Sample records for ingaas diode array

  1. Real-time continuous-wave terahertz line scanner based on a compact 1 × 240 InGaAs Schottky barrier diode array detector.

    PubMed

    Han, Sang-Pil; Ko, Hyunsung; Kim, Namje; Lee, Won-Hui; Moon, Kiwon; Lee, Il-Min; Lee, Eui Su; Lee, Dong Hun; Lee, Wangjoo; Han, Seong-Tae; Choi, Sung-Wook; Park, Kyung Hyun

    2014-11-17

    We demonstrate real-time continuous-wave terahertz (THz) line-scanned imaging based on a 1 × 240 InGaAs Schottky barrier diode (SBD) array detector with a scan velocity of 25 cm/s, a scan line length of 12 cm, and a pixel size of 0.5 × 0.5 mm². Foreign substances, such as a paper clip with a spatial resolution of approximately 1 mm that is hidden under a cracker, are clearly detected by this THz line-scanning system. The system consists of the SBD array detector, a 200-GHz gyrotron source, a conveyor system, and several optical components such as a high-density polyethylene cylindrical lens, metal cylindrical mirror, and THz wire-grid polarizer. Using the THz polarizer, the signal-to-noise ratio of the SBD array detector improves because the quality of the source beam is enhanced.

  2. Laser excitation dynamics of argon metastables generated in atmospheric pressure flows by microwave frequency microplasma arrays

    NASA Astrophysics Data System (ADS)

    Rawlins, W. T.; Galbally-Kinney, K. L.; Davis, S. J.; Hoskinson, A. R.; Hopwood, J. A.

    2014-03-01

    The optically pumped rare-gas metastable laser is a chemically inert analogue to diode-pumped alkali (DPAL) and alkali-exciplex (XPAL) laser systems. Scaling of these devices requires efficient generation of electronically excited metastable atoms in a continuous-wave electric discharge in flowing gas mixtures at atmospheric pressure. This paper describes initial investigations of the use of linear microwave micro-discharge arrays to generate metastable rare-gas atoms at atmospheric pressure in optical pump-and-probe experiments for laser development. Power requirements to ignite and sustain the plasma at 1 atm are low, <30 W. We report on the laser excitation dynamics of argon metastables, Ar (4s, 1s5) (Paschen notation), generated in flowing mixtures of Ar and He at 1 atm. Tunable diode laser absorption measurements indicate Ar(1s5) concentrations near 3 × 1012 cm-3 at 1 atm. The metastables are optically pumped by absorption of a focused beam from a continuous-wave Ti:S laser, and spectrally selected fluorescence is observed with an InGaAs camera and an InGaAs array spectrometer. We observe the optical excitation of the 1s5-->2p9 transition at 811.5 nm and the corresponding laser-induced fluorescence on the 2p10-->1s5 transition at 912.3 nm; the 2p10 state is efficiently populated by collisional energy transfer from 2p9. Using tunable diode laser absorption/gain spectroscopy, we observe small-signal gains of ~1 cm-1 over a 1.9 cm path. We also observe stable, continuous-wave laser oscillation at 912.3 nm, with preliminary optical efficiency ~55%. These results are consistent with efficient collisional coupling within the Ar(4s) manifold.

  3. Diode-pumped ytterbium-doped Sr{sub 5}(PO{sub 4}){sub 3}F laser performance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Marshall, C.D.; Smith, L.K.; Beach, R.J.

    The performance of the first diode-pumped Yb{sup 3+}-doped Sr{sub 5}(PO{sub 4}){sup 3}F (Yb:S-FAP) solid-state laser is discussed. An InGaAs diode array has been fabricated that has suitable specifications for pumping a 3 x 3 x 30 mm Yb:S-FAP rod. The saturation fluence for diode pumping was deduced to be 5.5 J/cm{sup 2} for the particular 2.8 kW peak power diode array utilized in the studies. This is 2.5{times} higher than the intrinsic 2.2 J/cm{sup 2} saturation fluence as is attributed to the 6.5 nm bandwidth of the diode pump array. The small signal gain is consistent with the previously measuredmore » emission cross section of 6.0 {times} 10{sup {minus}20} cm{sup 2}, obtained from a narrowband-laser pumped gain experiment. Up to 1.7 J/cm{sup 3} of stored energy density was achieved in a 6 x 6 x 44 mm Yb:S-FAP amplifier rod. In a free running configuration, diode-pumped slope efficiencies up to 43% (laser output energy/absorbed pump energy) were observed with output energies up to {approximately}0.5 J per 1 ms pulse. When the rod was mounted in a copper block for cooling, 13 W of average power was produced with power supply limited operation at 70 Hz with 500 {micro}s pulses.« less

  4. Low dark current InGaAs detector arrays for night vision and astronomy

    NASA Astrophysics Data System (ADS)

    MacDougal, Michael; Geske, Jon; Wang, Chad; Liao, Shirong; Getty, Jonathan; Holmes, Alan

    2009-05-01

    Aerius Photonics has developed large InGaAs arrays (1K x 1K and greater) with low dark currents for use in night vision applications in the SWIR regime. Aerius will present results of experiments to reduce the dark current density of their InGaAs detector arrays. By varying device designs and passivations, Aerius has achieved a dark current density below 1.0 nA/cm2 at 280K on small-pixel, detector arrays. Data is shown for both test structures and focal plane arrays. In addition, data from cryogenically cooled InGaAs arrays will be shown for astronomy applications.

  5. 2.75 THz tuning with a triple-DFB laser system at 1550 nm and InGaAs photomixers

    NASA Astrophysics Data System (ADS)

    Deninger, Anselm J.; Roggenbuck, A.; Schindler, S.; Preu, S.

    2015-03-01

    To date, exploiting the full bandwidth of state-of-the-art InGaAs photomixers for generation and detection of continuous-wave (CW) THz radiation (typ. ~50 GHz to ~3 THz) required complex and costly external-cavity diode lasers with motorized resonator control. Distributed feedback (DFB) lasers, by contrast, are compact and inexpensive, but the tuning range per diode is limited to ~600 GHz at 1.5 μm. In this paper, we show that a combination of three DFB diodes covers the complete frequency range from 0 - 2750 GHz without any gaps. In combination with InGaAs-based photomixers for terahertz generation and detection, the system achieves a dynamic range of > 100 dB at 56 GHz, 64 dB at 1000 GHz, and 26 dB at 2500 GHz. A field-programmable gate array (FPGA)-based lock-in amplifier permits a flexible adjustment of the integration time from 0.5 ms to 600 ms. Employing an optimized "fast scan" mode, a spectrum of ~1200 GHz - the bandwidth of each subset of two lasers - and 40 MHz steps is acquired in less than one minute, still maintaining a reasonable dynamic range. To the best of our knowledge, the bandwidth of 2.75 THz presents a new record for DFB-based CW-terahertz systems.

  6. Tunable continuous-wave terahertz generation/detection with compact 1.55 μm detuned dual-mode laser diode and InGaAs based photomixer.

    PubMed

    Kim, Namje; Han, Sang-Pil; Ko, Hyunsung; Leem, Young Ahn; Ryu, Han-Cheol; Lee, Chul Wook; Lee, Donghun; Jeon, Min Yong; Noh, Sam Kyu; Park, Kyung Hyun

    2011-08-01

    We demonstrate a tunable continuous-wave (CW) terahertz (THz) homodyne system with a novel detuned dual-mode laser diode (DML) and low-temperature-grown (LTG) InGaAs photomixers. The optical beat source with the detuned DML showed a beat frequency tuning range of 0.26 to over 1.07 THz. Log-spiral antenna integrated LTG InGaAs photomixers are used as THz wave generators and detectors. The CW THz radiation frequency was continuously tuned to over 1 THz. Our results clearly show the feasibility of a compact and fast scanning CW THz spectrometer consisting of a fiber-coupled detuned DML and photomixers operating in the 1.55-μm range.

  7. Characteristics of Monolithically Integrated InGaAs Active Pixel Imager Array

    NASA Technical Reports Server (NTRS)

    Kim, Q.; Cunningham, T. J.; Pain, B.; Lange, M. J.; Olsen, G. H.

    2000-01-01

    Switching and amplifying characteristics of a newly developed monolithic InGaAs Active Pixel Imager Array are presented. The sensor array is fabricated from InGaAs material epitaxially deposited on an InP substrate. It consists of an InGaAs photodiode connected to InP depletion-mode junction field effect transistors (JFETs) for low leakage, low power, and fast control of circuit signal amplifying, buffering, selection, and reset. This monolithically integrated active pixel sensor configuration eliminates the need for hybridization with silicon multiplexer. In addition, the configuration allows the sensor to be front illuminated, making it sensitive to visible as well as near infrared signal radiation. Adapting the existing 1.55 micrometer fiber optical communication technology, this integration will be an ideal system of optoelectronic integration for dual band (Visible/IR) applications near room temperature, for use in atmospheric gas sensing in space, and for target identification on earth. In this paper, two different types of small 4 x 1 test arrays will be described. The effectiveness of switching and amplifying circuits will be discussed in terms of circuit effectiveness (leakage, operating frequency, and temperature) in preparation for the second phase demonstration of integrated, two-dimensional monolithic InGaAs active pixel sensor arrays for applications in transportable shipboard surveillance, night vision, and emission spectroscopy.

  8. FPGA-based gating and logic for multichannel single photon counting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pooser, Raphael C; Earl, Dennis Duncan; Evans, Philip G

    2012-01-01

    We present results characterizing multichannel InGaAs single photon detectors utilizing gated passive quenching circuits (GPQC), self-differencing techniques, and field programmable gate array (FPGA)-based logic for both diode gating and coincidence counting. Utilizing FPGAs for the diode gating frontend and the logic counting backend has the advantage of low cost compared to custom built logic circuits and current off-the-shelf detector technology. Further, FPGA logic counters have been shown to work well in quantum key distribution (QKD) test beds. Our setup combines multiple independent detector channels in a reconfigurable manner via an FPGA backend and post processing in order to perform coincidencemore » measurements between any two or more detector channels simultaneously. Using this method, states from a multi-photon polarization entangled source are detected and characterized via coincidence counting on the FPGA. Photons detection events are also processed by the quantum information toolkit for application testing (QITKAT)« less

  9. 640x512 pixel InGaAs FPAs for short-wave infrared and visible light imaging

    NASA Astrophysics Data System (ADS)

    Shao, Xiumei; Yang, Bo; Huang, Songlei; Wei, Yang; Li, Xue; Zhu, Xianliang; Li, Tao; Chen, Yu; Gong, Haimei

    2017-08-01

    The spectral irradiance of moonlight and air glow is mainly in the wavelength region from visible to short-wave infrared (SWIR) band. The imaging over the wavelength range of visible to SWIR is of great significance for applications such as civil safety, night vision, and agricultural sorting. In this paper, 640×512 visible-SWIR InGaAs focal plane arrays (FPAs) were studied for night vision and SWIR imaging. A special epitaxial wafer structure with etch-stop layer was designed and developed. Planar-type 640×512 InGaAs detector arrays were fabricated. The photosensitive arrays were bonded with readout circuit through Indium bumps by flip-chip process. Then, the InP substrate was removed by mechanical thinning and chemical wet etching. The visible irradiance can reach InGaAs absorption layer and then to be detected. As a result, the detection spectrum of the InGaAs FPAs has been extended toward visible spectrum from 0.5μm to 1.7μm. The quantum efficiency is approximately 15% at 0.5μm, 30% at 0.7μm, 50% at 0.8μm, 90% at 1.55μm. The average peak detectivity is higher than 2×1012 cm·Hz1/2/W at room temperature with an integrated time of 10 ms. The Visible-SWIR InGaAs FPAs were applied to an imaging system for SWIR and visible light imaging.

  10. Atmospheric CH 4 and H 2 O Monitoring With Near-Infrared InGaAs Laser Diodes by the SDLA, a Balloonborne Spectrometer for Tropospheric and Stratospheric In Situ Measurements

    NASA Astrophysics Data System (ADS)

    Durry, Georges; Megie, Gerard

    1999-12-01

    The Spectrom tre Diodes Laser Accordables (SDLA), a balloonborne spectrometer devoted to the in situ measurement of CH 4 and H 2 O in the atmosphere that uses commercial distributed-feedback InGaAs laser diodes in combination with differential absorption spectroscopy, is described. Absorption spectra of CH 4 (in the 1.653- m region) and H 2 O (in the 1.393- m region) are simultaneously sampled at 1-s intervals by coupling with optical fibers of two near-infrared laser diodes to a Herriott multipass cell open to the atmosphere. Spectra of methane and water vapor in an altitude range of 1 to 31 km recorded during the recent balloon flights of the SDLA are presented. Mixing ratios with a precision error ranging from 5% to 10% are retrieved from the atmospheric spectra by a nonlinear least-squares fit to the spectral line shape in conjunction with in situ simultaneous pressure and temperature measurements.

  11. Evaluation of InGaAS array detector suitability to space environment

    NASA Astrophysics Data System (ADS)

    Tauziede, L.; Beulé, K.; Boutillier, M.; Bernard, F.; Reverchon, J.-L.; Buffaz, A.

    2017-11-01

    InGaAs material has a natural cutoff wavelength of 1.65µm so it is naturally suitable for detection in Short Wavelength InfraRed (SWIR) spectral range. Regarding Earth Observation Spacecraft missions this spectral range can be used for the CO2 concentration measurements in the atmosphere. CNES (French Space agency) is studying a new mission, Microcarb with a spectral band centered on 1.6µm wavelength. InGaAs detector looks attractive for space application because its low dark current allows high temperature operation, reducing by the way the needed instrument resources. The Alcatel Thales III-VLab group has developed InGaAs arrays technology (320x256 & 640x512) that has been studied by CNES, using internal facilities. Performance tests and technological evaluation were performed on a 320x256 pixels array with a pitch of 30µm. The aim of this evaluation was to assess this new technology suitability for space applications. The carried out test plan includes proton radiations with Random Telegraph Signal (RTS) study, operating lifetest and evolution of performances as a function of the operating temperature.

  12. Modeling of a sensitive time-of-flight flash LiDAR system

    NASA Astrophysics Data System (ADS)

    Fathipour, V.; Wheaton, S.; Johnson, W. E.; Mohseni, H.

    2016-09-01

    used for monitoring and profiling structures, range, velocity, vibration, and air turbulence. Remote sensing in the IR region has several advantages over the visible region, including higher transmitter energy while maintaining eye-safety requirements. Electron-injection detectors are a new class of detectors with high internal avalanche-free amplification together with an excess-noise-factor of unity. They have a cutoff wavelength of 1700 nm. Furthermore, they have an extremely low jitter. The detector operates in linear-mode and requires only bias voltage of a few volts. This together with the feedback stabilized gain mechanism, makes formation of large-format high pixel density electron-injection FPAs less challenging compared to other detector technologies such as avalanche photodetectors. These characteristics make electron-injection detectors an ideal choice for flash LiDAR application with mm scale resolution at longer ranges. Based on our experimentally measured device characteristics, a detailed theoretical LiDAR model was developed. In this model we compare the performance of the electron-injection detector with commercially available linear-mode InGaAs APD from (Hamamatsu G8931-20) as well as a p-i-n diode (Hamamatsu 11193 p-i-n). Flash LiDAR images obtained by our model, show the electron-injection detector array (of 100 x 100 element) achieves better resolution with higher signal-to-noise compared with both the InGaAs APD and the p-i-n array (of 100 x 100 element).

  13. Large-format InGaAs focal plane arrays for SWIR imaging

    NASA Astrophysics Data System (ADS)

    Hood, Andrew D.; MacDougal, Michael H.; Manzo, Juan; Follman, David; Geske, Jonathan C.

    2012-06-01

    FLIR Electro Optical Components will present our latest developments in large InGaAs focal plane arrays, which are used for low light level imaging in the short wavelength infrared (SWIR) regime. FLIR will present imaging from their latest small pitch (15 μm) focal plane arrays in VGA and High Definition (HD) formats. FLIR will present characterization of the FPA including dark current measurements as well as the use of correlated double sampling to reduce read noise. FLIR will show imagery as well as FPA-level characterization data.

  14. Low-Power Consumption InGaAs PIN Diode Switches for V-band Applications

    NASA Astrophysics Data System (ADS)

    Ziegler, Volker; Berg, Michael; Tobler, Hans; Woelk, Claus; Deufel, Reinhard; Trasser, Andreas; Schumacher, Hermann; Alekseev, Egor; Pavlidis, Dimitris; Dickmann, Juergen

    1999-02-01

    In this paper, we present the measurement results of two InP-based coplanar SPST (single pole single throw) PIN diode switches operating at V-band frequencies. The switches show excellent mm-wave performance combined with a very low DC-power consumption. The SPST with on-chip biasing and DC-blocking capacitors demonstrates an insertion loss as low as 0.84 dB and a high isolation value of 21.8 dB at a center frequency of 53 GHz with only 0.8 mW of DC-power consumption. A more simple SPST exhibits under equivalent conditions (0.9 mW) an excellent insertion loss of 0.52 dB and an isolation of 21.7 dB. Furthermore the power-handling capability of the InGaAs PIN diodes, which are used as active switching elements, is investigated in this paper and found to exceed 25 dBm at a reverse voltage of -5 V.

  15. Progress on single barrier varactors for submillimeter wave power generation

    NASA Technical Reports Server (NTRS)

    Nilsen, Svein M.; Groenqvist, Hans; Hjelmgren, Hans; Rydberg, Anders; Kollberg, Erik L.

    1992-01-01

    Theoretical work on Single Barrier Varactor (SBV) diodes, indicate that the efficiency for a multiplier has a maximum for a considerably smaller capacitance variation than previously thought. The theoretical calculations are performed, both with a simple theoretical model and a complete computer simulation using the method of harmonic balance. Modeling of the SBV is carried out in two steps. First, the semiconductor transport equations are solved simultaneously using a finite difference scheme in one dimension. Secondly, the calculated I-V, and C-V characteristics are input to a multiplier simulator which calculates the optimum impedances, and output powers at the frequencies of interest. Multiple barrier varactors can also be modeled in this way. Several examples on how to design the semiconductor layers to obtain certain characteristics are given. The calculated conversion efficiencies of the modeled structures, in a multiplier circuit, are also presented. Computer simulations for a case study of a 750 GHz multiplier show that InAs diodes perform favorably compared to GaAs diodes. InAs and InGaAs SBV diodes have been fabricated and their current vs. voltage characteristics are presented. In the InAs diode, was the large bandgap semiconductor AlSb used as barrier. The InGaAs diode was grown lattice matched to an InP substrate with InAlAs as a barrier material. The current density is greatly reduced for these two material combinations, compared to that of GaAs/AlGaAs SBV diodes. GaAs based diodes can be biased to higher voltages than InAs diodes.

  16. Life test of the InGaAs focal plane arrays detector for space applications

    NASA Astrophysics Data System (ADS)

    Zhu, Xian-Liang; Zhang, Hai-Yan; Li, Xue; Huang, Zhang-Cheng; Gong, Hai-Mei

    2017-08-01

    The short-wavelength infrared (SWIR) InGaAs focal plane array (FPA) detector consists of infrared detector chip, readout integrated circuit (ROIC), and flip-chip bonding interconnection by Indium bump. In order to satisfy space application requirements for failure rates or Mean Time to Failure (MTTF), which can only be demonstrated with the large number of detectors manufactured, the single pixel in InGaAs FPAs was chosen as the research object in this paper. The constant-stress accelerated life tests were carried out at 70°C 80°C 90°C and100°C. The failed pixels increased gradually during more than 14000 hours at each elevated temperatures. From the random failure data the activation energy was estimated to be 0.46eV, and the average lifetime of a single pixel in InGaAs FPAs was estimated to be longer than 1E+7h at the practical operating temperature (5°C).

  17. Development of 1300 nm GaAs-Based Microcavity Light-Emitting Diodes

    DTIC Science & Technology

    2001-06-01

    vertical - cavity surface emitting lasers ( VCSEL ) and micro- cavity light- emitting diodes (MC-LED) for short-to-medium... epitaxial growth run [1 ]. Self-organized In(Ga)As quantum dot (QD) heterostructures grown by molecular beam epitaxy ( MBE ) are promising candidates as...successfully grown by molecular beam epitaxy on GaAs substrates without the need to rely on any in-situ calibration technique. Fabricated

  18. Tunable, diode side-pumped Er: YAG laser

    DOEpatents

    Hamilton, Charles E.; Furu, Laurence H.

    1997-01-01

    A discrete-element Er:YAG laser, side pumped by a 220 Watt peak-power InGaAs diode array, generates >500 mWatts at 2.94 .mu.m, and is tunable over a 6 nm range near about 2.936 .mu.m. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, a Er:YAG crystal and a YAG intracavity etalon, which serves as the tuning element. The cavity length is variable from 3 cm to 4 cm. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. With the tuning element removed, the oscillator produces up to 1.3 Watts of average power at 2.94 .mu.m. The duty factor of the laser is 6.5% and the repetition rate is variable up to 1 kHz. This laser is useful for tuning to an atmospheric transmission window at 2.935 .mu.m (air wavelength). The laser is also useful as a spectroscopic tool because it can access several infrared water vapor transitions, as well as transitions in organic compounds. Other uses include medical applications (e.g., for tissue ablation and uses with fiber optic laser scalpels) and as part of industrial effluent monitoring systems.

  19. Tunable, diode side-pumped Er:YAG laser

    DOEpatents

    Hamilton, C.E.; Furu, L.H.

    1997-04-22

    A discrete-element Er:YAG laser, side pumped by a 220 Watt peak-power InGaAs diode array, generates >500 mWatts at 2.94 {micro}m, and is tunable over a 6 nm range near about 2.936 {micro}m. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, a Er:YAG crystal and a YAG intracavity etalon, which serves as the tuning element. The cavity length is variable from 3 cm to 4 cm. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. With the tuning element removed, the oscillator produces up to 1.3 Watts of average power at 2.94 {micro}m. The duty factor of the laser is 6.5% and the repetition rate is variable up to 1 kHz. This laser is useful for tuning to an atmospheric transmission window at 2.935 {micro}m (air wavelength). The laser is also useful as a spectroscopic tool because it can access several infrared water vapor transitions, as well as transitions in organic compounds. Other uses include medical applications (e.g., for tissue ablation and uses with fiber optic laser scalpels) and as part of industrial effluent monitoring systems. 4 figs.

  20. Shot-Noise-Limited Dual-Beam Detector for Atmospheric Trace-Gas Monitoring with Near-Infrared Diode Lasers

    NASA Astrophysics Data System (ADS)

    Durry, Georges; Pouchet, Ivan; Amarouche, Nadir; Danguy, Théodore; Megie, Gerard

    2000-10-01

    A dual-beam detector is used to measure atmospheric trace species by differential absorption spectroscopy with commercial near-infrared InGaAs laser diodes. It is implemented on the Spectrom tre Diodes Laser Accordables, a balloonborne tunable diode laser spectrometer devoted to the in situ monitoring of CH 4 and H 2 O. The dual-beam detector is made of simple analogical subtractor circuits combined with InGaAs photodiodes. The detection strategy consists in taking the balanced analogical difference between the reference and the sample signals detected at the input and the output of an open optical multipass cell to apply the full dynamic range of the measurements (16 digits) to the weak molecular absorption information. The obtained sensitivity approaches the shot-noise limit. With a 56-m optical cell, the detection limit obtained when the spectra is recorded within 8 ms is 10 4 (expressed in absorbance units). The design and performances of both a simple substractor and an upgraded feedback substractor circuit are discussed with regard to atmospheric in situ CH 4 absorption spectra measured in the 1.653- m region. Mixing ratios are obtained from the absorption spectra by application of a nonlinear least-squares fit to the full molecular line shape in conjunction with in situ P and T measurements.

  1. Modeling and simulation of blazed grating based on MEMS scanning micro-mirror for NIR micro-spectrometer

    NASA Astrophysics Data System (ADS)

    Zhou, Ying; Wen, Zhiyu; Yang, Tingyan; Lei, Hongjie

    2015-11-01

    Near infrared micro-spectrometer (NIRMS) as a vital detection equipment for various elements has been investigated over the last few years. Traditional MEMS NIRMS employs CCD array detectors for NIR spectrum collection and this leads to higher fabrication cost. In this paper, to ensure the higher diffraction efficiency as well as lower fabrication cost, a novel blazed grating based on MEMS scanning micro-mirror (SMM) is proposed. By our design method, the NIRMS needs only one single InGaAs detector photo diode to collect NIR spectrum and ensure the high diffraction efficiency. Our results show that the diffraction efficiency of the blazed grating is almost 50% and the peak value reaches to 90% in the range of 900-2,100 nm while the optical scanning angle is 14.2°.

  2. Diode-pumped Yb:Sr{sub 5}(PO{sub 4}){sub 3}F laser performance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Marshall, C.D.; Payne, S.A.; Smith, L.K.

    The performance of the first diode-pumped Yb{sup 3+}-doped Sr{sub 5}(PO{sub 4}){sub 3}F (Yb:S-FAP) laser is discussed. We found the pumping dynamics and extraction cross-sections of Yb:S-FAP crystals to be similar to those previously inferred by purely spectroscopic techniques. The saturation fluence for pumping was measured to be 2.2 J/cm{sup 2} using three different methods based on either the spatial, temporal, or energy transmission properties of a Yb:S-FAP rod. The small signal gain implies an emission cross section of 6.0 x 10{sup -20} cm{sup 2} that falls within error bars of the previously reported value of 7.3 x 10{sup -20} cm{supmore » 2}, obtained from spectroscopic techniques. Up to 1.7 J/cm{sup 3} of stored energy density was achieved in a 6 x 6 x 44 mm Yb:S-FAP amplifier rod. An InGaAs diode array has been fabricated that has suitable specifications for pumping a 3 x 3 x 30 mm Yb:S-FAP rod. In a free running configuration diode-pumped slope efficiencies up to 43% were observed with output energies up to {approximately}0.5 J per 1 ms pulse. When the rod was mounted in a copper block for cooling, 13 W of average power was produced with power supply limited operation at 70 Hz and 500 {mu}s pulses.« less

  3. High-speed, large-area, p-i-n InGaAs photodiode linear array at 2-micron wavelength

    NASA Astrophysics Data System (ADS)

    Joshi, Abhay; Datta, Shubhashish

    2012-06-01

    We present 16-element and 32-element lattice-mismatched InGaAs photodiode arrays having a cut-off wavelength of ~2.2 um. Each 100 um × 200 um large pixel of the 32-element array has a capacitance of 2.5 pF at 5 V reverse bias, thereby allowing a RC-limited bandwidth of ~1.3 GHz. At room temperature, each pixel demonstrates a dark current of 25 uA at 5 V reverse bias. Corresponding results for the 16-element array having 200 um × 200 um pixels are also reported. Cooling the photodiode array to 150K is expected to reduce its dark current to < 50 nA per pixel at 5 V reverse bias. Additionally, measurement results of 2-micron single photodiodes having 16 GHz bandwidth and corresponding PIN-TIA photoreceiver having 6 GHz bandwidth are also reported.

  4. InGaAs focal plane arrays for low-light-level SWIR imaging

    NASA Astrophysics Data System (ADS)

    MacDougal, Michael; Hood, Andrew; Geske, Jon; Wang, Jim; Patel, Falgun; Follman, David; Manzo, Juan; Getty, Jonathan

    2011-06-01

    Aerius Photonics will present their latest developments in large InGaAs focal plane arrays, which are used for low light level imaging in the short wavelength infrared (SWIR) regime. Aerius will present imaging in both 1280x1024 and 640x512 formats. Aerius will present characterization of the FPA including dark current measurements. Aerius will also show the results of development of SWIR FPAs for high temperaures, including imagery and dark current data. Finally, Aerius will show results of using the SWIR camera with Aerius' SWIR illuminators using VCSEL technology.

  5. Composition controllability of InGaAs nanowire arrays in selective area growth with controlled pitches on Si platform

    NASA Astrophysics Data System (ADS)

    Chiba, Kohei; Tomioka, Katsuhiro; Yoshida, Akinobu; Motohisa, Junichi

    2017-12-01

    Composition controllability of vertical InGaAs nanowires (NWs) on Si integrated by selective area growth was characterized for Si photonics in the optical telecommunication bands. The pitch of pre-patterned holes (NW sites) changed to an In/Ga alloy-composition in the solid phase during the NW growth. The In composition with a nanometer-scaled pitch differed completely from that with a μm-scaled pitch. Accordingly, the growth morphologies of InGaAs NWs show different behavior with respect to the In/Ga ratio.

  6. Quantum dots for GaAs-based surface emitting lasers at 1300 nm

    NASA Astrophysics Data System (ADS)

    Grundmann, M.; Ledentsov, N. N.; Hopfer, F.; Heinrichsdorff, F.; Guffarth, F.; Bimberg, D.; Ustinov, V. M.; Zhukov, A. E.; Kovsh, A. R.; Maximov, M. V.; Musikhin, Yu. G.; Alferov, Zh. I.; Lott, J. A.; Zhakharov, N. D.; Werner, P.

    InGaAs quantum dots (QD's) on GaAs substrate have been fabricated using metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) for the use in vertical cavity surface emitting laser diodes. Similar recombination spectra are obtained by employing the two different approaches of seeding and overgrowth with a quantum well. Despite the shift to larger wavelengths a large separation (=80 meV) between excited states is maintained. The introduction of such QD's into a vertical cavity leads to strong narrowing of the emission spectrum. Lasing from a 1300 nm InGaAs quantum dot VCSEL is reported.

  7. Photoionization of Trapped Carriers in Avalanche Photodiodes to Reduce Afterpulsing During Geiger-Mode Photon Counting

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    2005-01-01

    We reduced the afterpulsing probability by a factor of five in a Geiger-mode photon-counting InGaAs avalanche photodiode by using sub-band-gap (lambda = 1.95 micron) laser diode illumination, which we believe photoionizes the trapped carriers.

  8. High-power diode laser modules from 410 nm to 2200 nm

    NASA Astrophysics Data System (ADS)

    Köhler, Bernd; Kissel, Heiko; Flament, Marco; Wolf, Paul; Brand, Thomas; Biesenbach, Jens

    2010-02-01

    In this work we report on high-power diode laser modules covering a wide spectral range from 410 nm to 2200 nm. Driven by improvements in the technology of diode laser bars with non-standard wavelengths, such systems are finding a growing number of applications. Fields of application that benefit from these developments are direct medical applications, printing industry, defense technology, polymer welding and pumping of solid-sate lasers. Diode laser bars with standard wavelengths from 800 - 1000 nm are based on InGaAlAs, InGaAlP, GaAsP or InGaAs semiconductor material with an optical power of more than 100 W per bar. For shorter wavelengths from 630 - 690 nm InGaAlP semiconductor material is used with an optical power of about 5 W per bar. Extending the wavelength range beyond 1100 nm is realized by using InGaAs on InP substrates or with InAs quantum dots embedded in GaAs for wavelengths up to 1320 nm and (AlGaIn)(AsSb) for wavelengths up to 2200 nm. In these wavelength ranges the output power per bar is about 6 - 20 W. In this paper we present a detailed characterization of these diode laser bars, including measurements of power, spectral data and life time data. In addition, we will show different fiber coupled modules, ranging from 638 nm with 13 W output power (400 μm fiber, NA 0.22) up to 1940 nm with more than 50 W output power (600 μm fiber NA 0.22).

  9. Distributed feedback laser diode integrated with distributed Bragg reflector for continuous-wave terahertz generation.

    PubMed

    Kim, Namje; Han, Sang-Pil; Ryu, Han-Cheol; Ko, Hyunsung; Park, Jeong-Woo; Lee, Donghun; Jeon, Min Yong; Park, Kyung Hyun

    2012-07-30

    A widely tunable dual mode laser diode with a single cavity structure is demonstrated. This novel device consists of a distributed feedback (DFB) laser diode and distributed Bragg reflector (DBR). Micro-heaters are integrated on the top of each section for continuous and independent wavelength tuning of each mode. By using a single gain medium in the DFB section, an effective common optical cavity and common modes are realized. The laser diode shows a wide tunability of the optical beat frequency, from 0.48 THz to over 2.36 THz. Continuous wave THz radiation is also successfully generated with low-temperature grown InGaAs photomixers from 0.48 GHz to 1.5 THz.

