mach-Zehnder interferometer based on photonic crystal fiber and its application in switchable multi-wavelength fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, Weiguo; Lou, Shuqin; Wang, Liwen; Li, Honglei; Guo, Tieying; Jian, Shuisheng

    2009-08-01

    The compact Mach-Zehnder interferometer is proposed by splicing a section of photonic crystal fiber (PCF) and two pieces of single mode fiber (SMF) with the air-holes of PCF intentionally collapsed in the vicinity of the splices. The depedence of the fringe spacing on the length of PCF is investigated. Based on the Mach-Zehnder interferometer as wavelength-selective filter, a switchable dual-wavelength fiber ring laser is demonstrated with a homemade erbiumdoped fiber amplifier (EDFA) as the gain medium at room temperature. By adjusting the states of the polarization controller (PC) appropriately, the laser can be switched among the stable single-and dual -wavelength lasing operations by exploiting polarization hole burning (PHB) effect.

  14. Satellite laser ranging using superconducting nanowire single-photon detectors at 1064  nm wavelength.

    PubMed

    Xue, Li; Li, Zhulian; Zhang, Labao; Zhai, Dongsheng; Li, Yuqiang; Zhang, Sen; Li, Ming; Kang, Lin; Chen, Jian; Wu, Peiheng; Xiong, Yaoheng

    2016-08-15

    Satellite laser ranging operating at 1064 nm wavelength using superconducting nanowire single-photon detectors (SNSPDs) is successfully demonstrated. A SNSPD with an intrinsic quantum efficiency of 80% and a dark count rate of 100 cps at 1064 nm wavelength is developed and introduced to Yunnan Observatory in China. With improved closed-loop telescope systems (field of view of about 26''), satellites including Cryosat, Ajisai, and Glonass with ranges of 1600 km, 3100 km, and 19,500 km, respectively, are experimentally ranged with mean echo rates of 1200/min, 4200/min, and 320/min, respectively. To the best of our knowledge, this is the first demonstration of laser ranging for satellites using SNSPDs at 1064 nm wavelength. Theoretical analysis of the detection efficiency and the mean echo rate for typical satellites indicate that it is possible for a SNSPD to range satellites from low Earth orbit to geostationary Earth orbit.

  15. Effect of frequency chirp on supercontinuum generation in photonic crystal fibers with two zero-dispersion wavelengths.

    PubMed

    Zhang, Hua; Yu, Song; Zhang, Jie; Gu, Wanyi

    2007-02-05

    The effect of initial frequency chirp is investigated numerically to obtain efficient supercontinuum radiation in photonic crystal fibers (PCFs) with two closely spaced zero-dispersion wavelengths. The positive chirps, instead of zero or negative chirps, are recommended because self phase modulation and four-wave mixing can be facilitated by employing positive chirps. In contrast with the complicated and irregular spectrum generated by negative-chirped pulse, the spectrums generated by positive-chirped pulses are wider and much more regular. Moreover, the saturated length of the PCF, corresponding to the maximal spectrum width, can be shortened greatly and the efficiency of frequency conversion is also improved because of initial positive chirps. Nearly all the energy between the zero-dispersion wavelengths can be transferred to the normal dispersion region from the region within the two zero-dispersion wavelengths provided that the initial positive chirp is large enough.

  16. Design of the First Infrared Beamline at the Siam Photon Laboratory

    SciTech Connect

    Pattanasiriwisawa, W.; Songsiriritthigul, P.; Dumas, P.

    2010-06-23

    This report presents the optical design and optical simulations for the first infrared beamline at the Siam Photon Laboratory. The beamline collects the edge radiation and bending magnet radiation, producing from the BM4 bending magnet of the 1.2 GeV storage ring of the Siam Photon Source. The optical design is optimized for the far- to mid-infrared spectral range (4000-100 cm{sup -1}) for microspectroscopic applications. The optical performance has been examined by computer simulations.

  17. Infrared transparent graphene heater for silicon photonic integrated circuits.

    PubMed

    Schall, Daniel; Mohsin, Muhammad; Sagade, Abhay A; Otto, Martin; Chmielak, Bartos; Suckow, Stephan; Giesecke, Anna Lena; Neumaier, Daniel; Kurz, Heinrich

    2016-04-18

    Thermo-optical tuning of the refractive index is one of the pivotal operations performed in integrated silicon photonic circuits for thermal stabilization, compensation of fabrication tolerances, and implementation of photonic operations. Currently, heaters based on metal wires provide the temperature control in the silicon waveguide. The strong interaction of metal and light, however, necessitates a certain gap between the heater and the photonic structure to avoid significant transmission loss. Here we present a graphene heater that overcomes this constraint and enables an energy efficient tuning of the refractive index. We achieve a tuning power as low as 22 mW per free spectral range and fast response time of 3 µs, outperforming metal based waveguide heaters. Simulations support the experimental results and suggest that for graphene heaters the spacing to the silicon can be further reduced yielding the best possible energy efficiency and operation speed.

  18. Long-Wavelength 256X256 GaAs/AIGaAs Quantum Well Infrared Photodetector (QWIP) Palm-Size Camera

    NASA Technical Reports Server (NTRS)

    Gunapala, S.; Bandara, S.; Liu, J.; Luong, E.; McKelvey, M.; Mumolo, J.; Rafol, S.; Shott, C.; Stetson, N.

    1999-01-01

    In this paper, we discuss the development of this very sensitive long-wavelength infrared (LWIR) camera based on a GaAs/AlGaAs QWIP focal plane array (FPA) and its performance in terms of quantum efficiency, NET, MRDT, uniformity, and operability.

  19. Long-Wavelength 256X256 GaAs/AIGaAs Quantum Well Infrared Photodetector (QWIP) Palm-Size Camera

    NASA Technical Reports Server (NTRS)

    Gunapala, S.; Bandara, S.; Liu, J.; Luong, E.; McKelvey, M.; Mumolo, J.; Rafol, S.; Shott, C.; Stetson, N.

    1999-01-01

    In this paper, we discuss the development of this very sensitive long-wavelength infrared (LWIR) camera based on a GaAs/AlGaAs QWIP focal plane array (FPA) and its performance in terms of quantum efficiency, NET, MRDT, uniformity, and operability.

  20. A short-wavelength infrared emitting multimodal probe for non-invasive visualization of phagocyte cell migration in living mice.

    PubMed

    Tsukasaki, Y; Komatsuzaki, A; Mori, Y; Ma, Q; Yoshioka, Y; Jin, T

    2014-11-28

    For the non-invasive visualization of cell migration in deep tissues, we synthesized a short-wavelength infrared (SWIR) emitting multimodal probe that contains PbS/CdS quantum dots, rhodamine 6G and iron oxide nanoparticles. This probe enables multimodal (SWIR fluorescence/magnetic resonance) imaging of phagocyte cell migration in living mice.

  1. Near-infrared photonic energy penetration: can infrared phototherapy effectively reach the human brain?

    PubMed Central

    Henderson, Theodore A; Morries, Larry D

    2015-01-01

    Traumatic brain injury (TBI) is a growing health concern effecting civilians and military personnel. Research has yielded a better understanding of the pathophysiology of TBI, but effective treatments have not been forthcoming. Near-infrared light (NIR) has shown promise in animal models of both TBI and stroke. Yet, it remains unclear if sufficient photonic energy can be delivered to the human brain to yield a beneficial effect. This paper reviews the pathophysiology of TBI and elaborates the physiological effects of NIR in the context of this pathophysiology. Pertinent aspects of the physical properties of NIR, particularly in regards to its interactions with tissue, provide the background for understanding this critical issue of light penetration through tissue. Our recent tissue studies demonstrate no penetration of low level NIR energy through 2 mm of skin or 3 cm of skull and brain. However, at 10–15 W, 0.45%–2.90% of 810 nm light penetrated 3 cm of tissue. A 15 W 810 nm device (continuous or non-pulsed) NIR delivered 2.9% of the surface power density. Pulsing at 10 Hz reduced the dose of light delivered to the surface by 50%, but 2.4% of the surface energy reached the depth of 3 cm. Approximately 1.22% of the energy of 980 nm light at 10–15 W penetrated to 3 cm. These data are reviewed in the context of the literature on low-power NIR penetration, wherein less than half of 1% of the surface energy could reach a depth of 1 cm. NIR in the power range of 10–15 W at 810 and 980 nm can provide fluence within the range shown to be biologically beneficial at 3 cm depth. A companion paper reviews the clinical data on the treatment of patients with chronic TBI in the context of the current literature. PMID:26346298

  2. Near-infrared photonic energy penetration: can infrared phototherapy effectively reach the human brain?

    PubMed

    Henderson, Theodore A; Morries, Larry D

    2015-01-01

    Traumatic brain injury (TBI) is a growing health concern effecting civilians and military personnel. Research has yielded a better understanding of the pathophysiology of TBI, but effective treatments have not been forthcoming. Near-infrared light (NIR) has shown promise in animal models of both TBI and stroke. Yet, it remains unclear if sufficient photonic energy can be delivered to the human brain to yield a beneficial effect. This paper reviews the pathophysiology of TBI and elaborates the physiological effects of NIR in the context of this pathophysiology. Pertinent aspects of the physical properties of NIR, particularly in regards to its interactions with tissue, provide the background for understanding this critical issue of light penetration through tissue. Our recent tissue studies demonstrate no penetration of low level NIR energy through 2 mm of skin or 3 cm of skull and brain. However, at 10-15 W, 0.45%-2.90% of 810 nm light penetrated 3 cm of tissue. A 15 W 810 nm device (continuous or non-pulsed) NIR delivered 2.9% of the surface power density. Pulsing at 10 Hz reduced the dose of light delivered to the surface by 50%, but 2.4% of the surface energy reached the depth of 3 cm. Approximately 1.22% of the energy of 980 nm light at 10-15 W penetrated to 3 cm. These data are reviewed in the context of the literature on low-power NIR penetration, wherein less than half of 1% of the surface energy could reach a depth of 1 cm. NIR in the power range of 10-15 W at 810 and 980 nm can provide fluence within the range shown to be biologically beneficial at 3 cm depth. A companion paper reviews the clinical data on the treatment of patients with chronic TBI in the context of the current literature.

  3. Electro- and thermo-optic effects on multi-wavelength Solc filters based on chi(2) nonlinear quasi-periodic photonic crystals.

    PubMed

    Kee, Chul-Sik; Lee, Yeong Lak; Lee, Jongmin

    2008-04-28

    We investigate electro- and thermo-optic effects on multi-wavelength Solc filters based on chi(2) nonlinear quasi-periodic photonic crystals. The multi-wavelength Solc filters are composed of two building blocks A and B, in which each containing a pair of antiparallel poled domains, arranged as a Fibonacci sequence. The transmittances at filtering wavelengths can be modulated from 0 to 100% by applying an external voltage but the filtering wave-lengths are unchanged. The filtering wavelengths can be tuned by varying temperature. As temperature decreases, the filtering wavelengths increase (approximately -0.45 nm/degrees C).

  4. Sculpting narrowband Fano resonances inherent in the large-area mid-infrared photonic crystal microresonators for spectroscopic imaging

    PubMed Central

    Liu, Jui-Nung; Schulmerich, Matthew V.; Bhargava, Rohit; Cunningham, Brian T.

    2014-01-01

    Fourier transform infrared (FT-IR) imaging spectrometers are almost universally used to record microspectroscopic imaging data in the mid-infrared (mid-IR) spectral region. While the commercial standard, interferometry necessitates collection of large spectral regions, requires a large data handling overhead for microscopic imaging and is slow. Here we demonstrate an approach for mid-IR spectroscopic imaging at selected discrete wavelengths using narrowband resonant filtering of a broadband thermal source, enabled by high-performance guided-mode Fano resonances in one-layer, large-area mid-IR photonic crystals on a glass substrate. The microresonant devices enable discrete frequency IR (DF-IR), in which a limited number of wavelengths that are of interest are recorded using a mechanically robust instrument. This considerably simplifies instrumentation as well as overhead of data acquisition, storage and analysis for large format imaging with array detectors. To demonstrate the approach, we perform DF-IR spectral imaging of a polymer USAF resolution target and human tissue in the C−H stretching region (2600−3300 cm−1). DF-IR spectroscopy and imaging can be generalized to other IR spectral regions and can serve as an analytical tool for environmental and biomedical applications. PMID:25089433

  5. Realization of compatible stealth material for infrared, laser and radar based on one-dimensional doping-structure photonic crystals

    NASA Astrophysics Data System (ADS)

    Zhang, Ji-Kui; Shi, Jia-Ming; Zhao, Da-Peng; Wang, Qi-Chao; Wang, Cheng-Ming

    2017-09-01

    To inhibit the radiant infrared energy between 8 and 14 μm, which is the infrared atmospheric window, and decrease the echo power of detecting laser and radar, to achieve compatible stealth, a doping structural one-dimensional photonic crystal (1-D PC) with Ge, ZnSe and Si was fabricated; and then combine it with radar absorbing material (RAM) to make a compound. After that, the reflection spectra of this compound was tested, and the result shows a high average reflectance (89.5%) in 8-14 μm waveband, and a reflective valley (39.8%) in the wavelength of 10.6 μm, which is the wavelength of CO2 laser; and the reflectance in radar band shows that at high frequency, especially between 7.8 and 18 GHz, the radar power is strongly absorbed by this material and the reflected energy attenuate over 10 dB within the range from 11.1 GHz to 18.3 GHz, even 24.5 dB to the most in the frequency of 14.6 GHz.