  10. Detector with internal gain for short-wave infrared ranging applications

    NASA Astrophysics Data System (ADS)

    Fathipour, Vala; Mohseni, Hooman

    2017-09-01

    Abstarct.Highly sensitive photon detectors are regarded as the key enabling elements in many applications. Due to the low photon energy at the short-wave infrared (SWIR), photon detection and imaging at this band are very challenging. As such, many efforts in photon detector research are directed toward improving the performance of the photon detectors operating in this wavelength range. To solve these problems, we have developed an electron-injection (EI) technique. The significance of this detection mechanism is that it can provide both high efficiency and high sensitivity at room temperature, a condition that is very difficult to achieve in conventional SWIR detectors. An EI detector offers an overall system-level sensitivity enhancement due to a feedback stabilized internal avalanche-free gain. Devices exhibit an excess noise of unity, operate in linear mode, require bias voltage of a few volts, and have a cutoff wavelength of 1700 nm. We review the material system, operating principle, and development of EI detectors. The shortcomings of the first-generation devices were addressed in the second-generation detectors. Measurement on second-generation devices showed a high-speed response of ˜6 ns rise time, low jitter of less than 20 ps, high amplification of more than 2000 (at optical power levels larger than a few nW), unity excess noise factor, and low leakage current (amplified dark current ˜10 nA at a bias voltage of -3 V and at room temperature. These characteristics make EI detectors a good candidate for high-resolution flash light detection and ranging (LiDAR) applications with millimeter scale depth resolution at longer ranges compared with conventional p-i-n diodes. Based on our experimentally measured device characteristics, we compare the performance of the EI detector with commercially available linear mode InGaAs avalanche photodiode (APD) as well as a p-i-n diode using a theoretical model. Flash LiDAR images obtained by our model show that the EI detector array achieves better resolution with higher signal-to-noise compared with both the InGaAs APD and the p-i-n array (of 100×100 elements). We have designed a laboratory setup with a receiver optics aperture diameter of 3 mm that allows an EI detector (with 30-μm absorber diameter) to be used for long-range LiDAR imaging with subcentimeter resolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020086293','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020086293"><span>Small Business Innovations (Photodetector)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1991-01-01</p> <p>Epitaxx, Inc. of Princeton, NJ, developed the Epitaxx Near Infrared Room Temperature Indium-Gallium-Arsenide (InGaAs) Photodetector based on their Goddard Space Flight Center Small Business Innovation Research (SBIR) contract work to develop a linear detector array for satellite imaging applications using InGaAs alloys that didn't need to be cooled to (difficult and expensive) cryogenic temperatures. The photodetectors can be used for remote sensing, fiber optic and laser position-sensing applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994seoi.rept.....M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994seoi.rept.....M"><span>ARPA solid state laser and nonlinear materials program</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moulton, Peter F.</p> <p>1994-06-01</p> <p>The Research Division of Schwartz Electro-Optics, as part of the ARPA Solid State Laser and Nonlinear Materials Program, conducted a three-year study 'Erbium-Laser-Based Infrared Sources.' The aim of the study was to improve the understanding of semiconductor-laser-pumped, infrared (IR) solid state lasers based on the trivalent rare-earth ion erbium (Er) doped into a variety of host crystals. The initial program plan emphasized operation of erbium-doped materials on the 2.8-3.0 micrometers laser transition. Pulsed, Q-switched sources using that transition, when employed as a pump source for parametric oscillators, can provide tunable mid-IR energy. The dynamics of erbium lasers are more complex than conventional neodymium (Nd)-doped lasers and we intended to use pump-probe techniques to measure the level and temporal behavior of gain in various materials. To do so we constructed a number of different cw Er-doped lasers as probe sources and employed the Cr:LiSAF(LiSrAlF6) laser as a pulsed pump source that would simulate pulsed diode arrays. We identified the 970-nm wavelength pump band of Er as the most efficient and were able to make use of recently developed cw and pulsed InGaAs strained-quantum-well diode lasers in the effort. At the conclusion of the program we demonstrated the first pulsed diode bar pumping of the most promising materials for pulsed operation, the oxide garnets YSGG and GGG and the fluoride BaY2F8.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960054142','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960054142"><span>Optically-Switched Resonant Tunneling Diodes for Space-Based Optical Communication Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moise, T. S.; Kao, Y. -C.; Jovanovic, D.; Sotirelis, P.</p> <p>1995-01-01</p> <p>We are developing a new type of digital photo-receiver that has the potential to perform high speed optical-to-electronic conversion with a factor of 10 reduction in component count and power dissipation. In this paper, we describe the room-temperature photo-induced switching of this InP-based device which consists of an InGaAs/AlAs resonant tunneling diode integrated with an InGaAs absorber layer. When illuminated at an irradiance of greater than 5 Wcm(exp -2) using 1.3 micromillimeter radiation, the resonant tunneling diode switches from a high-conductance to a low-conductance electrical state and exhibits a voltage swing of up to 800 mV.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7660E..0KM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7660E..0KM"><span>Low-Light-Level InGaAs focal plane arrays with and without illumination</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Macdougal, Michael; Geske, Jon; Wang, Chad; Follman, David</p> <p>2010-04-01</p> <p>Short wavelength IR imaging using InGaAs-based FPAs is shown. Aerius demonstrates low dark current in InGaAs detector arrays with 15 μm pixel pitch. The same material is mated with a 640x 512 CTIA-based readout integrated circuit. The resulting FPA is capable of imaging photon fluxes with wavelengths between 1 and 1.6 microns at low light levels. The mean dark current density on the FPAs is extremely low at 0.64 nA/cm2 at 10°C. Noise due to the readout can be reduced from 95 to 57 electrons by using off-chip correlated double sampling (CDS). In addition, Aerius has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide speckle-free illumination, provide artifact-free imagery versus conventional laser illuminators.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1178806','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1178806"><span>High Pressure Sensing and Dynamics Using High Speed Fiber Bragg Grating Interrogation Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Rodriguez, G.; Sandberg, R. L.; Lalone, B. M.</p> <p>2014-06-01</p> <p>Fiber Bragg gratings (FBGs) are developing into useful sensing tools for measuring high pressure dynamics in extreme environments under shock loading conditions. Approaches using traditional diode array coupled FBG interrogation systems are often limited to readout speeds in the sub-MHz range. For shock wave physics, required detection speeds approaching 100 MHz are desired. We explore the use of two types of FBG sensing systems that are aimed at applying this technology as embedded high pressure probes for transient shock events. Both approaches measure time resolved spectral shifts in the return light from short (few mm long) uniform FBGs at 1550more » nm. In the first approach, we use a fiber coupled spectrometer to demultiplex spectral channels into an array (up to 12) of single element InGaAs photoreceivers. By monitoring the detectors during a shock impact event with high speed recording, we are able to track the pressure induced spectral shifting in FBG down to a time resolution of 20 ns. In the second approach, developed at the Special Technologies Lab, a coherent mode-locked fiber laser is used to illuminate the FBG sensor. After the sensor, wavelength-to-time mapping is accomplished with a chromatic dispersive element, and entire spectra are sampled using a single detector at the modelocked laser repetition rate of 50 MHz. By sampling with a 12 GHz InGaAs detector, direct wavelength mapping in time is recorded, and the pressure induced FBG spectral shift is sampled at 50 MHz. Here, the sensing systems are used to monitor the spectral shifts of FBGs that are immersed into liquid water and shock compressed using explosives. In this configuration, the gratings survive to pressures approaching 50 kbar. We describe both approaches and present the measured spectral shifts from the shock experiments.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.110k3501T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.110k3501T"><span>Radial tunnel diodes based on InP/InGaAs core-shell nanowires</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tizno, Ofogh; Ganjipour, Bahram; Heurlin, Magnus; Thelander, Claes; Borgström, Magnus T.; Samuelson, Lars</p> <p>2017-03-01</p> <p>We report on the fabrication and characterization of radial tunnel diodes based on InP(n+)/InGaAs(p+) core-shell nanowires, where the effect of Zn-dopant precursor flow on the electrical properties of the devices is evaluated. Selective and local etching of the InGaAs shell is employed to access the nanowire core in the contact process. Devices with an n+-p doping profile show normal diode rectification, whereas n+-p+ junctions exhibit typical tunnel diode characteristics with peak-to-valley current ratios up to 14 at room temperature and 100 at 4.2 K. A maximum peak current density of 28 A/cm2 and a reverse current density of 7.3 kA/cm2 at VSD = -0.5 V are extracted at room temperature after normalization with the effective junction area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JCrGr.491...31B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JCrGr.491...31B"><span>Lifetime behavior of laser diodes with highly strained InGaAs QWs and emission wavelength between 1120 nm and 1180 nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bugge, F.; Bege, R.; Blume, G.; Feise, D.; Sumpf, B.; Werner, N.; Zeimer, U.; Paschke, K.; Weyers, M.</p> <p>2018-06-01</p> <p>Highly strained InxGa1-xAs QWs are commonly used for laser diodes in the wavelength range beyond 1100 nm, but they suffer from strain induced formation of defects. The effect of different laser structures and different laser layouts on the aging behavior was investigated. If grown and processed under optimized conditions, laser diodes emitting at 1120 nm, 1156 nm and 1180 nm have lifetimes of several 1000 h up to more than 20,000 h in dependence on structure or indium content. Laser diodes with three different emission wavelength were mounted in a microoptical bench with a second harmonic generation crystal. From these benches laser emission in the green-yellow spectral range with more than 800 mW output power was obtained.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NanoF...2a5001K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NanoF...2a5001K"><span>Emission enhancement, light extraction and carrier dynamics in InGaAs/GaAs nanowire arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kivisaari, Pyry; Chen, Yang; Anttu, Nicklas</p> <p>2018-03-01</p> <p>Nanowires (NWs) have the potential for a wide range of new optoelectronic applications. For example, light-emitting diodes that span over the whole visible spectrum are currently being developed from NWs to overcome the well known green gap problem. However, due to their small size, NW devices exhibit special properties that complicate their analysis, characterization, and further development. In this paper, we develop a full optoelectronic simulation tool for NW array light emitters accounting for carrier transport and wave-optical emission enhancement (EE), and we use the model to simulate InGaAs/GaAs NW array light emitters with different geometries and temperatures. Our results show that NW arrays emit light preferentially to certain angles depending on the NW diameter and temperature, encouraging temperature- and angle-resolved measurements of NW array light emission. On the other hand, based on our results both the EE and light extraction efficiency can easily change by at least a factor of two between room temperature and 77 K, complicating the characterization of NW light emitters if conventional methods are used. Finally, simulations accounting for surface recombination emphasize its major effect on the device performance. For example, a surface recombination velocity of 104 cm s-1 reported earlier for bare InGaAs surfaces results in internal quantum efficiencies less than 30% for small-diameter NWs even at the temperature of 30 K. This highlights that core-shell structures or high-quality passivation techniques are eventually needed to achieve efficient NW-based light emitters.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29178141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29178141"><span>Probing and Manipulating the Interfacial Defects of InGaAs Dual-Layer Metal Oxides at the Atomic Scale.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Xing; Luo, Chen; Hao, Peng; Sun, Tao; Wang, Runsheng; Wang, Chaolun; Hu, Zhigao; Li, Yawei; Zhang, Jian; Bersuker, Gennadi; Sun, Litao; Pey, Kinleong</p> <p>2018-01-01</p> <p>The interface between III-V and metal-oxide-semiconductor materials plays a central role in the operation of high-speed electronic devices, such as transistors and light-emitting diodes. The high-speed property gives the light-emitting diodes a high response speed and low dark current, and they are widely used in communications, infrared remote sensing, optical detection, and other fields. The rational design of high-performance devices requires a detailed understanding of the electronic structure at this interface; however, this understanding remains a challenge, given the complex nature of surface interactions and the dynamic relationship between the morphology evolution and electronic structures. Herein, in situ transmission electron microscopy is used to probe and manipulate the structural and electrical properties of ZrO 2 films on Al 2 O 3 and InGaAs substrate at the atomic scale. Interfacial defects resulting from the spillover of the oxygen-atom conduction-band wavefunctions are resolved. This study unearths the fundamental defect-driven interfacial electric structure of III-V semiconductor materials and paves the way to future high-speed and high-reliability devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8453E..2GJ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8453E..2GJ"><span>Ultra-low noise large-area InGaAs quad photoreceiver with low crosstalk for laser interferometry space antenna</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, Abhay; Datta, Shubhashish; Rue, Jim; Livas, Jeffrey; Silverberg, Robert; Guzman Cervantes, Felipe</p> <p>2012-07-01</p> <p>Quad photoreceivers, namely a 2 x 2 array of p-i-n photodiodes followed by a transimpedance amplifier (TIA) per diode, are required as the front-end photonic sensors in several applications relying on free-space propagation with position and direction sensing capability, such as long baseline interferometry, free-space optical communication, and biomedical imaging. It is desirable to increase the active area of quad photoreceivers (and photodiodes) to enhance the link gain, and therefore sensitivity, of the system. However, the resulting increase in the photodiode capacitance reduces the photoreceiver's bandwidth and adds to the excess system noise. As a result, the noise performance of the front-end quad photoreceiver has a direct impact on the sensitivity of the overall system. One such particularly challenging application is the space-based detection of gravitational waves by measuring distance at 1064 nm wavelength with ~ 10 pm/√Hz accuracy over a baseline of millions of kilometers. We present a 1 mm diameter quad photoreceiver having an equivalent input current noise density of < 1.7 pA/√Hz per quadrant in 2 MHz to 20 MHz frequency range. This performance is primarily enabled by a rad-hard-by-design dualdepletion region InGaAs quad photodiode having 2.5 pF capacitance per quadrant. Moreover, the quad photoreceiver demonstrates a crosstalk of < -45 dB between the neighboring quadrants, which ensures an uncorrected direction sensing resolution of < 50 nrad. The sources of this primarily capacitive crosstalk are presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017InPhT..85...74Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017InPhT..85...74Y"><span>Noise characteristics analysis of short wave infrared InGaAs focal plane arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Chunlei; Li, Xue; Yang, Bo; Huang, Songlei; Shao, Xiumei; Zhang, Yaguang; Gong, Haimei</p> <p>2017-09-01</p> <p>The increasing application of InGaAs short wave infrared (SWIR) focal plane arrays (FPAs) in low light level imaging requires ultra-low noise FPAs. This paper presents the theoretical analysis of FPA noise, and point out that both dark current and detector capacitance strongly affect the FPA noise. The impact of dark current and detector capacitance on FPA noise is compared in different situations. In order to obtain low noise performance FPAs, the demand for reducing detector capacitance is higher especially when pixel pitch is smaller, integration time is shorter, and integration capacitance is larger. Several InGaAs FPAs were measured and analyzed, the experiments' results could be well fitted to the calculated results. The study found that the major contributor of FPA noise is coupled noise with shorter integration time. The influence of detector capacitance on FPA noise is more significant than that of dark current. To investigate the effect of detector performance on FPA noise, two kinds of photodiodes with different concentration of the absorption layer were fabricated. The detectors' performance and noise characteristics were measured and analyzed, the results are consistent with that of theoretical analysis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870014527','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870014527"><span>Means for phase locking the outputs of a surface emitting laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lesh, James R. (Inventor)</p> <p>1987-01-01</p> <p>An array of diode lasers, either a two-dimensional array of surface emitting lasers, or a linear array of stripe lasers, is phase locked by a diode laser through a hologram which focuses the output of the diode laser into a set of distinct, spatially separated beams, each one focused onto the back facet of a separate diode laser of the array. The outputs of the diode lasers thus form an emitted coherent beam out of the front of the array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018LaPhL..15d5807T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018LaPhL..15d5807T"><span>Passively mode-locked diode-pumped Tm3+:YLF laser emitting at 1.91 µm using a GaAs-based SESAM</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tyazhev, A.; Soulard, R.; Godin, T.; Paris, M.; Brasse, G.; Doualan, J.-L.; Braud, A.; Moncorgé, R.; Laroche, M.; Camy, P.; Hideur, A.</p> <p>2018-04-01</p> <p>We report on a diode-pumped Tm:YLF laser passively mode-locked with an InGaAs saturable absorber. The laser emits a train of 31 ps pulses at a wavelength of 1.91 µm with a repetition rate of 94 MHz and a maximum average power of 95 mW. A sustained and robust mode-locking with a signal-to-noise ratio of ~70 dB is obtained even at high relative air humidity, making this system attractive for applications requiring ultra-short pulses in the spectral window just below 2 µm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/104975','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/104975"><span>Update on diode-pumped solid-state laser experiments for inertial fusion energy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Marshall, C.; Smith, L.; Payne, S.</p> <p></p> <p>The authors have completed the initial phase of the diode-pumped solid-state laser (DPSSL) experimental program to validate the expected pumping dynamics and extraction cross-sections of Yb{sup 3+}-doped Sr{sub 5}(PO{sub 4}){sub 3}F (Yb:S-FAP) crystals. Yb:S-FAP crystals up to 25 x 25 x 175 mm in size have been grown for this purpose which have acceptable loss characteristics (<1 %/cm) and laser damage thresholds ({approximately}20 J/cm{sup 2}). The saturation fluence for pumping has been measured to be 2.2 J/cm{sup 2} using three different methods based on either the spatial, temporal, or energy transmission properties of a Yb:S-FAP rod. The small signal gainmore » under saturated pumping conditions was measured. These measurements imply an emission cross section of 6.0 x 10{sup {minus}20} cm{sup 2} that falls within error bars of the previously reported value of 7.3 x 10{sup {minus}20} cm{sup 2}, obtained from purely spectroscopic techniques. The effects of radiation trapping on the emission lifetime have been quantified. The long lifetime of Yb:S-FAP has beneficial effects for diode-pumped amplifier designs, relative to materials with equivalent cross sections but shorter lifetimes, in that less peak pump intensity is required (thus lower diode costs) and that lower spontaneous emission rates lead to a reduction in amplified spontaneous emission. Consequently, up to 1.7 J/cm{sup 3} of stored energy density was achieved in a 6x6x44 mm Yb:S-FAP amplifier rod; this stored energy density is large relative to typical flashlamp-pumped Nd:glass values of 0.3 to 0.5 J/cm{sup 3}. A 2.4 kW peak power InGaAs diode array has been fabricated by Beach, Emanuel, and co-workers which meets the central wavelength, bandwidth, and energy specifications for the author`s immediate experiments. These results further increase their optimism of being able to produce a {approximately} 10% efficient diode-pumped solid state laser for inertial fusion energy.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011OptEn..50f1011M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011OptEn..50f1011M"><span>Short-wavelength infrared imaging using low dark current InGaAs detector arrays and vertical-cavity surface-emitting laser illuminators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Macdougal, Michael; Geske, Jon; Wang, Chad; Follman, David</p> <p>2011-06-01</p> <p>We describe the factors that go into the component choices for a short wavelength IR (SWIR) imager, which include the SWIR sensor, the lens, and the illuminator. We have shown the factors for reducing dark current, and shown that we can achieve well below 1.5 nA/cm2 for 15 μm devices at 7 °C. In addition, we have mated our InGaAs detector arrays to 640×512 readout integrated integrated circuits to make focal plane arrays (FPAs). The resulting FPAs are capable of imaging photon fluxes with wavelengths between 1 and 1.6 μm at low light levels. The dark current associated with these FPAs is extremely low, exhibiting a mean dark current density of 0.26 nA/cm2 at 0 °C. Noise due to the readout can be reduced from 95 to 57 electrons by using off-chip correlated double sampling. In addition, Aerius has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide low-speckle illumination, and provide artifact-free imagery versus conventional laser illuminators.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8907E..3TM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8907E..3TM"><span>Vacuum packaging of InGaAs focal plane array with four-stage thermoelectric cooler</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mo, De-feng; Liu, Da-fu; Yang, Li-yi; Xu, Qin-fei; Li, Xue</p> <p>2013-09-01</p> <p>The InGaAs focal plane array (FPA) detectors, covering the near-infrared 1~2.4 μm wavelength range, have been developed for application in space-based spectroscopy of the Earth atmosphere. This paper shows an all-metal vacuum package design for area array InGaAs detector of 1024×64 pixels, and its architecture will be given. Four-stage thermoelectric cooler (TEC) is used to cool down the FPA chip. To acquire high heat dissipation for TEC's Joule-heat, tungsten copper (CuW80) and kovar (4J29) is used as motherboard and cavity material respectively which joined by brazing. The heat loss including conduction, convection and radiation is analyzed. Finite element model is established to analyze the temperature uniformity of the chip substrate which is made of aluminum nitride (AlN). The performance of The TEC with and without heat load in vacuum condition is tested. The results show that the heat load has little influence to current-voltage relationship of TEC. The temperature difference (ΔT) increases as the input current increases. A linear relationship exists between heat load and ΔT of the TEC. Theoretical analysis and calculation show that the heat loss of radiation and conduction is about 187 mW and 82 mW respectively. Considering the Joule-heat of readout circuit and the heat loss of radiation and conduction, the FPA for a 220 K operation at room temperature can be achieved. As the thickness of AlN chip substrate is thicker than 1 millimeter, the temperature difference can be less than 0.3 K.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptEn..56c1224W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptEn..56c1224W"><span>Optimization of eyesafe avalanche photodiode lidar for automobile safety and autonomous navigation systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, George M.</p> <p>2017-03-01</p> <p>Newly emerging accident-reducing, driver-assistance, and autonomous-navigation technology for automobiles is based on real-time three-dimensional mapping and object detection, tracking, and classification using lidar sensors. Yet, the lack of lidar sensors suitable for meeting application requirements appreciably limits practical widespread use of lidar in trucking, public livery, consumer cars, and fleet automobiles. To address this need, a system-engineering perspective to eyesafe lidar-system design for high-level advanced driver-assistance sensor systems and a design trade study including 1.5-μm spot-scanned, line-scanned, and flash-lidar systems are presented. A cost-effective lidar instrument design is then proposed based on high-repetition-rate diode-pumped solid-state lasers and high-gain, low-excess-noise InGaAs avalanche photodiode receivers and focal plane arrays. Using probabilistic receiver-operating-characteristic analysis, derived from measured component performance, a compact lidar system is proposed that is capable of 220 m ranging with 5-cm accuracy, which can be readily scaled to a 360-deg field of regard.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......581S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......581S"><span>Multi-Quantum Well Structures to Improve the Performance of Multijunction Solar Cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Samberg, Joshua Paul</p> <p></p> <p>Current, lattice matched triple junction solar cell efficiency is approximately 44% at a solar concentration of 942x. Higher efficiency for such cells can be realized with the development of a 1eV bandgap material lattice matched to Ge. One of the more promising materials for this application is that of the InGaAs/GaAsP multi-quantum well (MQW) structure. By inserting a stress/strain-balanced InGaAs/GaAsP MQW structure into the iregion of a GaAs p-i-n diode, the absorption edge of the p-i-n diode can be red shifted with respect to that of a standard GaAs p-n diode. Compressive stress in the InGaAs wells are balanced via GaAsP barriers subjected to tensile stress. Individually, the InGaAs and GaAsP layers are grown below their critical layer thickness to prevent the formation of misfit and threading dislocations. Until recently InGaAs/GaAsP MQWs have been somewhat hindered by their usage of low phosphorus-GaAsP barriers. Presented within is the development of a high-P composition GaAsP and the merits for using such a high composition of phosphorus are discussed. It is believed that these barriers represent the highest phosphorus content to date in such a structure. By using high composition GaAsP the carriers are collected via tunneling (for barriers .30A) as opposed to thermionic emission. Thus, by utilizing thin, high content GaAsP barriers one can increase the percentage of the intrinsic region in a p-i-n structure that is comprised of the InGaAs well in addition to increasing the number of periods that can be grown for a given depletion width. However, standard MQWs of this type inherently possess undesirable compressive strain and quantum size effects (QSE) that cause the optical absorption of the InGaAs wells to blue shift. To circumvent these deleterious QSEs stress balanced, pseudomorphic InGaAs/GaAsP staggered MQWs were developed. Tunneling is still a viable mode for carrier transport in the staggered MQW structures. GaAs interfacial layers within the multi-quantum well have been found to be critical in producing quality multi-quantum well structures. The effect of the GaAs interfacial layers has been investigated. It was determined that a phosphorus carry-over had a profound effect on the absorption edge of the InGaAs wells. It was shown that the phosphorus carry-over can be prevented with sufficiently thick GaAs transition layers. Preliminary results for GaAs p-in solar cells utilizing the improved MQWs are presented. In addition to investigating the utilization of quantum wells in the i-region of a GaAs p-i-n diode to improve the efficiency of multijunction solar cells, an investigation into the effect a single GaAs:Te doped quantum well has on the performance of high bandgap InxGa1- xP:Te/Al0.6Ga 0.4As:C tunnel junctions was investigated. The insertion of 30A of GaAs:Te at the junction interface resulted in a peak current of 1000A/cm2 and a voltage drop of ~3mV for 30A/cm2 (2000x concentration). The presence of this GaAs interfacial layer also improved the uniformity across the wafer. This architecture could be used within multijunction solar cells to extend the range of usable solar concentration with minimal voltage drop.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1079218','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1079218"><span>Near-infrared photodetector with reduced dark current</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Klem, John F; Kim, Jin K</p> <p>2012-10-30</p> <p>A photodetector is disclosed for the detection of near-infrared light with a wavelength in the range of about 0.9-1.7 microns. The photodetector, which can be formed as either an nBp device or a pBn device on an InP substrate, includes an InGaAs light-absorbing layer, an InAlGaAs graded layer, an InAlAs or InP barrier layer, and an InGaAs contact layer. The photodetector can detect near-infrared light with or without the use of an applied reverse-bias voltage and is useful as an individual photodetector, or to form a focal plane array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25280080','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25280080"><span>Axial diffusion barriers in near-infrared nanopillar LEDs.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scofield, Adam C; Lin, Andrew; Haddad, Michael; Huffaker, Diana L</p> <p>2014-11-12</p> <p>The growth of GaAs/GaAsP axial heterostructures is demonstrated and implemented as diffusion current barriers in nanopillar light-emitting diodes at near-infrared wavelengths. The nanopillar light-emitting diodes utilize an n-GaAs/i-InGaAs/p-GaAs axial heterostructure for current injection. Axial GaAsP segments are inserted into the n- and p-GaAs portions of the nanopillars surrounding the InGaAs emitter region, acting as diffusion barriers to provide enhanced carrier confinement. Detailed characterization of growth of the GaAsP inserts and electronic band-offset measurements are used to effectively implement the GaAsP inserts as diffusion barriers. The implementation of these barriers in nanopillar light-emitting diodes provides a 5-fold increase in output intensity, making this a promising approach to high-efficiency pillar-based emitters in the near-infrared wavelength range.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhDT........48J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhDT........48J"><span>Increasing the critical thickness of InGaAs quantum wells using strain-relief technologies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, Andrew Marquis</p> <p></p> <p>The advantages of optical communication through silica fiber have made long-distance electrical communication through copper wire obsolete. The two windows of operation for long-haul optical communication are centered around the wavelengths of 1.3 mum and 1.55 mum, which have minimal amounts of signal attenuation and dispersion. Benefits of optical communications within these windows include low system costs, high bandwidth, and high system reliability which have encouraged the development of emitters and receivers at these relatively long wavelengths. Long-wavelength semiconductor lasers are typically fabricated on InP substrates, but their performance suffers greatly with increases in operating temperature. Laser diodes on GaAs substrates are not as sensitive to operating temperature due to quantum-well active regions with relative deep potential barriers, but critical thickness limits the wavelength ceiling to 1.1 mum. Strain-relief technologies are currently being investigated to enable long-wavelength lasers with deeper potential wells leading to a corresponding increase in characteristic temperatures. Having a larger lattice constant than GaAs enables ternary InGaAs substrates to increase the 1.1-mum wavelength ceiling. Extending this ceiling to one of the optical communication windows could enable high-characteristic-temperature, long-wavelength lasers. Broad-area and buried-heterostructure lasers have demonstrated the potential of ternary substrates to increase characteristic temperatures and emission wavelengths. Wavelengths as long as 1.15 mum and characteristic temperatures as high as 145 K have been achieved. Reduced-area metalorganic chemical vapor deposition involves the deposition of strained materials on isolated islands. Due to the discontinuous nature of reduced-area epitaxy, strained materials are allowed to expand near the mesa edges, decreasing the overall strain in the structure. Laser diodes using this technology have been successfully fabricated, and evidence for partial relief of strain energy has been obtained. Compliant membranes enable strain relief by depositing on an ultra-thin semiconductor base. Unlike growth on typical thick substrates, expansion of the compliant membrane during strained-layer regrowth allows the membrane to accommodate most of the strain energy. Ternary InGaAs compliant films supported above a GaAs substrate with single AlGaAs pedestals have been utilized to fabricate long-wavelength (1.35 mum) InGaAs quantum wells on a GaAs substrate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8353E..08R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8353E..08R"><span>InGaAs focal plane array developments at III-V Lab</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rouvié, Anne; Reverchon, Jean-Luc; Huet, Odile; Djedidi, Anis; Robo, Jean-Alexandre; Truffer, Jean-Patrick; Bria, Toufiq; Pires, Mauricio; Decobert, Jean; Costard, Eric</p> <p>2012-06-01</p> <p>SWIR detection band benefits from natural (sun, night glow, thermal radiation) or artificial (eye safe lasers) photons sources combined to low atmospheric absorption and specific contrast compared to visible wavelengths. It gives the opportunity to address a large spectrum of applications such as defense and security (night vision, active imaging), space (earth observation), transport (automotive safety) or industry (non destructive process control). InGaAs material appears as a good candidate to satisfy SWIR detection needs. The lattice matching with InP constitutes a double advantage to this material: attractive production capacity and uncooled operation thanks to low dark current level induced by high quality material. For few years, III-VLab has been studying InGaAs imagery, gathering expertise in InGaAs material growth and imaging technology respectively from Alcatel-Lucent and Thales, its two mother companies. This work has lead to put quickly on the market a 320x256 InGaAs module, exhibiting high performances in terms of dark current, uniformity and quantum efficiency. In this paper, we present the last developments achieved in our laboratory, mainly focused on increasing the pixels number to VGA format associated to pixel pitch decrease (15μm) and broadening detection spectrum toward visible wavelengths. Depending on targeted applications, different Read Out Integrated Circuits (ROIC) have been used. Low noise ROIC have been developed by CEA LETI to fit the requirements of low light level imaging whereas logarithmic ROIC designed by NIT allows high dynamic imaging adapted for automotive safety.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9070E..07Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9070E..07Y"><span>Low-dark current 1024×1280 InGaAs PIN arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Ping; Chang, James; Boisvert, Joseph C.; Karam, Nasser</p> <p>2014-06-01</p> <p>Photon counting imaging applications requires low noise from both detector and readout integrated circuit (ROIC) arrays. In order to retain the photon-counting-level sensitivity, a long integration time has to be employed and the dark current has to be minimized. It is well known that the PIN dark current is sensitive to temperature and a dark current density of 0.5 nA/cm2 was demonstrated at 7 °C previously. In order to restrain the size, weight, and power consumption (SWaP) of cameras for persistent large-area surveillance on small platforms, it is critical to develop large format PIN arrays with small pitch and low dark current density at higher operation temperatures. Recently Spectrolab has grown, fabricated and tested 1024x1280 InGaAs PIN arrays with 12.5 μm pitch and achieved 0.7 nA/cm2 dark current density at 15 °C. Based on our previous low-dark-current PIN designs, the improvements were focused on 1) the epitaxial material design and growth control; and 2) PIN device structure to minimize the perimeter leakage current and junction diffusion current. We will present characterization data and analyses that illustrate the contribution of various dark current mechanisms.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991ElL....27..437O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991ElL....27..437O"><span>Matrix addressable vertical cavity surface emitting laser array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Orenstein, M.; von Lehmen, A. C.; Chang-Hasnain, C.; Stoffel, N. G.; Harbison, J. P.</p> <p>1991-02-01</p> <p>The design, fabrication and characterization of 1024-element matrix-addressable vertical-cavity surface-emitting laser (VCSEL) arrays are described. A strained InGaAs quantum-well VCSEL structure was grown by MBE, and an array of 32 x 32 lasers was defined using a proton implantation process. A matrix addressing architecture was employed, which enables the individual addressing of each of the 1024 lasers using only 64 electrical contacts. All the lasers in the array, measured after the laser definition step, were operating with fairly homogeneous characteristics; threshold current of 6.8 mA and output quantum differential efficiency of about 8 percent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA248645','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA248645"><span>Noncontact Characterization of PV Detector Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1990-06-01</p> <p>11-7 3 III DIODE ARRAY AS A SAW CONVOLVER/STORAGE CORRELATOR .... III-1 III.A NONLINEAR ( VARACTOR ) ACTION OF THE DIODES .......................... I...associated with the diodes in the detector array. The varactor action of the diodes produces a voltage across the diodes which is pro- portional to the...type of interactions desired herein. An alternative approach is to em- ploy thin dielectric overlays, such as zinc oxide or silicon nitride</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080014104','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080014104"><span>Reliability of High Power Laser Diode Arrays Operating in Long Pulse Mode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron L.; Barnes, Bruce W.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.; Baker, Nathaniel R.</p> <p>2006-01-01</p> <p>Reliability and lifetime of quasi-CW laser diode arrays are greatly influenced by their thermal characteristics. This paper examines the thermal properties of laser diode arrays operating in long pulse duration regime.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/868246','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/868246"><span>Thin planar package for cooling an array of edge-emitting laser diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Mundinger, David C.; Benett, William J.</p> <p>1992-01-01</p> <p>A laser diode array is disclosed that includes a plurality of planar assemblies and active cooling of each assembly. The laser diode array may be operated in a long duty cycle, or in continuous operation. A laser diode bar and a microchannel heat sink are thermally coupled in a compact, thin planar assembly having the laser diode bar located proximate to one edge. In an array, a number of such thin planar assemblies are secured together in a stacked configuration, in close proximity so that the laser diodes are spaced closely. The cooling means includes a microchannel heat sink proximate to the laser diode bar to absorb heat generated by laser operation. To provide the coolant to the microchannels, each thin planar assembly comprises passageways that connect the microchannels to inlet and outlet corridors. Each inlet passageway may comprise a narrow slot that directs coolant into the microchannels and increases the velocity of flow therethrough. The corridors comprises holes extending through each of the assemblies in the array. The inlet and outlet corridors are connected to a conventional coolant circulation system. The laser diode array with active cooling has applications as an optical pump for high power solid state lasers, or by mating the diodes with fiber optic lenses. Further, the arrays can be useful in applications having space constraints and energy limitations, and in military and space applications. The arrays can be incorporated in equipment such as communications devices and active sensors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20180000061','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20180000061"><span>Qualification of Laser Diode Arrays for Mercury Laser Altimeter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stephen, Mark; Vasilyev, Aleksey; Schafer, John; Allan, Graham R.</p> <p>2004-01-01</p> <p>NASA's requirements for high reliability, high performance satellite laser instruments have driven the investigation of many critical components; specifically, 808 nm laser diode array (LDA) pump devices. Performance of Quasi-CW, High-power, laser diode arrays under extended use is presented. We report the optical power over several hundred million pulse operation and the effect of power cycling and temperature cycling of the laser diode arrays. Data on the initial characterization of the devices is also presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA173617','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA173617"><span>Effects of 30 Mev Electron Irradiation on InGaAsP LEDs (Light Emitting Diodes) and InGaAs Photodiodes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1986-06-01</p> <p>devices in satellites and military combat systems, the reliability of LEDs and photodiodes when exposed to the typical radiation of a space or nuclear ...could be exposed to: nuclear power plants, space environments or a nuclear weapon detonation. When located on the 15 surface of the earth, nuclear power...35,000 miles above the earth’s surface. Additionally, electrons, neutrons and other products from a high altitude detonation of a nuclear weapon can</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA158013','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA158013"><span>Solid State Research.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1984-11-15</p> <p>Coupling to Surface Plasma Waves 20 2.3 Theory of the Effect of Traps on the Spectral Charac- teristics of Diode Lasers 23 3 . MATERIALS RESEARCH 27...Page 1-1(a) Schematic Cross Section of InGaAs PSIN Structure. Gap Spac- ing (d) Is 3 , 5, 10, or 20 pm. 2 1-1(b) Curve Tracer I-V Characteristics of a...20-pim PSIN Device in Dark and Under Illumination 2 1-2 Pulse Response of a 3 -#Am PSIN Device, Under Forward and Reverse Bias. to a Comb-Generator</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA593758','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA593758"><span>Semi-insulating GaN Substrates for High-frequency Device Fabrication</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2008-06-18</p> <p>of the undoped and iron-doped samples were probed by X-ray diffraction (XRD) measurements using a Philips X’pert MRD triple axis diffracted beam system...diode laser. The light emitted by the samples was dispersed by a Princeton/Acton Trivista 557 triple spectrometer fit with an LN2 cool OMA V InGaAs... point out that the relative intensity of all these bands decreases with increasing of the iron doping. This observation is consistent with the change in</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26219013','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26219013"><span>Robotic radiosurgery system patient-specific QA for extracranial treatments using the planar ion chamber array and the cylindrical diode array.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Mu-Han; Veltchev, Iavor; Koren, Sion; Ma, Charlie; Li, Jinsgeng</p> <p>2015-07-08</p> <p>Robotic radiosurgery system has been increasingly employed for extracranial treatments. This work is aimed to study the feasibility of a cylindrical diode array and a planar ion chamber array for patient-specific QA with this robotic radiosurgery system and compare their performance. Fiducial markers were implanted in both systems to enable image-based setup. An in-house program was developed to postprocess the movie file of the measurements and apply the beam-by-beam angular corrections for both systems. The impact of noncoplanar delivery was then assessed by evaluating the angles created by the incident beams with respect to the two detector arrangements and cross-comparing the planned dose distribution to the measured ones with/without the angular corrections. The sensitivity of detecting the translational (1-3 mm) and the rotational (1°-3°) delivery errors were also evaluated for both systems. Six extracranial patient plans (PTV 7-137 cm³) were measured with these two systems and compared with the calculated doses. The plan dose distributions were calculated with ray-tracing and the Monte Carlo (MC) method, respectively. With 0.8 by 0.8 mm² diodes, the output factors measured with the cylindrical diode array agree better with the commissioning data. The maximum angular correction for a given beam is 8.2% for the planar ion chamber array and 2.4% for the cylindrical diode array. The two systems demonstrate a comparable sensitivity of detecting the translational targeting errors, while the cylindrical diode array is more sensitive to the rotational targeting error. The MC method is necessary for dose calculations in the cylindrical diode array phantom because the ray-tracing algorithm fails to handle the high-Z diodes and the acrylic phantom. For all the patient plans, the cylindrical diode array/ planar ion chamber array demonstrate 100% / > 92% (3%/3 mm) and > 96% / ~ 80% (2%/2 mm) passing rates. The feasibility of using both systems for robotic radiosurgery system patient-specific QA has been demonstrated. For gamma evaluation, 2%/2 mm criteria for cylindrical diode array and 3%/3 mm criteria for planar ion chamber array are suggested. The customized angular correction is necessary as proven by the improved passing rate, especially with the planar ion chamber array system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050244823','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050244823"><span>Characterization of High-power Quasi-cw Laser Diode Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stephen, Mark A.; Vasilyev, Aleksey; Troupaki, Elisavet; Allan, Graham R.; Kashem, Nasir B.</p> <p>2005-01-01</p> <p>NASA s requirements for high reliability, high performance satellite laser instruments have driven the investigation of many critical components; specifically, 808 nm laser diode array (LDA) pump devices. Performance and comprehensive characterization data of Quasi-CW, High-power, laser diode arrays is presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050223559','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050223559"><span>Improving Reliability of High Power Quasi-CW Laser Diode Arrays for Pumping Solid State Lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Baggott, Renee S.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.</p> <p>2005-01-01</p> <p>Most Lidar applications rely on moderate to high power solid state lasers to generate the required transmitted pulses. However, the reliability of solid state lasers, which can operate autonomously over long periods, is constrained by their laser diode pump arrays. Thermal cycling of the active regions is considered the primary reason for rapid degradation of the quasi-CW high power laser diode arrays, and the excessive temperature rise is the leading suspect in premature failure. The thermal issues of laser diode arrays are even more drastic for 2-micron solid state lasers which require considerably longer pump pulses compared to the more commonly used pump arrays for 1-micron lasers. This paper describes several advanced packaging techniques being employed for more efficient heat removal from the active regions of the laser diode bars. Experimental results for several high power laser diode array devices will be reported and their performance when operated at long pulsewidths of about 1msec will be described.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1082127','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1082127"><span>V-shaped resonators for addition of broad-area laser diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Liu, Bo; Liu, Yun; Braiman, Yehuda Y.</p> <p>2012-12-25</p> <p>A system and method for addition of broad-area semiconductor laser diode arrays are described. The system can include an array of laser diodes, a V-shaped external cavity, and grating systems to provide feedback for phase-locking of the laser diode array. A V-shaped mirror used to couple the laser diode emissions along two optical paths can be a V-shaped prism mirror, a V-shaped stepped mirror or include multiple V-shaped micro-mirrors. The V-shaped external cavity can be a ring cavity. The system can include an external injection laser to further improve coherence and phase-locking.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1228728','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1228728"><span>Stacked, Filtered Multi-Channel X-Ray Diode Array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>MacNeil, Lawrence P.; Dutra, Eric C.; Raphaelian, Mark</p> <p>2015-08-01</p> <p>This system meets the need for a low-cost, robust X-ray diode array to use for experiments in hostile environments on multiple platforms, and for experiments utilizing forces that may destroy the diode(s). Since these uses require a small size with a minimal single line-of-sight, a parallel array often cannot be used. So a stacked, filtered multi-channel X-ray diode array was developed that was called the MiniXRD. The design was modeled, built, and tested at National Security Technologies, LLC (NSTec) Livermore Operations (LO) to determine fundamental characteristics. Then, several different systems were fielded as ancillary “ridealong” diagnostics at several national facilitiesmore » to allow us to iteratively improve the design and usability. Presented here are design considerations and experimental results. This filtered diode array is currently at Technical Readiness Level (TRL) 6.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4407673','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4407673"><span>Multispectral measurement of contrast in tissue-mimicking phantoms in near-infrared spectral range of 650 to 1600 nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Salo, Daniel; Zhang, Hairong; Kim, David M.; Berezin, Mikhail Y.</p> <p>2014-01-01</p> <p>Abstract. In order to identify the optimal imaging conditions for the highest spatial contrast in biological tissue, we explored the properties of a tissue-mimicking phantom as a function of the wavelengths in a broad range of near-infrared spectra (650 to 1600 nm). Our customized multispectral hardware, which featured a scanning transmission microscope and imaging spectrographs equipped with silicon and InGaAs charge-coupled diode array detectors, allowed for direct comparison of the Michelson contrast obtained from a phantom composed of a honeycomb grid, Intralipid, and India ink. The measured contrast depended on the size of the grid, luminance, and the wavelength of measurements. We demonstrated that at low thickness of the phantom, a reasonable contrast of the objects can be achieved at any wavelength between 700 and 1400 nm and between 1500 and 1600 nm. At larger thicknesses, such contrast can be achieved mostly between 1200 and 1350 nm. These results suggest that distinguishing biological features in deep tissue and developing contrast agents for in vivo may benefit from imaging in this spectral range. PMID:25104414</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1174579','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1174579"><span>Ruggedized microchannel-cooled laser diode array with self-aligned microlens</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Freitas, Barry L.; Skidmore, Jay A.</p> <p>2003-11-11</p> <p>A microchannel-cooled, optically corrected, laser diode array is fabricated by mounting laser diode bars onto Si surfaces. This approach allows for the highest thermal impedance, in a ruggedized, low-cost assembly that includes passive microlens attachment without the need for lens frames. The microlensed laser diode array is usable in all solid-state laser systems that require efficient, directional, narrow bandwidth, high optical power density pump sources.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160008885','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160008885"><span>By-Pass Diode Temperature Tests of a Solar Array Coupon under Space Thermal Environment Conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon</p> <p>2016-01-01</p> <p>By-Pass diodes are a key design feature of solar arrays and system design must be robust against local heating, especially with implementation of larger solar cells. By-Pass diode testing was performed to aid thermal model development for use in future array designs that utilize larger cell sizes that result in higher string currents. Testing was performed on a 56-cell Advanced Triple Junction solar array coupon provided by SSL. Test conditions were vacuum with cold array backside using discrete by-pass diode current steps of 0.25 A ranging from 0 A to 2.0 A.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JaJAP..57f4101F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JaJAP..57f4101F"><span>InGaAs-based planar barrier diode as microwave rectifier</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farhani Zakaria, Nor; Rizal Kasjoo, Shahrir; Zailan, Zarimawaty; Mohamad Isa, Muammar; Arshad, Mohd Khairuddin Md; Taking, Sanna</p> <p>2018-06-01</p> <p>In this report, we proposed and simulated a new planar nonlinear rectifying device fabricated using InGaAs substrate and referred to as a planar barrier diode (PBD). Using an asymmetrical inverse-arrowhead-shaped structure between the electrodes, a nonuniform depletion region is developed, which creates a triangular energy barrier in the conducting channel. This barrier is voltage dependent and can be controlled by the applied voltage across the PBD, thus resulting in nonlinear diode-like current–voltage characteristics; thus it can be used as a rectifying device. The PBD’s working principle is explained using thermionic emission theory. Furthermore, by varying the PBD’s geometric design, the asymmetry of the current–voltage characteristics can be optimized to realize superior rectification performance. By employing the optimized structural parameters, the obtained cut-off frequency of the device was approximately 270 GHz with a curvature coefficient peak of 14 V‑1 at a low DC bias voltage of 50 mV.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930018588','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930018588"><span>Planar doped barrier subharmonic mixers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lee, T. H.; East, J. R.; Haddad, G. I.</p> <p>1992-01-01</p> <p>The Planar Doped Barrier (PDB) diode is a device consisting of a p(+) doping spike between two intrinsic layers and n(+) ohmic contacts. This device has the advantages of controllable barrier height, diode capacitance and forward to reverse current ratio. A symmetrically designed PDB has an anti-symmetric current vs. voltage characteristic and is ideal for use as millimeter wave subharmonic mixers. We have fabricated such devices with barrier heights of 0.3, 0.5 and 0.7 volts from GaAs and InGaAs using a multijunction honeycomb structure with junction diameters between one and ten microns. Initial RF measurements are encouraging. The 0.7 volt barrier height 4 micron GaAs devices were tested as subharmonic mixers at 202 GHz with an IF frequency of 1 GHz and had 18 dB of conversion loss. The estimated mismatch loss was 7 dB and was due to higher diode capacitance. The LO frequency was 100.5 GHz and the pump power was 8 mW.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/868245','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/868245"><span>Modular package for cooling a laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Mundinger, David C.; Benett, William J.; Beach, Raymond J.</p> <p>1992-01-01</p> <p>A laser diode array is disclosed that includes a plurality of planar packages and active cooling. The laser diode array may be operated in a long duty cycle, or in continuous operation. A laser diode bar and a microchannel heat sink are thermally coupled in a compact, thin planar package having the laser diode bar located proximate to one edge. In an array, a number of such thin planar packages are secured together in a stacked configuration, in close proximity so that the laser diodes are spaced closely. The cooling means includes a microchannel heat sink that is attached proximate to the laser bar so that it absorbs heat generated by laser operation. To provide the coolant to the microchannels, each thin planar package comprises a thin inlet manifold and a thin outlet manifold connected to an inlet corridor and an outlet corridor. The inlet corridor comprises a hole extending through each of the packages in the array, and the outlet corridor comprises a hole extending through each of the packages in the array. The inlet and outlet corridors are connected to a conventional coolant circulation system. The laser diode array with active cooling has application as an optical pump for high power solid state lasers. Further, it can be incorporated in equipment such as communications devices and active sensors, and in military and space applications, and it can be useful in applications having space constraints and energy limitations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060010005','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060010005"><span>A Novel, Free-Space Optical Interconnect Employing Vertical-Cavity Surface Emitting Laser Diodes and InGaAs Metal-Semiconductor-Metal Photodetectors for Gbit/s RF/Microwave Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Savich, Gregory R.; Simons, Rainee N.</p> <p>2006-01-01</p> <p>Emerging technologies and continuing progress in vertical-cavity surface emitting laser (VCSEL) diode and metal-semiconductor-metal (MSM) photodetector research are making way for novel, high-speed forms of optical data transfer in communication systems. VCSEL diodes operating at 1550 nm have only recently become commercially available, while MSM photodetectors are pushing the limits of contact lithography with interdigitated electrode widths reaching sub micron levels. We propose a novel, free-space optical interconnect operating at about 1Gbit/s utilizing VCSEL diodes and MSM photodetectors. We report on development, progress, and current work, which are as follows: first, analysis of the divergent behavior of VCSEL diodes for coupling to MSM photodetectors with a 50 by 50 m active area and second, the normalized frequency response of the VCSEL diode as a function of the modulating frequency. Third, the calculated response of MSM photodetectors with varying electrode width and spacing on the order of 1 to 3 m as well as the fabrication and characterization of these devices. The work presented here will lead to the formation and characterization of a fully integrated 1Gbit/s free-space optical interconnect at 1550 nm and demonstrates both chip level and board level functionality for RF/microwave digital systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9346E..07Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9346E..07Z"><span>Effect of interface layer on the performance of high power diode laser arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Pu; Wang, Jingwei; Xiong, Lingling; Li, Xiaoning; Hou, Dong; Liu, Xingsheng</p> <p>2015-02-01</p> <p>Packaging is an important part of high power diode laser (HPLD) development and has become one of the key factors affecting the performance of high power diode lasers. In the package structure of HPLD, the interface layer of die bonding has significant effects on the thermal behavior of high power diode laser packages and most degradations and failures in high power diode laser packages are directly related to the interface layer. In this work, the effects of interface layer on the performance of high power diode laser array were studied numerically by modeling and experimentally. Firstly, numerical simulations using finite element method (FEM) were conducted to analyze the effects of voids in the interface layer on the temperature rise in active region of diode laser array. The correlation between junction temperature rise and voids was analyzed. According to the numerical simulation results, it was found that the local temperature rise of active region originated from the voids in the solder layer will lead to wavelength shift of some emitters. Secondly, the effects of solder interface layer on the spectrum properties of high power diode laser array were studied. It showed that the spectrum shape of diode laser array appeared "right shoulder" or "multi-peaks", which were related to the voids in the solder interface layer. Finally, "void-free" techniques were developed to minimize the voids in the solder interface layer and achieve high power diode lasers with better optical-electrical performances.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070031769','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070031769"><span>Qualification Testing of Laser Diode Pump Arrays for a Space-Based 2-micron Coherent Doppler Lidar</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Singh, Upendra N.; Kavaya, Michael J.</p> <p>2007-01-01</p> <p>The 2-micron thulium and holmium-based lasers being considered as the transmitter source for space-based coherent Doppler lidar require high power laser diode pump arrays operating in a long pulse regime of about 1 msec. Operating laser diode arrays over such long pulses drastically impact their useful lifetime due to the excessive localized heating and substantial pulse-to-pulse thermal cycling of their active regions. This paper describes the long pulse performance of laser diode arrays and their critical thermal characteristics. A viable approach is then offered that allows for determining the optimum operational parameters leading to the maximum attainable lifetime.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110016065&hterms=FBG&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFBG','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110016065&hterms=FBG&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFBG"><span>High-Reliability Pump Module for Non-Planar Ring Oscillator Laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liu, Duncan T.; Qiu, Yueming; Wilson, Daniel W.; Dubovitsky, Serge; Forouhar, Siamak</p> <p>2007-01-01</p> <p>We propose and have demonstrated a prototype high-reliability pump module for pumping a Non-Planar Ring Oscillator (NPRO) laser suitable for space missions. The pump module consists of multiple fiber-coupled single-mode laser diodes and a fiber array micro-lens array based fiber combiner. The reported Single-Mode laser diode combiner laser pump module (LPM) provides a higher normalized brightness at the combined beam than multimode laser diode based LPMs. A higher brightness from the pump source is essential for efficient NPRO laser pumping and leads to higher reliability because higher efficiency requires a lower operating power for the laser diodes, which in turn increases the reliability and lifetime of the laser diodes. Single-mode laser diodes with Fiber Bragg Grating (FBG) stabilized wavelength permit the pump module to be operated without a thermal electric cooler (TEC) and this further improves the overall reliability of the pump module. The single-mode laser diode LPM is scalable in terms of the number of pump diodes and is capable of combining hundreds of fiber-coupled laser diodes. In the proof-of-concept demonstration, an e-beam written diffractive micro lens array, a custom fiber array, commercial 808nm single mode laser diodes, and a custom NPRO laser head are used. The reliability of the proposed LPM is discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4901317','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4901317"><span>Barrier inhomogeneities limited current and 1/f noise transport in GaN based nanoscale Schottky barrier diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kumar, Ashutosh; Heilmann, M.; Latzel, Michael; Kapoor, Raman; Sharma, Intu; Göbelt, M.; Christiansen, Silke H.; Kumar, Vikram; Singh, Rajendra</p> <p>2016-01-01</p> <p>The electrical behaviour of Schottky barrier diodes realized on vertically standing individual GaN nanorods and array of nanorods is investigated. The Schottky diodes on individual nanorod show highest barrier height in comparison with large area diodes on nanorods array and epitaxial film which is in contrast with previously published work. The discrepancy between the electrical behaviour of nanoscale Schottky diodes and large area diodes is explained using cathodoluminescence measurements, surface potential analysis using Kelvin probe force microscopy and 1ow frequency noise measurements. The noise measurements on large area diodes on nanorods array and epitaxial film suggest the presence of barrier inhomogeneities at the metal/semiconductor interface which deviate the noise spectra from Lorentzian to 1/f type. These barrier inhomogeneities in large area diodes resulted in reduced barrier height whereas due to the limited role of barrier inhomogeneities in individual nanorod based Schottky diode, a higher barrier height is obtained. PMID:27282258</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171490','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171490"><span>Advancement of High Power Quasi-CW Laser Diode Arrays For Space-based Laser Instruments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron L.; Baker, nathaniel R.; Baggott, Renee S.; Singh, Upendra N.; Kavaya, Michael J.</p> <p>2004-01-01</p> <p>Space-based laser and lidar instruments play an important role in NASA s plans for meeting its objectives in both Earth Science and Space Exploration areas. Almost all the lidar instrument concepts being considered by NASA scientist utilize moderate to high power diode-pumped solid state lasers as their transmitter source. Perhaps the most critical component of any solid state laser system is its pump laser diode array which essentially dictates instrument efficiency, reliability and lifetime. For this reason, premature failures and rapid degradation of high power laser diode arrays that have been experienced by laser system designers are of major concern to NASA. This work addresses these reliability and lifetime issues by attempting to eliminate the causes of failures and developing methods for screening laser diode arrays and qualifying them for operation in space.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24176930','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24176930"><span>Flexible and twistable non-volatile memory cell array with all-organic one diode-one resistor architecture.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ji, Yongsung; Zeigler, David F; Lee, Dong Su; Choi, Hyejung; Jen, Alex K-Y; Ko, Heung Cho; Kim, Tae-Wook</p> <p>2013-01-01</p> <p>Flexible organic memory devices are one of the integral components for future flexible organic electronics. However, high-density all-organic memory cell arrays on malleable substrates without cross-talk have not been demonstrated because of difficulties in their fabrication and relatively poor performances to date. Here we demonstrate the first flexible all-organic 64-bit memory cell array possessing one diode-one resistor architectures. Our all-organic one diode-one resistor cell exhibits excellent rewritable switching characteristics, even during and after harsh physical stresses. The write-read-erase-read output sequence of the cells perfectly correspond to the external pulse signal regardless of substrate deformation. The one diode-one resistor cell array is clearly addressed at the specified cells and encoded letters based on the standard ASCII character code. Our study on integrated organic memory cell arrays suggests that the all-organic one diode-one resistor cell architecture is suitable for high-density flexible organic memory applications in the future.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA267715','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA267715"><span>Development of Ultra-Low Noise, High Performance III-V Quantum Well Infrared Photodetectors (QWIPs) for Focal Plane Array Staring Image Sensor Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1993-08-01</p> <p>Development of Ultra-Low Noise , High Performance III-V Quantum Well Infrared Photodetectors ( QWIPs ) for Focal Plane Array Staring Image Sensor Systems...using a 2-D square mesh grating coupler to achieve maximum responsivity for an InGaAs SBTM QWIP , and (iv) performed noise characterization on four...different types of Ir-V QWIPs and identified their noise sources. Detailed results and accomplishments are discussed in this report. 1 SJ •aTEtcRMrtlS</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22590786-growing-ingaas-quasi-quantum-wires-inside-semi-rhombic-shaped-planar-inp-nanowires-exact-silicon','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22590786-growing-ingaas-quasi-quantum-wires-inside-semi-rhombic-shaped-planar-inp-nanowires-exact-silicon"><span>Growing InGaAs quasi-quantum wires inside semi-rhombic shaped planar InP nanowires on exact (001) silicon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Han, Yu; Li, Qiang; Lau, Kei May, E-mail: eekmlau@ust.hk</p> <p></p> <p>We report InGaAs quasi-quantum wires embedded in planar InP nanowires grown on (001) silicon emitting in the 1550 nm communication band. An array of highly ordered InP nanowire with semi-rhombic cross-section was obtained in pre-defined silicon V-grooves through selective-area hetero-epitaxy. The 8% lattice mismatch between InP and Si was accommodated by an ultra-thin stacking disordered InP/GaAs nucleation layer. X-ray diffraction and transmission electron microscope characterizations suggest excellent crystalline quality of the nanowires. By exploiting the morphological evolution of the InP and a self-limiting growth process in the V-grooves, we grew embedded InGaAs quantum-wells and quasi-quantum-wires with tunable shape and position. Roommore » temperature analysis reveals substantially improved photoluminescence in the quasi-quantum wires as compared to the quantum-well reference, due to the reduced intrusion defects and enhanced quantum confinement. These results show great promise for integration of III-V based long wavelength nanowire lasers on the well-established (001) Si platform.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1250437','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1250437"><span>Method and system for homogenizing diode laser pump arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bayramian, Andrew James</p> <p>2016-05-03</p> <p>An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1107571','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1107571"><span>Method and system for homogenizing diode laser pump arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bayramian, Andy J</p> <p>2013-10-01</p> <p>An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10177E..2KA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10177E..2KA"><span>Array size and area impact on nanorectenna performance properties</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arsoy, Elif Gul; Durmaz, Emre Can; Shafique, Atia; Ozcan, Meric; Gurbuz, Yasar</p> <p>2017-02-01</p> <p>The metal-insulator-metal (MIM) diodes have high speed and compatibility with integrated circuits (IC's) making MIM diodes very attractive to detect and harvest energy for infrared (IR) regime of the electromagnetic spectrum. Due to the fact that small size of the MIM diodes, it is possible to obtain large volume of devices in same unit area. Hence, MIM diodes offer a feasible solution for nanorectennas (nano rectifiying antenna) in IR regime. The aim of this study is to design and develop MIM diodes as array format coupled with antennas for energy harvesting and IR detection. Moreover, varying number of elements which are 4x4, and 40x30 has been fabricated in parallel having 0.040, 0.065 and 0.080 μm2 diode area. For this work we have studied given type of material; Ti-HfO2-Ni, is used for fabricating MIM diodes as a part of rectenna. The effect of the diode array size is investigated. Furthermore, the effect of the array size is also investigated for larger arrays by applying given type of material set; Cr-HfO2-Ni. The fabrication processes in physical vapor deposition (PVD) systems for the MIM diodes resulted in the devices having high non-linearity and responsivity. Also, to achieve uniform and very thin insulator layer atomic layer deposition (ALD) was used. The nonlinearity 1.5 mA/V2 and responsivity 3 A/W are achieved for Ti-HfO2-Ni MIM diodes under low applied bias of 400 mV. The responsivity and nonlinearity of Cr-HfO2-Ni are found to be 5 A/W and 65 μA/V2, respectively. The current level of Cr-HfO2-Ni and Ti-HfO2-Ni is around μA range therefore corresponding resistance values are in 1-10 kΩ range. The comparison of single and 4x4 elements revealed that 4x4 elements have higher current level hence lower resistance value is obtained for 4x4 elements. The array size is 40x30 elements for Cr-HfO2-Ni type of MIM diodes with 40, 65 nm2 diode areas. By increasing the diode area, the current level increases for same size of array. The current level is increased from10 μA to100 μA with increasing the diode area. Therefore resistance decreased in the range of 10 kΩ and nonlinearity is increased from 58 μA/V2 to 65 μA/V2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867716','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867716"><span>Integrated injection-locked semiconductor diode laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hadley, G. Ronald; Hohimer, John P.; Owyoung, Adelbert</p> <p>1991-01-01</p> <p>A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990SPIE.1219..284M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990SPIE.1219..284M"><span>Vertical cavity surface-emitting semiconductor lasers with injection laser pumping</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDaniel, D. L., Jr.; McInerney, J. G.; Raja, M. Y. A.; Schaus, C. F.; Brueck, S. R. J.</p> <p>1990-05-01</p> <p>Continuous-wave GaAs/GaAlAs edge-emitting diode lasers were used to pump GaAs/AlGaAs and InGaAs/AlGaAs vertical cavity surface-emitting lasers (VCSELs) with resonant periodic gain (RPG) at room temperature. Pump threshold as low as 11 mW, output powers as high as 27 mW at 850 nm, and external differential quantum efficiencies of about 70 percent were observed in GaAs/AlGaAs surface -emitters; spectral brightness 22 times that of the pump laser was also observed. Output powers as high as 85 mW at 950 nm and differential quantum efficiencies of up to 58 percent were recorded for the InGaAs surface-emitting laser. This is the highest quasi-CW output power ever reported for any RPG VCSEL, and the first time such a device has been pumped using an injection laser diode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27069647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27069647"><span>InGaAs/InAlAs single photon avalanche diode for 1550 nm photons.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meng, Xiao; Xie, Shiyu; Zhou, Xinxin; Calandri, Niccolò; Sanzaro, Mirko; Tosi, Alberto; Tan, Chee Hing; Ng, Jo Shien</p> <p>2016-03-01</p> <p>A single photon avalanche diode (SPAD) with an InGaAs absorption region, and an InAlAs avalanche region was designed and demonstrated to detect 1550 nm wavelength photons. The characterization included leakage current, dark count rate and single photon detection efficiency as functions of temperature from 210 to 294 K. The SPAD exhibited good temperature stability, with breakdown voltage dependence of approximately 45 mV K(-1). Operating at 210 K and in a gated mode, the SPAD achieved a photon detection probability of 26% at 1550 nm with a dark count rate of 1 × 10(8) Hz. The time response of the SPAD showed decreasing timing jitter (full width at half maximum) with increasing overbias voltage, with 70 ps being the smallest timing jitter measured.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4821258','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4821258"><span>InGaAs/InAlAs single photon avalanche diode for 1550 nm photons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xie, Shiyu; Zhou, Xinxin; Calandri, Niccolò; Sanzaro, Mirko; Tosi, Alberto; Tan, Chee Hing; Ng, Jo Shien</p> <p>2016-01-01</p> <p>A single photon avalanche diode (SPAD) with an InGaAs absorption region, and an InAlAs avalanche region was designed and demonstrated to detect 1550 nm wavelength photons. The characterization included leakage current, dark count rate and single photon detection efficiency as functions of temperature from 210 to 294 K. The SPAD exhibited good temperature stability, with breakdown voltage dependence of approximately 45 mV K−1. Operating at 210 K and in a gated mode, the SPAD achieved a photon detection probability of 26% at 1550 nm with a dark count rate of 1 × 108 Hz. The time response of the SPAD showed decreasing timing jitter (full width at half maximum) with increasing overbias voltage, with 70 ps being the smallest timing jitter measured. PMID:27069647</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3299579','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3299579"><span>Effect of self-assembled InAs islands on the interfacial roughness of optical-switched resonant tunneling diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Embedding a quantum dot [QD] layer between the double barriers of resonant tunneling diode [RTD] is proved to be an effective method to increase the sensitivity of QD-RTD single-photon detector. However, the interfacial flatness of this device would be worsened due to the introduction of quantum dots. In this paper, we demonstrate that the interfacial quality of this device can be optimized through increasing the growth temperature of AlAs up barrier. The glancing incidence X-ray reflectivity and the high-resolution transmission electron microscopy measurements show that the interfacial smoothness has been greatly improved, and the photo-luminescence test indicated that the InAs QDs were maintained at the same time. The smoother interface was attributed to the evaporation of segregated indium atoms at InGaAs surface layer. PACS 73.40.GK, 73.23._b, 73.21.La, 74.62.Dh PMID:22333518</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22333518','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22333518"><span>Effect of self-assembled InAs islands on the interfacial roughness of optical-switched resonant tunneling diode.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tian, Haitao; Wang, Lu; Shi, Zhenwu; Gao, Huaiju; Zhang, Shuhui; Wang, Wenxin; Chen, Hong</p> <p>2012-02-14</p> <p>Embedding a quantum dot [QD] layer between the double barriers of resonant tunneling diode [RTD] is proved to be an effective method to increase the sensitivity of QD-RTD single-photon detector. However, the interfacial flatness of this device would be worsened due to the introduction of quantum dots. In this paper, we demonstrate that the interfacial quality of this device can be optimized through increasing the growth temperature of AlAs up barrier. The glancing incidence X-ray reflectivity and the high-resolution transmission electron microscopy measurements show that the interfacial smoothness has been greatly improved, and the photo-luminescence test indicated that the InAs QDs were maintained at the same time. The smoother interface was attributed to the evaporation of segregated indium atoms at InGaAs surface layer. PACS: 73.40.GK, 73.23._b, 73.21.La, 74.62.Dh.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112l3302K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112l3302K"><span>Air-stable memory array of bistable rectifying diodes based on ferroelectric-semiconductor polymer blends</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Manasvi; Sharifi Dehsari, Hamed; Anwar, Saleem; Asadi, Kamal</p> <p>2018-03-01</p> <p>Organic bistable diodes based on phase-separated blends of ferroelectric and semiconducting polymers have emerged as promising candidates for non-volatile information storage for low-cost solution processable electronics. One of the bottlenecks impeding upscaling is stability and reliable operation of the array in air. Here, we present a memory array fabricated with an air-stable amine-based semiconducting polymer. Memory diode fabrication and full electrical characterizations were carried out in atmospheric conditions (23 °C and 45% relative humidity). The memory diodes showed on/off ratios greater than 100 and further exhibited robust and stable performance upon continuous write-read-erase-read cycles. Moreover, we demonstrate a 4-bit memory array that is free from cross-talk with a shelf-life of several months. Demonstration of the stability and reliable air operation further strengthens the feasibility of the resistance switching in ferroelectric memory diodes for low-cost applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960054097','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960054097"><span>Resonant Tunneling Analog-To-Digital Converter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Broekaert, T. P. E.; Seabaugh, A. C.; Hellums, J.; Taddiken, A.; Tang, H.; Teng, J.; vanderWagt, J. P. A.</p> <p>1995-01-01</p> <p>As sampling rates continue to increase, current analog-to-digital converter (ADC) device technologies will soon reach a practical resolution limit. This limit will most profoundly effect satellite and military systems used, for example, for electronic countermeasures, electronic and signal intelligence, and phased array radar. New device and circuit concepts will be essential for continued progress. We describe a novel, folded architecture ADC which could enable a technological discontinuity in ADC performance. The converter technology is based on the integration of multiple resonant tunneling diodes (RTD) and hetero-junction transistors on an indium phosphide substrate. The RTD consists of a layered semiconductor hetero-structure AlAs/InGaAs/AlAs(2/4/2 nm) clad on either side by heavily doped InGaAs contact layers. Compact quantizers based around the RTD offer a reduction in the number of components and a reduction in the input capacitance Because the component count and capacitance scale with the number of bits N, rather than by 2 (exp n) as in the flash ADC, speed can be significantly increased, A 4-bit 2-GSps quantizer circuit is under development to evaluate the performance potential. Circuit designs for ADC conversion with a resolution of 6-bits at 25GSps may be enabled by the resonant tunneling approach.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20799842','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20799842"><span>Nondestructive assessment of the severity of occlusal caries lesions with near-infrared imaging at 1310 nm.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Chulsung; Lee, Dustin; Darling, Cynthia L; Fried, Daniel</p> <p>2010-01-01</p> <p>The high transparency of dental enamel in the near-infrared (NIR) at 1310 nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study is to determine whether the lesion contrast derived from NIR imaging in both transmission and reflectance can be used to estimate lesion severity. Two NIR imaging detector technologies are investigated: a new Ge-enhanced complementary metal-oxide-semiconductor (CMOS)-based NIR imaging camera, and an InGaAs focal plane array (FPA). Natural occlusal caries lesions are imaged with both cameras at 1310 nm, and the image contrast between sound and carious regions is calculated. After NIR imaging, teeth are sectioned and examined using polarized light microscopy (PLM) and transverse microradiography (TMR) to determine lesion severity. Lesions are then classified into four categories according to lesion severity. Lesion contrast increases significantly with lesion severity for both cameras (p<0.05). The Ge-enhanced CMOS camera equipped with the larger array and smaller pixels yields higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7549E..0KL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7549E..0KL"><span>In vitro near-infrared imaging of occlusal dental caries using a germanium-enhanced CMOS camera</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Chulsung; Darling, Cynthia L.; Fried, Daniel</p> <p>2010-02-01</p> <p>The high transparency of dental enamel in the near-infrared (NIR) at 1310-nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study was to determine whether the lesion contrast derived from NIR transillumination can be used to estimate lesion severity. Another aim was to compare the performance of a new Ge enhanced complementary metal-oxide-semiconductor (CMOS) based NIR imaging camera with the InGaAs focal plane array (FPA). Extracted human teeth (n=52) with natural occlusal caries were imaged with both cameras at 1310-nm and the image contrast between sound and carious regions was calculated. After NIR imaging, teeth were sectioned and examined using more established methods, namely polarized light microscopy (PLM) and transverse microradiography (TMR) to calculate lesion severity. Lesions were then classified into 4 categories according to the lesion severity. Lesion contrast increased significantly with lesion severity for both cameras (p<0.05). The Ge enhanced CMOS camera equipped with the larger array and smaller pixels yielded higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2929264','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2929264"><span>Nondestructive assessment of the severity of occlusal caries lesions with near-infrared imaging at 1310 nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Chulsung; Lee, Dustin; Darling, Cynthia L.; Fried, Daniel</p> <p>2010-01-01</p> <p>The high transparency of dental enamel in the near-infrared (NIR) at 1310 nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study is to determine whether the lesion contrast derived from NIR imaging in both transmission and reflectance can be used to estimate lesion severity. Two NIR imaging detector technologies are investigated: a new Ge-enhanced complementary metal-oxide-semiconductor (CMOS)-based NIR imaging camera, and an InGaAs focal plane array (FPA). Natural occlusal caries lesions are imaged with both cameras at 1310 nm, and the image contrast between sound and carious regions is calculated. After NIR imaging, teeth are sectioned and examined using polarized light microscopy (PLM) and transverse microradiography (TMR) to determine lesion severity. Lesions are then classified into four categories according to lesion severity. Lesion contrast increases significantly with lesion severity for both cameras (p<0.05). The Ge-enhanced CMOS camera equipped with the larger array and smaller pixels yields higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity. PMID:20799842</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JBO....15d7011L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JBO....15d7011L"><span>Nondestructive assessment of the severity of occlusal caries lesions with near-infrared imaging at 1310 nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Chulsung; Lee, Dustin; Darling, Cynthia L.; Fried, Daniel</p> <p>2010-07-01</p> <p>The high transparency of dental enamel in the near-infrared (NIR) at 1310 nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study is to determine whether the lesion contrast derived from NIR imaging in both transmission and reflectance can be used to estimate lesion severity. Two NIR imaging detector technologies are investigated: a new Ge-enhanced complementary metal-oxide-semiconductor (CMOS)-based NIR imaging camera, and an InGaAs focal plane array (FPA). Natural occlusal caries lesions are imaged with both cameras at 1310 nm, and the image contrast between sound and carious regions is calculated. After NIR imaging, teeth are sectioned and examined using polarized light microscopy (PLM) and transverse microradiography (TMR) to determine lesion severity. Lesions are then classified into four categories according to lesion severity. Lesion contrast increases significantly with lesion severity for both cameras (p<0.05). The Ge-enhanced CMOS camera equipped with the larger array and smaller pixels yields higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22162916','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22162916"><span>In vitro near-infrared imaging of occlusal dental caries using germanium enhanced CMOS camera.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Chulsung; Darling, Cynthia L; Fried, Daniel</p> <p>2010-03-01</p> <p>The high transparency of dental enamel in the near-infrared (NIR) at 1310-nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study was to determine whether the lesion contrast derived from NIR transillumination can be used to estimate lesion severity. Another aim was to compare the performance of a new Ge enhanced complementary metal-oxide-semiconductor (CMOS) based NIR imaging camera with the InGaAs focal plane array (FPA). Extracted human teeth (n=52) with natural occlusal caries were imaged with both cameras at 1310-nm and the image contrast between sound and carious regions was calculated. After NIR imaging, teeth were sectioned and examined using more established methods, namely polarized light microscopy (PLM) and transverse microradiography (TMR) to calculate lesion severity. Lesions were then classified into 4 categories according to the lesion severity. Lesion contrast increased significantly with lesion severity for both cameras (p<0.05). The Ge enhanced CMOS camera equipped with the larger array and smaller pixels yielded higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/495669','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/495669"><span>High-power laser diodes at various wavelengths</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Emanuel, M.A.