  6. Measurement of the spectral signature of small carbon clusters at near and far infrared wavelengths

    NASA Technical Reports Server (NTRS)

    Tarter, J.; Saykally, R.

    1991-01-01

    A significant percentage of the carbon inventory of the circumstellar and interstellar media may be in the form of large refractory molecules (or small grains) referred to as carbon clusters. At the small end, uneven numbers of carbon atoms seem to be preferred, whereas above 12 atoms, clusters containing an even number of carbon atoms appear to be preferred in laboratory chemistry. In the lab, the cluster C-60 appears to be a particularly stable form and has been nicknamed Bucky Balls because of its resemblance to a soccer ball and to geodesic domes designed by Buckminster Fuller. In order to investigate the prevalence of these clusters, and their relationship to the polycyclic aromatic hydrocarbons (PAHs) that have become the newest focus of IR astronomy, it is necessary to determine the spectroscopic characteristics of these clusters at near and far infrared wavelengths. Described here is the construction of a near to far IR laser magnetic resonance spectrometer that has been built at the University of California Berkeley in order to detect and characterize these spectra. The equipment produces carbon clusters by laser evaporation of a graphitic target. The clusters are then cooled in a supersonic expansion beam in order to simulate conditions in the interstellar medium (ISM). The expansion beam feeds into the spectrometer chamber and permits concentrations of clusters sufficiently high as to permit ultra-high resolution spectroscopy at near and far IR wavelengths. The first successful demonstration of this apparatus occurred last year when the laboratory studies permitted the observational detection of C-5 in the stellar outflow surrounding IRC+10216 in the near-IR. Current efforts focus on reducing the temperature of the supersonic expansion beam that transport the C clusters evaporated from a graphite target into the spectrometer down to temperatures as low as 1 K.

  7. [Design and implementation of a long wavelength near infrared spectrometer based on MEMS scanning mirror].

    PubMed

    Ye, Kun-Tao; Dong, Tai-Yuan; He, Wen-Xi; Li, Yu-Xiao; Cheng, Xian-Ming; Li, Guang-Yong; Li, Hao-Yu; Xu, Hao-Yu

    2014-10-01

    Long Wavelength Near InfraRed (LW-NIR) spectrometer has wide applications. Miniaturization and low-cost are two major goals of the development of LW-NIR spectrometer in the industrial or research community. Under the background that having a trend of spectrometer miniaturization and integration, method and main problems involved in miniaturization of LW-NIR spectrometer through MEMS scanning mirror, such as the design strategy of the light-splitting optical system, selection considerations of the MEMS scanning mirror, design method of the preamplifier circuit, etc, have been presented in detail. A prototype of miniaturized LW-NIR spectrometer, with the spectrum range of detection of 900-2,055 nm, is designed and implemented using MEMS scanning mirror, InGaAs single detector unit with high sensitivity. Littrow optical layout is used for its light-splitting optical system, and the spectral resolution is between 9.4-16 nm at 1,000-1,965 nm detection wavelength range. The prototype is successfully applied in LW-NIR spectrum measurement on pure water and ethanol aqueous solution, and a forecast analysis on ethanol aqueous solution concentration is also demonstrated. Through adopting MEMS scanning mirror into the spectrometer system, the complexity of the mechanical scanning fixtures and its controlling mechanism is greatly reduced therefore the size of the spectrometer is reduced. Furthermore, due to MEMS scanning mirror technology, LW-NIR spectrometer with single InGaAs detector is achieved, thus the cost reduction of the NIR spectrometer system is also realized because the expensive InGaAs arrays are avoided.

  8. Design of a mid-wavelength infrared dual field of view zoom system

    NASA Astrophysics Data System (ADS)

    Duan, Jing; Li, Gang; Jiang, Kai; Liu, Kai; Yan, Peipei; Shan, Qiusha

    2016-10-01

    In order to effectively improve the target detection and recognition ability of IR imagers, based on a 320×256 cooled staring focal plane array(FPA) detector, pixel size 30μm×30μm, a mid-wavelength infrared dual field of view zoom system was designed. In this paper, the working wavelength is 3μm~5μm, the temperature range is -40°C +50°C, this system can realize 200mm and 400mm dual focal length, the F-number is 2, the full field of view of short focal length is 3.44° and long focal length is 1.72° respectively, satisfy 100% cold shield efficiency. A re-imaging refractive system was adopted in this designed optical system consists of main optics and projection components. First of all, the structural selection and the initial parameter calculation were introduced in detail. Secondly, on the basis of variety of the distance and temperature, a focusing lens was presented in this system to adjust to produce a clear image. Last but not the least, to improve image quality and environment adaptability, the analysis of temperature change and narcissus effect were described particularly. The design results prove that at the spatial frequency of 17 lp/mm, the MTF of the optical system is greater than 0.5(the axis MTF of the optical is greater than 0.6), the system can offer a high resolution and excellent images in whole range of the focal length, and it has the advantages of good adaptability, compact structure, high optical transmission and small size.

  9. Spectral correlation and interference in non-degenerate photon pairs at telecom wavelengths.

    PubMed

    Kuo, Paulina S; Gerrits, Thomas; Verma, Varun B; Nam, Sae Woo

    2016-11-01

    We characterize an entangled-photon-pair source that produces signal and idler photons at 1533 nm and 1567 nm using fiber-assisted signal-photon spectroscopy. By erasing the polarization distinguishability, we observe interference between the two down-conversion paths. The observed interference signature is closely related to the spectral correlations between photons in a Hong-Ou-Mandel interferometer. These measurements suggest good indistinguishability between the two down-conversion paths, which is required for high entanglement visibility.