</p> <p></p> <p>High power laser diodes at various wavelengths are described. First, performance and reliability of an optimized large transverse mode diode structure at 808 and 941 nm are presented. Next, data are presented on a 9.5 kW peak power array at 900 nm having a narrow emission bandwidth suitable for pumping Yb:S-FAP laser materials. Finally, results on a fiber-coupled laser diode array at {approx}730 nm are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8381E..1RW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8381E..1RW"><span>Large-area high-power VCSEL pump arrays optimized for high-energy lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chad; Geske, Jonathan; Garrett, Henry; Cardellino, Terri; Talantov, Fedor; Berdin, Glen; Millenheft, David; Renner, Daniel; Klemer, Daniel</p> <p>2012-06-01</p> <p>Practical, large-area, high-power diode pumps for one micron (Nd, Yb) as well as eye-safer wavelengths (Er, Tm, Ho) are critical to the success of any high energy diode pumped solid state laser. Diode efficiency, brightness, availability and cost will determine how realizable a fielded high energy diode pumped solid state laser will be. 2-D Vertical-Cavity Surface-Emitting Laser (VCSEL) arrays are uniquely positioned to meet these requirements because of their unique properties, such as low divergence circular output beams, reduced wavelength drift with temperature, scalability to large 2-D arrays through low-cost and high-volume semiconductor photolithographic processes, high reliability, no catastrophic optical damage failure, and radiation and vacuum operation tolerance. Data will be presented on the status of FLIR-EOC's VCSEL pump arrays. Analysis of the key aspects of electrical, thermal and mechanical design that are critical to the design of a VCSEL pump array to achieve high power efficient array performance will be presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990PhDT........50H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990PhDT........50H"><span>Study of phase-locked diode laser array and DFB/DBR surface emitting laser diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsin, Wei</p> <p></p> <p>New types of phased-array and surface-emitting lasers are designed. The importance and approaches (or structures) of different phased array and surface emitting laser diodes are reviewed. The following are described: (1) a large optical cavity channel substrate planar laser array with layer thickness chirping; (2) a vertical cavity surface emitter with distributed feedback (DFB) optical cavity and a transverse junction buried heterostructure; (3) a microcavity distributed Bragg reflector (DBR) surface emitter; and (4) two surface emitting laser structures which utilized lateral current injection schemes to overcome the problems occurring in the vertical injection scheme.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7275159','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/7275159"><span>Integrated injection-locked semiconductor diode laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hadley, G.R.; Hohimer, J.P.; Owyoung, A.</p> <p>1991-02-19</p> <p>A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet. 18 figures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987OptL...12...30S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987OptL...12...30S"><span>High-speed electronic beam steering using injection locking of a laser-diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swanson, E. A.; Abbas, G. L.; Yang, S.; Chan, V. W. S.; Fujimoto, J. G.</p> <p>1987-01-01</p> <p>High-speed electronic steering of the output beam of a 10-stripe laser-diode array is reported. The array was injection locked to a single-frequency laser diode. High-speed steering of the locked 0.5-deg-wide far-field lobe is demonstrated either by modulating the injection current of the array or by modulating the frequency of the master laser. Closed-loop tracking bandwidths of 70 kHz and 3 MHz, respectively, were obtained. The beam-steering bandwidths are limited by the FM responses of the modulated devices for both techniques.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900044888&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddiode%2Blaser%2BCW','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900044888&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddiode%2Blaser%2BCW"><span>Environmental testing of a diode-laser-pumped Nd:YAG laser and a set of diode-laser-arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hemmati, H.; Lesh, J. R.</p> <p>1989-01-01</p> <p>Results of the environmental test of a compact, rigid and lightweight diode-laser-pumped Nd:YAG laser module are discussed. All optical elements are bonded onto the module using space applicable epoxy, and two 200 mW diode laser arrays for pump sources are used to achieve 126 mW of CW output with about 7 percent electrical-to-optical conversion efficiency. This laser assembly and a set of 20 semiconductor diode laser arrays were environmentally tested by being subjected to vibrational and thermal conditions similar to those experienced during launch of the Space Shuttle, and both performed well. Nevertheless, some damage to the laser front facet in diode lasers was observed. Significant degradation was observed only on lasers which performed poorly in the life test. Improvements in the reliability of the Nd:YAG laser are suggested.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900051057&hterms=laser+spot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlaser%2Bspot','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900051057&hterms=laser+spot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlaser%2Bspot"><span>Far field beam pattern of one MW combined beam of laser diode array amplifiers for space power transmission</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kwon, Jin H.; Lee, Ja H.</p> <p>1989-01-01</p> <p>The far-field beam pattern and the power-collection efficiency are calculated for a multistage laser-diode-array amplifier consisting of about 200,000 5-W laser diode arrays with random distributions of phase and orientation errors and random diode failures. From the numerical calculation it is found that the far-field beam pattern is little affected by random failures of up to 20 percent of the laser diodes with reference of 80 percent receiving efficiency in the center spot. The random differences in phases among laser diodes due to probable manufacturing errors is allowed to about 0.2 times the wavelength. The maximum allowable orientation error is about 20 percent of the diffraction angle of a single laser diode aperture (about 1 cm). The preliminary results indicate that the amplifier could be used for space beam-power transmission with an efficiency of about 80 percent for a moderate-size (3-m-diameter) receiver placed at a distance of less than 50,000 km.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2547914','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2547914"><span>Versatile IEEE-488 data acquisition and control routines for a diode array spectrophotometer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shiundu, Paul M.</p> <p>1991-01-01</p> <p>The UV-visible diode array spectrophotometer is a work-horse instrument for many laboratories. This article provides simple data acquisition and control routines in Microsoft QuickBasic for a HP-8452A diode array spectrophotometer interfaced to an IBM PC/XT/AT, or compatible, microcomputer. These allow capture of full spectra and measure absorbance at one or several wavelengths at preset time intervals. The variance in absorbance at each wavelength is available as an option. PMID:18924888</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/873318','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/873318"><span>Photodiode arrays having minimized cross-talk between diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Guckel, Henry; McNamara, Shamus P.</p> <p>2000-10-17</p> <p>Photodiode arrays are formed with close diode-to-diode spacing and minimized cross-talk between diodes in the array by isolating the diodes from one another with trenches that are formed between the photodiodes in the array. The photodiodes are formed of spaced regions in a base layer, each spaced region having an impurity type opposite to that of the base layer to define a p-n junction between the spaced regions and the base layer. The base layer meets a substrate at a boundary, with the substrate being much more heavily doped than the base layer with the same impurity type. The trenches extend through the base layer and preferably into the substrate. Minority carriers generated by absorption of light photons in the base layer can only migrate to an adjacent photodiode through the substrate. The lifetime and the corresponding diffusion length of the minority carriers in the substrate is very short so that all minority carriers recombine in the substrate before reaching an adjacent photodiode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112o3108Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112o3108Z"><span>In-situ laser nano-patterning for ordered InAs/GaAs(001) quantum dot growth</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Wei; Shi, Zhenwu; Huo, Dayun; Guo, Xiaoxiang; Zhang, Feng; Chen, Linsen; Wang, Qinhua; Zhang, Baoshun; Peng, Changsi</p> <p>2018-04-01</p> <p>A study of in-situ laser interference nano-patterning on InGaAs wetting layers was carried out during InAs/GaAs (001) quantum dot molecular beam epitaxy growth. Periodic nano-islands with heights of a few atomic layers were obtained via four-beam laser interference irradiation on the InGaAs wetting layer at an InAs coverage of 0.9 monolayer. The quantum dots nucleated preferentially at edges of nano-islands upon subsequent deposition of InAs on the patterned surface. When the nano-islands are sufficiently small, the patterned substrate could be spontaneously re-flattened and an ordered quantum dot array could be produced on the smooth surface. This letter discusses the mechanisms of nano-patterning and ordered quantum dot nucleation in detail. This study provides a potential technique leading to site-controlled, high-quality quantum dot fabrication.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000hpdl.conf..225B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000hpdl.conf..225B"><span>Properties and Frequency Conversion of High-Brightness Diode-Laser Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boller, Klaus-Jochen; Beier, Bernard; Wallenstein, Richard</p> <p></p> <p>An overview of recent developments in the field of high-power, high-brightness diode-lasers, and the optically nonlinear conversion of their output into other wavelength ranges, is given. We describe the generation of continuous-wave (CW) laser beams at power levels of several hundreds of milliwatts to several watts with near-perfect spatial and spectral properties using Master-Oscillator Power-Amplifier (MOPA) systems. With single- or double-stage systems, using amplifiers of tapered or rectangular geometry, up to 2.85 W high-brightness radiation is generated at wavelengths around 810nm with AlGaAs diodes. Even higher powers, up to 5.2W of single-frequency and high spatial quality beams at 925nm, are obtained with InGaAs diodes. We describe the basic properties of the oscillators and amplifiers used. A strict proof-of-quality for the diode radiation is provided by direct and efficient nonlinear optical conversion of the diode MOPA output into other wavelength ranges. We review recent experiments with the highest power levels obtained so far by direct frequency doubling of diode radiation. In these experiments, 100mW single-frequency ultraviolet light at 403nm was generated, as well as 1W of single-frequency blue radiation at 465nm. Nonlinear conversion of diode radiation into widely tunable infrared radiation has recently yielded record values. We review the efficient generation of widely tunable single-frequency radiation in the infrared with diode-pumped Optical Parametric Oscillators (OPOs). With this system, single-frequency output radiation with powers of more than 0.5W was generated, widely tunable around wavelengths of <!- MATH 2.1 mu mathrm{m} -> 2.1,m and <!- MATH 1.65 mu mathrm{m} -> 1.65,m and with excellent spectral and spatial quality. These developments are clear indicators of recent advances in the field of high-brightness diode-MOPA systems, and may emphasize their future central importance for applications within a vast range of optical wavelengths.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6857500','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6857500"><span>Performance measurements of hybrid PIN diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jernigan, J.G.; Arens, J.F.; Kramer, G.</p> <p></p> <p>We report on the successful effort to develop hybrid PIN diode arrays and to demonstrate their potential as components of vertex detectors. Hybrid pixel arrays have been fabricated by the Hughes Aircraft Co. by bump bonding readout chips developed by Hughes to an array of PIN diodes manufactured by Micron Semiconductor Inc. These hybrid pixel arrays were constructed in two configurations. One array format having 10 {times} 64 pixels, each 120 {mu}m square, and the other format having 256 {times} 256 pixels, each 30 {mu}m square. In both cases, the thickness of the PIN diode layer is 300 {mu}m. Measurementsmore » of detector performance show that excellent position resolution can be achieved by interpolation. By determining the centroid of the charge cloud which spreads charge into a number of neighboring pixels, a spatial resolution of a few microns has been attained. The noise has been measured to be about 300 electrons (rms) at room temperature, as expected from KTC and dark current considerations, yielding a signal-to-noise ratio of about 100 for minimum ionizing particles. 4 refs., 13 figs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22648884-su-technique-modeling-diode-array-tps-lung-sbrt-patient-specific-qa','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22648884-su-technique-modeling-diode-array-tps-lung-sbrt-patient-specific-qa"><span>SU-F-T-270: A Technique for Modeling a Diode Array Into the TPS for Lung SBRT Patient Specific QA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Curley, C; Leventouri, T; Ouhib, Z</p> <p>2016-06-15</p> <p>Purpose: To accurately match the treatment planning system (TPS) with the measurement environment, where quality assurance (QA) devices are used to collect data, for lung Stereotactic Body Radiation Therapy (SBRT) patient specific QA. Incorporation of heterogeneities is also studied. Methods: Dual energy computerized tomography (DECT) and single energy computerized tomography (SECT) were used to model phantoms incorporating a 2-D diode array into the TPS. A water-equivalent and a heterogeneous phantom (simulating the thoracic region of a patient) were studied. Monte Carlo and pencil beam planar dose distributions were compared to measured distributions. Composite and individual fields were analyzed for normallymore » incident and planned gantry angle deliveries. γ- analysis was used with criteria 3% 3mm, 2% 2mm, and 1% 1mm. Results: The Monte Carlo calculations for the DECT resulted in improved agreements with the diode array for 46.4% of the fields at 3% 3mm, 85.7% at 2% 2mm, and 92.9% at 1% 1mm.For the SECT, the Monte Carlo calculations gave no agreement for the same γ-analysis criteria. Pencil beam calculations resulted in lower agreements with the diode array in the TPS. The DECT showed improvements for 14.3% of the fields at 3% 3mm and 2% 2mm, and 28.6% at 1% 1mm.In SECT comparisons, 7.1% of the fields at 3% 3mm, 10.7% at 2% 2mm, and 17.9% at 1% 1mm showed improved agreements with the diode array. Conclusion: This study demonstrates that modeling the diode array in the TPS is viable using DECT with Monte Carlo for patient specific lung SBRT QA. As recommended by task groups (e.g. TG 65, TG 101, TG 244) of the American Association of Physicists in Medicine (AAPM), pencil beam algorithms should be avoided in the presence of heterogeneous materials, including a diode array.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7583E..0CK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7583E..0CK"><span>High duty cycle hard soldered kilowatt laser diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klumel, Genady; Karni, Yoram; Oppenheim, Jacob; Berk, Yuri; Shamay, Moshe; Tessler, Renana; Cohen, Shalom</p> <p>2010-02-01</p> <p>High-brightness laser diode arrays operating at a duty cycle of 10% - 20% are in ever-increasing demand for the optical pumping of solid state lasers and directed energy applications. Under high duty-cycle operation at 10% - 20%, passive (conductive) cooling is of limited use, while micro-coolers using de-ionized cooling water can considerably degrade device reliability. When designing and developing actively-cooled collimated laser diode arrays for high duty cycle operation, three main problems should be carefully addressed: an effective local and total heat removal, a minimization of packaging-induced and operational stresses, and high-precision fast axis collimation. In this paper, we present a novel laser diode array incorporating a built-in tap water cooling system, all-hard-solder bonded assembly, facet-passivated high-power 940 nm laser bars and tight fast axis collimation. By employing an appropriate layout of water cooling channels, careful choice of packaging materials, proper design of critical parts, and active optics alignment, we have demonstrated actively-cooled collimated laser diode arrays with extended lifetime and reliability, without compromising their efficiency, optical power density, brightness or compactness. Among the key performance benchmarks achieved are: 150 W/bar optical peak power at 10% duty cycle, >50% wallplug efficiency and <1° collimated fast axis divergence. A lifetime of >0.5 Ghots with <2% degradation has been experimentally proven. The laser diode arrays have also been successfully tested under harsh environmental conditions, including thermal cycling between -20°C and 40°C and mechanical shocks at 500g acceleration. The results of both performance and reliability testing bear out the effectiveness and robustness of the manufacturing technology for high duty-cycle laser arrays.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740007032','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740007032"><span>Short range laser obstacle detector. [for surface vehicles using laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuriger, W. L. (Inventor)</p> <p>1973-01-01</p> <p>A short range obstacle detector for surface vehicles is described which utilizes an array of laser diodes. The diodes operate one at a time, with one diode for each adjacent azimuth sector. A vibrating mirror a short distance above the surface provides continuous scanning in elevation for all azimuth sectors. A diode laser is synchronized with the vibrating mirror to enable one diode laser to be fired, by pulses from a clock pulse source, a number of times during each elevation scan cycle. The time for a given pulse of light to be reflected from an obstacle and received is detected as a measure of range to the obstacle.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1334796','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1334796"><span>Stacked, filtered multi-channel X-ray diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>MacNeil, Lawrence; Dutra, Eric; Raphaelian, Mark</p> <p>2015-08-01</p> <p>There are many types of X-ray diodes used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need exists for a low-cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustnessmore » and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. The authors fielded individual and stacked systems at several national facilities as ancillary "ride-along" diagnostics to test and improve the design usability. This paper presents the MiniXRD system performance, which supports consideration as a viable low-costalternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869131','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/869131"><span>Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Krupke, William F.; Payne, Stephen A.; Chase, Lloyd L.</p> <p></p> <p>An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises Ytterbium doped apatite (Yb:Ca.sub.5 (PO.sub.4).sub.3 F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5221265-yb-fap-related-materials-laser-gain-medium-comprising-same-laser-systems-using-same','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5221265-yb-fap-related-materials-laser-gain-medium-comprising-same-laser-systems-using-same"><span>Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Krupke, W.F.; Payne, S.A.; Chase, L.L.</p> <p></p> <p>An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises ytterbium doped apatite (Yb:Ca[sub 5](PO[sub 4])[sub 3]F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode. 9 figures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5221265','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5221265"><span>Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Krupke, W.F.; Payne, S.A.; Chase, L.L.; Smith, L.K.</p> <p>1994-01-18</p> <p>An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises ytterbium doped apatite (Yb:Ca[sub 5](PO[sub 4])[sub 3]F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode. 9 figures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/140146','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/140146"><span>Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Krupke, W.F.; Payne, S.A.; Chase, L.L.</p> <p></p> <p>An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises ytterbium doped apatite (Yb:Ca{sub 5}(PO{sub 4}){sub 3}F) or Yb:FAP, or ytterbium doped crystals structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA489537','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA489537"><span>Defense Industrial Base Assessment: U.S. Imaging and Sensors Industry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2006-10-01</p> <p>uncooled devices, but provide much higher resolution. The semiconductor material used in the detector is typically mercury cadmium telluride (HgCdTe...The material principally used in the arrays was mercury cadmium telluride (HgCdTe). Generation 2 detectors significantly improved the signal-to...Silicide (PtSi), Gallium Arsenide (GaAs), Aluminum Gallium Arsenide (AlGaAs), Mercury Cadmium Telluride (HgCdTe), Indium Gallium Arsenide (InGaAs</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8907E..44Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8907E..44Z"><span>Design and implementation of Gm-APD array readout integrated circuit for infrared 3D imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Li-xia; Yang, Jun-hao; Liu, Zhao; Dong, Huai-peng; Wu, Jin; Sun, Wei-feng</p> <p>2013-09-01</p> <p>A single-photon detecting array of readout integrated circuit (ROIC) capable of infrared 3D imaging by photon detection and time-of-flight measurement is presented in this paper. The InGaAs avalanche photon diodes (APD) dynamic biased under Geiger operation mode by gate controlled active quenching circuit (AQC) are used here. The time-of-flight is accurately measured by a high accurate time-to-digital converter (TDC) integrated in the ROIC. For 3D imaging, frame rate controlling technique is utilized to the pixel's detection, so that the APD related to each pixel should be controlled by individual AQC to sense and quench the avalanche current, providing a digital CMOS-compatible voltage pulse. After each first sense, the detector is reset to wait for next frame operation. We employ counters of a two-segmental coarse-fine architecture, where the coarse conversion is achieved by a 10-bit pseudo-random linear feedback shift register (LFSR) in each pixel and a 3-bit fine conversion is realized by a ring delay line shared by all pixels. The reference clock driving the LFSR counter can be generated within the ring delay line Oscillator or provided by an external clock source. The circuit is designed and implemented by CSMC 0.5μm standard CMOS technology and the total chip area is around 2mm×2mm for 8×8 format ROIC with 150μm pixel pitch. The simulation results indicate that the relative time resolution of the proposed ROIC can achieve less than 1ns, and the preliminary test results show that the circuit function is correct.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870053128&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddiode%2Blaser%2BCW','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870053128&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Ddiode%2Blaser%2BCW"><span>A ten-element array of individually addressable channeled-substrate-planar AlGaAs diode lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carlin, D. B.; Goldstein, B.; Bednarz, J. P.; Harvey, M. G.; Dinkel, N. A.</p> <p>1987-01-01</p> <p>The fabrication of arrays of channeled-substrate-planar (CSP) AlGaAs diode lasers which emit up to 150 mW CW in a single spatial mode and are applicable to mulitchannel optical recording systems is described. The CSP diode lasers are incorporated in ten-array geometry, and each array is 1.95 nm in width and 100 microns in thickness and is cleaved to have a cavity length of 200 microns and coated to produce 90-percent reflectivity on the back facet and 10-percent reflectivity on the front facet. The array is attached to a thermoelectrically cooled submount. The optical output power versus input current characteristics for the array are evaluated, and the lateral far-field intensity profiles for each of the lasers (at 30 mW CW) and CW spectra of the lasers are analyzed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/870892','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/870892"><span>Fiber optic coupling of a microlens conditioned, stacked semiconductor laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Beach, Raymond J.; Benett, William J.; Mills, Steven T.</p> <p>1997-01-01</p> <p>The output radiation from the two-dimensional aperture of a semiconductor laser diode array is efficiently coupled into an optical fiber. The two-dimensional aperture is formed by stacking individual laser diode bars on top of another in a "rack and stack" configuration. Coupling into the fiber is then accomplished using individual microlenses to condition the output radiation of the laser diode bars. A lens that matches the divergence properties and wavefront characteristics of the laser light to the fiber optic is used to focus this conditioned radiation into the fiber.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NatSR...2E.477Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NatSR...2E.477Z"><span>1.55 µm InAs/GaAs Quantum Dots and High Repetition Rate Quantum Dot SESAM Mode-locked Laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Z. Y.; Oehler, A. E. H.; Resan, B.; Kurmulis, S.; Zhou, K. J.; Wang, Q.; Mangold, M.; Süedmeyer, T.; Keller, U.; Weingarten, K. J.; Hogg, R. A.</p> <p>2012-06-01</p> <p>High pulse repetition rate (>=10 GHz) diode-pumped solid-state lasers, modelocked using semiconductor saturable absorber mirrors (SESAMs) are emerging as an enabling technology for high data rate coherent communication systems owing to their low noise and pulse-to-pulse optical phase-coherence. Quantum dot (QD) based SESAMs offer potential advantages to such laser systems in terms of reduced saturation fluence, broader bandwidth, and wavelength flexibility. Here, we describe the development of an epitaxial process for the realization of high optical quality 1.55 µm In(Ga)As QDs on GaAs substrates, their incorporation into a SESAM, and the realization of the first 10 GHz repetition rate QD-SESAM modelocked laser at 1.55 µm, exhibiting ~2 ps pulse width from an Er-doped glass oscillator (ERGO). With a high areal dot density and strong light emission, this QD structure is a very promising candidate for many other applications, such as laser diodes, optical amplifiers, non-linear and photonic crystal based devices.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070018159','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070018159"><span>Improving Lifetime of Quasi-CW Laser Diode Arrays for Pumping 2-Micron Solid State Lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Singh, Upendra N.; Kavaya, Michael J.</p> <p>2007-01-01</p> <p>Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data on the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060048507','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060048507"><span>Improving Reliability of High Power Quasi-CW Laser Diode Arrays Operating in Long Pulse Mode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron L.; Barnes, Bruce W.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.; Baker, Nathaniel R.</p> <p>2006-01-01</p> <p>Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data of the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017QuEle..47..693L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017QuEle..47..693L"><span>Laser diode arrays based on AlGaAs/GaAs quantum-well heterostructures with an efficiency up to 62%</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ladugin, M. A.; Marmalyuk, A. A.; Padalitsa, A. A.; Telegin, K. Yu; Lobintsov, A. V.; Sapozhnikov, S. M.; Danilov, A. I.; Podkopaev, A. V.; Simakov, V. A.</p> <p>2017-08-01</p> <p>The results of development of quasi-cw laser diode arrays operating at a wavelength of 808 nm with a high efficiency are demonstrated. The laser diodes are based on semiconductor AlGaAs/GaAs quantum-well heterostructures grown by MOCVD. The measured spectral, spatial, electric and power characteristics are presented. The output optical power of the array with an emitting area of 5 × 10 mm is 2.7 kW at a pump current of 100 A, and the maximum efficiency reaches 62%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910061600&hterms=laser+gold&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlaser%2Bgold','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910061600&hterms=laser+gold&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlaser%2Bgold"><span>Scalable diode array pumped Nd rod laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zenzie, H. H.; Knights, M. G.; Mosto, J. R.; Chicklis, E. P.; Perkins, P. E.</p> <p>1991-01-01</p> <p>Experiments were carried out on a five-array pump head which utilizes gold-coated reflective cones to couple the pump energy to Nd:YAG and Nd:YLF rod lasers, demonstrating high efficiency and uniform energy deposition. Because the cones function as optical diodes to light outside their acceptance angle (typically 10-15 deg), much of the diode energy not absorbed on the first pass can be returned to the rod.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA303223','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA303223"><span>Micromirror Array Control of a Phase-Locked Laser Diode Array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1995-12-01</p> <p>Micromirror Intensity-Voltage Curve . From the intensity plot, maxima (Ix) and minima (IMN) are noted. If IMAX and IMn are known, A4 can be calculated for...of the micromirror array used. Mirror 9 600 500 E 400- S300- C, -0200 lOO_ 0 0 5 10 15 20 25 30 Volts Figure 3b. Mirror Deflection Curve Corresponding...AFIT/GAP/ENP/95D-2 MICROMIRROR ARRAY CONTROL OF A PHASE-LOCKED LASER DIODE ARRAY THESIS Carl J. Christensen, Captain, USAF AFIT/GAP/ENP/95D-2</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/865830','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/865830"><span>DC switching regulated power supply for driving an inductive load</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dyer, George R.</p> <p>1986-01-01</p> <p>A power supply for driving an inductive load current from a dc power supply hrough a regulator circuit including a bridge arrangement of diodes and switching transistors controlled by a servo controller which regulates switching in response to the load current to maintain a selected load current. First and second opposite legs of the bridge are formed by first and second parallel-connected transistor arrays, respectively, while the third and fourth legs of the bridge are formed by appropriately connected first and second parallel connected diode arrays, respectively. The regulator may be operated in three "stages" or modes: (1) For current runup in the load, both first and second transistor switch arrays are turned "on" and current is supplied to the load through both transistor arrays. (2) When load current reaches the desired level, the first switch is turned "off", and load current "flywheels" through the second switch array and the fourth leg diode array connecting the second switch array in series with the load. Current is maintained by alternating between modes 1 and 2 at a suitable duty cycle and switching rate set by the controller. (3) Rapid current rundown is accomplished by turning both switch arrays "off", allowing load current to be dumped back into the source through the third and fourth diode arrays connecting the source in series opposition with the load to recover energy from the inductive load. The three operating states are controlled automatically by the controller.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6671703','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6671703"><span>DC switching regulated power supply for driving an inductive load</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dyer, G.R.</p> <p>1983-11-29</p> <p>A dc switching regulated power supply for driving an inductive load is provided. The regulator basic circuit is a bridge arrangement of diodes and transistors. First and second opposite legs of the bridge are formed by first and second parallel-connected transistor arrays, respectively, while the third and fourth legs of the bridge are formed by appropriately connected first and second parallel connected diode arrays, respectively. A dc power supply is connected to the input of the bridge and the output is connected to the load. A servo controller is provided to control the switching rate of the transistors to maintain a desired current to the load. The regulator may be operated in three stages or modes: (1) for current runup in the load, both first and second transistor switch arrays are turned on and current is supplied to the load through both transistor arrays. (2) When load current reaches the desired level, the first switch is turned off, and load current flywheels through the second switch array and the fourth leg diode array connecting the second switch array in series with the load. Current is maintained by alternating between modes 1 and 2 at a suitable duty cycle and switching rate set by the controller. (3) Rapid current rundown is accomplished by turning both switch arrays off, allowing load current to be dumped back into the source through the third and fourth diode arrays connecting the source in series opposition with the load to recover energy from the inductive load.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1025262','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1025262"><span>Optogenetic Stimulation of Peripheral Vagus Nerves using Flexible OLED Display Technology to Treat Chronic Inflammatory Disease and Mental Health Disorders</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-03-31</p> <p>transcutaneously via the outer ear using a high-resolution, addressable array of organic light emitting diodes (OLEDs) manufactured on a flexible...therapeutic optical stimulation in optogenetically modified neural tissue. Keywords: Optogenetics; neuromodulation; organic light emitting diode ...the outer ear using a high-resolution, two-dimensional (2-D), addressable array of red organic light - emitting diodes (OLEDs) manufactured on a thin</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871943','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871943"><span>High density, optically corrected, micro-channel cooled, v-groove monolithic laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Freitas, Barry L.</p> <p>1998-01-01</p> <p>An optically corrected, micro-channel cooled, high density laser diode array achieves stacking pitches to 33 bars/cm by mounting laser diodes into V-shaped grooves. This design will deliver>4kW/cm2 of directional pulsed laser power. This optically corrected, micro-channel cooled, high density laser is usable in all solid state laser systems which require efficient, directional, narrow bandwidth, high optical power density pump sources.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1013214','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1013214"><span>Phase and Frequency Control of Laser Arrays for Pulse Synthesis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-01-02</p> <p>with the laser array to understand the phase noise of elements on a common heat sink, and the relationship between linewidth and feedback speed...spatial brightness operation of a phase-locked stripe -array diode laser,” Laser Phys. 22, 160 (2012). [2] J. R. Leger, “Lateral mode control of an AlGaAs...Jechow, D. Skoczowsky, and R. Menzel, “Multi-wavelength, high spatial brightness operation of a phase-locked stripe -array diode laser,” Laser Phys. 22</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/462864','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/462864"><span>Fiber optic coupling of a microlens conditioned, stacked semiconductor laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Beach, R.J.; Benett, W.J.; Mills, S.T.</p> <p>1997-04-01</p> <p>The output radiation from the two-dimensional aperture of a semiconductor laser diode array is efficiently coupled into an optical fiber. The two-dimensional aperture is formed by stacking individual laser diode bars on top of another in a ``rack and stack`` configuration. Coupling into the fiber is then accomplished using individual microlenses to condition the output radiation of the laser diode bars. A lens that matches the divergence properties and wavefront characteristics of the laser light to the fiber optic is used to focus this conditioned radiation into the fiber. 3 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10124E..0HB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10124E..0HB"><span>InGaN/GaN dot-in-nanowire monolithic LEDs and lasers on (001) silicon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhattacharya, P.; Hazari, A.; Jahangir, S.</p> <p>2017-02-01</p> <p>GaN-based nanowire arrays have been grown on (001)Si substrate by plasma-assisted molecular beam epitaxy and their structural and optical properties have been determined. InxGa1-xN disks inserted in the nanowires behave as quantum dots with emission ranging from visible to near-infrared. We have exploited these nanowire heterostructure arrays to realize light-emitting diodes and diode lasers in which the quantum dots form the active light emitting media. The fabrication and characteristics of 630nm light-emitting diodes and 1.3μm edge-emitting diode lasers are described.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900018731','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900018731"><span>Linear laser diode arrays for improvement in optical disk recording for space stations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alphonse, G. A.; Carlin, D. B.; Connolly, J. C.</p> <p>1990-01-01</p> <p>The design and fabrication of individually addressable laser diode arrays for high performance magneto-optic recording systems are presented. Ten diode arrays with 30 mW cW light output, linear light vs. current characteristics and single longitudinal mode spectrum were fabricated using channel substrate planar (CSP) structures. Preliminary results on the inverse CSP structure, whose fabrication is less critically dependent on device parameters than the CSP, are also presented. The impact of systems parameters and requirements, in particular, the effect of feedback on laser design is assessed, and techniques to reduce feedback or minimize its effect on systems performance, including mode-stabilized structures, are evaluated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23421162','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23421162"><span>Fabrication and characterization of n-ZnO nanonails array/p(+)-GaN heterojunction diode.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, G Y; Chen, G F; Li, J T; Shi, Z L; Lin, Y; Ding, T; Xu, X Y; Dai, J; Xu, C X</p> <p>2012-10-01</p> <p>A novel heterojunctional structure of n-ZnO nanonails array/p(+)-GaN light-emitting diode was fabricated by Chemical Vapor Deposition method. A broad electroluminescence spectrum shows two peaks centered at 435 nm and 478 nm at room temperature, respectively. By comparing the photoluminescence and electroluminescence spectra, together with analyzing the energy band structure of heterojunction light emitting diode, it suggested that the electroluminescence peak located at 435 nm originates from Mg acceptor level of p(+)-GaN layer, whereas the electroluminescence peak located at 478 nm originates from the defects of n-ZnO nanonails array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9974E..0HP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9974E..0HP"><span>Extended short wavelength infrared HgCdTe detectors on silicon substrates</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, J. H.; Hansel, D.; Mukhortova, A.; Chang, Y.; Kodama, R.; Zhao, J.; Velicu, S.; Aqariden, F.</p> <p>2016-09-01</p> <p>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.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=uv+AND+vis&pg=3&id=EJ823776','ERIC'); return false;" href="https://eric.ed.gov/?q=uv+AND+vis&pg=3&id=EJ823776"><span>The Fuge Tube Diode Array Spectrophotometer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.</p> <p>2008-01-01</p> <p>We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/675847','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/675847"><span>High density, optically corrected, micro-channel cooled, v-groove monolithic laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Freitas, B.L.</p> <p>1998-10-27</p> <p>An optically corrected, micro-channel cooled, high density laser diode array achieves stacking pitches to 33 bars/cm by mounting laser diodes into V-shaped grooves. This design will deliver > 4kW/cm{sup 2} of directional pulsed laser power. This optically corrected, micro-channel cooled, high density laser is usable in all solid state laser systems which require efficient, directional, narrow bandwidth, high optical power density pump sources. 13 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhST..126...31H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhST..126...31H"><span>Imaging photovoltaic infrared CdHgTe detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haakenaasen, R.; Steen, H.; Selvig, E.; Lorentzen, T.; van Rheenen, A. D.; Trosdahl-Iversen, L.; Hall, D.; Gordon, N.; Skauli, T.; Vaskinn, A. H.</p> <p>2006-09-01</p> <p>CdxHg1-xTe layers with bandgap in the mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) regions were grown by molecular beam epitaxy, and one-dimensional (1D) and two-dimensional (2D) arrays of planar photodiodes were fabricated by ion milling of vacancy-doped layers. The grown layers have varying densities of needle-shaped structures on the surface. The needles are not associated with twins or dislocations in the layers, but could instead be due to (111) facets being reinforced by a preferential Te diffusion direction over steps on the surface. The needles do not seem to affect diode quality. 64 element 1D arrays of 26×26 μm2 or 26×56 μm2 diodes were processed, and zero-bias resistance-times-area values (R0A) at 77 K of 4×106 Ω cm2 at cutoff wavelength λCO=4.5 μm were measured, as well as high quantum efficiencies. To avoid creating a leakage current during ball-bonding to the 1D array diodes, a ZnS layer was deposited on top of the CdTe passivation layer, as well as extra electroplated Au on the bonding pads. The median measured noise equivalent temperature difference (NETD) on a LWIR array was 14 mK for the 42 operable diodes. 2D arrays showed reasonably good uniformity of R0A and zero-bias current (I0) values. The first 64×64 element 2D array of 16×16 μm2 MWIR diodes has been hybridized to read-out electronics and gave median NETD of 60 mK. Images from both a 1D and a 2D array are shown.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=hplc&pg=4&id=EJ324423','ERIC'); return false;" href="https://eric.ed.gov/?q=hplc&pg=4&id=EJ324423"><span>Instrumentation: Photodiode Array Detectors in UV-VIS Spectroscopy. Part II.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jones, Dianna G.</p> <p>1985-01-01</p> <p>A previous part (Analytical Chemistry; v57 n9 p1057A) discussed the theoretical aspects of diode ultraviolet-visual (UV-VIS) spectroscopy. This part describes the applications of diode arrays in analytical chemistry, also considering spectroelectrochemistry, high performance liquid chromatography (HPLC), HPLC data processing, stopped flow, and…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950020474','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950020474"><span>Solid-state image sensor with focal-plane digital photon-counting pixel array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fossum, Eric R. (Inventor); Pain, Bedabrata (Inventor)</p> <p>1995-01-01</p> <p>A photosensitive layer such as a-Si for a UV/visible wavelength band is provided for low light level imaging with at least a separate CMOS amplifier directly connected to each PIN photodetector diode to provide a focal-plane array of NxN pixels, and preferably a separate photon-counting CMOS circuit directly connected to each CMOS amplifier, although one row of counters may be time shared for reading out the photon flux rate of each diode in the array, together with a buffer memory for storing all rows of the NxN image frame before transfer to suitable storage. All CMOS circuitry is preferably fabricated in the same silicon layer as the PIN photodetector diode for a monolithic structure, but when the wavelength band of interest requires photosensitive material different from silicon, the focal-plane array may be fabricated separately on a different semiconductor layer bump-bonded or otherwise bonded for a virtually monolithic structure with one free terminal of each diode directly connected to the input terminal of its CMOS amplifier and digital counter for integration of the photon flux rate at each photodetector of the array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25652498','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25652498"><span>Monte Carlo simulation of the dose response of a novel 2D silicon diode array for use in hybrid MRI-LINAC systems.