  10. Tunable and switchable multi-wavelength fiber laser based on semiconductor optical amplifier and twin-core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Kim, Bongkyun; Han, Jihee; Chung, Youngjoo

    2012-02-01

    Multi-wavelength fiber lasers have attracted a lot of interest, recently, because of their potential applications in wavelength-division-multiplexing (WDM) systems, optical fiber sensing, and fiber-optics instruments, due to their numerous advantages such as multiple wavelength operation, low cost, and compatibility with the fiber optic systems. Semiconductor optical amplifier (SOA)-based multi-wavelength fiber lasers exhibit stable operation because of the SOA has the property of primarily inhomogeneous broadening and thus can support simultaneous oscillation of multiple lasing wavelengths. In this letter, we propose and experimentally demonstrate a switchable multi-wavelength fiber laser employing a semiconductor optical amplifier and twin-core photonic crystal fiber (TC-PCF) based in-line interferometer comb filter. The fabricated two cores are not symmetric due to the associated fiber fabrication process such as nonuniform heat gradient in furnace and asymmetric microstructure expansion during the gas pressurization which results in different silica strut thickness and core size. The induced asymmetry between two cores considerably alters the linear power transfer, by seriously reducing it. These nominal twin cores form effective two optical paths and associated effective refractive index difference. The in-fiber comb filter is effectively constructed by splicing a section of TC-PCF between two single mode fibers (SMFs). The proposed laser can be designed to operate in stable multi-wavelength lasing states by adjusting the states of the polarization controller (PC). The lasing modes are switched by varying the state of PC and the change is reversible. In addition, we demonstrate a tunable multi-wavelength fiber laser operation by applying temperature changes to TC-PCF in the multi-channel filter.

  11. Carcinogenic damage to deoxyribonucleic acid is induced by near-infrared laser pulses in multiphoton microscopy via combination of two- and three-photon absorption

    NASA Astrophysics Data System (ADS)

    Nadiarnykh, Oleg; Thomas, Giju; Van Voskuilen, Johan; Sterenborg, Henricus J. C. M.; Gerritsen, Hans C.

    2012-11-01

    Nonlinear optical imaging modalities (multiphoton excited fluorescence, second and third harmonic generation) applied in vivo are increasingly promising for clinical diagnostics and the monitoring of cancer and other disorders, as they can probe tissue with high diffraction-limited resolution at near-infrared (IR) wavelengths. However, high peak intensity of femtosecond laser pulses required for two-photon processes causes formation of cyclobutane-pyrimidine-dimers (CPDs) in cellular deoxyribonucleic acid (DNA) similar to damage from exposure to solar ultraviolet (UV) light. Inaccurate repair of subsequent mutations increases the risk of carcinogenesis. In this study, we investigate CPD damage that results in Chinese hamster ovary cells in vitro from imaging them with two-photon excited autofluorescence. The CPD levels are quantified by immunofluorescent staining. We further evaluate the extent of CPD damage with respect to varied wavelength, pulse width at focal plane, and pixel dwell time as compared with more pronounced damage from UV sources. While CPD damage has been expected to result from three-photon absorption, our results reveal that CPDs are induced by competing two- and three-photon absorption processes, where the former accesses UVA absorption band. This finding is independently confirmed by nonlinear dependencies of damage on laser power, wavelength, and pulse width.

  12. Small band gap superlattices as intrinsic long wavelength infrared detector materials

    NASA Technical Reports Server (NTRS)

    Smith, Darryl L.; Mailhiot, C.

    1990-01-01

    Intrinsic long wavelength (lambda greater than or equal to 10 microns) infrared (IR) detectors are currently made from the alloy (Hg, Cd)Te. There is one parameter, the alloy composition, which can be varied to control the properties of this material. The parameter is chosen to set the band gap (cut-off wavelength). The (Hg, Cd)Te alloy has the zincblend crystal structure. Consequently, the electron and light-hole effective masses are essentially inversely proportional to the band gap. As a result, the electron and light-hole effective masses are very small (M sub(exp asterisk)/M sub o approx. M sub Ih/M sub o approx. less than 0.01) whereas the heavy-hole effective mass is ordinary size (M sub hh(exp asterisk)/M sub o approx. 0.4) for the alloy compositions required for intrinsic long wavelength IR detection. This combination of effective masses leads to rather easy tunneling and relatively large Auger transition rates. These are undesirable characteristics, which must be designed around, of an IR detector material. They follow directly from the fact that (Hg, Cd)Te has the zincblend crystal structure and a small band gap. In small band gap superlattices, such as HgTe/CdTe, In(As, Sb)/InSb and InAs/(Ga,In)Sb, the band gap is determined by the superlattice layer thicknesses as well as by the alloy composition (for superlattices containing an alloy). The effective masses are not directly related to the band gap and can be separately varied. In addition, both strain and quantum confinement can be used to split the light-hole band away from the valence band maximum. These band structure engineering options can be used to reduce tunneling probabilities and Auger transition rates compared with a small band gap zincblend structure material. Researchers discuss the different band structure engineering options for the various classes of small band gap superlattices.

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

    PubMed

    Slivken, Steven; Wu, Donghai; Razeghi, Manijeh

    2017-08-16

    The mid-infrared (2.5 < λ < 25 μm) spectral region is utilized for many purposes, such as chemical/biological sensing, free space communications, and illuminators/countermeasures. Compared to near-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.

  14. High quality factor and high sensitivity chalcogenide 1D photonic crystal microbridge cavity for mid-infrared sensing

    NASA Astrophysics Data System (ADS)

    Xu, Peipeng; Yu, Zenghui; Shen, Xiang; Dai, Shixun

    2017-01-01

    We present and theoretically investigate a mid-infrared (mid-IR) optical sensor based on a Ge11.5As24Se64.5 one-dimensional photonic crystal microbridge cavity (PhC-MC). Optimizing the structure of the PhC-MC strongly confines the resonant mode field to the air region, thereby greatly enhancing the overlap and interaction of the light field and target analytes. A high calculated sensitivity (2280 nm per refractive index unit) is achieved with a resonant wavelength of 4132 nm. The figure of merit of the device for sensing is extremely high (929,750) because of the high quality factor and sensitivity of the cavity. The sensing part of the cavity is also small (50×3 μm2). The proposed PhC-MC can be an ideal platform for on-chip integrated mid-IR optical sensing.