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gargett, Maegan; Oborn, Brad; Metcalfe, Peter; Rosenfeld, Anatoly</p> <p>2015-02-01</p> <p>MRI-guided radiation therapy systems (MRIgRT) are being developed to improve online imaging during treatment delivery. At present, the operation of single point dosimeters and an ionization chamber array have been characterized in such systems. This work investigates a novel 2D diode array, named "magic plate," for both single point calibration and 2D positional performance, the latter being a key element of modern radiotherapy techniques that will be delivered by these systems. geant4 Monte Carlo methods have been employed to study the dose response of a silicon diode array to 6 MV photon beams, in the presence of in-line and perpendicularly aligned uniform magnetic fields. The array consists of 121 silicon diodes (dimensions 1.5 × 1.5 × 0.38 mm(3)) embedded in kapton substrate with 1 cm pitch, spanning a 10 × 10 cm(2) area in total. A geometrically identical, water equivalent volume was simulated concurrently for comparison. The dose response of the silicon diode array was assessed for various photon beam field shapes and sizes, including an IMRT field, at 1 T. The dose response was further investigated at larger magnetic field strengths (1.5 and 3 T) for a 4 × 4 cm(2) photon field size. The magic plate diode array shows excellent correspondence (< ± 1%) to water dose in the in-line orientation, for all beam arrangements and magnetic field strengths investigated. The perpendicular orientation, however, exhibits a dose shift with respect to water at the high-dose-gradient beam edge of jaw-defined fields [maximum (4.3 ± 0.8)% over-response, maximum (1.8 ± 0.8)% under-response on opposing side for 1 T, uncertainty 1σ]. The trend is not evident in areas with in-field dose gradients typical of IMRT dose maps. A novel 121 pixel silicon diode array detector has been characterized by Monte Carlo simulation for its performance inside magnetic fields representative of current prototype and proposed MRI-linear accelerator systems. In the in-line orientation, the silicon dose is directly proportional to the water dose. In the perpendicular orientation, there is a shift in dose response relative to water in the highest dose gradient regions, at the edge of jaw-defined and single-segment MLC fields. The trend was not observed in-field for an IMRT beam. The array is expected to be a valuable tool in MRIgRT dosimetry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22413450-monte-carlo-simulation-dose-response-novel-silicon-diode-array-use-hybrid-mrilinac-systems','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22413450-monte-carlo-simulation-dose-response-novel-silicon-diode-array-use-hybrid-mrilinac-systems"><span>Monte Carlo simulation of the dose response of a novel 2D silicon diode array for use in hybrid MRI–LINAC systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gargett, Maegan, E-mail: mg406@uowmail.edu.au; Rosenfeld, Anatoly; Oborn, Brad</p> <p>2015-02-15</p> <p>Purpose: MRI-guided radiation therapy systems (MRIgRT) are being developed to improve online imaging during treatment delivery. At present, the operation of single point dosimeters and an ionization chamber array have been characterized in such systems. This work investigates a novel 2D diode array, named “magic plate,” for both single point calibration and 2D positional performance, the latter being a key element of modern radiotherapy techniques that will be delivered by these systems. Methods: GEANT4 Monte Carlo methods have been employed to study the dose response of a silicon diode array to 6 MV photon beams, in the presence of in-linemore » and perpendicularly aligned uniform magnetic fields. The array consists of 121 silicon diodes (dimensions 1.5 × 1.5 × 0.38 mm{sup 3}) embedded in kapton substrate with 1 cm pitch, spanning a 10 × 10 cm{sup 2} area in total. A geometrically identical, water equivalent volume was simulated concurrently for comparison. The dose response of the silicon diode array was assessed for various photon beam field shapes and sizes, including an IMRT field, at 1 T. The dose response was further investigated at larger magnetic field strengths (1.5 and 3 T) for a 4 × 4 cm{sup 2} photon field size. Results: The magic plate diode array shows excellent correspondence (< ± 1%) to water dose in the in-line orientation, for all beam arrangements and magnetic field strengths investigated. The perpendicular orientation, however, exhibits a dose shift with respect to water at the high-dose-gradient beam edge of jaw-defined fields [maximum (4.3 ± 0.8)% over-response, maximum (1.8 ± 0.8)% under-response on opposing side for 1 T, uncertainty 1σ]. The trend is not evident in areas with in-field dose gradients typical of IMRT dose maps. Conclusions: A novel 121 pixel silicon diode array detector has been characterized by Monte Carlo simulation for its performance inside magnetic fields representative of current prototype and proposed MRI–linear accelerator systems. In the in-line orientation, the silicon dose is directly proportional to the water dose. In the perpendicular orientation, there is a shift in dose response relative to water in the highest dose gradient regions, at the edge of jaw-defined and single-segment MLC fields. The trend was not observed in-field for an IMRT beam. The array is expected to be a valuable tool in MRIgRT dosimetry.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871709','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871709"><span>Broadband light-emitting diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Fritz, Ian J.; Klem, John F.; Hafich, Michael J.</p> <p>1998-01-01</p> <p>A broadband light-emitting diode. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3-2 .mu.m. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-division-multiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/672588','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/672588"><span>Broadband light-emitting diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Fritz, I.J.; Klem, J.F.; Hafich, M.J.</p> <p>1998-07-14</p> <p>A broadband light-emitting diode is disclosed. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3--2 {micro}m. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-divisionmultiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft. 10 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840020521','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840020521"><span>Integrating IR detector imaging systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bailey, G. C. (Inventor)</p> <p>1984-01-01</p> <p>An integrating IR detector array for imaging is provided in a hybrid circuit with InSb mesa diodes in a linear array, a single J-FET preamplifier for readout, and a silicon integrated circuit multiplexer. Thin film conductors in a fan out pattern deposited on an Al2O3 substrate connect the diodes to the multiplexer, and thick film conductors also connect the reset switch and preamplifier to the multiplexer. Two phase clock pulses are applied with a logic return signal to the multiplexer through triax comprised of three thin film conductors deposited between layers. A lens focuses a scanned image onto the diode array for horizontal read out while a scanning mirror provides vertical scan.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22649259-su-verification-dose-distributions-from-high-dose-rate-brachytherapy-ir-source-using-multiple-array-diode-detector-mapcheck2','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22649259-su-verification-dose-distributions-from-high-dose-rate-brachytherapy-ir-source-using-multiple-array-diode-detector-mapcheck2"><span>SU-G-201-17: Verification of Dose Distributions From High-Dose-Rate Brachytherapy Ir-192 Source Using a Multiple-Array-Diode-Detector (MapCheck2)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Harpool, K; De La Fuente Herman, T; Ahmad, S</p> <p></p> <p>Purpose: To investigate quantitatively the accuracy of dose distributions for the Ir-192 high-dose-rate (HDR) brachytherapy source calculated by the Brachytherapy-Planning system (BPS) and measured using a multiple-array-diode-detector in a heterogeneous medium. Methods: A two-dimensional diode-array-detector system (MapCheck2) was scanned with a catheter and the CT-images were loaded into the Varian-Brachytherapy-Planning which uses TG-43-formalism for dose calculation. Treatment plans were calculated for different combinations of one dwell-position and varying irradiation times and different-dwell positions and fixed irradiation time with the source placed 12mm from the diode-array plane. The calculated dose distributions were compared to the measured doses with MapCheck2 delivered bymore » an Ir-192-source from a Nucletron-Microselectron-V2-remote-after-loader. The linearity of MapCheck2 was tested for a range of dwell-times (2–600 seconds). The angular effect was tested with 30 seconds irradiation delivered to the central-diode and then moving the source away in increments of 10mm. Results: Large differences were found between calculated and measured dose distributions. These differences are mainly due to absence of heterogeneity in the dose calculation and diode-artifacts in the measurements. The dose differences between measured and calculated due to heterogeneity ranged from 5%–12% depending on the position of the source relative to the diodes in MapCheck2 and different heterogeneities in the beam path. The linearity test of the diode-detector showed 3.98%, 2.61%, and 2.27% over-response at short irradiation times of 2, 5, and 10 seconds, respectively, and within 2% for 20 to 600 seconds (p-value=0.05) which depends strongly on MapCheck2 noise. The angular dependency was more pronounced at acute angles ranging up to 34% at 5.7 degrees. Conclusion: Large deviations between measured and calculated dose distributions for HDR-brachytherapy with Ir-192 may be improved when considering medium heterogeneity and dose-artifact of the diodes. This study demonstrates that multiple-array-diode-detectors provide practical and accurate dosimeter to verify doses delivered from the brachytherapy Ir-192-source.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880000949','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880000949"><span>Diode pumped solid-state laser oscillators for spectroscopic applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Byer, R. L.; Basu, S.; Fan, T. Y.; Kozlovsky, W. J.; Nabors, C. D.; Nilsson, A.; Huber, G.</p> <p>1987-01-01</p> <p>The rapid improvement in diode laser pump sources has led to the recent progress in diode laser pumped solid state lasers. To date, electrical efficiencies of greater than 10 percent were demonstrated. As diode laser costs decrease with increased production volume, diode laser and diode laser array pumped solid state lasers will replace the traditional flashlamp pumped Nd:YAG laser sources. The use of laser diode array pumping of slab geometry lasers will allow efficient, high peak and average power solid state laser sources to be developed. Perhaps the greatest impact of diode laser pumped solid state lasers will be in spectroscopic applications of miniature, monolithic devices. Single-stripe diode-pumped operation of a continuous-wave 946 nm Nd:YAG laser with less than 10 m/w threshold was demonstrated. A slope efficiency of 16 percent near threshold was shown with a projected slope efficiency well above a threshold of 34 percent based on results under Rhodamine 6G dye-laser pumping. Nonlinear crystals for second-harmonic generation of this source were evaluated. The KNbO3 and periodically poled LiNbO3 appear to be the most promising.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26832039','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26832039"><span>Fill-factor improvement of Si CMOS single-photon avalanche diode detector arrays by integration of diffractive microlens arrays.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Intermite, Giuseppe; McCarthy, Aongus; Warburton, Ryan E; Ren, Ximing; Villa, Federica; Lussana, Rudi; Waddie, Andrew J; Taghizadeh, Mohammad R; Tosi, Alberto; Zappa, Franco; Buller, Gerald S</p> <p>2015-12-28</p> <p>Single-photon avalanche diode (SPAD) detector arrays generally suffer from having a low fill-factor, in which the photo-sensitive area of each pixel is small compared to the overall area of the pixel. This paper describes the integration of different configurations of high efficiency diffractive optical microlens arrays onto a 32 × 32 SPAD array, fabricated using a 0.35 µm CMOS technology process. The characterization of SPAD arrays with integrated microlens arrays is reported over the spectral range of 500-900 nm, and a range of f-numbers from f/2 to f/22. We report an average concentration factor of 15 measured for the entire SPAD array with integrated microlens array. The integrated SPAD and microlens array demonstrated a very high uniformity in overall efficiency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28759243','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28759243"><span>Telecom-Wavelength Bottom-up Nanobeam Lasers on Silicon-on-Insulator.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Hyunseok; Lee, Wook-Jae; Farrell, Alan C; Balgarkashi, Akshay; Huffaker, Diana L</p> <p>2017-09-13</p> <p>Semiconductor nanowire lasers are considered promising ultracompact and energy-efficient light sources in the field of nanophotonics. Although the integration of nanowire lasers onto silicon photonic platforms is an innovative path toward chip-scale optical communications and photonic integrated circuits, operating nanowire lasers at telecom-wavelengths remains challenging. Here, we report on InGaAs nanowire array lasers on a silicon-on-insulator platform operating up to 1440 nm at room temperature. Bottom-up photonic crystal nanobeam cavities are formed by growing nanowires as ordered arrays using selective-area epitaxy, and single-mode lasing by optical pumping is demonstrated. We also show that arrays of nanobeam lasers with individually tunable wavelengths can be integrated on a single chip by the simple adjustment of the lithographically defined growth pattern. These results exemplify a practical approach toward nanowire lasers for silicon photonics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhA.123..701S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhA.123..701S"><span>Performance of InGaAs short wave infrared avalanche photodetector for low flux imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Anand; Pal, Ravinder</p> <p>2017-11-01</p> <p>Opto-electronic performance of the InGaAs/i-InGaAs/InP short wavelength infrared focal plane array suitable for high resolution imaging under low flux conditions and ranging is presented. More than 85% quantum efficiency is achieved in the optimized detector structure. Isotropic nature of the wet etching process poses a challenge in maintaining the required control in the small pitch high density detector array. Etching process is developed to achieve low dark current density of 1 nA/cm2 in the detector array with 25 µm pitch at 298 K. Noise equivalent photon performance less than one is achievable showing single photon detection capability. The reported photodiode with low photon flux is suitable for active cum passive imaging, optical information processing and quantum computing applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=8939&keyword=uv+AND+vis&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=8939&keyword=uv+AND+vis&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>DETERMINATION OF CARBENDAZIM IN WATER BY HIGH-PERFORMANCE IMMUNOAFFINITY CHROMATOGRAPHY ON-LINE WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH DIODE-ARRAY OR MASS SPECTROMETRIC DETECTION</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>An automated method for the determination of carbendazim in water that combines high-performance immunoaffinity chromatography (HPIAC), high-performance liquid chromatography (HPLC) in the reversed-phase mode, and detection by either UV-Vis diode array detector (DAD) spectroscopy...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22494808-impact-la-sub-sub-interfacial-layers-ingaas-metal-oxide-semiconductor-interface-properties-al-sub-sub-la-sub-sub-ingaas-gate-stacks-deposited-atomic-layer-deposition','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22494808-impact-la-sub-sub-interfacial-layers-ingaas-metal-oxide-semiconductor-interface-properties-al-sub-sub-la-sub-sub-ingaas-gate-stacks-deposited-atomic-layer-deposition"><span>Impact of La{sub 2}O{sub 3} interfacial layers on InGaAs metal-oxide-semiconductor interface properties in Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks deposited by atomic-layer-deposition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Chang, C.-Y., E-mail: cychang@mosfet.t.u-tokyo.ac.jp; Takenaka, M.; Takagi, S.</p> <p></p> <p>We examine the electrical properties of atomic layer deposition (ALD) La{sub 2}O{sub 3}/InGaAs and Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs metal-oxide-semiconductor (MOS) capacitors. It is found that the thick ALD La{sub 2}O{sub 3}/InGaAs interface provides low interface state density (D{sub it}) with the minimum value of ∼3 × 10{sup 11} cm{sup −2} eV{sup −1}, which is attributable to the excellent La{sub 2}O{sub 3} passivation effect for InGaAs surfaces. It is observed, on the other hand, that there are a large amount of slow traps and border traps in La{sub 2}O{sub 3}. In order to simultaneously satisfy low D{sub it} and small hysteresis, the effectivenessmore » of Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks with ultrathin La{sub 2}O{sub 3} interfacial layers is in addition evaluated. The reduction of the La{sub 2}O{sub 3} thickness to 0.4 nm in Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs gate stacks leads to the decrease in hysteresis. On the other hand, D{sub it} of the Al{sub 2}O{sub 3}/La{sub 2}O{sub 3}/InGaAs interfaces becomes higher than that of the La{sub 2}O{sub 3}/InGaAs ones, attributable to the diffusion of Al{sub 2}O{sub 3} through La{sub 2}O{sub 3} into InGaAs and resulting modification of the La{sub 2}O{sub 3}/InGaAs interface structure. As a result of the effective passivation effect of La{sub 2}O{sub 3} on InGaAs, however, the Al{sub 2}O{sub 3}/10 cycle (0.4 nm) La{sub 2}O{sub 3}/InGaAs gate stacks can realize still lower D{sub it} with maintaining small hysteresis and low leakage current than the conventional Al{sub 2}O{sub 3}/InGaAs MOS interfaces.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10514E..11J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10514E..11J"><span>Custom ceramic microchannel-cooled array for high-power fiber-coupled application</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Junghans, Jeremy; Feeler, Ryan; Stephens, Ed</p> <p>2018-03-01</p> <p>A low-SWaP (Size, Weight and Power) diode array has been developed for a high-power fiber-coupled application. High efficiency ( 65%) diodes enable high optical powers while minimizing thermal losses. A large amount of waste heat is still generated and must be extracted. Custom ceramic microchannel-coolers (MCCs) are used to dissipate the waste heat. The custom ceramic MCC was designed to accommodate long cavity length diodes and micro-lenses. The coolers provide similar thermal performance as copper MCCs however they are not susceptible to erosion and can be cooled with standard filtered water. The custom ceramic micro-channel cooled array was designed to be a form/fit replacement for an existing copperbased solution. Each array consisted of three-vertically stacked MCCs with 4 mm CL, 976 nm diodes and beamshaping micro-optics. The erosion and corrosion resistance of ceramic array is intended to mitigate the risk of copperbased MCC corrosion failures. Elimination of the water delivery requirements (pH, resistivity and dissolved oxygen control) further reduces the system SWaP while maintaining reliability. The arrays were fabricated and fully characterized. This work discusses the advantages of the ceramic MCC technology and describes the design parameters that were tailored for the fiber-coupled application. Additional configuration options (form/fit, micro-lensing, alternate coolants, etc.) and on-going design improvements are also discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8298E..0CG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8298E..0CG"><span>A low-noise 15-μm pixel-pitch 640×512 hybrid InGaAs image sensor for night vision</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guellec, Fabrice; Dubois, Sébastien; de Borniol, Eric; Castelein, Pierre; Martin, Sébastien; Guiguet, Romain; Tchagaspanian, Micha"l.; Rouvié, Anne; Bois, Philippe</p> <p>2012-03-01</p> <p>Hybrid InGaAs focal plane arrays are very interesting for night vision because they can benefit from the nightglow emission in the Short Wave Infrared band. Through a collaboration between III-V Lab and CEA-Léti, a 640x512 InGaAs image sensor with 15μm pixel pitch has been developed. The good crystalline quality of the InGaAs detectors opens the door to low dark current (around 20nA/cm2 at room temperature and -0.1V bias) as required for low light level imaging. In addition, the InP substrate can be removed to extend the detection range towards the visible spectrum. A custom readout IC (ROIC) has been designed in a standard CMOS 0.18μm technology. The pixel circuit is based on a capacitive transimpedance amplifier (CTIA) with two selectable charge-to-voltage conversion gains. Relying on a thorough noise analysis, this input stage has been optimized to deliver low-noise performance in high-gain mode with a reasonable concession on dynamic range. The exposure time can be maximized up to the frame period thanks to a rolling shutter approach. The frame rate can be up to 120fps or 60fps if the Correlated Double Sampling (CDS) capability of the circuit is enabled. The first results show that the CDS is effective at removing the very low frequency noise present on the reference voltage in our test setup. In this way, the measured total dark noise is around 90 electrons in high-gain mode for 8.3ms exposure time. It is mainly dominated by the dark shot noise for a detector temperature settling around 30°C when not cooled. The readout noise measured with shorter exposure time is around 30 electrons for a dynamic range of 71dB in high-gain mode and 108 electrons for 79dB in low-gain mode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120014093','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120014093"><span>ASIC Readout Circuit Architecture for Large Geiger Photodiode Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vasile, Stefan; Lipson, Jerold</p> <p>2012-01-01</p> <p>The objective of this work was to develop a new class of readout integrated circuit (ROIC) arrays to be operated with Geiger avalanche photodiode (GPD) arrays, by integrating multiple functions at the pixel level (smart-pixel or active pixel technology) in 250-nm CMOS (complementary metal oxide semiconductor) processes. In order to pack a maximum of functions within a minimum pixel size, the ROIC array is a full, custom application-specific integrated circuit (ASIC) design using a mixed-signal CMOS process with compact primitive layout cells. The ROIC array was processed to allow assembly in bump-bonding technology with photon-counting infrared detector arrays into 3-D imaging cameras (LADAR). The ROIC architecture was designed to work with either common- anode Si GPD arrays or common-cathode InGaAs GPD arrays. The current ROIC pixel design is hardwired prior to processing one of the two GPD array configurations, and it has the provision to allow soft reconfiguration to either array (to be implemented into the next ROIC array generation). The ROIC pixel architecture implements the Geiger avalanche quenching, bias, reset, and time to digital conversion (TDC) functions in full-digital design, and uses time domain over-sampling (vernier) to allow high temporal resolution at low clock rates, increased data yield, and improved utilization of the laser beam.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8012548','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8012548"><span>Determination of patulin in apple juice by high-performance liquid chromatography with diode-array detection.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bartolomé, B; Bengoechea, M L; Pérez-Ilzarbe, F J; Hernández, T; Estrella, I; Gómez-Cordovés, C</p> <p>1994-03-25</p> <p>A method is described for the detection of patulin in apple juice and the simultaneous determination of the phenolic composition. Spectral data obtained with diode-array detection showed that patulin can be easily distinguished from compounds eluting under the same conditions. The detection limit for patulin was 8.96 micrograms/l.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.111q3301A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.111q3301A"><span>Aluminum-nanodisc-induced collective lattice resonances: Controlling the light extraction in organic light emitting diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Auer-Berger, Manuel; Tretnak, Veronika; Wenzl, Franz-Peter; Krenn, Joachim R.; List-Kratochvil, Emil J. W.</p> <p>2017-10-01</p> <p>We examine aluminum-nanodisc-induced collective lattice resonances as a means to enhance the efficiency of organic light emitting diodes. Thus, nanodisc arrays were embedded in the hole transporting layer of a solution-processed phosphorescent organic blue-light emitting diode. Through extinction spectroscopy, we confirm the emergence of array-induced collective lattice resonances within the organic light emitting diode. Through finite-difference time domain simulations, we show that the collective lattice resonances yield an enhancement of the electric field intensity within the emissive layer. The effectiveness for improving the light generation and light outcoupling is demonstrated by electro-optical characterization, realizing a gain in a current efficiency of 35%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JKPS...72.1020K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JKPS...72.1020K"><span>Dependence of Laminar Flow Fluctuation on Indium Composition in In0.07GaAs/GaAs Quantum Wells for 940-nm Infrared Light-Emitting Diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Dae-Kwang; Lee, Hyung-Joo; An, Won-Chan; Kim, Hong-Gun; Kwac, Lee-Ku</p> <p>2018-05-01</p> <p>The effect of laminar flow fluctuation on the indium composition of In0.07GaAs quantum wells was investigated in order to obtain a higher output power from infrared lighting-emitting diodes (IR-LEDs) having a 940-nm wavelength. By controlling the injection pressure, we obtained various laminar flow conditions. Through subsequent photoluminescence (PL) and X-ray diffraction (XRD) measurements, a noticeable improvement in the optical and the crystalline characteristics of the In0.07GaAs quantum wells was observed at an optimum laminar flow. This result could be attributed to a reduction of non-crystallization in InGaAs quantum wells that had their indium composition improved via the optimized laminar flow. Overall, a significantly improved output power (11.2 mW) was obtained from a 940-nm IR-LED chip fabricated at an optimum laminar flow of 500 sccm, and a remarkable increase of approximately 250% was displayed compared to a conventional chip (3.9 mW) fabricated at a laminar flow of 100 sccm.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhDT........45A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhDT........45A"><span>Single mode, broad-waveguide ARROW-type semiconductor diode lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Al-Muhanna, Abdulrahman Ali</p> <p></p> <p>A broad transverse waveguide (low confinement) concept is used to achieve a record-high spatially incoherent cw output power of 11W for InGaAs active devices (λ = 0.97 μm) from 100μm wide-stripe and 2mm-long devices with low internal loss, α1 = 1cm-1, and high characteristic temperatures, T0 = 210K, and T1 = 1800K. A detailed above-threshold analysis reveals that reduction in gain spatial hole burning (GSHB) is possible in ARROW-type structures by using a low transverse confinement factor; consequently, a wider ARROW-core can be utilized. By incorporating both a broad-waveguide concept as well as an asymmetric structure in the transverse direction, and an ARROW-type structure in the lateral direction, a novel single-spatial mode diode laser with improved performance is obtained. Devices with low transverse confinement factor (Γ ~ 1%) and a core-region width of 7.8 μm achieved 510mW single-spatial mode pulsed output power (λ = 0.946 μm) with a full- width at half-maximum (FWHM) of the lateral far-field pattern of 4.7°.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAP...115r4503S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAP...115r4503S"><span>InGaAs tunnel diodes for the calibration of semi-classical and quantum mechanical band-to-band tunneling models</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smets, Quentin; Verreck, Devin; Verhulst, Anne S.; Rooyackers, Rita; Merckling, Clément; Van De Put, Maarten; Simoen, Eddy; Vandervorst, Wilfried; Collaert, Nadine; Thean, Voon Y.; Sorée, Bart; Groeseneken, Guido; Heyns, Marc M.</p> <p>2014-05-01</p> <p>Promising predictions are made for III-V tunnel-field-effect transistor (FET), but there is still uncertainty on the parameters used in the band-to-band tunneling models. Therefore, two simulators are calibrated in this paper; the first one uses a semi-classical tunneling model based on Kane's formalism, and the second one is a quantum mechanical simulator implemented with an envelope function formalism. The calibration is done for In0.53Ga0.47As using several p+/intrinsic/n+ diodes with different intrinsic region thicknesses. The dopant profile is determined by SIMS and capacitance-voltage measurements. Error bars are used based on statistical and systematic uncertainties in the measurement techniques. The obtained parameters are in close agreement with theoretically predicted values and validate the semi-classical and quantum mechanical models. Finally, the models are applied to predict the input characteristics of In0.53Ga0.47As n- and p-lineTFET, with the n-lineTFET showing competitive performance compared to MOSFET.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1415619','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1415619"><span>System and method for high power diode based additive manufacturing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>El-Dasher, Bassem S.; Bayramian, Andrew; Demuth, James A.; Farmer, Joseph C.; Torres, Sharon G.</p> <p>2018-01-02</p> <p>A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1246919','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1246919"><span>System and method for high power diode based additive manufacturing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>El-Dasher, Bassem S.; Bayramian, Andrew; Demuth, James A.; Farmer, Joseph C.; Torres, Sharon G.</p> <p>2016-04-12</p> <p>A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhRvB..71k5314S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhRvB..71k5314S"><span>Power generation in random diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shvydka, Diana; Karpov, V. G.</p> <p>2005-03-01</p> <p>We discuss nonlinear disordered systems, random diode arrays (RDAs), which can represent such objects as large-area photovoltaics and ion channels of biological membranes. Our numerical modeling has revealed several interesting properties of RDAs. In particular, the geometrical distribution of nonuniformities across a RDA has only a minor effect on its integral characteristics determined by RDA parameter statistics. In the meantime, the dispersion of integral characteristics vs system size exhibits a nontrivial scaling dependence. Our theoretical interpretation here remains limited and is based on the picture of eddy currents flowing through weak diodes in the RDA.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28241517','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28241517"><span>Real-time imaging of methane gas leaks using a single-pixel camera.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gibson, Graham M; Sun, Baoqing; Edgar, Matthew P; Phillips, David B; Hempler, Nils; Maker, Gareth T; Malcolm, Graeme P A; Padgett, Miles J</p> <p>2017-02-20</p> <p>We demonstrate a camera which can image methane gas at video rates, using only a single-pixel detector and structured illumination. The light source is an infrared laser diode operating at 1.651μm tuned to an absorption line of methane gas. The light is structured using an addressable micromirror array to pattern the laser output with a sequence of Hadamard masks. The resulting backscattered light is recorded using a single-pixel InGaAs detector which provides a measure of the correlation between the projected patterns and the gas distribution in the scene. Knowledge of this correlation and the patterns allows an image to be reconstructed of the gas in the scene. For the application of locating gas leaks the frame rate of the camera is of primary importance, which in this case is inversely proportional to the square of the linear resolution. Here we demonstrate gas imaging at ~25 fps while using 256 mask patterns (corresponding to an image resolution of 16×16). To aid the task of locating the source of the gas emission, we overlay an upsampled and smoothed image of the low-resolution gas image onto a high-resolution color image of the scene, recorded using a standard CMOS camera. We demonstrate for an illumination of only 5mW across the field-of-view imaging of a methane gas leak of ~0.2 litres/minute from a distance of ~1 metre.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28773656','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28773656"><span>The Development of High-Density Vertical Silicon Nanowires and Their Application in a Heterojunction Diode.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chang, Wen-Chung; Su, Sheng-Chien; Wu, Chia-Ching</p> <p>2016-06-30</p> <p>Vertically aligned p-type silicon nanowire (SiNW) arrays were fabricated through metal-assisted chemical etching (MACE) of Si wafers. An indium tin oxide/indium zinc oxide/silicon nanowire (ITO/IZO/SiNW) heterojunction diode was formed by depositing ITO and IZO thin films on the vertically aligned SiNW arrays. The structural and electrical properties of the resulting ITO/IZO/SiNW heterojunction diode were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and current-voltage (I-V) measurements. Nonlinear and rectifying I-V properties confirmed that a heterojunction diode was successfully formed in the ITO/IZO/SiNW structure. The diode had a well-defined rectifying behavior, with a rectification ratio of 550.7 at 3 V and a turn-on voltage of 2.53 V under dark conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920038832&hterms=gay&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgay','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920038832&hterms=gay&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgay"><span>A 128 x 128 InGaAs detector array for 1.0 - 1.7 microns</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Olsen, G.; Joshi, A.; Lange, M.; Woodruff, K.; Mykietyn, E.; Gay, D.; Ackley, D.; Erickson, G.; Ban, V.; Staller, C.</p> <p>1990-01-01</p> <p>A two-dimensional 128 x 128 detector array for the 1.0 - 1.7 micron spectral region has been demonstrated with indium gallium arsenide. The 30 micron square pixels had 60 micron spacing in both directions and were designed to be compatible with a 2D Reticon multiplexer. Dark currents below 100 pA, capacitance near 0.1 pF, and quantum efficiencies above 80 percent were measured. Probe maps of dark current and quantum efficiency are presented along with pixel dropout data and wafer yield which was as high as 99.89 percent (7 dropouts) in an area of 6528 pixels and 99.37 percent (103 dropouts) over an entire 128 x 128 pixel region.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20820594','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20820594"><span>Photochemical induced growth and aggregation of metal nanoparticles in diode-array spectrophotometer via excited dimethyl-sulfoxide.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zidki, Tomer; Cohen, Haim; Meyerstein, Dan</p> <p>2010-10-21</p> <p>Ag(0) and Au(0) nanoparticles suspended in dilute aqueous solutions containing (CH(3))(2)SO are photochemically unstable. The light source of a diode-array spectrophotometer induces, within less than a minute, particle growth and aggregation. The results indicate that this process is triggered by UV light absorption by the (CH(3))(2)SO.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070021467','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070021467"><span>Degradation of the Adhesive Properties of MD-944 Diode Tape by Simulated Low Earth Orbit Environmental Factors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Albyn, K.; Finckenor, M.</p> <p>2006-01-01</p> <p>The International Space Station (ISS) solar arrays utilize MD-944 diode tape with silicone pressure-sensitive adhesive to protect the underlying diodes and also provide a high-emittance surface. On-orbit, the silicone adhesive will be exposed and ultimately convert to a glass-like silicate due to atomic oxygen (AO). The current operational plan is to retract ISS solar array P6 and leave it stored under load for a long duration (6 mo or more). The exposed silicone adhesive must not cause the solar array to stick to itself or cause the solar array to fail during redeployment. The Environmental Effects Branch at Marshall Space Flight Center, under direction from the ISS Program Office Environments Team, performed simulated space environment exposures with 5-eV AO, near ultraviolet radiation and ionizing radiation. The exposed diode tape samples were put under preload and then the resulting blocking force was measured using a tensile test machine. Test results indicate that high-energy AO, ultraviolet radiation, and electron ionizing radiation exposure all reduce the blocking force for a silicone-to-silicone bond. AO exposure produces the most significant reduction in blocking force</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770015520','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770015520"><span>Diode pumped Nd:YAG laser development</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reno, C. W.; Herzog, D. G.</p> <p>1976-01-01</p> <p>A low power Nd:YAG laser was constructed which employs GaAs injection lasers as a pump source. Power outputs of 125 mW TEM CW with the rod at 250 K and the pump at 180 K were achieved for 45 W input power to the pump source. Operation of the laser, with array and laser at a common heat sink temperature of 250 K, was inhibited by difficulties in constructing long-life GaAs LOC laser arrays. Tests verified pumping with output power of 20 to 30 mW with rod and pump at 250 K. Although life tests with single LOC GaAs diodes were somewhat encouraging (with single diodes operating as long as 9000 hours without degradation), failures of single diodes in arrays continue to occur, and 50 percent power is lost in a few hundred hours at 1 percent duty factor. Because of the large recent advances in the state of the art of CW room temperature AlGaAs diodes, their demonstrated lifetimes of greater than 5,000 hours, and their inherent advantages for this task, it is recommended that these sources be used for further CW YAG injection laser pumping work.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NanoL..18.2666F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NanoL..18.2666F"><span>Template-Assisted Scalable Nanowire Networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Friedl, Martin; Cerveny, Kris; Weigele, Pirmin; Tütüncüoglu, Gozde; Martí-Sánchez, Sara; Huang, Chunyi; Patlatiuk, Taras; Potts, Heidi; Sun, Zhiyuan; Hill, Megan O.; Güniat, Lucas; Kim, Wonjong; Zamani, Mahdi; Dubrovskii, Vladimir G.; Arbiol, Jordi; Lauhon, Lincoln J.; Zumbühl, Dominik M.; Fontcuberta i Morral, Anna</p> <p>2018-04-01</p> <p>Topological qubits based on Majorana fermions have the potential to revolutionize the emerging field of quantum computing by making information processing significantly more robust to decoherence. Nanowires (NWs) are a promising medium for hosting these kinds of qubits, though branched NWs are needed to perform qubit manipulations. Here we report gold-free templated growth of III-V NWs by molecular beam epitaxy using an approach that enables patternable and highly regular branched NW arrays on a far greater scale than what has been reported thus far. Our approach relies on the lattice-mismatched growth of InAs on top of defect-free GaAs nanomembranes (NMs) yielding laterally-oriented, low-defect InAs and InGaAs NWs whose shapes are determined by surface and strain energy minimization. By controlling NM width and growth time, we demonstrate the formation of compositionally graded NWs with cross-sections less than 50 nm. Scaling the NWs below 20 nm leads to the formation of homogenous InGaAs NWs which exhibit phase-coherent, quasi-1D quantum transport as shown by magnetoconductance measurements. These results are an important advance towards scalable topological quantum computing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29579392','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29579392"><span>Template-Assisted Scalable Nanowire Networks.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Friedl, Martin; Cerveny, Kris; Weigele, Pirmin; Tütüncüoglu, Gozde; Martí-Sánchez, Sara; Huang, Chunyi; Patlatiuk, Taras; Potts, Heidi; Sun, Zhiyuan; Hill, Megan O; Güniat, Lucas; Kim, Wonjong; Zamani, Mahdi; Dubrovskii, Vladimir G; Arbiol, Jordi; Lauhon, Lincoln J; Zumbühl, Dominik M; Fontcuberta I Morral, Anna</p> <p>2018-04-11</p> <p>Topological qubits based on Majorana Fermions have the potential to revolutionize the emerging field of quantum computing by making information processing significantly more robust to decoherence. Nanowires are a promising medium for hosting these kinds of qubits, though branched nanowires are needed to perform qubit manipulations. Here we report a gold-free templated growth of III-V nanowires by molecular beam epitaxy using an approach that enables patternable and highly regular branched nanowire arrays on a far greater scale than what has been reported thus far. Our approach relies on the lattice-mismatched growth of InAs on top of defect-free GaAs nanomembranes yielding laterally oriented, low-defect InAs and InGaAs nanowires whose shapes are determined by surface and strain energy minimization. By controlling nanomembrane width and growth time, we demonstrate the formation of compositionally graded nanowires with cross-sections less than 50 nm. Scaling the nanowires below 20 nm leads to the formation of homogeneous InGaAs nanowires, which exhibit phase-coherent, quasi-1D quantum transport as shown by magnetoconductance measurements. These results are an important advance toward scalable topological quantum computing.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JaJAP..40.6852K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JaJAP..40.6852K"><span>Quasi-CW 110 kW AlGaAs Laser Diode Array Module for Inertial Fusion Energy Laser Driver</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawashima, Toshiyuki; Kanzaki, Takeshi; Matsui, Ken; Kato, Yoshinori; Matsui, Hiroki; Kanabe, Tadashi; Yamanaka, Masanobu; Nakatsuka, Masahiro; Izawa, Yasukazu; Nakai, Sadao; Miyamoto, Masahiro; Kan, Hirofumi; Hiruma, Teruo</p> <p>2001-12-01</p> <p>We have successfully demonstrated a large aperture 803 nm AlGaAs diode laser module as a pump source for a 1053 nm, 10 J output Nd:glass slab laser amplifier for diode-pumped solid-state laser (DPSSL) fusion driver. Detailed performance results of the laser diode module are presented, including bar package and stack configuration, and their thermal design and analysis. A sufficiently low thermal impedance of the stack was realized by combining backplane liquid cooling configuration with modular bar package architecture. Total peak power of 110 kW and electrical to optical conversion efficiency of 46% were obtained from the module consisting of a total of 1000 laser diode bars. A peak intensity of 2.6 kW/cm2 was accomplished across an emitting area of 418 mm× 10 mm. Currently, this laser diode array module with a large two-dimensional aperture is, to our knowledge, the only operational pump source for the high output energy DPSSL.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21863179','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21863179"><span>Synthesis and characterization of axial heterojunction inorganic-organic semiconductor nanowire arrays.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Nan; Qian, Xuemin; Lin, Haowei; Liu, Huibiao; Li, Yongjun; Li, Yuliang</p> <p>2011-11-07</p> <p>The end-to-end P-N heterojunction nanowire arrays combined organic (poly[1,4-bis(pyrrol-2-yl)benzene], BPB) and inorganic (CdS) molecules have been successfully designed and fabricated. The electrical properties of P-N heterojunctions of organic-inorganic nanowire arrays were investigated. The diode nature and rectifying feature of P-N heterojunction nanowire arrays were observed. The rectification ratio of the diode increased from 29.9 to 129.7 as the illumination intensity increased. The material exhibits a new property, which is an improvement in the integration of the physical and chemical properties of the two independent components.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080013396&hterms=control+group+design&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcontrol%2Bgroup%2Bdesign','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080013396&hterms=control+group+design&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcontrol%2Bgroup%2Bdesign"><span>Promoting Robust Design of Diode Lasers for Space: A National Initiative</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tratt, David M.; Amzajerdian, Farzin; Kashem, Nasir B.; Shapiro, Andrew A.; Mense, Allan T.</p> <p>2007-01-01</p> <p>The Diode-laser Array Working Group (DAWG) is a national-level consumer/provider forum for discussion of engineering and manufacturing issues which influence the reliability and survivability of high-power broad-area laser diode devices in space, with an emphasis on laser diode arrays (LDAs) for optical pumping of solid-state laser media. The goals of the group are to formulate and validate standardized test and qualification protocols, operational control recommendations, and consensus manufacturing and certification standards. The group is using reliability and lifetime data collected by laser diode manufacturers and the user community to develop a set of standardized guidelines for specifying and qualifying laser diodes for long-duration operation in space, the ultimate goal being to promote an informed U.S. Government investment and procurement strategy for assuring the availability and durability of space-qualified LDAs. The group is also working to establish effective implementation of statistical design techniques at the supplier design, development, and manufacturing levels to help reduce product performance variability and improve product reliability for diodes employed in space applications</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5456864','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5456864"><span>The Development of High-Density Vertical Silicon Nanowires and Their Application in a Heterojunction Diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chang, Wen-Chung; Su, Sheng-Chien; Wu, Chia-Ching</p> <p>2016-01-01</p> <p>Vertically aligned p-type silicon nanowire (SiNW) arrays were fabricated through metal-assisted chemical etching (MACE) of Si wafers. An indium tin oxide/indium zinc oxide/silicon nanowire (ITO/IZO/SiNW) heterojunction diode was formed by depositing ITO and IZO thin films on the vertically aligned SiNW arrays. The structural and electrical properties of the resulting ITO/IZO/SiNW heterojunction diode were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and current−voltage (I−V) measurements. Nonlinear and rectifying I−V properties confirmed that a heterojunction diode was successfully formed in the ITO/IZO/SiNW structure. The diode had a well-defined rectifying behavior, with a rectification ratio of 550.7 at 3 V and a turn-on voltage of 2.53 V under dark conditions. PMID:28773656</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1174411','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1174411"><span>Beam position monitor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf</p> <p>2003-07-22</p> <p>An apparatus for determining the position of an x-ray beam relative to a desired beam axis. Where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in an a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5415..561S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5415..561S"><span>Airborne laser-diode-array illuminator assessment for the night vision's airborne mine-detection arid test</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stetson, Suzanne; Weber, Hadley; Crosby, Frank J.; Tinsley, Kenneth; Kloess, Edmund; Nevis, Andrew J.; Holloway, John H., Jr.; Witherspoon, Ned H.</p> <p>2004-09-01</p> <p>The Airborne Littoral Reconnaissance Technologies (ALRT) project has developed and tested a nighttime operational minefield detection capability using commercial off-the-shelf high-power Laser Diode Arrays (LDAs). The Coastal System Station"s ALRT project, under funding from the Office of Naval Research (ONR), has been designing, developing, integrating, and testing commercial arrays using a Cessna airborne platform over the last several years. This has led to the development of the Airborne Laser Diode Array Illuminator wide field-of-view (ALDAI-W) imaging test bed system. The ALRT project tested ALDAI-W at the Army"s Night Vision Lab"s Airborne Mine Detection Arid Test. By participating in Night Vision"s test, ALRT was able to collect initial prototype nighttime operational data using ALDAI-W, showing impressive results and pioneering the way for final test bed demonstration conducted in September 2003. This paper describes the ALDAI-W Arid Test and results, along with processing steps used to generate imagery.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1103..501V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1103..501V"><span>Proposed Use of Zero Bias Diode Arrays as Thermal Electric Noise Rectifiers and Non-Thermal Energy Harvesters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valone, Thomas F.</p> <p>2009-03-01</p> <p>The well known built-in voltage potential for some select semiconductor p-n junctions and various rectifying devices is proposed to be favorable for generating DC electricity at "zero bias" (with no DC bias voltage applied) in the presence of Johnson noise or 1/f noise which originates from the quantum vacuum (Koch et al., 1982). The 1982 Koch discovery that certain solid state devices exhibit measurable quantum noise has also recently been labeled a finding of dark energy in the lab (Beck and Mackey, 2004). Tunnel diodes are a class of rectifiers that are qualified and some have been credited with conducting only because of quantum fluctuations. Microwave diodes are also good choices since many are designed for zero bias operation. A completely passive, unamplified zero bias diode converter/detector for millimeter (GHz) waves was developed by HRL Labs in 2006 under a DARPA contract, utilizing a Sb-based "backward tunnel diode" (BTD). It is reported to be a "true zero-bias diode." It was developed for a "field radiometer" to "collect thermally radiated power" (in other words, 'night vision'). The diode array mounting allows a feed from horn antenna, which functions as a passive concentrating amplifier. An important clue is the "noise equivalent power" of 1.1 pW per root hertz and the "noise equivalent temperature difference" of 10° K, which indicate sensitivity to Johnson noise (Lynch, et al., 2006). There also have been other inventions such as "single electron transistors" that also have "the highest signal to noise ratio" near zero bias. Furthermore, "ultrasensitive" devices that convert radio frequencies have been invented that operate at outer space temperatures (3 degrees above zero point: 3° K). These devices are tiny nanotech devices which are suitable for assembly in parallel circuits (such as a 2-D array) to possibly produce zero point energy direct current electricity with significant power density (Brenning et al., 2006). Photovoltaic p-n junction cells are also considered for possible higher frequency ZPE transduction. Diode arrays of self-assembled molecular rectifiers or preferably, nano-sized cylindrical diodes are shown to reasonably provide for rectification of electron fluctuations from thermal and non-thermal ZPE sources to create an alternative energy DC electrical generator in the picowatt per diode range.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1174783','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1174783"><span>Cylindrical microlens with an internally reflecting surface and a method of fabrication</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Beach, Raymond J.; Freitas, Barry L.</p> <p>2004-03-23</p> <p>A fast (high numerical aperture) cylindrical microlens, which includes an internally reflective surface, that functions to deviate the direction of the light that enters the lens from its original propagation direction is employed in optically conditioning laser diodes, laser diode arrays and laser diode bars.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/880308','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/880308"><span>A Cylindrical Microlens With An Internally Reflective Surface And A Method Of Fabrication</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Beach, Raymond J.; Freitas, Barry L.</p> <p>2005-09-27</p> <p>A fast (high numerical aperture) cylindrical microlens, which includes an internally reflective surface, that functions to deviate the direction of the light that enters the lens from its original propagation direction is employed in optically conditioning laser diodes, laser diode arrays and laser diode bars.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2285140','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2285140"><span>Construction of a fast, inexpensive rapid-scanning diode-array detector and spectrometer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carter, T P; Baek, H K; Bonninghausen, L; Morris, R J; van Wart, H E</p> <p>1990-10-01</p> <p>A 512-element diode-array spectroscopic detection system capable of acquiring multiple spectra at a rate of 5 ms per spectrum with an effective scan rate of 102.9 kHz has been constructed. Spectra with fewer diode elements can also be acquired at scan rates up to 128 kHz. The detector utilizes a Hamamatsu silicon photodiode-array sensor that is interfaced to Hamamatsu driver/amplifier and clock generator boards and a DRA laboratories 12-bit 160-kHz analog-to-digital converter. These are standard, commercially available devices which cost approximately $3500. The system is interfaced to and controlled by an IBM XT microcomputer. Detailed descriptions of the home-built detector housing and control/interface circuitry are presented and its application to the study of the reaction of horseradish peroxidase with hydrogen peroxide is demonstrated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10553E..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10553E..02B"><span>III-nitride nanowire LEDs and diode lasers: monolithic light sources on (001) Si emitting in the 600-1300nm range</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhattacharya, P.; Hazari, A.; Jahangir, S.</p> <p>2018-02-01</p> <p>GaN-based nanowire heterostructure arrays epitaxially grown on (001)Si substrates have unique properties and present the potential to realize useful devices. The active light-emitting region in the nanowire heterostructures are usually InGaN disks, whose composition can be varied to tune the emission wavelength. We have demonstrated light emitting diodes and edgeemitting diode lasers with power outputs 10mW with emission in the 600-1300nm wavelength range. These light sources are therefore useful for a variety of applications, including silicon photonics. Molecular beam epitaxial growth of the nanowire heterostructure arrays on (001)Si substrates and the characteristics of 1.3μm nanowire array edge emitting lasers, guided wave photodiodes and a monolithic photonic integrated circuit designed for 1.3μm operation are described.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10514E..0HC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10514E..0HC"><span>Advancements of ultra-high peak power laser diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crawford, D.; Thiagarajan, P.; Goings, J.; Caliva, B.; Smith, S.; Walker, R.</p> <p>2018-02-01</p> <p>Enhancements of laser diode epitaxy in conjunction with process and packaging improvements have led to the availability of 1cm bars capable of over 500W peak power at near-infrared wavelengths (770nm to 1100nm). Advances in cooler design allow for multi-bar stacks with bar-to-bar pitches as low as 350μm and a scalable package architecture enabled a single diode assembly with total peak powers of over 1MegaWatt of peak power. With the addition of micro-optics, overall array brightness greater than 10kW/cm2 was achieved. Performance metrics of barbased diode lasers specifically engineered for high peak power and high brightness at wavelengths and pulse conditions commonly used to pump a variety of fiber and solid-state materials are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20940991','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20940991"><span>Directional control of infrared antenna-coupled tunnel diodes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Slovick, Brian A; Bean, Jeffrey A; Krenz, Peter M; Boreman, Glenn D</p> <p>2010-09-27</p> <p>Directional control of received infrared radiation is demonstrated with a phased-array antenna connected by a coplanar strip transmission line to a metal-oxide-metal (MOM) tunnel diode. We implement a MOM diode to ensure that the measured response originates from the interference of infrared antenna currents at specific locations in the array. The reception angle of the antenna is altered by shifting the diode position along the transmission line connecting the antenna elements. By fabricating the devices on a quarter wave dielectric layer above a ground plane, narrow beam widths of 35° FWHM in power and reception angles of ± 50° are achieved with minimal side lobe contributions. Measured radiation patterns at 10.6 μm are substantiated by electromagnetic simulations as well as an analytic interference model.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040079713&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddiode%2Blaser%2BCW','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040079713&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddiode%2Blaser%2BCW"><span>Qualification of Laser Diode Arrays for Mercury Laser Altimeter Mission</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stephen, Mark; Vasilyev, Aleksey; Schafer, John; Allan, Graham R.</p> <p>2004-01-01</p> <p>NASA's requirements for high reliability, high performance satellite laser instruments have driven the investigation of many critical components; specifically, 808 nm laser diode array (LDA) pump devices. The MESSENGER mission is flying the Mercury Laser Altimeter (MLA) which is a diode-pumped Nd:YAG laser instrument designed to map the topography of Mercury. The environment imposed on the instrument by the orbital dynamics places special requirements on the laser diode arrays. In order to limit the radiative heating of the satellite from the surface of Mercury, the satellite is designed to have a highly elliptical orbit. The satellite will heat near perigee and cool near apogee. The laser power is cycled during these orbits so that the laser is on for only 30 minutes (perigee) in a 12 hour orbit. The laser heats 10 C while powered up and cools while powered down. In order to simulate these operational conditions, we designed a test to measure the LDA performance while being temperature and power cycled. Though the mission requirements are specific to NASA and performance requirements are derived from unique operating conditions, the results are general and widely applicable. We present results on the performance of twelve LDAs operating for several hundred million pulses. The arrays are 100 watt, quasi-CW, conductively-cooled, 808 nm devices. Prior to testing, we fully characterize each device to establish a baseline for individual array performance and status. Details of this characterization can be found in reference. Arrays are divided into four groups and subjected to the temperature and power cycling matrix are shown.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11690685','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11690685"><span>A linear diode array (JFD-5) for match line in vivo dosimetry in photon and electron beams; evaluation for a chest wall irradiation technique.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Essers, M; van Battum, L; Heijmen, B J</p> <p>2001-11-01</p> <p>In vivo dosimetry using thermoluminiscence detectors (TLD) is routinely performed in our institution to determine dose inhomogeneities in the match line region during chest wall irradiation. However, TLDs have some drawbacks: online in vivo dosimetry cannot be performed; generally, doses delivered by the contributing fields are not measured separately; measurement analysis is time consuming. To overcome these problems, the Joined Field Detector (JFD-5), a detector for match line in vivo dosimetry based on diodes, has been developed. This detector and its characteristics are presented. The JFD-5 is a linear array of 5 p-type diodes. The middle three diodes, used to measure the dose in the match line region, are positioned at 5-mm intervals. The outer two diodes, positioned at 3-cm distance from the central diode, are used to measure the dose in the two contributing fields. For three JFD-5 detectors, calibration factors for different energies, and sensitivity correction factors for non-standard field sizes, patient skin temperature, and oblique incidence have been determined. The accuracy of penumbra and match line dose measurements has been determined in phantom studies and in vivo. Calibration factors differ significantly between diodes and between photon and electron beams. However, conversion factors between energies can be applied. The correction factor for temperature is 0.35%/ degrees C, and for oblique incidence 2% at maximum. The penumbra measured with the JFD-5 agrees well with film and linear diode array measurements. JFD-5 in vivo match line dosimetry reproducibility was 2.0% (1 SD) while the agreement with TLD was 0.999+/-0.023 (1 SD). The JFD-5 can be used for accurate, reproducible, and fast on-line match line in vivo dosimetry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070011645','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070011645"><span>High Power Laser Diode Array Qualification and Guidelines for Space Flight Environments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eegholm, Niels; Ott, Melanie; Stephen, Mark; Leidecker, Henning</p> <p>2005-01-01</p> <p>Semiconductor laser diodes emit coherent light by simulated emission generated inside the cavity formed by the cleaved end facets of a slab of semiconductor that is typically less than a millimeter in any dimension for single emitters. The diode is pumped by current injection in the p-n junction through the metallic contacts. Laser diodes emitting in the range of 0.8 micron to 1.06 micron have a wide variety of applications from pumping erbium doped fiber amplifiers, dual-clad fiber lasers, solid-state lasers used in telecom, aerospace, military, medical purposes and all the way to CD players, laser printers and other consumer and industrial products. Laser diode bars have many single emitters side by side and spaced approximately .5 mm on a single slab of semiconductor material approximately .5 mm x 10 mm. The individual emitters are connected in parallel maintaining the voltage at -2V but increasing the current to 50-100A/bar. Stacking these laser diode bars in multiple layers, 2 to 20+ high, yields high power laser diode arrays capable of emitting several hundreds of Watts. Electrically the bars are wired in series increasing the voltage by 2V/bar but maintaining the total current at 50-100A. These arrays are one of the enabling technologies for efficient, high power solid-state lasers. Traditionally these arrays are operated in QCW (Quasi CW) mode with pulse widths 10-200 (mu)s and with repetition rates of 10-200Hz. In QCW mode the wavelength and the output power of the laser reaches steady-state but the temperature does not. The advantage is a substantially higher output power than in CW mode, where the output power would be limited by the internal heating and hence the thermal and heat sinking properties of the device. The down side is a much higher thermal induced mechanical stress caused by the constant heating and cooling cycle inherent to the QCW mode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA221502','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA221502"><span>Transition to Complicated Behavior in Infinite Dimensional Dynamical Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1990-03-01</p> <p>solitons in nonlinear refractive periodic media," Phys. Lett. A. 141 37 (1989). A.3. Dynamics of Free-Running and Injection- Locked Laser Diode Arrays...Fibers * Dynamics of Free-Running and Injection- Locked Laser Diode Arrays I Diffraction/Diffusion Mediated Instabilities in Self-focusing/Defocusing...optics, the interplay between the coherence of solitons and the scattering (Anderson localization) effects of randomness, and the value in looking at</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA413515','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA413515"><span>Micromachined Radio Frequency (RF) Switches and Tunable Capacitors for Higher Performance Secure Communications Systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2003-04-01</p> <p>range filters implemented with traditional semiconductor varactor diodes can require complex series-parallel circuit constructions to achieve sufficient...filter slice of the AIU and the varactor array modules are shown in Fig. 6.2. The complexity of the varactor array is clearly apparent. Further, it is...38 Fig. 6.2: Schematic of F-22 AIU UHF tracking filter, 2-pole filter, and varactor diode assembly</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4257526','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4257526"><span>Electroluminescence of ordered ZnO nanorod array/p-GaN light-emitting diodes with graphene current spreading layer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Ordered ZnO nanorod array/p-GaN heterojunction light-emitting diodes (LEDs) have been fabricated by introducing graphene as the current spreading layer, which exhibit improved electroluminescence performance by comparison to the LED using a conventional structure (indium-tin-oxide as the current spreading layer). In addition, by adjusting the diameter of ZnO nanorod array in use, the light emission of the ZnO nanorod array/p-GaN heterojunction LEDs was enhanced further. This work has great potential applications in solid-state lighting, high performance optoelectronic devices, and so on. PACS 78.60.Fi; 85.60.Jb; 78.67.Lt; 81.10.Dn PMID:25489284</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25489284','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25489284"><span>Electroluminescence of ordered ZnO nanorod array/p-GaN light-emitting diodes with graphene current spreading layer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dong, Jing-Jing; Hao, Hui-Ying; Xing, Jie; Fan, Zhen-Jun; Zhang, Zi-Li</p> <p>2014-01-01</p> <p>Ordered ZnO nanorod array/p-GaN heterojunction light-emitting diodes (LEDs) have been fabricated by introducing graphene as the current spreading layer, which exhibit improved electroluminescence performance by comparison to the LED using a conventional structure (indium-tin-oxide as the current spreading layer). In addition, by adjusting the diameter of ZnO nanorod array in use, the light emission of the ZnO nanorod array/p-GaN heterojunction LEDs was enhanced further. This work has great potential applications in solid-state lighting, high performance optoelectronic devices, and so on. 78.60.Fi; 85.60.Jb; 78.67.Lt; 81.10.Dn.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970041420','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970041420"><span>SiC-Based Schottky Diode Gas Sensors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hunter, Gary W.; Neudeck, Philip G.; Chen, Liang-Yu; Knight, Dak; Liu, Chung-Chiun; Wu, Quing-Hai</p> <p>1997-01-01</p> <p>Silicon carbide based Schottky diode gas sensors are being developed for high temperature applications such as emission measurements. Two different types of gas sensitive diodes will be discussed in this paper. By varying the structure of the diode, one can affect the diode stability as well as the diode sensitivity to various gases. It is concluded that the ability of SiC to operate as a high temperature semiconductor significantly enhances the versatility of the Schottky diode gas sensing structure and will potentially allow the fabrication of a SiC-based gas sensor arrays for versatile high temperature gas sensing applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960020686&hterms=hmx&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dhmx','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960020686&hterms=hmx&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dhmx"><span>Laser Diode Ignition (LDI)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kass, William J.; Andrews, Larry A.; Boney, Craig M.; Chow, Weng W.; Clements, James W.; Merson, John A.; Salas, F. Jim; Williams, Randy J.; Hinkle, Lane R.</p> <p>1994-01-01</p> <p>This paper reviews the status of the Laser Diode Ignition (LDI) program at Sandia National Labs. One watt laser diodes have been characterized for use with a single explosive actuator. Extensive measurements of the effect of electrostatic discharge (ESD) pulses on the laser diode optical output have been made. Characterization of optical fiber and connectors over temperature has been done. Multiple laser diodes have been packaged to ignite multiple explosive devices and an eight element laser diode array has been recently tested by igniting eight explosive devices at predetermined 100 ms intervals.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750029304&hterms=laser+gold&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlaser%2Bgold','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750029304&hterms=laser+gold&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlaser%2Bgold"><span>GaAs laser diode pumped Nd:YAG laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Conant, L. C.; Reno, C. W.</p> <p>1974-01-01</p> <p>A 1.5-mm by 3-cm neodymium-ion doped YAG laser rod has been side pumped using a GaAs laser diode array tuned to the 8680-A absorption line, achieving a multimode average output power of 120 mW for a total input power of 20 W to the final-stage laser diode drivers. The pumped arrangement was designed to take advantage of the high brightness of a conventional GaAs array as a linear source by introducing the pump light through a slit into a close-wrapped gold coated pump cavity. This cavity forms an integrating chamber for the pump light.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890019450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890019450"><span>Monolithic narrow-linewidth InGaAsP semiconductor laser for coherent optical communications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Palfrey, S. L.; Enstrom, R. E.; Longeway, P. A.</p> <p>1989-01-01</p> <p>A design for a monolithic narrow-linewidth InGaAsP diode laser has been developed using a multiple-quantum-well (MQW) extended-passive-cavity distributed-Bragg-reflector (DBR) laser design. Theoretical results indicate that this structure has the potential for a linewidth of 100 kHz or less. To realize this device, a number of the fabrication techniques required to integrate low-loss passive waveguides with active regions have been developed using a DBR laser structure. In addition, the MOCVD growth of InGaAs MQW laser structures has been developed, and threshold current densities as low as 1.6 kA/sq cm have been obtained from broad-stripe InGaAs/InGaAsP separate-confinement-heterostructure MQW lasers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22303390-broadband-superluminescent-diodes-bell-shaped-spectra-emitting-range-from-nm','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22303390-broadband-superluminescent-diodes-bell-shaped-spectra-emitting-range-from-nm"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Andreeva, E V; Il'ichenko, S N; Kostin, Yu O</p> <p></p> <p>Quantum-well superluminescent diodes (SLD) with extremely thin active (AlGa)As and (InGa)As layers and centre wavelengths about 810, 840, 860 and 880 nm are experimentally studied. Their emission spectrum possesses the shape close to Gaussian, its FWHM being 30 – 60 nm depending on the length of the active channel and the level of pumping. Under cw injection, the output power of light-emitting modules based on such SLDs can amount to 1.0 – 25 mW at the output of a single-mode fibre. It is demonstrated that the operation lifetime of these devices exceeds 30000 hours. Based on the light-emitting modules themore » prototypes of combined BroadLighter series light sources are implemented having a bell-shaped spectrum with the width up to 100 nm. (optical radiation sources)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23314640','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23314640"><span>Design and calibration of field deployable ground-viewing radiometers.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anderson, Nikolaus; Czapla-Myers, Jeffrey; Leisso, Nathan; Biggar, Stuart; Burkhart, Charles; Kingston, Rob; Thome, Kurtis</p> <p>2013-01-10</p> <p>Three improved ground-viewing radiometers were built to support the Radiometric Calibration Test Site (RadCaTS) developed by the Remote Sensing Group (RSG) at the University of Arizona. Improved over previous light-emitting diode based versions, these filter-based radiometers employ seven silicon detectors and one InGaAs detector covering a wavelength range of 400-1550 nm. They are temperature controlled and designed for greater stability and lower noise. The radiometer systems show signal-to-noise ratios of greater than 1000 for all eight channels at typical field calibration signal levels. Predeployment laboratory radiance calibrations using a 1 m spherical integrating source compare well with in situ field calibrations using the solar radiation based calibration method; all bands are within ±2.7% for the case tested.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870017753','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870017753"><span>Dynamic characteristics of far-field radiation of current modulated phase-locked diode laser arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elliott, R. A.; Hartnett, K.</p> <p>1987-01-01</p> <p>A versatile and powerful streak camera/frame grabber system for studying the evolution of the near and far field radiation patterns of diode lasers was assembled and tested. Software needed to analyze and display the data acquired with the steak camera/frame grabber system was written and the total package used to record and perform preliminary analyses on the behavior of two types of laser, a ten emitter gain guided array and a flared waveguide Y-coupled array. Examples of the information which can be gathered with this system are presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5177..140Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5177..140Z"><span>Analysis and design of fiber-coupled high-power laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Chongxi; Liu, Yinhui; Xie, Weimin; Du, Chunlei</p> <p>2003-11-01</p> <p>A conclusion that a single conventional optical system could not realize fiber coupled high-power laser diode array is drawn based on the BPP of laser beam. According to the parameters of coupled fiber, a method to couple LDA beams into a single multi-mode fiber including beams collimating, shaping, focusing and coupling is present. The divergence angles after collimating are calculated and analyzed; the shape equation of the collimating micro-lenses array is deprived. The focusing lens is designed. A fiber coupled LDA result with the core diameter of 800 um and numeric aperture of 0.37 is gotten.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4867586','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4867586"><span>Plasmon-enhanced Electrically Light-emitting from ZnO Nanorod Arrays/p-GaN Heterostructure Devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lu, Junfeng; Shi, Zengliang; Wang, Yueyue; Lin, Yi; Zhu, Qiuxiang; Tian, Zhengshan; Dai, Jun; Wang, Shufeng; Xu, Chunxiang</p> <p>2016-01-01</p> <p>Effective and bright light-emitting-diodes (LEDs) have attracted broad interests in fundamental research and industrial application, especially on short wavelength LEDs. In this paper, a well aligned ZnO nanorod arrays grown on the p-GaN substrate to form a heterostructured light-emitting diode and Al nanoparticles (NPs) were decorated to improve the electroluminescence performance. More than 30-folds enhancement of the electroluminescence intensity was obtained compared with the device without Al NPs decoration. The investigation on the stable and transient photoluminescence spectraof the ZnO nanorod arrays before and after Al NPs decoration demonstrated that the metal surface plasmon resonance coupling with excitons of ZnO leads to the enhancement of the internal quantum efficiency (IQE). Our results provide aneffective approach to design novel optoelectronic devices such as light-emitting diodes and plasmonic nanolasers. PMID:27181337</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27181337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27181337"><span>Plasmon-enhanced Electrically Light-emitting from ZnO Nanorod Arrays/p-GaN Heterostructure Devices.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Junfeng; Shi, Zengliang; Wang, Yueyue; Lin, Yi; Zhu, Qiuxiang; Tian, Zhengshan; Dai, Jun; Wang, Shufeng; Xu, Chunxiang</p> <p>2016-05-16</p> <p>Effective and bright light-emitting-diodes (LEDs) have attracted broad interests in fundamental research and industrial application, especially on short wavelength LEDs. In this paper, a well aligned ZnO nanorod arrays grown on the p-GaN substrate to form a heterostructured light-emitting diode and Al nanoparticles (NPs) were decorated to improve the electroluminescence performance. More than 30-folds enhancement of the electroluminescence intensity was obtained compared with the device without Al NPs decoration. The investigation on the stable and transient photoluminescence spectraof the ZnO nanorod arrays before and after Al NPs decoration demonstrated that the metal surface plasmon resonance coupling with excitons of ZnO leads to the enhancement of the internal quantum efficiency (IQE). Our results provide aneffective approach to design novel optoelectronic devices such as light-emitting diodes and plasmonic nanolasers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptCo.304..123L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptCo.304..123L"><span>New dual-curvature microlens array with a high fill-factor for organic light emitting diode modules</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Tsung-Hung; Yang, Hsiharng; Chao, Ching-Kong; Shui, Hung-Chi</p> <p>2013-09-01</p> <p>A new method for fabricating a novel dual-curvature microlens array with a high fill-factor using proximity printing in a lithography process is reported. The lens shapes include dual-curvature, which is a novel shape composed of triangles and hexagons. We utilized UV proximity printing by controlling a printing gap between the mask and substrate. The designed high density microlens array pattern can fabricate a dual-curvature microlens array with a high fill-factor in a photoresist material. It is due to the UV light diffraction which deflects away from the aperture edges and produces a certain exposure in the photoresist material outside the aperture edges. A dual-curvature microlens array with a height ratio of 0.48 can boost axial luminance up to 22%. Therefore, the novel dual-curvature microlens array offers an economical solution for increasing the luminance of organic light emitting diodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000SPIE.4087..863D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000SPIE.4087..863D"><span>Mode locking of a ring cavity semiconductor diode laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Desbiens, Louis; Yesayan, Ararat; Piche, Michel</p> <p>2000-12-01</p> <p>We report new results on the generation and characterization of picosecond pulses from a self-mode-locked semiconductor diode laser. The active medium (InGaAs, 830-870 nm) is a semiconductor optical amplifier whose facets are cut at angle and AR coated. The amplifier is inserted in a three-minor ring cavity. Mode locking is purely passive; it takes place for specific alignment conditions. Trains of counterpropagating pulses are produced, with pulse duration varying from 1 .2 to 2 ps. The spectra of the counterpropagatmg pulses do not fully overlap; their central wavelengths differ by a few nm. The pulse repetition rate has been varied from 0.3 to 3 GHz. The pulses have been compressed to less than 500-fs duration with a grating pair. We discuss some of the potential physical mechanisms that could be involved in the dynamics of the mode-locked regime. Hysteresis in the LI curve has been observed. To characterize the pulses, we introduce the idea of a Pulse Quality Factor, where the pulse duration and spectral width are calculated from the second-order moments of the measured intensity autocorrelation and power spectral density.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/866626','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/866626"><span>Single-element optical injection locking of diode-laser arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hadley, G. Ronald; Hohimer, John P.; Owyoung, Adelbert</p> <p>1988-01-01</p> <p>By optically injecting a single end-element of a semiconductor laser array, both the spatial and spectral emission characteristics of the entire laser array is controlled. With the output of the array locked, the far-field emission angle of the array is continuously scanned over several degrees by varying the injection frequency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840010469','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840010469"><span>Deep diode arrays for X-ray detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zemel, J. N.</p> <p>1984-01-01</p> <p>Temperature gradient zone melting process was used to form p-n junctions in bulk of high purity silicon wafers. These diodes were patterned to form arrays for X-ray spectrometers. The whole fabrication processes for these X-ray detectors are reviewed in detail. The p-n junctions were evaluated by (1) the dark diode I-V measurements, (2) the diode C sub I - V measurements, and (3) the MOS C-V measurements. The results showed that these junctions were linearly graded in charge distribution with low reverse bias leakage current flowing through them (few nA at -10 volts). The X-ray detection experiments showed that an FWHM of 500 eV was obtained from these diodes with a small bias of just -5 volts (for X-ray source Fe55). A theoretical model was proposed to explain the extra peaks found in the energy spectra and a very interesting point - cross talk effect was pointed out. This might be a solution to the problem of making really high resolution X-ray spectrometers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10157E..0RW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10157E..0RW"><span>Investigation of polarization-selective InGaAs sensor with elliptical two-dimensional holes array structure</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Wenbo; Fu, Dong; Hu, Xiaobin; Xu, Yun; Song, Guofeng; Wei, Xin</p> <p>2016-10-01</p> <p>Polarimetric imaging in infrared wavelengths have attracted more and more attention for broad applications in meteorological observations, medicine, remote sensing and many other fields. Metal metamaterial structures are used in nanophotonics in order to localize and enhance the incident electromagnetic field. Here we develop an elliptical gold Two-Dimensional Holes Array (2DHA) in which photons can be manipulated by surface plasmon resonance, and the ellipse introduce the asymmetry to realize a polarization selective function. Strong polarization dependence is observed in the simulated transmission spectra. To further understand the coupling mechanism between gold holes array and InP, the different parameters of the 2DHA are analyzed. It is shown that the polarization axis is perpendicular to the major axis of the ellipse, and the degree of polarization is determined by the aspect ratio of the ellipse. Furthermore, the resonance frequency of the 2DHA shows a linear dependence on the array period, the bandwidth of transmission spectra closely related to duty cycle of the ellipse in each period. This result will establish a basis for the development of innovative polarization selective infrared sensor.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110024141','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110024141"><span>Advanced Rainbow Solar Photovoltaic Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mardesich, Nick; Shields, Virgil</p> <p>2003-01-01</p> <p>Photovoltaic arrays of the rainbow type, equipped with light-concentrator and spectral-beam-splitter optics, have been investigated in a continuing effort to develop lightweight, high-efficiency solar electric power sources. This investigation has contributed to a revival of the concept of the rainbow photovoltaic array, which originated in the 1950s but proved unrealistic at that time because the selection of solar photovoltaic cells was too limited. Advances in the art of photovoltaic cells since that time have rendered the concept more realistic, thereby prompting the present development effort. A rainbow photovoltaic array comprises side-by-side strings of series-connected photovoltaic cells. The cells in each string have the same bandgap, which differs from the bandgaps of the other strings. Hence, each string operates most efficiently in a unique wavelength band determined by its bandgap. To obtain maximum energy-conversion efficiency and to minimize the size and weight of the array for a given sunlight input aperture, the sunlight incident on the aperture is concentrated, then spectrally dispersed onto the photovoltaic array plane, whereon each string of cells is positioned to intercept the light in its wavelength band of most efficient operation. The number of cells in each string is chosen so that the output potentials of all the strings are the same; this makes it possible to connect the strings together in parallel to maximize the output current of the array. According to the original rainbow photovoltaic concept, the concentrated sunlight was to be split into multiple beams by use of an array of dichroic filters designed so that each beam would contain light in one of the desired wavelength bands. The concept has since been modified to provide for dispersion of the spectrum by use of adjacent prisms. A proposal for an advanced version calls for a unitary concentrator/ spectral-beam-splitter optic in the form of a parabolic curved Fresnel-like prism array with panels of photovoltaic cells on two sides (see figure). The surface supporting the solar cells can be adjusted in length or angle to accommodate the incident spectral pattern. An unoptimized prototype assembly containing ten adjacent prisms and three photovoltaic cells with different bandgaps (InGaP2, GaAs, and InGaAs) was constructed to demonstrate feasibility. The actual array will consist of a lightweight thin-film silicon layer of prisms curved into a parabolic shape. In an initial test under illumination of 1 sun at zero airmass, the energy-conversion efficiency of the assembly was found to be 20 percent. Further analysis of the data from this test led to a projected energy conversion efficiency as high as 41 percent for an array of 6 cells or strings (GaP, AlGaAs, InGaP2, GaAs, and two different InGaAs cells or strings).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1025406','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1025406"><span>Super-Lattice Light Emitting Diodes (SLEDS) on GaAs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-03-31</p> <p>Super-Lattice Light Emitting Diodes (SLEDS) on GaAs Kassem Nabha1, Russel Ricker2, Rodney McGee1, Nick Waite1, John Prineas2, Sydney Provence2...infrared light emitting diodes (LEDs). Typically, the LED arrays are mated with CMOS read-in integrated circuit (RIIC) chips using flip-chip bonding. In...circuit (RIIC) chips using flip-chip bonding. This established technology is called Hybrid-super-lattice light emitting diodes (Hybrid- SLEDS). In</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/372583','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/372583"><span>Monolithic microchannel heatsink</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Benett, W.J.; Beach, R.J.; Ciarlo, D.R.</p> <p>1996-08-20</p> <p>A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density. 9 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/870579','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/870579"><span>Monolithic microchannel heatsink</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Benett, William J.; Beach, Raymond J.; Ciarlo, Dino R.</p> <p>1996-01-01</p> <p>A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22212800','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22212800"><span>Improving the optical performance of InGaN light-emitting diodes by altering light reflection and refraction with triangular air prism arrays.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kang, Ji Hye; Kim, Hyung Gu; Chandramohan, S; Kim, Hyun Kyu; Kim, Hee Yun; Ryu, Jae Hyoung; Park, Young Jae; Beak, Yun Seon; Lee, Jeong-Sik; Park, Joong Seo; Lysak, Volodymyr V; Hong, Chang-Hee</p> <p>2012-01-01</p> <p>The effect of triangular air prism (TAP) arrays with different distance-to-width (d/w) ratios on the enhancement of light extraction efficiency (LEE) of InGaN light-emitting diodes (LEDs) is investigated. The TAP arrays embedded at the sapphire/GaN interface act as light reflectors and refractors, and thereby improve the light output power due to the redirection of light into escape cones on both the front and back sides of the LED. Enhancement in radiometric power as high as 117% and far-field angle as low as 129° are realized with a compact arrangement of TAP arrays compared with that of a conventional LED made without TAP arrays under an injection current of 20 mA. © 2012 Optical Society of America</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8731E..0HR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8731E..0HR"><span>Helicopter flight test of 3D imaging flash LIDAR technology for safe, autonomous, and precise planetary landing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert</p> <p>2013-05-01</p> <p>Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GNC) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 μm Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GNC system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of humanmade geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in realtime for later reconstruction into Digital Elevation Maps (DEM's).