  15. Towards nano-scale photonics with micro-scale photons: the opportunities and challenges of mid-infrared plasmonics

    NASA Astrophysics Data System (ADS)

    Law, Stephanie; Podolskiy, Viktor; Wasserman, Daniel

    2013-04-01

    Surface plasmon polaritons and their localized counterparts, surface plasmons, are widely used at visible and near-infrared (near-IR) frequencies to confine, enhance, and manipulate light on the subwavelength scale. At these frequencies, surface plasmons serve as enabling mechanisms for future on-chip communications architectures, high-performance sensors, and high-resolution imaging and lithography systems. Successful implementation of plasmonics-inspired solutions at longer wavelengths, in the mid-infrared (mid-IR) frequency range, would benefit a number of highly important technologies in health- and defense-related fields that include trace-gas detection, heat-signature sensing, mimicking, and cloaking, and source and detector development. However, the body of knowledge of visible/near-IR frequency plasmonics cannot be easily transferred to the mid-IR due to the fundamentally different material response of metals in these two frequency ranges. Therefore, mid-IR plasmonic architectures for subwavelength light manipulation require both new materials and new geometries. In this work we attempt to provide a comprehensive review of recent approaches to realize nano-scale plasmonic devices and structures operating at mid-IR wavelengths. We first discuss the motivation for the development of the field of mid-IR plasmonics and the fundamental differences between plasmonics in the mid-IR and at shorter wavelengths. We then discuss early plasmonics work in the mid-IR using traditional plasmonic metals, illuminating both the impressive results of this work, as well as the challenges arising from the very different behavior of metals in the mid-IR, when compared to shorter wavelengths. Finally, we discuss the potential of new classes of mid-IR plasmonic materials, capable of mimicking the behavior of traditional metals at shorter wavelengths, and allowing for true subwavelength, and ultimately, nano-scale confinement at long wavelengths.

  16. Multi-wavelength thermal-infrared imaging of SL9 impact phenomena.

    NASA Astrophysics Data System (ADS)

    Livengood, T. A.; Käufl, H. U.; Kostiuk, T.; Bjoraker, G. L.; Romani, P. N.; Wiedemann, G.; Mosser, B.; Sauvage, M.

    Jupiter was imaged in the thermal-infrared (λ ≍ 10 μm) on 15 - 18 and 22 - 31 July 1994 (UT). The site of fragment A impact showed substantial emission at λ ≍ 10 μm shortly after impact and a light curve was measured for 40 minutes post-impact. Strong emission was observed from the fragment H impact, including a "precursor" brightening observed 56 seconds after impact, well before the nominal impact longitude rotated into view on Jupiter's disc. The precursor event is interpreted as the debris front ("plume") from the explosive fireball phase of the impact, arriving at an altitude visible past the limb. Straightforward geometry (neglecting refraction) indicates that the impact H plume reached an altitude of at least ≍450 km above the tropopause (≍100 mbar), with a vertical speed of order 8 km/s. The main peak of the lightcurve for both impacts is interpreted as arising from the re-entry of plume ejecta into the upper atmosphere. The A and H lightcurves differ in the post-peak phase. Wavelength-dependent emission from the impact sites as of several hours post-impact differs between the filters and between the two impacts and is inconsistent with gray-body thermal emission.

  17. Exploring the transition to planetary nebula using high-resolution techniques at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Wendolyn Blanco Cárdenas, Mónica

    2015-08-01

    A planetary nebula (PN) is the ionised envelope surrounding a white dwarf, the final fate of low- and intermediate-mass stars. This stellar phase is also important for its contribution to the interstellar medium, when PNe drive out s-process elements, molecules as well as different dust species, the building blocks of life. One of the most discussed topics in the PNe research field is their huge variety of morphologies and how the more complex forms are sculpted. The theoretical models predict the existence of collimating agents such as disks (steady and/or rotating), jets, and binary systems to sculpt these perplexing morphologies. However, the observations able to detect these shaping engines are often quite difficult to accomplish. Furthermore, the transition to PN hides the clues of these process, that is, when the AGB, post-AGBs, proto-PN, and the circumstellar environments of young PNe are compact and embeded in dust. In this work, we present our results implementing observational techniques and different analysis to inspect and resolve these structures by means of high-resolution imaging, high- and low-resolution spectroscopy at infrared wavelengths and using two VLT instruments: CRIRES (near-IR) and VISIR (mid-IR).

  18. All-optical modulation in Mid-Wavelength Infrared using porous Si membranes

    NASA Astrophysics Data System (ADS)

    Park, Sung Jin; Zakar, Ammar; Zerova, Vera L.; Chekulaev, Dimitri; Canham, Leigh T.; Kaplan, Andre

    2016-07-01

    We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural transparency window centred around 4 μm. Yet, about 55% of modulation contrast can be achieved by means of optical excitation at the pump power of 60 mW (4.8 mJ/cm2). Our analysis shows that the main mechanism of the modulation is interaction of the MWIR signal with the free charge carrier excited by the pump. The time-resolved measurements showed a sub-picosecond rise time and a recovery time of about 66 ps, which suggests a modulation speed performance of ~15 GHz. This optical modulation of pSi membrane in MWIR can be applied to a variety of applications such as thermal imaging and free space communications.

  19. Atomic layer deposition of absorbing thin films on nanostructured electrodes for short-wavelength infrared photosensing

    SciTech Connect

    Xu, Jixian; Sutherland, Brandon R.; Hoogland, Sjoerd; Fan, Fengjia; Sargent, Edward H.; Kinge, Sachin

    2015-10-12

    Atomic layer deposition (ALD), prized for its high-quality thin-film formation in the absence of high temperature or high vacuum, has become an industry standard for the large-area deposition of a wide array of oxide materials. Recently, it has shown promise in the formation of nanocrystalline sulfide films. Here, we demonstrate the viability of ALD lead sulfide for photodetection. Leveraging the conformal capabilities of ALD, we enhance the absorption without compromising the extraction efficiency in the absorbing layer by utilizing a ZnO nanowire electrode. The nanowires are first coated with a thin shunt-preventing TiO{sub 2} layer, followed by an infrared-active ALD PbS layer for photosensing. The ALD PbS photodetector exhibits a peak responsivity of 10{sup −2} A W{sup −1} and a shot-derived specific detectivity of 3 × 10{sup 9} Jones at 1530 nm wavelength.

  20. All-optical modulation in Mid-Wavelength Infrared using porous Si membranes

    PubMed Central

    Park, Sung Jin; Zakar, Ammar; Zerova, Vera L.; Chekulaev, Dimitri; Canham, Leigh T.; Kaplan, Andre

    2016-01-01

    We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural transparency window centred around 4 μm. Yet, about 55% of modulation contrast can be achieved by means of optical excitation at the pump power of 60 mW (4.8 mJ/cm2). Our analysis shows that the main mechanism of the modulation is interaction of the MWIR signal with the free charge carrier excited by the pump. The time-resolved measurements showed a sub-picosecond rise time and a recovery time of about 66 ps, which suggests a modulation speed performance of ~15 GHz. This optical modulation of pSi membrane in MWIR can be applied to a variety of applications such as thermal imaging and free space communications. PMID:27440224

  1. Infrared-induced conformer interconversion processes for allylamine in argon matrices: Wavelength dependence on the kinetics

    NASA Astrophysics Data System (ADS)

    Schriver, A.; Racine, S.; Schriver, L.

    1985-12-01

    Infrared photoisomerization of allylamine trapped in solid argon is studied by irradiation either at specific wavelengths emitted by a CO 2 laser in coincidence with bands of the three conformers (S + G +, ST and CT) or in several mid- or near-IR domains using broad band filters. Upon irradiation with broad band filters the CT → ST process is mainly observed whatever the frequency domain, with only a slight intensity increase of the S + G + bands. Upon irradiation with CO 2 lines in coincidence with CT bands the conversion CT → ST is observed; the reverse process is evidenced by irradiation at ST frequencies. Irradiation at S + G + frequency shows no effect on the conformational equilibrium. Kinetic rate constants are measured and normalized to constant light power absorbed by the sample. They are compared with those calculated by the RRKM theory of first-order processes, assuming the same torsional barrier around the CC bond as in the gas phase. The good agreement between experimental and calculated values suggests the absence of vibrational selectivity in this photoisomerization process.

  2. Wavelength-Dependent Penetration Depth of Near Infrared Radiation into Cartilage

    PubMed Central

    Padalkar, M.V.; Pleshko, N.

    2015-01-01

    Articular cartilage is a hyaline cartilage that lines the subchondral bone in a diarthrodial joint. Near infrared (NIR) spectroscopy has been emerging as a nondestructive modality for evaluation of cartilage pathology. However, studies of the depth of penetration of NIR radiation into cartilage are lacking. The average thickness of human cartilage is about 1-3 mm, and it becomes even thinner as OA progresses. To ensure that the spectral data collected is restricted to the tissue of interest i.e. cartilage in this case, and not from the underlying subchondral bone, it is necessary to determine the depth of penetration of NIR radiation in different wavelength (frequency) regions. In the current study we establish how the depth of penetration varies throughout the NIR frequency range (4000-10000 cm-1). NIR spectra were collected from cartilage samples of different thicknesses (0.5 mm to 5 mm) with and without polystyrene placed underneath. A separate NIR spectrum of polystyrene was collected as a reference. It was found that the depth of penetration varied from ∼1 mm to 2 mm in the 4000-5100 cm-1 range, to ∼3 mm in the 5100-7000 cm-1 range, and to ∼5 mm in the 7000-9000 cm-1 frequency range. These findings suggest that the best NIR region to evaluate cartilage only with no subchondral bone contribution is between 4000-7000 cm-1. PMID:25630381

  3. Recent progress in MOCVD growth for thermoelectrically cooled HgCdTe medium wavelength infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Gawron, W.; Martyniuk, P.; Kębłowski, A.; Kolwas, K.; Stępień, D.; Piotrowski, J.; Madejczyk, P.; Pędzińska, M.; Rogalski, A.

    2016-04-01

    The authors report on advanced metalorganic chemical vapour deposition (MOCVD) of Hg1-xCdxTe (HgCdTe) structures for high operating temperature, medium wavelength infrared (MWIR) detector application. MOCVD technology with wide range of composition and donor/acceptor doping and without post grown annealing was proved to be an excellent tool for HgCdTe heterostructure epitaxial growth used for uncooled photodetector design. The interdiffused multilayer process (IMP) technique was applied for the HgCdTe deposition. HgCdTe epilayers were grown at 350 °C with Hg source kept at 210 °C. The II/VI mole ratio was assumed in the range from 1.5 to 3 during CdTe/HgTe cycles of the IMP process. The MWIR detectors grown by MOCVD exhibit detectivity ∼7.3 × 1011 Jones at λPEAK = 3.5 μm and T = 230 K being determined by background limited photodetector (BLIP) condition.

  4. All-optical modulation in Mid-Wavelength Infrared using porous Si membranes.

    PubMed

    Park, Sung Jin; Zakar, Ammar; Zerova, Vera L; Chekulaev, Dimitri; Canham, Leigh T; Kaplan, Andre

    2016-07-21

    We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural transparency window centred around 4 μm. Yet, about 55% of modulation contrast can be achieved by means of optical excitation at the pump power of 60 mW (4.8 mJ/cm(2)). Our analysis shows that the main mechanism of the modulation is interaction of the MWIR signal with the free charge carrier excited by the pump. The time-resolved measurements showed a sub-picosecond rise time and a recovery time of about 66 ps, which suggests a modulation speed performance of ~15 GHz. This optical modulation of pSi membrane in MWIR can be applied to a variety of applications such as thermal imaging and free space communications.

  5. Photon counting performance measurements of transfer electron InGaAsP photocathode hybrid photomultiplier tubes at 1064 nm wavelength

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoli; Krainak, Michael A.; Hasselbrack, William B.; La Rue, Ross A.

    2007-05-01

    We report the test results of a hybrid photomultiplier tube (HPMT) with a transfer electron (TE) InGaAsP photocathode and GaAs Schottky avalanche photodiode (APD) anode. Unlike Geiger mode InGaAsP APDs, these HPMTs (also known as intensified photodiode (IPD), vacuum APD, or hybrid photodetector) operate in linear mode without the need for quenching and gating. Their greatest advantages are wide dynamic range, high speed, large photosensitive area, and potential for photon counting and analog detection dual mode operation. The photon detection efficiency we measured was 25% at 1064 nm wavelength with a dark count rate of 60,000/s at -22 degrees Celsius. The output pulse width in response to a single photon detection is about 0.9 ns. The maximum count rate was 90 Mcts/s and was limited solely by the speed of the discriminator used in the measurement (10 ns dead time). The spectral response of these devices extended from 900 to 1300 nm. We also measured the HPMT response to 60 ps laser pulses. The average output pulse amplitude increased monotonically with the input pulse energy, which suggested that we can resolve photon number in an incident pulse. The jitter of the HPMT output was found to be about 0.5 ns standard deviation and depended on bias voltage applied to the TE photocathode. To our knowledge, these HPMTs are the most sensitive non gating photon detectors at 1064 nm wavelength, and they will have many applications in laser altimeters, atmospheric lidars, and free space laser communication systems.

  6. Photonically Engineered Incandescent Emitter

    DOEpatents

    Gee, James M.; Lin, Shawn-Yu; Fleming, James G.; Moreno, James B.

    2005-03-22

    A photonically engineered incandescence is disclosed. The emitter materials and photonic crystal structure can be chosen to modify or suppress thermal radiation above a cutoff wavelength, causing the emitter to selectively emit in the visible and near-infrared portions of the spectrum. An efficient incandescent lamp is enabled thereby. A method for fabricating a three-dimensional photonic crystal of a structural material, suitable for the incandescent emitter, is also disclosed.