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090023412&hterms=geology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgeology','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090023412&hterms=geology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgeology"><span>A Multispectral Micro-Imager for Lunar Field Geology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nunez, Jorge; Farmer, Jack; Sellar, Glenn; Allen, Carlton</p> <p>2009-01-01</p> <p>Field geologists routinely assign rocks to one of three basic petrogenetic categories (igneous, sedimentary or metamorphic) based on microtextural and mineralogical information acquired with a simple magnifying lens. Indeed, such observations often comprise the core of interpretations of geological processes and history. The Multispectral Microscopic Imager (MMI) uses multi-wavelength, light-emitting diodes (LEDs) and a substrate-removed InGaAs focal-plane array to create multispectral, microscale reflectance images of geological samples (FOV 32 X 40 mm). Each pixel (62.5 microns) of an image is comprised of 21 spectral bands that extend from 470 to 1750 nm, enabling the discrimination of a wide variety of rock-forming minerals, especially Fe-bearing phases. MMI images provide crucial context information for in situ robotic analyses using other onboard analytical instruments (e.g. XRD), or for the selection of return samples for analysis in terrestrial labs. To further assess the value of the MMI as a tool for lunar exploration, we used a field-portable, tripod-mounted version of the MMI to image a variety of Apollo samples housed at the Lunar Experiment Laboratory, NASA s Johnson Space Center. MMI images faithfully resolved the microtextural features of samples, while the application of ENVI-based spectral end member mapping methods revealed the distribution of Fe-bearing mineral phases (olivine, pyroxene and magnetite), along with plagioclase feldspars within samples. Samples included a broad range of lithologies and grain sizes. Our MMI-based petrogenetic interpretations compared favorably with thin section-based descriptions published in the Lunar Sample Compendium, revealing the value of MMI images for astronaut and rover-mediated lunar exploration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130013472','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130013472"><span>Helicopter Flight Test of 3-D Imaging Flash LIDAR Technology for Safe, Autonomous, and Precise Planetary Landing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert</p> <p>2013-01-01</p> <p>Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GN&C) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 micrometer Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GN&C system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of human-made geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in real-time for later reconstruction into Digital Elevation Maps (DEM's).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160008886','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160008886"><span>Bypass Diode Temperature Tests of a Solar Array Coupon Under Space Thermal Environment Conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon</p> <p>2016-01-01</p> <p>Tests were performed on a 56-cell Advanced Triple Junction solar array coupon whose purpose was to determine margin available for bypass diodes integrated with new, large multi-junction solar cells that are manufactured from a 4-inch wafer. The tests were performed under high vacuum with coupon back side thermal conditions of both cold and ambient. The bypass diodes were subjected to a sequence of increasing discrete current steps from 0 Amp to 2.0 Amp in steps of 0.25 Amp. At each current step, a temperature measurement was obtained via remote viewing by an infrared camera. This paper discusses the experimental methodology, experiment results, and the thermal model.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160008898','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160008898"><span>By-Pass Diode Temperature Tests of a Solar Array Coupon Under Space Thermal Environment Conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie</p> <p>2016-01-01</p> <p>Tests were performed on a 56-cell Advanced Triple Junction solar array coupon whose purpose was to determine margin available for bypass diodes integrated with new, large multi-junction solar cells that are manufactured from a 4-inch wafer. The tests were performed under high vacuum with cold and ambient coupon back-side. The bypass diodes were subjected to a sequence of increasing discrete current steps from 0 Amp to 2.0 Amp in steps of 0.25 Amp. At each current step, a temperature measurement was obtained via remote viewing by an infrared camera. This paper discusses the experimental methodology, including the calibration of the thermal imaging system, and the results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9254E..0ZN','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9254E..0ZN"><span>AlGaInN laser diode technology for defence, security and sensing applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lucja; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.</p> <p>2014-10-01</p> <p>The latest developments in AlGaInN laser diode technology are reviewed for defence, security and sensing applications. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., i.e, 380nm, to the visible, i.e., 530nm, by tuning the indium content of the laser GaInN quantum well. Advantages of using Plasma assisted MBE (PAMBE) compared to more conventional MOCVD epitaxy to grow AlGaInN laser structures are highlighted. Ridge waveguide laser diode structures are fabricated to achieve single mode operation with optical powers of <100mW in the 400-420nm wavelength range that are suitable for telecom applications. Visible light communications at high frequency (up to 2.5 Gbit/s) using a directly modulated 422nm Gallium-nitride (GaN) blue laser diode is reported. High power operation of AlGaInN laser diodes is demonstrated with a single chip, AlGaInN laser diode `mini-array' with a common p-contact configuration at powers up to 2.5W cw at 410nm. Low defectivity and highly uniform GaN substrates allow arrays and bars of nitride lasers to be fabricated. GaN laser bars of up to 5mm with 20 emitters, mounted in a CS mount package, give optical powers up to 4W cw at ~410nm with a common contact configuration. An alternative package configuration for AlGaInN laser arrays allows for each individual laser to be individually addressable allowing complex free-space and/or fibre optic system integration within a very small form-factor.or.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA198855','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA198855"><span>Semiconductor Laser Diode Arrays by MOCVD (Metalorganic Chemical Vapor Deposition)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1987-09-01</p> <p>laser diode arrays are intended to be used as an optical pump for solid state yttrium aluminum garnet (YAG) lasers. In particular, linear uniform...corresponds to about . , 8080A. Such thin layer structures, while difficult to grow by such conventional growth methods as liquid phase epitaxy ( LPE ...lower yet than for DH lasers grown by LPE . , - Conventional self-aligned stripe laser This structure is formed by growing (on an n-type GaAs substrate</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22482154-optimizing-photon-pair-generation-electronically-using-diode-incorporated-silicon-microring-resonator','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22482154-optimizing-photon-pair-generation-electronically-using-diode-incorporated-silicon-microring-resonator"><span>Optimizing photon-pair generation electronically using a p-i-n diode incorporated in a silicon microring resonator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Savanier, Marc, E-mail: msavanier@eng.ucsd.edu; Kumar, Ranjeet; Mookherjea, Shayan, E-mail: smookherjea@eng.ucsd.edu</p> <p></p> <p>Silicon photonic microchips may be useful for compact, inexpensive, room-temperature optically pumped photon-pair sources, which unlike conventional photon-pair generators based on crystals or optical fibers, can be manufactured using CMOS-compatible processes on silicon wafers. It has been shown that photon pairs can be created in simple structures such as microring resonators at a rate of a few hundred kilohertz using less than a milliwatt of optical pump power, based on the process of spontaneous four-wave mixing. To create a practical photon-pair source, however, also requires some way of monitoring the device and aligning the pump wavelength when the temperature varies,more » since silicon resonators are highly sensitive to temperature. In fact, monitoring photodiodes are standard components in classical laser diodes, but the incorporation of germanium or InGaAs photodiodes would raise the cost and fabrication complexity. Here, we present a simple and effective all-electronic technique for finding the optimum operating point for the microring used to generate photon pairs, based on measuring the reverse-biased current in a silicon p-i-n junction diode fabricated across the waveguide that constitutes the silicon microring. We show that by monitoring the current, and using it to tune the pump laser wavelength, the photon-pair generation properties of the microring can be preserved over a temperature range of more than 30 °C.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JaJAP..52eDC22H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JaJAP..52eDC22H"><span>Solution-Processed Organic Thin-Film Transistor Array for Active-Matrix Organic Light-Emitting Diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harada, Chihiro; Hata, Takuya; Chuman, Takashi; Ishizuka, Shinichi; Yoshizawa, Atsushi</p> <p>2013-05-01</p> <p>We developed a 3-in. organic thin-film transistor (OTFT) array with an ink-jetted organic semiconductor. All layers except electrodes were fabricated by solution processes. The OTFT performed well without hysteresis, and the field-effect mobility in the saturation region was 0.45 cm2 V-1 s-1, the threshold voltage was 3.3 V, and the on/off current ratio was more than 106. We demonstrated a 3-in. active-matrix organic light-emitting diode (AMOLED) display driven by the OTFT array. The display could provide clear moving images. The peak luminance of the display was 170 cd/m2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptLT.100...75Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptLT.100...75Z"><span>303 nm continuous wave ultraviolet laser generated by intracavity frequency-doubling of diode-pumped Pr3+:LiYF4 laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Pengfei; Zhang, Chaomin; Zhu, Kun; Ping, Yunxia; Song, Pei; Sun, Xiaohui; Wang, Fuxin; Yao, Yi</p> <p>2018-03-01</p> <p>We demonstrate an efficient and compact ultraviolet laser at 303 nm generated by intracavity frequency doubling of a continuous wave (CW) laser diode-pumped Pr3+:YLiF4 laser at 607 nm. A cesium lithium borate (CLBO) crystal, cut for critical type I phase matching at room temperature, is used for second-harmonic generation (SHG) of the fundamental laser. By using an InGaN laser diode array emitting at 444.3 nm with a maximum incident power of 10 W, as high as 68 mW of CW output power at 303 nm is achieved. The output power stability in 4 h is better than 2.85%. To the best of our knowledge, this is high efficient UV laser generated by frequency doubling of an InGaN laser diode array pumped Pr3+:YLiF4 laser.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1083800','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1083800"><span>Strain-compensated infrared photodetector and photodetector array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kim, Jin K; Hawkins, Samuel D; Klem, John F; Cich, Michael J</p> <p>2013-05-28</p> <p>A photodetector is disclosed for the detection of infrared light with a long cutoff wavelength in the range of about 4.5-10 microns. The photodetector, which can be formed on a semiconductor substrate as an nBn device, has a light absorbing region which includes InAsSb light-absorbing layers and tensile-strained layers interspersed between the InAsSb light-absorbing layers. The tensile-strained layers can be formed from GaAs, InAs, InGaAs or a combination of these III-V compound semiconductor materials. A barrier layer in the photodetector can be formed from AlAsSb or AlGaAsSb; and a contact layer in the photodetector can be formed from InAs, GaSb or InAsSb. The photodetector is useful as an individual device, or to form a focal plane array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1125012','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1125012"><span>Method and system for powering and cooling semiconductor lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Telford, Steven J; Ladran, Anthony S</p> <p></p> <p>A semiconductor laser system includes a diode laser tile. The diode laser tile includes a mounting fixture having a first side and a second side opposing the first side and an array of semiconductor laser pumps coupled to the first side of the mounting fixture. The semiconductor laser system also includes an electrical pulse generator thermally coupled to the diode bar and a cooling member thermally coupled to the diode bar and the electrical pulse generator.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10323E..0BG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10323E..0BG"><span>Compact multichannel MEMS based spectrometer for FBG sensing</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ganziy, D.; Rose, B.; Bang, O.</p> <p>2017-04-01</p> <p>We propose a novel type of compact multichannel MEMS based spectrometer, where we replace the linear detector with a Digital Micromirror Device (DMD). The DMD is typically cheaper and has better pixel sampling than an InGaAs detector used in the 1550 nm range, which leads to cost reduction and better performance. Moreover, the DMD is a 2D array, which means that multichannel systems can be implemented without any additional optical components in the spectrometer. This makes the proposed interrogator highly cost-effective. The digital nature of the DMD also provides opportunities for advanced programmable spectroscopy.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8730E..0CM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8730E..0CM"><span>Flexible amorphous silicon PIN diode x-ray detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marrs, Michael; Bawolek, Edward; Smith, Joseph T.; Raupp, Gregory B.; Morton, David</p> <p>2013-05-01</p> <p>A low temperature amorphous silicon (a-Si) thin film transistor (TFT) and amorphous silicon PIN photodiode technology for flexible passive pixel detector arrays has been developed using active matrix display technology. The flexible detector arrays can be conformed to non-planar surfaces with the potential to detect x-rays or other radiation with an appropriate conversion layer. The thin, lightweight, and robust backplanes may enable the use of highly portable x-ray detectors for use in the battlefield or in remote locations. We have fabricated detector arrays up to 200 millimeters along the diagonal on a Gen II (370 mm x 470 mm rectangular substrate) using plasma enhanced chemical vapor deposition (PECVD) a-Si as the active layer and PECVD silicon nitride (SiN) as the gate dielectric and passivation. The a-Si based TFTs exhibited an effective saturation mobility of 0.7 cm2/V-s, which is adequate for most sensing applications. The PIN diode material was fabricated using a low stress amorphous silicon (a-Si) PECVD process. The PIN diode dark current was 1.7 pA/mm2, the diode ideality factor was 1.36, and the diode fill factor was 0.73. We report on the critical steps in the evolution of the backplane process from qualification of the low temperature (180°C) TFT and PIN diode process on the 150 mm pilot line, the transfer of the process to flexible plastic substrates, and finally a discussion and demonstration of the scale-up to the Gen II (370 x 470 mm) panel scale pilot line.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.415....1L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.415....1L"><span>Comparative study on stained InGaAs quantum wells for high-speed optical-interconnect VCSELs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Hui; Jia, Xiaowei</p> <p>2018-05-01</p> <p>The gain-carrier characteristics of InGaAs quantum well for 980 nm high-speed, energy-efficient vertical-cavity surface-emitting lasers are investigated. We specially studied the potentially InGaAs quantum well designs can be used for the active region of energy-efficient, temperature-stable 980-nm VCSEL, which introduced a quantum well gain peak wavelength-to-cavity resonance wavelength offset to improve the dynamic performance at high operation temperature. Several candidate quantum wells are being compared in theory and measurement. We found that ∼5 nm InGaAs QW with ∼6 nm barrier thickness is suitable for the active region of high-speed optical interconnect 980 nm VCSELs, and no significant improvement in the 20% range of In content of InGaAs QWs. The results are useful for next generation green photonic device design.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5794..403S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5794..403S"><span>Wide-field airborne laser diode array illuminator: demonstration results</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suiter, H. R.; Holloway, J. H., Jr.; Tinsley, K. R.; Pham, C. N.; Kloess, E. C., III; Witherspoon, N. H.; Stetson, S.; Crosby, F.; Nevis, A.; McCarley, K. A.; Seales, T. C.</p> <p>2005-06-01</p> <p>The Airborne Littoral Reconnaissance Technology (ALRT) program has successfully demonstrated the Wide-Field Airborne Laser Diode Array Illuminator (ALDAI-W). This illuminator is designed to illuminate a large area from the air with limited power, weight, and volume. A detection system, of which the ALDAI-W is a central portion, is capable of detecting surface-laid minefields in absolute darkness, extending the allowed mission times to night operations. This will be an overview report, giving processing results and suggested paths for additional development.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1029771','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1029771"><span>Characterization of Aluminum Magnesium Alloy Reverse Sensitized via Heat Treatment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-09-01</p> <p>been on ships that had seen an unknown cycle of painting - stripping -repainting, so some variation was expected. 16 The exact age and range of...Figure 44. Effect of Temperature on Al-Mg Alloys. Adapted from [9]. d. Other heat treatment techniques – high power diode laser (HPDL) arrays Because...25] B. Baker et. al, "Use of High-Power diode Laser Arrays for Pre- and Post- Weld Heating During Friction Stir Welding of Steels," in Friction</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6325707','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6325707"><span>Low-cost laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Freitas, B.L.; Skidmore, J.A.</p> <p>1999-06-01</p> <p>A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost. 19 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872318','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872318"><span>Low-cost laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Freitas, Barry L.; Skidmore, Jay A.</p> <p>1999-01-01</p> <p>A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4235651','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4235651"><span>Toward optimizing patient-specific IMRT QA techniques in the accurate detection of dosimetrically acceptable and unacceptable patient plans</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McKenzie, Elizabeth M.; Balter, Peter A.; Stingo, Francesco C.; Jones, Jimmy; Followill, David S.; Kry, Stephen F.</p> <p>2014-01-01</p> <p>Purpose: The authors investigated the performance of several patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) dosimeters in terms of their ability to correctly identify dosimetrically acceptable and unacceptable IMRT patient plans, as determined by an in-house-designed multiple ion chamber phantom used as the gold standard. A further goal was to examine optimal threshold criteria that were consistent and based on the same criteria among the various dosimeters. Methods: The authors used receiver operating characteristic (ROC) curves to determine the sensitivity and specificity of (1) a 2D diode array undergoing anterior irradiation with field-by-field evaluation, (2) a 2D diode array undergoing anterior irradiation with composite evaluation, (3) a 2D diode array using planned irradiation angles with composite evaluation, (4) a helical diode array, (5) radiographic film, and (6) an ion chamber. This was done with a variety of evaluation criteria for a set of 15 dosimetrically unacceptable and 9 acceptable clinical IMRT patient plans, where acceptability was defined on the basis of multiple ion chamber measurements using independent ion chambers and a phantom. The area under the curve (AUC) on the ROC curves was used to compare dosimeter performance across all thresholds. Optimal threshold values were obtained from the ROC curves while incorporating considerations for cost and prevalence of unacceptable plans. Results: Using common clinical acceptance thresholds, most devices performed very poorly in terms of identifying unacceptable plans. Grouping the detector performance based on AUC showed two significantly different groups. The ion chamber, radiographic film, helical diode array, and anterior-delivered composite 2D diode array were in the better-performing group, whereas the anterior-delivered field-by-field and planned gantry angle delivery using the 2D diode array performed less well. Additionally, based on the AUCs, there was no significant difference in the performance of any device between gamma criteria of 2%/2 mm, 3%/3 mm, and 5%/3 mm. Finally, optimal cutoffs (e.g., percent of pixels passing gamma) were determined for each device and while clinical practice commonly uses a threshold of 90% of pixels passing for most cases, these results showed variability in the optimal cutoff among devices. Conclusions: IMRT QA devices have differences in their ability to accurately detect dosimetrically acceptable and unacceptable plans. Field-by-field analysis with a MapCheck device and use of the MapCheck with a MapPhan phantom while delivering at planned rotational gantry angles resulted in a significantly poorer ability to accurately sort acceptable and unacceptable plans compared with the other techniques examined. Patient-specific IMRT QA techniques in general should be thoroughly evaluated for their ability to correctly differentiate acceptable and unacceptable plans. Additionally, optimal agreement thresholds should be identified and used as common clinical thresholds typically worked very poorly to identify unacceptable plans. PMID:25471949</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25471949','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25471949"><span>Toward optimizing patient-specific IMRT QA techniques in the accurate detection of dosimetrically acceptable and unacceptable patient plans.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McKenzie, Elizabeth M; Balter, Peter A; Stingo, Francesco C; Jones, Jimmy; Followill, David S; Kry, Stephen F</p> <p>2014-12-01</p> <p>The authors investigated the performance of several patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA) dosimeters in terms of their ability to correctly identify dosimetrically acceptable and unacceptable IMRT patient plans, as determined by an in-house-designed multiple ion chamber phantom used as the gold standard. A further goal was to examine optimal threshold criteria that were consistent and based on the same criteria among the various dosimeters. The authors used receiver operating characteristic (ROC) curves to determine the sensitivity and specificity of (1) a 2D diode array undergoing anterior irradiation with field-by-field evaluation, (2) a 2D diode array undergoing anterior irradiation with composite evaluation, (3) a 2D diode array using planned irradiation angles with composite evaluation, (4) a helical diode array, (5) radiographic film, and (6) an ion chamber. This was done with a variety of evaluation criteria for a set of 15 dosimetrically unacceptable and 9 acceptable clinical IMRT patient plans, where acceptability was defined on the basis of multiple ion chamber measurements using independent ion chambers and a phantom. The area under the curve (AUC) on the ROC curves was used to compare dosimeter performance across all thresholds. Optimal threshold values were obtained from the ROC curves while incorporating considerations for cost and prevalence of unacceptable plans. Using common clinical acceptance thresholds, most devices performed very poorly in terms of identifying unacceptable plans. Grouping the detector performance based on AUC showed two significantly different groups. The ion chamber, radiographic film, helical diode array, and anterior-delivered composite 2D diode array were in the better-performing group, whereas the anterior-delivered field-by-field and planned gantry angle delivery using the 2D diode array performed less well. Additionally, based on the AUCs, there was no significant difference in the performance of any device between gamma criteria of 2%/2 mm, 3%/3 mm, and 5%/3 mm. Finally, optimal cutoffs (e.g., percent of pixels passing gamma) were determined for each device and while clinical practice commonly uses a threshold of 90% of pixels passing for most cases, these results showed variability in the optimal cutoff among devices. IMRT QA devices have differences in their ability to accurately detect dosimetrically acceptable and unacceptable plans. Field-by-field analysis with a MapCheck device and use of the MapCheck with a MapPhan phantom while delivering at planned rotational gantry angles resulted in a significantly poorer ability to accurately sort acceptable and unacceptable plans compared with the other techniques examined. Patient-specific IMRT QA techniques in general should be thoroughly evaluated for their ability to correctly differentiate acceptable and unacceptable plans. Additionally, optimal agreement thresholds should be identified and used as common clinical thresholds typically worked very poorly to identify unacceptable plans.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730038000&hterms=Separation+powers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DSeparation%2Bof%2Bpowers','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730038000&hterms=Separation+powers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DSeparation%2Bof%2Bpowers"><span>Power subsystem performance prediction /PSPP/ computer program.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weiner, H.; Weinstein, S.</p> <p>1972-01-01</p> <p>A computer program which simulates the operation of the Viking Orbiter Power Subsystem has been developed. The program simulates the characteristics and interactions of a solar array, battery, battery charge controls, zener diodes, power conditioning equipment, and the battery spacecraft and zener diode-spacecraft thermal interfaces. This program has been used to examine the operation of the Orbiter power subsystem during critical phases of the Viking mission - from launch, through midcourse maneuvers, Mars orbital insertion, orbital trims, Lander separation, solar occultations and unattended operation - until the end of the mission. A typical computer run for the first 24 hours after launch is presented which shows the variations in solar array, zener diode, battery charger, batteries and user load characteristics during this period.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20820281','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20820281"><span>Modeling of the gain distribution for diode pumping of a solid-state laser rod with nonimaging optics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koshel, R J; Walmsley, I A</p> <p>1993-03-20</p> <p>We investigate the absorption distribution in a cylindrical gain medium that is pumped by a source of distributed laser diodes by means of a pump cavity developed from the edge-ray principle of nonimaging optics. The performance of this pumping arrangement is studied by using a nonsequential, numerical, three-dimensional ray-tracing scheme. A figure of merit is defined for the pump cavities that takes into account the coupling efficiency and uniformity of the absorption distribution. It is found that the nonimaging pump cavity maintains a high coupling efficiency with extended two-dimensional diode arrays and obtains a fairly uniform absorption distribution. The nonimaging cavity is compared with two other designs: a close-coupled side-pumped cavity and an imaging design in the form of a elliptical cavity. The nonimaging cavity has a better figure of merit per diode than these two designs. It also permits the use of an extended, sparse, two-dimensional diode array, which reduces thermal loading of the source and eliminates all cavity optics other than the main reflector.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171596','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171596"><span>Optical and Thermal Analyses of High-Power Laser Diode Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vasilyev, Aleksey; Allan, Graham R.; Schafer, John; Stephen, Mark A.; Young, Stefano</p> <p>2004-01-01</p> <p>An important need, especially for space-borne applications, is the early identification and rejection of laser diode arrays which may fail prematurely. The search for reliable failure predictors is ongoing and has led to the development of two techniques, infrared imagery and monitoring the Temporally-resolved and Spectrally-Resolved (TSR) optical output from which temperature of the device can be measured. This is in addition to power monitoring on long term burn stations. A direct measurement of the temperature of the active region is an important parameter as the lifetime of Laser Diode Arrays (LDA) decreases exponentially with increasing temperature. We measure the temperature from time-resolving the spectral emission in an analogous method to Voss et al. In this paper we briefly discuss the measurement setup and present temperature data derived from thermal images and TSR data for two differently designed high-power 808 nanometer LDA packages of similar specification operated in an electrical and thermal environment that mimic the expected operational conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1378946','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1378946"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.</p> <p></p> <p>An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22250746-low-noise-low-jitter-pixels-cmos-single-photon-avalanche-diodes-array-single-photon-counting-from-nm-nm','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22250746-low-noise-low-jitter-pixels-cmos-single-photon-avalanche-diodes-array-single-photon-counting-from-nm-nm"><span>Low-noise low-jitter 32-pixels CMOS single-photon avalanche diodes array for single-photon counting from 300 nm to 900 nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Scarcella, Carmelo; Tosi, Alberto, E-mail: alberto.tosi@polimi.it; Villa, Federica</p> <p>2013-12-15</p> <p>We developed a single-photon counting multichannel detection system, based on a monolithic linear array of 32 CMOS SPADs (Complementary Metal-Oxide-Semiconductor Single-Photon Avalanche Diodes). All channels achieve a timing resolution of 100 ps (full-width at half maximum) and a photon detection efficiency of 50% at 400 nm. Dark count rate is very low even at room temperature, being about 125 counts/s for 50 μm active area diameter SPADs. Detection performance and microelectronic compactness of this CMOS SPAD array make it the best candidate for ultra-compact time-resolved spectrometers with single-photon sensitivity from 300 nm to 900 nm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...122n4901M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...122n4901M"><span>Phased laser diode array permits selective excitation of ultrasonic guided waves in coated bone-mimicking tubes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moilanen, Petro; Salmi, Ari; Kilappa, Vantte; Zhao, Zuomin; Timonen, Jussi; Hæggström, Edward</p> <p>2017-10-01</p> <p>This paper validates simulation predictions, which state that specific modes could be enhanced in quantitative ultrasonic bone testing. Tunable selection of ultrasonic guided wave excitation is useful in non-destructive testing since it permits the mediation of energy into diagnostically useful modes while reducing the energy mediated into disturbing contributions. For instance, it is often challenging to distinguish and extract the useful modes from ultrasound signals measured in bone covered by a soft tissue. We show that a laser diode array can selectively excite ultrasound in bone mimicking phantoms. A fiber-coupled diode array (4 elements) illuminated two solid tubes (2-3 mm wall thickness) embraced by an opaque soft-tissue mimicking elastomer coating (5 mm thick). A predetermined time delay matching the selected mode and frequency was employed between the outputs of the elements. The generated ultrasound was detected by a 215 kHz piezo receiver. Our results suggest that this array reduces the disturbances caused by the elastomer cover and so pave way to permit non-contacting in vivo guided wave ultrasound assessment of human bones. The implementation is small, inexpensive, and robust in comparison with the conventional pulsed lasers.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110004361','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110004361"><span>Technique for Radiometer and Antenna Array Calibration with a Radiated Noise Diode</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Srinivasan, Karthik; Limaye, Ashutosh; Laymon, Charles; Meyer, Paul</p> <p>2009-01-01</p> <p>This paper presents a new technique to calibrate a microwave radiometer and antenna array system. This calibration technique uses a radiated noise source in addition to two calibration sources internal to the radiometer. The method accurately calibrates antenna arrays with embedded active devices (such as amplifiers) which are used extensively in active phased array antennas.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29495813','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29495813"><span>Evaluation of fiber Bragg grating sensor interrogation using InGaAs linear detector arrays and Gaussian approximation on embedded hardware.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, Saurabh; Amrutur, Bharadwaj; Asokan, Sundarrajan</p> <p>2018-02-01</p> <p>Fiber Bragg Grating (FBG) sensors have become popular for applications related to structural health monitoring, biomedical engineering, and robotics. However, for successful large scale adoption, FBG interrogation systems are as important as sensor characteristics. Apart from accuracy, the required number of FBG sensors per fiber and the distance between the device in which the sensors are used and the interrogation system also influence the selection of the interrogation technique. For several measurement devices developed for applications in biomedical engineering and robotics, only a few sensors per fiber are required and the device is close to the interrogation system. For these applications, interrogation systems based on InGaAs linear detector arrays provide a good choice. However, their resolution is dependent on the algorithms used for curve fitting. In this work, a detailed analysis of the choice of algorithm using the Gaussian approximation for the FBG spectrum and the number of pixels used for curve fitting on the errors is provided. The points where the maximum errors occur have been identified. All comparisons for wavelength shift detection have been made against another interrogation system based on the tunable swept laser. It has been shown that maximum errors occur when the wavelength shift is such that one new pixel is included for curve fitting. It has also been shown that an algorithm with lower computation cost compared to the more popular methods using iterative non-linear least squares estimation can be used without leading to the loss of accuracy. The algorithm has been implemented on embedded hardware, and a speed-up of approximately six times has been observed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10177E..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10177E..03F"><span>Development of low-SWaP and low-noise InGaAs detectors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fraenkel, R.; Berkowicz, E.; Bikov, L.; Elishkov, R.; Giladi, A.; Hirsh, I.; Ilan, E.; Jakobson, C.; Kondrashov, P.; Louzon, E.; Nevo, I.; Pivnik, I.; Tuito, A.; Vasserman, S.</p> <p>2017-02-01</p> <p>In recent years SCD has developed InGaAs/InP technology for Short-Wave Infrared (SWIR) imaging. The first product, Cardinal 640, has a 640×512 (VGA) format at 15μm pitch, and more than two thousand units have already been delivered to customers. Recently we have also introduced Cardinal 1280 which is an SXGA array with 10μm pitch aimed for long-range high end platforms [1]. One of the big challenges facing the SWIR technology is its proliferation to widespread low cost and low SWaP applications, specifically Low Light Level (LLL) and Image Intensifier (II) replacements. In order to achieve this goal we have invested and combined efforts in several design and development directions: 1. Optimization of the InGaAs pixel array, reducing the dark current below 2fA at 20° C in order to save TEC cooling power under harsh light and environmental conditions. 2. Design of a new "Low Noise" ROIC targeting 15e noise floor and improved active imaging capabilities 3. Design of compact, low SWaP and low cost packages. In this context we have developed 2 types of packages: a non-hermetic package with thermo-electric cooler (TEC) and a hermetic TEC-Less ceramic package. 4. Development of efficient TEC-Less algorithms for optimal imaging at both day-light and low light level conditions. The result of these combined efforts is a compact low SWaP detector that provides equivalent performance to Gen III image intensifier under starlight conditions. In this paper we will present results from lab and field experiments that will support this claim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RScI...89b5102K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RScI...89b5102K"><span>Evaluation of fiber Bragg grating sensor interrogation using InGaAs linear detector arrays and Gaussian approximation on embedded hardware</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Saurabh; Amrutur, Bharadwaj; Asokan, Sundarrajan</p> <p>2018-02-01</p> <p>Fiber Bragg Grating (FBG) sensors have become popular for applications related to structural health monitoring, biomedical engineering, and robotics. However, for successful large scale adoption, FBG interrogation systems are as important as sensor characteristics. Apart from accuracy, the required number of FBG sensors per fiber and the distance between the device in which the sensors are used and the interrogation system also influence the selection of the interrogation technique. For several measurement devices developed for applications in biomedical engineering and robotics, only a few sensors per fiber are required and the device is close to the interrogation system. For these applications, interrogation systems based on InGaAs linear detector arrays provide a good choice. However, their resolution is dependent on the algorithms used for curve fitting. In this work, a detailed analysis of the choice of algorithm using the Gaussian approximation for the FBG spectrum and the number of pixels used for curve fitting on the errors is provided. The points where the maximum errors occur have been identified. All comparisons for wavelength shift detection have been made against another interrogation system based on the tunable swept laser. It has been shown that maximum errors occur when the wavelength shift is such that one new pixel is included for curve fitting. It has also been shown that an algorithm with lower computation cost compared to the more popular methods using iterative non-linear least squares estimation can be used without leading to the loss of accuracy. The algorithm has been implemented on embedded hardware, and a speed-up of approximately six times has been observed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11312761','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11312761"><span>Determination of flavonoids in plant material by HPLC with diode-array and electro-array detections.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mattila, P; Astola, J; Kumpulainen, J</p> <p>2000-12-01</p> <p>A high-performance liquid chromatographic (HPLC) method with in-line connected diode-array (DAD) and electro-array (EC) detection to identify and quantify 17 flavonoids in plant-derived foods is described. Catechins were extracted from the samples using ethyl acetate, and quantification of these compounds was performed with the EC detector. Other flavonoids were quantified with DAD after acid hydrolysis. The methods developed were effective for the determination of catechins and other flavonoids in plant-derived foods. Responses of the detection systems were linear within the range evaluated, 20-200 ng/injection (DAD) and 20-100 ng/injection (EC), with correlation coefficients exceeding 0.999. Coefficient of variation was under 10.5%, and recoveries of flavonoids ranged from 70 to 124%. Purity of the flavonoid peaks was confirmed by combining the spectral and voltammetric data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4717831','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4717831"><span>Processes for design, construction and utilisation of arrays of light-emitting diodes and light-emitting diode-coupled optical fibres for multi-site brain light delivery</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bernstein, Jacob G.; Allen, Brian D.; Guerra, Alexander A.; Boyden, Edward S.</p> <p>2016-01-01</p> <p>Optogenetics enables light to be used to control the activity of genetically targeted cells in the living brain. Optical fibers can be used to deliver light to deep targets, and LEDs can be spatially arranged to enable patterned light delivery. In combination, arrays of LED-coupled optical fibers can enable patterned light delivery to deep targets in the brain. Here we describe the process flow for making LED arrays and LED-coupled optical fiber arrays, explaining key optical, electrical, thermal, and mechanical design principles to enable the manufacturing, assembly, and testing of such multi-site targetable optical devices. We also explore accessory strategies such as surgical automation approaches as well as innovations to enable low-noise concurrent electrophysiology. PMID:26798482</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1260215','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1260215"><span>LED module with high index lens</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.</p> <p>2016-07-05</p> <p>An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940027942','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940027942"><span>High power diode lasers for solid-state laser pumps</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Linden, Kurt J.; Mcdonnell, Patrick N.</p> <p>1994-01-01</p> <p>The development and commercial application of high power diode laser arrays for use as solid-state laser pumps is described. Such solid-state laser pumps are significantly more efficient and reliable than conventional flash-lamps. This paper describes the design and fabrication of diode lasers emitting in the 780 - 900 nm spectral region, and discusses their performance and reliability. Typical measured performance parameters include electrical-to-optical power conversion efficiencies of 50 percent, narrow-band spectral emission of 2 to 3 nm FWHM, pulsed output power levels of 50 watts/bar with reliability values of over 2 billion shots to date (tests to be terminated after 10 billion shots), and reliable operation to pulse lengths of 1 ms. Pulse lengths up to 5 ms have been demonstrated at derated power levels, and CW performance at various power levels has been evaluated in a 'bar-in-groove' laser package. These high-power 1-cm stacked-bar arrays are now being manufactured for OEM use. Individual diode laser bars, ready for package-mounting by OEM customers, are being sold as commodity items. Commercial and medical applications of these laser arrays include solid-state laser pumping for metal-working, cutting, industrial measurement and control, ranging, wind-shear/atmospheric turbulence detection, X-ray generation, materials surface cleaning, microsurgery, ophthalmology, dermatology, and dental procedures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013250','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013250"><span>670-GHz Schottky Diode-Based Subharmonic Mixer with CPW Circuits and 70-GHz IF</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chattopadhyay, Goutam; Schlecht, Erich T.; Lee, Choonsup; Lin, Robert H.; Gill, John J.; Mehdi, Imran; Sin, Seth; Deal, William; Loi, Kwok K.; Nam, Peta; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20120013250'); toggleEditAbsImage('author_20120013250_show'); toggleEditAbsImage('author_20120013250_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20120013250_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20120013250_hide"></p> <p>2012-01-01</p> <p>GaAs-based, sub-harmonically pumped Schottky diode mixers offer a number of advantages for array implementation in a heterodyne receiver system. Since the radio frequency (RF) and local oscillator (LO) signals are far apart, system design becomes much simpler. A proprietary planar GaAs Schottky diode process was developed that results in very low parasitic anodes that have cutoff frequencies in the tens of terahertz. This technology enables robust implementation of monolithic mixer and frequency multiplier circuits well into the terahertz frequency range. Using optical and e-beam lithography, and conventional epitaxial layer design with innovative usage of GaAs membranes and metal beam leads, high-performance terahertz circuits can be designed with high fidelity. All of these mixers use metal waveguide structures for housing. Metal machined structures for RF and LO coupling hamper these mixers to be integrated in multi-pixel heterodyne array receivers for spectroscopic and imaging applications. Moreover, the recent developments of terahertz transistors on InP substrate provide an opportunity, for the first time, to have integrated amplifiers followed by Schottky diode mixers in a heterodyne receiver at these frequencies. Since the amplifiers are developed on a planar architecture to facilitate multi-pixel array implementation, it is quite important to find alternative architecture to waveguide-based mixers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1226568','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1226568"><span>Aerosol Optical Depth Value-Added Product for the SAS-He Instrument</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ermold, B; Flynn, CJ; Barnard, J</p> <p>2013-11-27</p> <p>The Shortwave Array Spectroradiometer – Hemispheric (SAS-He) is a ground-based, shadowband instrument that measures the direct and diffuse solar irradiance. In this regard, the instrument is similar to the Multi-Filter Rotating Shadowband Radiometer (MFRSR) – an instrument that has been in the ARM suite of instruments for more than 15 years. However, the two instruments differ significantly in wavelength resolution and range. In particular, the MFRSR only observes the spectrum in six discrete wavelength channels of about 10 nm width from 415 to 940 nm. The SAS-He, in contrast, incorporates two fiber-coupled grating spectrometers: a Si CCD spectrometer with overmore » 2000 pixels covering the range from 325-1040 nm with ~ 2.5 nm resolution ,and an InGaAs array spectrometer with 256 pixels covering the wavelength range from 960-1700 nm with ~ 6 nm resolution.