  7. Photonically engineered incandescent emitter

    DOEpatents

    Gee, James M.; Lin, Shawn-Yu; Fleming, James G.; Moreno, James B.

    2003-08-26

    A photonically engineered incandescence is disclosed. The emitter materials and photonic crystal structure can be chosen to modify or suppress thermal radiation above a cutoff wavelength, causing the emitter to selectively emit in the visible and near-infrared portions of the spectrum. An efficient incandescent lamp is enabled thereby. A method for fabricating a three-dimensional photonic crystal of a structural material, suitable for the incandescent emitter, is also disclosed.

  8. Mid-wavelength infrared InAsSb/InSb nBn detector with extended cut-off wavelength

    NASA Astrophysics Data System (ADS)

    Soibel, Alexander; Ting, David Z.; Hill, Cory J.; Fisher, Anita M.; Hoglund, Linda; Keo, Sam. A.; Gunapala, Sarath D.

    2016-09-01

    We extended the cut-off wavelength λc of bulk InAsSb nBn detectors to λc = 4.6 μm at T = 200 K by incorporating series of single InSb monolayer into InAsSb absorber. Detectors with 2 μm thick absorber showed a temperature independent quantum efficiency QEm≈ 0.45 for back-side illumination without antireflection coating. The dark current density was jd = 5 × 10-6 A/cm2 at T = 150 K, and increased to jd = 2 × 10-3 A/cm2 at T = 200 K. At temperatures of T = 150 K and below, the demonstrated photodetectors operate in the background limited performance mode, with detectivity D*(λ) = 3-6 × 1011 cm Hz0.5/W for the background temperature of 300 K, and f/2 field of view.

  9. Silicon-on-insulator shortwave infrared wavelength meter with integrated photodiodes for on-chip laser monitoring.

    PubMed

    Muneeb, M; Ruocco, A; Malik, A; Pathak, S; Ryckeboer, E; Sanchez, D; Cerutti, L; Rodriguez, J B; Tournié, E; Bogaerts, W; Smit, M K; Roelkens, G

    2014-11-03

    This paper demonstrates a very compact wavelength meter for on-chip laser monitoring in the shortwave infrared wavelength range based on an optimized arrayed waveguide grating (AWG) filter with an integrated photodiode array. The AWG response is designed to obtain large nearest neighbor crosstalk (i.e. large overlap) between output channels, which allows accurately measuring the wavelength of a laser under test using the centroid detection technique. The passive AWG is fabricated on a 220 nm silicon-on-insulator (SOI) platform and is combined with GaInAsSb-based photodiodes. The photodiodes are heterogeneously integrated on the output grating couplers of the AWG using DVS-BCB adhesive bonding. The complete device with AWG and detectors has a footprint of only 2 mm(2) while the measured accuracy and resolution of the detected wavelength is better than 20pm.

  10. Mid-Infrared Photonic Devices Fabricated by Ultrafast Laser Inscription

    DTIC Science & Technology

    2016-07-01

    follows on from an initial grant that lead to the developed of the first ZnSe waveguides. In this report will detail our development of Cr:ZnSe waveguide...TERMS inscription bulk materials, photonic inscription, integrated waveguids in ZnSe , laser inscription, EOARD 16.  SECURITY CLASSIFICATION OF: 17...Ultrafast laser inscription ...................................................................................... 5 First waveguides in Cr2+: ZnSe

  11. Near-infrared Single-photon-counting Detectors for Free-space Laser Receivers

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Sun, Xiaoli; Hasselbrack, William; Wu, Stewart; Waczynski, Augustyn; Miko, Laddawan

    2007-01-01

    We compare several photon-counting detector technologies for use as near-infrared timeresolved laser receivers in science instrument, communication and navigation systems. The key technologies are InGaAs(P) photocathode hybrid photomultiplier tubes and InGaAs(P) and HgCdTe avalanche photodiodes. We discuss recent experimental results and application.

  12. A near-infrared 64-pixel superconducting nanowire single photon detector array with integrated multiplexed readout

    SciTech Connect

    Allman, M. S. Verma, V. B.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Mirin, R.; Nam, S. W.; Marsili, F.; Beyer, A.; Shaw, M. D.; Kumor, D.

    2015-05-11

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array as well as characterization measurements are discussed.

  13. Wavelength-tunable sources of entangled photons interfaced with atomic vapours.

    PubMed

    Trotta, Rinaldo; Martín-Sánchez, Javier; Wildmann, Johannes S; Piredda, Giovanni; Reindl, Marcus; Schimpf, Christian; Zallo, Eugenio; Stroj, Sandra; Edlinger, Johannes; Rastelli, Armando

    2016-01-27

    The prospect of using the quantum nature of light for secure communication keeps spurring the search and investigation of suitable sources of entangled photons. A single semiconductor quantum dot is one of the most attractive, as it can generate indistinguishable entangled photons deterministically and is compatible with current photonic-integration technologies. However, the lack of control over the energy of the entangled photons is hampering the exploitation of dissimilar quantum dots in protocols requiring the teleportation of quantum entanglement over remote locations. Here we introduce quantum dot-based sources of polarization-entangled photons whose energy can be tuned via three-directional strain engineering without degrading the degree of entanglement of the photon pairs. As a test-bench for quantum communication, we interface quantum dots with clouds of atomic vapours, and we demonstrate slow-entangled photons from a single quantum emitter. These results pave the way towards the implementation of hybrid quantum networks where entanglement is distributed among distant parties using optoelectronic devices.

  14. Wavelength-tunable sources of entangled photons interfaced with atomic vapours

    NASA Astrophysics Data System (ADS)

    Trotta, Rinaldo; Martín-Sánchez, Javier; Wildmann, Johannes S.; Piredda, Giovanni; Reindl, Marcus; Schimpf, Christian; Zallo, Eugenio; Stroj, Sandra; Edlinger, Johannes; Rastelli, Armando

    2016-01-01

    The prospect of using the quantum nature of light for secure communication keeps spurring the search and investigation of suitable sources of entangled photons. A single semiconductor quantum dot is one of the most attractive, as it can generate indistinguishable entangled photons deterministically and is compatible with current photonic-integration technologies. However, the lack of control over the energy of the entangled photons is hampering the exploitation of dissimilar quantum dots in protocols requiring the teleportation of quantum entanglement over remote locations. Here we introduce quantum dot-based sources of polarization-entangled photons whose energy can be tuned via three-directional strain engineering without degrading the degree of entanglement of the photon pairs. As a test-bench for quantum communication, we interface quantum dots with clouds of atomic vapours, and we demonstrate slow-entangled photons from a single quantum emitter. These results pave the way towards the implementation of hybrid quantum networks where entanglement is distributed among distant parties using optoelectronic devices.

  15. Wavelength-tunable sources of entangled photons interfaced with atomic vapours

    PubMed Central

    Trotta, Rinaldo; Martín-Sánchez, Javier; Wildmann, Johannes S.; Piredda, Giovanni; Reindl, Marcus; Schimpf, Christian; Zallo, Eugenio; Stroj, Sandra; Edlinger, Johannes; Rastelli, Armando

    2016-01-01

    The prospect of using the quantum nature of light for secure communication keeps spurring the search and investigation of suitable sources of entangled photons. A single semiconductor quantum dot is one of the most attractive, as it can generate indistinguishable entangled photons deterministically and is compatible with current photonic-integration technologies. However, the lack of control over the energy of the entangled photons is hampering the exploitation of dissimilar quantum dots in protocols requiring the teleportation of quantum entanglement over remote locations. Here we introduce quantum dot-based sources of polarization-entangled photons whose energy can be tuned via three-directional strain engineering without degrading the degree of entanglement of the photon pairs. As a test-bench for quantum communication, we interface quantum dots with clouds of atomic vapours, and we demonstrate slow-entangled photons from a single quantum emitter. These results pave the way towards the implementation of hybrid quantum networks where entanglement is distributed among distant parties using optoelectronic devices. PMID:26815609

  16. Vertically integrated (Ga, In)N nanostructures for future single photon emitters operating in the telecommunication wavelength range.

    PubMed

    Winden, A; Mikulics, M; Grützmacher, D; Hardtdegen, H

    2013-10-11

    Important technological steps are discussed and realized for future room-temperature operation of III-nitride single photon emitters. First, the growth technology of positioned single pyramidal InN nanostructures capped by Mg-doped GaN is presented. The optimization of their optical characteristics towards narrowband emission in the telecommunication wavelength range is demonstrated. In addition, a device concept and technology was developed so that the nanostructures became singularly addressable. It was found that the nanopyramids emit in the telecommunication wavelength range if their size is chosen appropriately. A p-GaN contacting layer was successfully produced as a cap to the InN pyramids and the top p-contact was achievable using an intrinsically conductive polymer PEDOT:PSS, allowing a 25% increase in light transmittance compared to standard Ni/Au contact technology. Single nanopyramids were successfully integrated into a high-frequency device layout. These decisive technology steps provide a promising route to electrically driven and room-temperature operating InN based single photon emitters in the telecommunication wavelength range.

  17. Large-area, near-infrared (IR) photonic crystals with colloidal gold nanoparticles embedding.

    PubMed

    Shukla, Shobha; Baev, Alexander; Jee, Hongsub; Hu, Rui; Burzynski, Ryszard; Yoon, Yong-Kyu; Prasad, Paras N

    2010-04-01

    A polymeric composite material composed of colloidal gold nanoparticles (<10 nm) and SU8 has been utilized for the fabrication of large-area, high-definition photonic crystal. We have successfully fabricated near-infrared photonic crystal slabs from composite materials using a combination of multiple beam interference lithography and reactive ion etching processes. Doping of colloidal gold nanoparticles into the SU8 photopolymer results in a better definition of structural features and hence in the enhancement of the optical properties of the fabricated photonic crystals. A 2D air hole array of triangular symmetry with a hole-to-hole pitch of approximately 500 nm has been successfully fabricated in a large circular area of 1 cm diameter. Resonant features observed in reflectance spectra of our slabs are found to depend on the exposure time, and can be tuned over a range of near-infrared frequencies.

  18. Continuous-wave mid-infrared photonic crystal light emitters at room temperature

    NASA Astrophysics Data System (ADS)

    Weng, Binbin; Qiu, Jijun; Shi, Zhisheng

    2017-01-01

    Mid-infrared photonic crystal enhanced lead-salt light emitters operating under continuous-wave mode at room temperature were investigated in this work. For the device, an active region consisting of 9 pairs of PbSe/Pb0.96Sr0.04Se quantum wells was grown by molecular beam epitaxy method on top of a Si(111) substrate which was initially dry-etched with a two-dimensional photonic crystal structure in a pattern of hexagonal holes. Because of the photonic crystal structure, an optical band gap between 3.49 and 3.58 µm was formed, which matched with the light emission spectrum of the quantum wells at room temperature. As a result, under optical pumping, using a near-infrared continuous-wave semiconductor laser, the device exhibited strong photonic crystal band-edge mode emissions and delivered over 26.5 times higher emission efficiency compared to the one without photonic crystal structure. The output power obtained was up to 7.68 mW (the corresponding power density was 363 mW/cm2), and a maximum quantum efficiency reached to 1.2%. Such photonic crystal emitters can be used as promising light sources for novel miniaturized gas-sensing systems.

  19. Highly efficient heralded single-photon source for telecom wavelengths based on a PPLN waveguide.

    PubMed

    Bock, Matthias; Lenhard, Andreas; Chunnilall, Christopher; Becher, Christoph

    2016-10-17

    We present the realization of a highly efficient photon pair source based on spontaneous parametric downconversion (SPDC) in a periodically poled lithium niobate (PPLN) ridge waveguide. The source is suitable for long distance quantum communication applications as the photon pairs are located at the centers of the telecommunication O- and C- band at 1312 nm and 1557 nm. The high efficiency is confirmed by a conversion efficiency of 4 × 10-6 - which is to our knowledge among the highest conversion efficiencies reported so far - and a heralding efficiency of 64.1 ± 2.1%. The heralded single-photon properties are confirmed by the measurement of the photon statistics with a Click/No-Click method as well as the heralded g(2)-function. A minimum value for g(2)(0) of 0.001 ± 0.0003 indicating clear antibunching has been observed.

  20. Phase memory across two single-photon interferometers including wavelength conversion

    NASA Astrophysics Data System (ADS)

    Heuer, A.; Raabe, S.; Menzel, R.

    2014-10-01

    Spontaneous parametric down-conversion (SPDC) in a nonlinear crystal generates two single photons (signal and idler) with random phases. Thus, no first-order interference between them occurs. However, coherence can be induced in a cascaded setup of two crystals if, e.g., the idler modes of both crystals are aligned to be indistinguishable. Due to the effect of phase memory it is found that the first-order interference of the signal beams can be controlled by the phase delay between the pump beams. Even for pump photon delays much larger than the coherence length of the SPDC photons, the visibility is above 90%. The high visibilities reported here prove an almost perfect phase memory effect across the two interferometers for the pump and the signal photon modes.