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19547474','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19547474"><span>Optical sectioning microscopes with no moving parts using a micro-stripe array light emitting diode.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poher, V; Zhang, H X; Kennedy, G T; Griffin, C; Oddos, S; Gu, E; Elson, D S; Girkin, M; French, P M W; Dawson, M D; Neil, M A</p> <p>2007-09-03</p> <p>We describe an optical sectioning microscopy system with no moving parts based on a micro-structured stripe-array light emitting diode (LED). By projecting arbitrary line or grid patterns onto the object, we are able to implement a variety of optical sectioning microscopy techniques such as grid-projection structured illumination and line scanning confocal microscopy, switching from one imaging technique to another without modifying the microscope setup. The micro-structured LED and driver are detailed and depth discrimination capabilities are measured and calculated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6295E..0OJ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6295E..0OJ"><span>CMOS minimal array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janesick, James; Cheng, John; Bishop, Jeanne; Andrews, James T.; Tower, John; Walker, Jeff; Grygon, Mark; Elliot, Tom</p> <p>2006-08-01</p> <p>A high performance prototype CMOS imager is introduced. Test data is reviewed for different array formats that utilize 3T photo diode, 5T pinned photo diode and 6T photo gate CMOS pixel architectures. The imager allows several readout modes including progressive scan, snap and windowed operation. The new imager is built on different silicon substrates including very high resistivity epitaxial wafers for deep depletion operation. Data products contained in this paper focus on sensor's read noise, charge capacity, charge transfer efficiency, thermal dark current, RTS dark spikes, QE, pixel cross- talk and on-chip analog circuitry performance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985MiJo...28..197A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985MiJo...28..197A"><span>Monolithic control components for high power mm-waves</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Armstrong, A.; Goodrich, J.; Moroney, W.; Wheeler, D.</p> <p>1985-09-01</p> <p>Monolithic PIN diode arrays are shown to provide significant advances in switching ratios, bandwidth, and high-power capability for millimeter control applications The PIN diodes are arranged in a series/parallel configuration and form an electronically controlled window for switching RF power by applying DC voltage. At Ka band, an SPST switch using the window array (WINAR) design typically has 0.6 dB insertion loss and 22 dB isolation over the 26.5 to 40.0 GHz band. The switch has over 500 W peak power and 25 W average power capability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867997','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867997"><span>Device having two optical ports for switching applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Rosen, Ayre; Stabile, Paul J.</p> <p>1991-09-24</p> <p>A two-sided light-activatable semiconductor switch device having an optical port on each side thereof. The semiconductor device may be a p-i-n diode or of bulk intrinsic material. A two ported p-i-n diode, reverse-biased to "off" by a 1.3 kV dc power supply, conducted 192 A when activated by two 1 kW laser diode arrays, one for each optical port.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8268E..2YM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8268E..2YM"><span>Wide-area SWIR arrays and active illuminators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>MacDougal, Michael; Hood, Andrew; Geske, Jon; Wang, Chad; Renner, Daniel; Follman, David; Heu, Paula</p> <p>2012-01-01</p> <p>We describe the factors that go into the component choices for a short wavelength (SWIR) imager, which include the SWIR sensor, the lens, and the illuminator. We have shown the factors for reducing dark current, and shown that we can achieve well below 1.5 nA/cm2 for 15 μm devices at 7°C. We have mated our InGaAs detector arrays to 640x512 readout integrated integrated circuits (ROICs) to make focal plane arrays (FPAs). In addition, we have fabricated high definition 1920x1080 FPAs for wide field of view imaging. The resulting FPAs are capable of imaging photon fluxes with wavelengths between 1 and 1.6 microns at low light levels. The dark current associated with these FPAs is extremely low, exhibiting a mean dark current density of 0.26 nA/cm2 at 0°C. FLIR has also developed a high definition, 1920x1080, 15 um pitch SWIR sensor. In addition, FLIR has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide low-speckle illumination, provide artifact-free imagery versus conventional laser illuminators.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NIMPA.617..432N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NIMPA.617..432N"><span>Design and characterization of single photon avalanche diodes arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neri, L.; Tudisco, S.; Lanzanò, L.; Musumeci, F.; Privitera, S.; Scordino, A.; Condorelli, G.; Fallica, G.; Mazzillo, M.; Sanfilippo, D.; Valvo, G.</p> <p>2010-05-01</p> <p>During the last years, in collaboration with ST-Microelectronics, we developed a new avalanche photo sensor, single photon avalanche diode (SPAD) see Ref.[S. Privitera, et al., Sensors 8 (2008) 4636 [1];S. Tudisco et al., IEEE Sensors Journal 8 (2008) 1324 [2</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22545288-su-characterization-novel-high-resolution-silicon-monolithic-array-small-field-commissioning-quality-assurance','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22545288-su-characterization-novel-high-resolution-silicon-monolithic-array-small-field-commissioning-quality-assurance"><span>SU-E-T-163: Characterization of a Novel High Resolution 1D Silicon Monolithic Array for Small Field Commissioning and Quality Assurance</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bisello, F; IBA Dosimetry, Schwarzenbruck, DE; McGlade, J</p> <p>2015-06-15</p> <p>Purpose: To study the suitability of a novel 1D silicon monolithic array for dosimetry of small radiation fields and for QA of high dose gradient treatment modalities (IMRT and SBRT). Methods: A 1D array composed of 4 monolithic silicon modules of 64 mm length and 1 mm pixel pitch was developed by IBA Dosimetry. Measurements were carried out for 6MV and 15MV photons on two commercial different linacs (TrueBeam and Clinac iX, Varian Medical Systems, Palo Alto, CA) and for a CyberKnife G4 (Accuray Inc., Sunnyvale, CA). The 1D array was used to measure output factors (OF), profiles and offmore » axis correction factors (OACF) for the Iris CyberKnife variable collimator (5–60 mm). In addition, dose profiles (at the isocenter plane) were measured for multiple IMRT and SBRT treatment plans and compared with those obtained using EDR2radiographic film (Carestream Health, Rochester NY), a commercial 2D diode array and with the dose distribution calculated using a commercial TPS (Eclipse, Varian Medical Systems, Palo Alto, CA). Results: Due to the small pixel pitch of the detector, IMRT and SBRT plan profiles deviate from film measurements by less than 2%. Similarly, the 1D array exhibits better performance than the 2D diode array due to the larger (7 mm) pitch of that device. Iris collimator OFs measured using the 1D silicon array are in good agreement with the commissioning values obtained using a commercial stereotactic diode as well as with published data. Maximum deviations are < 3% for the smallest field (5 and 7.5mm) and below 1% for all other dimensions. Conclusion: We have demonstrated good performances of the array for commissioning of small photon fields and in patient QA, compared with diodes and film typically used in these clinical applications. The technology compares favorably with existing commercial solutions The presenting author is founded by a Marie Curie Early Initial Training Network Fellowship of the European Communitys Seventh Framework Programme under contract number (PITN-GA-2011-289198-ARDENT). The research activity is hosted by IBA Dosimetry, Gmbh.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26974642','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26974642"><span>Photodiode-based cutting interruption sensor for near-infrared lasers.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Adelmann, B; Schleier, M; Neumeier, B; Hellmann, R</p> <p>2016-03-01</p> <p>We report on a photodiode-based sensor system to detect cutting interruptions during laser cutting with a fiber laser. An InGaAs diode records the thermal radiation from the process zone with a ring mirror and optical filter arrangement mounted between a collimation unit and a cutting head. The photodiode current is digitalized with a sample rate of 20 kHz and filtered with a Chebyshev Type I filter. From the measured signal during the piercing, a threshold value is calculated. When the diode signal exceeds this threshold during cutting, a cutting interruption is indicated. This method is applied to sensor signals from cutting mild steel, stainless steel, and aluminum, as well as different material thicknesses and also laser flame cutting, showing the possibility to detect cutting interruptions in a broad variety of applications. In a series of 83 incomplete cuts, every cutting interruption is successfully detected (alpha error of 0%), while no cutting interruption is reported in 266 complete cuts (beta error of 0%). With this remarkable high detection rate and low error rate, the possibility to work with different materials and thicknesses in combination with the easy mounting of the sensor unit also to existing cutting machines highlight the enormous potential for this sensor system in industrial applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830027230','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830027230"><span>Photovoltaic module bypass diode encapsulation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shepard, N. J., Jr.</p> <p>1983-01-01</p> <p>The design and processing techniques necessary to incorporate bypass diodes within the module encapsulant are presented. The Semicon PN junction diode cells were selected. Diode junction to heat spreader thermal resistance measurements, performed on a variety of mounted diode chip types and sizes, have yielded values which are consistently below 1 deg C per watt, but show some instability when thermally cycled over the temperature range from -40 to 150 deg C. Three representative experimental modules, each incorporating integral bypass diode/heat spreader assemblies of various sizes, were designed. Thermal testing of these modules enabled the formulation of a recommended heat spreader plate sizing relationship. The production cost of three encapsulated bypass diode/heat spreader assemblies were compared with similarly rated externally mounted packaged diodes. It is concluded that, when proper designed and installed, these bypass diode devices will improve the overall reliability of a terrestrial array over a 20 year design lifetime.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28362480','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28362480"><span>Flexible Light Emission Diode Arrays Made of Transferred Si Microwires-ZnO Nanofilm with Piezo-Phototronic Effect Enhanced Lighting.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiaoyi; Liang, Renrong; Tao, Juan; Peng, Zhengchun; Xu, Qiming; Han, Xun; Wang, Xiandi; Wang, Chunfeng; Zhu, Jing; Pan, Caofeng; Wang, Zhong Lin</p> <p>2017-04-25</p> <p>Due to the fragility and the poor optoelectronic performances of Si, it is challenging and exciting to fabricate the Si-based flexible light-emitting diode (LED) array devices. Here, a flexible LED array device made of Si microwires-ZnO nanofilm, with the advantages of flexibility, stability, lightweight, and energy savings, is fabricated and can be used as a strain sensor to demonstrate the two-dimensional pressure distribution. Based on piezo-phototronic effect, the intensity of the flexible LED array can be increased more than 3 times (under 60 MPa compressive strains). Additionally, the device is stable and energy saving. The flexible device can still work well after 1000 bending cycles or 6 months placed in the atmosphere, and the power supplied to the flexible LED array is only 8% of the power of the surface-contact LED. The promising Si-based flexible device has wide range application and may revolutionize the technologies of flexible screens, touchpad technology, and smart skin.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA551280','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA551280"><span>Kinetics of the Electric Discharge Pumped Oxygen-Iodine Laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-09-01</p> <p>the (4 4 )Ar s p→ transition at 750 nm to determine the O-atom number density within an oxygen plasma.41 Energy level diagrams for these two states...mechanism for these two excited states is radiative38: 3 3(3 ) (3 ) (844.6 ) (2 1) (2 ) (750.4 ) o Ar A A O p P O s S hv...es s ) 0.90 0.92 0.94 0.96 0.98 1.00 1.02 1.04 1.06 1.08 1.10 1.12 Figure 3.3 The detectivity factor of the InGaAs array used to measure the O2(a</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApPhL.100o1104R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApPhL.100o1104R"><span>Rolled-up nanotechnology for the fabrication of three-dimensional fishnet-type GaAs-metal metamaterials with negative refractive index at near-infrared frequencies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rottler, Andreas; Harland, Malte; Bröll, Markus; Schwaiger, Stephan; Stickler, Daniel; Stemmann, Andrea; Heyn, Christian; Heitmann, Detlef; Mendach, Stefan</p> <p>2012-04-01</p> <p>We propose and demonstrate the fabrication of a three-dimensional fishnet metamaterial by utilizing rolled-up nanotechnology. It consists of 6 alternating layers of silver and (In)GaAs with an array of subwavelength holes "drilled" by focused ion beams. By means of finite-integration technique simulations, we show that the fabricated structure is a single-negative material possessing a negative real part of the refractive index in the near-infrared regime. We show that the fabricated material can be made double negative by slightly changing the size of the holes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4759585','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4759585"><span>Nanoscale imaging of the photoresponse in PN junctions of InGaAs infrared detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xia, Hui; Li, Tian-Xin; Tang, Heng-Jing; Zhu, Liang; Li, Xue; Gong, Hai-Mei; Lu, Wei</p> <p>2016-01-01</p> <p>Electronic layout, such as distributions of charge carriers and electric field, in PN junction is determinant for the photovoltaic devices to realize their functionality. Considerable efforts have been dedicated to the carrier profiling of this specific region with Scanning Probe Microscope, yet reliable analysis was impeded by the difficulty in resolving carriers with high mobility and the unclear surface effect, particularly on compound semiconductors. Here we realize nanometer Scanning Capacitance Microscopic study on the cross-section of InGaAs/InP photodetctors with the featured dC/dV layout of PN junction unveiled for the first time. It enables us to probe the photo-excited minority carriers in junction region and diagnose the performance deficiency of the diode devices. This work provides an illuminating insight into the PN junction for assessing its basic capability of harvesting photo-carriers as well as blocking leakage current in nanoscopic scale. PMID:26892069</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10473E..0UN','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10473E..0UN"><span>SWIR reflectance imaging of demineralization on the occlusal surfaces of teeth beyond 1700 nm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ng, Chung; Simon, Jacob C.; Fried, Daniel; Darling, Cynthia L.</p> <p>2018-02-01</p> <p>Most new lesions are found in the pits and fissures of the occlusal surface. Radiographs have extremely low sensitivity for early occlusal decay and by the time the lesion is severe enough on a radiograph it typically has penetrated well into the dentin and surgical intervention is required. The occlusal surfaces are heavily stained and visual and tactile methods for their detection also have poor sensitivity and specificity. Previous studies at wavelengths beyond 1300-nm have demonstrated that stains are not visible and demineralization on the occlusal surfaces can be viewed without interference from stains. New extended range InGaAs near- IR cameras allow access to wavelengths beyond 1700-nm. The objective of this study was to determine how the contrast of occlusal lesions varies with wavelength from the visible to 2350-nm. The lesion contrast was measured in 55 extracted teeth with suspected occlusal lesions using reflectance measurements from 400- 2350-nm using Si and InGaAs imaging arrays. The highest lesion contrast in reflectance was measured at wavelengths greater than 1700-nm. Stains interfered significantly at wavelengths shorter than 1150-nm. This study indicates that the optimum wavelengths for reflectance imaging decay in the occlusal surfaces are greater than 1700-nm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7686E..0KK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7686E..0KK"><span>Water-cooled hard-soldered kilowatt laser diode arrays operating at high duty cycle</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klumel, Genady; Karni, Yoram; Oppenhaim, Jacob; Berk, Yuri; Shamay, Moshe; Tessler, Renana; Cohen, Shalom; Risemberg, Shlomo</p> <p>2010-04-01</p> <p>High brightness laser diode arrays are increasingly found in defense applications either as efficient optical pumps or as direct energy sources. In many instances, duty cycles of 10- 20 % are required, together with precise optical collimation. System requirements are not always compatible with the use of microchannel based cooling, notwithstanding their remarkable efficiency. Simpler but effective solutions, which will not involve high fluid pressure drops as well as deionized water, are needed. The designer is faced with a number of challenges: effective heat removal, minimization of the built- in and operational stresses as well as precise and accurate fast axis collimation. In this article, we report on a novel laser diode array which includes an integral tap water cooling system. Robustness is achieved by all around hard solder bonding of passivated 940nm laser bars. Far field mapping of the beam, after accurate fast axis collimation will be presented. It will be shown that the design of water cooling channels , proper selection of package materials, careful design of fatigue sensitive parts and active collimation technique allow for long life time and reliability, while not compromising the laser diode array efficiency, optical power density ,brightness and compactness. Main performance characteristics are 150W/bar peak optical power, 10% duty cycle and more than 50% wall plug efficiency with less than 1° fast axis divergence. Lifetime of 0.5 Gshots with less than 10% power degradation has been proved. Additionally, the devices have successfully survived harsh environmental conditions such as thermal cycling of the coolant temperature and mechanical shocks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22830740','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22830740"><span>Technical note: patient-specific quality assurance methods for TomoDirect(TM) whole breast treatment delivery.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Catuzzo, P; Zenone, F; Aimonetto, S; Peruzzo, A; Casanova Borca, V; Pasquino, M; Franco, P; La Porta, M R; Ricardi, U; Tofani, S</p> <p>2012-07-01</p> <p>To investigate the feasibility of implementing a novel approach for patient-specific QA of TomoDirect(TM) whole breast treatment. The most currently used TomoTherapy DQA method, consisting in the verification of the 2D dose distribution in a coronal or sagittal plane of the Cheese Phantom by means of gafchromic films, was compared with an alternative approach based on the use of two commercially available diode arrays, MapCHECK2(TM) and ArcCHECK(TM). The TomoDirect(TM) plans of twenty patients with a primary unilateral breast cancer were applied to a CT scan of the Cheese Phantom and a MVCT dataset of the diode arrays. Then measurements of 2D dose distribution were performed and compared with the calculated ones using the gamma analysis method with different sets of DTA and DD criteria (3%-3 mm, 3%-2 mm). The sensitivity of the diode arrays to detect delivery and setup errors was also investigated. The measured dose distributions showed excellent agreement with the TPS calculations for each detector, with averaged fractions of passed Γ values greater than 95%. The percentage of points satisfying the constraint Γ < 1 was significantly higher for MapCHECK2(TM) than for ArcCHECK(TM) and gafchromic films using both the 3%-3 mm and 3%-2 mm gamma criteria. Both the diode arrays show a good sensitivity to delivery and setup errors using a 3%-2 mm gamma criteria. MapCHECK2™ and ArcCHECK(TM) may fulfill the demands of an adequate system for TomoDirect(TM) patient-specific QA.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19980236805&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddiode%2Blaser%2BCW','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19980236805&hterms=diode+laser+CW&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddiode%2Blaser%2BCW"><span>Thermal Lens Measurement in Diode-Pumped Nd:YAG Zig-Zag Slab</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smoak, M. C.; Kay, R. B.; Coyle, D. B.; Hopf, D.</p> <p>1998-01-01</p> <p>A major advantage that solid state zig-zag slab lasers have over conventional rod-based designs is that a much weaker thermal lens is produced in the slab when side-pumped with Quasi-CW laser diode arrays, particularly if the pump radiation is kept well away from the Brewster-cut ends. This paper reports on a rather strong thermal lens produced when diode pump radiation is collimated into a narrow portion of the zig-zag slab. The collimation of multi-bar pump packages to increase brightness and improve overlap is a direct consequence of designs which seek to maximize performance and efficiency. Our slab design employed a 8.1 cm x 2.5 mm x 5 mm slab with opposing Brewster end faces. It was pumped through the 2.5 mm direction by seven laser diode array packages, each housing four 6OW diode bars, 1 cm in width. The pump face, anti-reflection (AR) coated at 809 nm, was 6.8 cm in width and the 8.1 cm opposing side, high-reflection (HR) coated at 809 nm, reflected the unabsorbed pump beam for a second pass through the slab.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910008029','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910008029"><span>Linear laser diode arrays for improvement in optical disk recording</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alphonse, G. A.; Carlin, D. B.; Connolly, J. C.</p> <p>1990-01-01</p> <p>The development of individually addressable laser diode arrays for multitrack magneto-optic recorders for space stations is discussed. Three multi-element channeled substrate planar (CSP) arrays with output power greater than 30 mW with linear light vs current characteristics and stable single mode spectra were delivered to NASA. These devices have been used to demonstrate for the first time the simultaneous recording of eight data tracks on a 14-inch magneto-optic erasable disk. The yield of these devices is low, mainly due to non-uniformities inherent to the LPE growth that was used to fabricate them. The authors have recently developed the inverted CSP, based on the much more uniform MOCVD growth techniques, and have made low threshold quantum well arrays requiring about three times less current than the CSP to deliver 30 mW CW in a single spatial mode. The inverted CSP is very promising for use in space flight recorder applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/870895','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/870895"><span>Data acquisition system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Shapiro, Stephen L.; Mani, Sudhindra; Atlas, Eugene L.; Cords, Dieter H. W.; Holbrook, Britt</p> <p>1997-01-01</p> <p>A data acquisition circuit for a particle detection system that allows for time tagging of particles detected by the system. The particle detection system screens out background noise and discriminate between hits from scattered and unscattered particles. The detection system can also be adapted to detect a wide variety of particle types. The detection system utilizes a particle detection pixel array, each pixel containing a back-biased PIN diode, and a data acquisition pixel array. Each pixel in the particle detection pixel array is in electrical contact with a pixel in the data acquisition pixel array. In response to a particle hit, the affected PIN diodes generate a current, which is detected by the corresponding data acquisition pixels. This current is integrated to produce a voltage across a capacitor, the voltage being related to the amount of energy deposited in the pixel by the particle. The current is also used to trigger a read of the pixel hit by the particle.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6744E..11C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6744E..11C"><span>Focal plane arrays from UV up to VLWIR</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Costard, E.; Nedelcu, A.; Achouche, M.; Reverchon, J. L.; Truffer, J. P.; Huet, O.; Dua, L.; Robo, J. A.; Marcadet, X.; Brière de l'Isle, N.; Facoetti, H.; Bois, P.</p> <p>2007-10-01</p> <p>Since 2002, the THALES Group has been manufacturing sensitive arrays using QWIP technology based on GaAs and related III-V compounds, at the Alcatel-Thales-III-V Lab (formerly part of THALES Research and Technology Laboratory). In the past researchers claimed many advantages of QWIPs. Uniformity was one of these and has been the key parameter for the production to start. Another widely claimed advantage for QWIPs was the so-called band-gap engineering and versatility of the III-V processing allowing the custom design of quantum structures to fulfil the requirements of specific applications such as very long wavelength (VLWIR) or multispectral detection. In this presentation, we give the status of our LWIR QWIP production line, and also the current status of QWIPs for MWIR (<5μm) and VLWIR (>15μm) arrays. As the QWIP technology cannot cover the full electromagnetic spectrum, we develop other semiconductor compounds for SWIR and UV applications. We present here the status of our first FPA realization in UV with GaN alloy, and at 1.5μm with InGaAs photodiodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA204729','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA204729"><span>Unclassified Publications of Lincoln Laboratory, 1 January-31 December 1987. Volume 13</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1987-12-31</p> <p>Visible-Laser Photochemical Etching of Cr , Mo, and W 5901 High-Speed Electronic Beam Steering Using Injection Locking of a Laser-Diode Array...of High- Power Broad-Area Diode Lasers High-Temperature Point-Contact Transistors and Schottky Diodes Formed on Synthetic Boron- Doped Diamond...SPEECHES MS No. 593IB C02 Laser Radar 6550B Recent Advances in Transition-Metal- Doped Lasers 6714D Radiation Damage in Dry</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1221875','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1221875"><span>Photovoltaic device assembly and method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Keenihan, James R.; Langmaid, Joseph A.; Cleereman, Robert J.; Graham, Andrew T.</p> <p>2015-09-29</p> <p>The present invention is premised upon a connector device and method that can more easily electrically connect a plurality of PV arrays and/or locate these arrays upon a building or structure. It also can optionally provide some additional components (e.g. a bypass diode and/or an indicator means) and can enhance the serviceability of the array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20400821','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20400821"><span>A Pt/TiO(2)/Ti Schottky-type selection diode for alleviating the sneak current in resistance switching memory arrays.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Woo Young; Kim, Gun Hwan; Seok, Jun Yeong; Kim, Kyung Min; Song, Seul Ji; Lee, Min Hwan; Hwang, Cheol Seong</p> <p>2010-05-14</p> <p>This study examined the properties of Schottky-type diodes composed of Pt/TiO(2)/Ti, where the Pt/TiO(2) and TiO(2)/Ti junctions correspond to the blocking and ohmic contacts, respectively, as the selection device for a resistive switching cross-bar array. An extremely high forward-to-reverse current ratio of approximately 10(9) was achieved at 1 V when the TiO(2) film thickness was 19 nm. TiO(2) film was grown by atomic layer deposition at a substrate temperature of 250 degrees C. Conductive atomic force microscopy revealed that the forward current flew locally, which limits the maximum forward current density to < 10 A cm(-2) for a large electrode (an area of approximately 60 000 microm(2)). However, the local current measurement showed a local forward current density as high as approximately 10(5) A cm(-2). Therefore, it is expected that this type of Schottky diode effectively suppresses the sneak current without adverse interference effects in a nano-scale resistive switching cross-bar array with high block density.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptEn..56l4108W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptEn..56l4108W"><span>Polarization effects associated with thermal processing of HY-80 structural steel using high-power laser diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Sheldon S. Q.; Baker, Bradford W.; Rotter, Mark D.; Rubenchik, Alexander M.; Wiechec, Maxwell E.; Brown, Zachary M.; Beach, Raymond J.; Matthews, Manyalibo J.</p> <p>2017-12-01</p> <p>Localized heating of roughened steel surfaces using highly divergent laser light emitted from high-power laser diode arrays was experimentally demonstrated and compared with theoretical predictions. Polarization dependence was analyzed using Fresnel coefficients to understand the laser-induced temperature rise of HY-80 steel plates under 383- to 612-W laser irradiation. Laser-induced, transient temperature distributions were directly measured using bulk thermocouple probes and thermal imaging. Finite-element analysis yielded quantitative assessment of energy deposition and heat transport in HY-80 steel using absorptivity as a tuning parameter. The extracted absorptivity values ranged from 0.62 to 0.75 for S-polarized and 0.63 to 0.85 for P-polarized light, in agreement with partially oxidized iron surfaces. Microstructural analysis using electron backscatter diffraction revealed a heat affected zone for the highest temperature conditions (612 W, P-polarized) as evidence of rapid quenching and an austenite to martensite transformation. The efficient use of diode arrays for laser-assisted advanced manufacturing technologies, such as hybrid friction stir welding, is discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA097187','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA097187"><span>Advanced Wavefront Sensor Concepts.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1981-01-01</p> <p>internal optics (a) Characteristics (see Figure 47) - Intensification with a 256 element linear self scanned diode array - Optical input; lenticular ...34 diameter - Lenticular array input to fiber optics which spread out to tubes - Photon counting for low noise fac- tor (b) Pe r fo rmance - Bialkali...problem in making the lenslet arrays in the pupil divider rectangular. The last optical elements are the lenticular lens arrays. In this group, the first</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22391670-comparison-between-gallium-arsenide-indium-gallium-arsenide-materials-solar-cell-performance-using-silvaco-application','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22391670-comparison-between-gallium-arsenide-indium-gallium-arsenide-materials-solar-cell-performance-using-silvaco-application"><span>The comparison between gallium arsenide and indium gallium arsenide as materials for solar cell performance using Silvaco application</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zahari, Suhaila Mohd; Norizan, Mohd Natashah; Mohamad, Ili Salwani</p> <p>2015-05-15</p> <p>The work presented in this paper is about the development of single and multilayer solar cells using GaAs and InGaAs in AM1.5 condition. The study includes the modeling structure and simulation of the device using Silvaco applications. The performance in term of efficiency of Indium Gallium Arsenide (InGaAs) and GaAs material was studied by modification of the doping concentration and thickness of material in solar cells. The efficiency of the GaAs solar cell was higher than InGaAs solar cell for single layer solar cell. Single layer GaAs achieved an efficiency about 25% compared to InGaAs which is only 2.65% ofmore » efficiency. For multilayer which includes both GaAs and InGaAs, the output power, P{sub max} was 8.91nW/cm² with the efficiency only 8.51%. GaAs is one of the best materials to be used in solar cell as a based compared to InGaAs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006Nanot..17.2736L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006Nanot..17.2736L"><span>InGaAs quantum dots grown on B-type high index GaAs substrates: surface morphologies and optical properties</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, B. L.; Wang, Zh M.; Mazur, Yu I.; Strelchuck, V. V.; Holmes, K.; Lee, J. H.; Salamo, G. J.</p> <p>2006-06-01</p> <p>We systematically investigated the correlation between morphological and optical properties of InGaAs self-assembled quantum dots (QDs) grown by solid-source molecular beam epitaxy on GaAs (n 11)B (n = 9, 8, 7, 5, 3, 2) substrates. Remarkably, all InGaAs QDs on GaAs(n 11)B under investigation show optical properties superior to those for ones on GaAs(100) as regards the photoluminescence (PL) linewidth and intensity. The morphology for growth of InGaAs QDs on GaAs (n 11)B, where n = 9, 8, 7, 5, is observed to have a rounded shape with a higher degree of lateral ordering than that on GaAs(100). The optical property and the lateral ordering are best for QDs grown on a (511)B substrate surface, giving a strong correlation between lateral ordering and PL optical quality. Our results demonstrate the potential for high quality InGaAs QDs on GaAs(n 11)B for optoelectronic applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29475329','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29475329"><span>InGaAsP Mach-Zehnder interferometer optical modulator monolithically integrated with InGaAs driver MOSFET on a III-V CMOS photonics platform.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Jin-Kown; Takagi, Shinichi; Takenaka, Mitsuru</p> <p>2018-02-19</p> <p>We demonstrated the monolithic integration of a carrier-injection InGaAsP Mach-Zehnder interferometer (MZI) optical modulator and InGaAs metal-oxide-semiconductor field-effect transistor (MOSFET) on a III-V-on-insulator (III-V-OI) wafer. A low-resistivity lateral PIN junction was formed along an InGaAsP rib waveguide by Zn diffusion and Ni-InGaAsP alloy, enabling direct driving of the InGaAsP optical modulator by the InGaAs MOSFET. A π phase shift of the InGaAsP optical modulator was obtained through the injection of a drain current from the InGaAs MOSFET with a gate voltage of approximately 1 V. This proof-of-concept demonstration of the monolithic integration of the InGaAsP optical modulator and InGaAs driver MOSFET will enable us to develop high-performance and low-power electronic-photonic integrated circuits on a III-V CMOS photonics platform.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24632685','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24632685"><span>Microfluidic bead-based diodes with targeted circular microchannels for low Reynolds number applications.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sochol, Ryan D; Lu, Albert; Lei, Jonathan; Iwai, Kosuke; Lee, Luke P; Lin, Liwei</p> <p>2014-05-07</p> <p>Self-regulating fluidic components are critical to the advancement of microfluidic processors for chemical and biological applications, such as sample preparation on chip, point-of-care molecular diagnostics, and implantable drug delivery devices. Although researchers have developed a wide range of components to enable flow rectification in fluidic systems, engineering microfluidic diodes that function at the low Reynolds number (Re) flows and smaller scales of emerging micro/nanofluidic platforms has remained a considerable challenge. Recently, researchers have demonstrated microfluidic diodes that utilize high numbers of suspended microbeads as dynamic resistive elements; however, using spherical particles to block fluid flow through rectangular microchannels is inherently limited. To overcome this issue, here we present a single-layer microfluidic bead-based diode (18 μm in height) that uses a targeted circular-shaped microchannel for the docking of a single microbead (15 μm in diameter) to rectify fluid flow under low Re conditions. Three-dimensional simulations and experimental results revealed that adjusting the docking channel geometry and size to better match the suspended microbead greatly increased the diodicity (Di) performance. Arraying multiple bead-based diodes in parallel was found to adversely affect system efficacy, while arraying multiple diodes in series was observed to enhance device performance. In particular, systems consisting of four microfluidic bead-based diodes with targeted circular-shaped docking channels in series revealed average Di's ranging from 2.72 ± 0.41 to 10.21 ± 1.53 corresponding to Re varying from 0.1 to 0.6.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4346830','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4346830"><span>Vacuum Nanohole Array Embedded Phosphorescent Organic Light Emitting Diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jeon, Sohee; Lee, Jeong-Hwan; Jeong, Jun-Ho; Song, Young Seok; Moon, Chang-Ki; Kim, Jang-Joo; Youn, Jae Ryoun</p> <p>2015-01-01</p> <p>Light extraction from organic light-emitting diodes that utilize phosphorescent materials has an internal efficiency of 100% but is limited by an external quantum efficiency (EQE) of 30%. In this study, extremely high-efficiency organic light emitting diodes (OLEDs) with an EQE of greater than 50% and low roll-off were produced by inserting a vacuum nanohole array (VNHA) into phosphorescent OLEDs (PhOLEDs). The resultant extraction enhancement was quantified in terms of EQE by comparing experimentally measured results with those produced from optical modeling analysis, which assumes the near-perfect electric characteristics of the device. A comparison of the experimental data and optical modeling results indicated that the VNHA extracts the entire waveguide loss into the air. The EQE obtained in this study is the highest value obtained to date for bottom-emitting OLEDs. PMID:25732061</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10526E..1JJ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10526E..1JJ"><span>Reliability testing of ultra-low noise InGaAs quad photoreceivers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, Abhay M.; Datta, Shubhashish; Prasad, Narasimha; Sivertz, Michael</p> <p>2018-02-01</p> <p>We have developed ultra-low noise quadrant InGaAs photoreceivers for multiple applications ranging from Laser Interferometric Gravitional Wave Detection, to 3D Wind Profiling. Devices with diameters of 0.5 mm, 1mm, and 2 mm were processed, with the nominal capacitance of a single quadrant of a 1 mm quad photodiode being 2.5 pF. The 1 mm diameter InGaAs quad photoreceivers, using a low-noise, bipolar-input OpAmp circuitry exhibit an equivalent input noise per quadrant of <1.7 pA/√Hz in 2 to 20 MHz frequency range. The InGaAs Quad Photoreceivers have undergone the following reliability tests: 30 MeV Proton Radiation up to a Total Ionizing Dose (TID) of 50 krad, Mechanical Shock, and Sinusoidal Vibration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16949596','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16949596"><span>Detection, characterization and identification of crucifer phytoalexins using high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pedras, M Soledade C; Adio, Adewale M; Suchy, Mojmir; Okinyo, Denis P O; Zheng, Qing-An; Jha, Mukund; Sarwar, Mohammed G</p> <p>2006-11-10</p> <p>We have analyzed 23 crucifer phytoalexins (e.g. brassinin, dioxibrassinin, cyclobrassinin, brassicanals A and C) by HPLC with diode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS) using both negative and positive ion modes. Positive ion mode ESI-MS appeared more sensitive than negative ion mode ESI-MS in detecting this group of compounds. A new HPLC separation method, new LC-MS and LC-MS(2) data and proposed fragmentation pathways, LC retention times, and UV spectra for selected compounds are reported.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989AcSpe..44..197A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989AcSpe..44..197A"><span>Microcontroller interface for diode array spectrometry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aguo, L.; Williams, R. R.</p> <p></p> <p>An alternative to bus-based computer interfacing is presented using diode array spectrometry as a typical application. The new interface consists of an embedded single-chip microcomputer, known as a microcontroller, which provides all necessary digital I/O and analog-to-digital conversion (ADC) along with an unprecedented amount of intelligence. Communication with a host computer system is accomplished by a standard serial interface so this type of interfacing is applicable to a wide range of personal and minicomputers and can be easily networked. Data are acquired asynchronousty and sent to the host on command. New operating modes which have no traditional counterparts are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872916','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872916"><span>High-speed non-contact measuring apparatus for gauging the thickness of moving sheet material</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Grann, Eric B.; Holcomb, David E.</p> <p>2000-01-01</p> <p>An optical measurement apparatus is provided for measuring the thickness of a moving sheet material (18). The apparatus has a pair of optical measurement systems (21, 31) attached to opposing surfaces (14, 16) of a rigid support structure (10). A pair of high-power laser diodes (20,30) and a pair of photodetector arrays (22,32) are attached to the opposing surfaces. Light emitted from the laser diodes is reflected off of the sheet material surfaces (17, 19) and received by the respective photodetector arrays. An associated method for implementing the apparatus is also provided.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160001132','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160001132"><span>Solid-state Image Sensor with Focal-plane Digital Photon-counting Pixel Array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fossum, Eric R.; Pain, Bedabrata</p> <p>1997-01-01</p> <p>A solid-state focal-plane imaging system comprises an NxN array of high gain. low-noise unit cells. each unit cell being connected to a different one of photovoltaic detector diodes, one for each unit cell, interspersed in the array for ultra low level image detection and a plurality of digital counters coupled to the outputs of the unit cell by a multiplexer(either a separate counter for each unit cell or a row of N of counters time shared with N rows of digital counters). Each unit cell includes two self-biasing cascode amplifiers in cascade for a high charge-to-voltage conversion gain (greater than 1mV/e(-)) and an electronic switch to reset input capacitance to a reference potential in order to be able to discriminate detection of an incident photon by the photoelectron (e(-))generated in the detector diode at the input of the first cascode amplifier in order to count incident photons individually in a digital counter connected to the output of the second cascade amplifier. Reseting the input capacitance and initiating self-biasing of the amplifiers occurs every clock cycle of an integratng period to enable ultralow light level image detection by the may of photovoltaic detector diodes under such ultralow light level conditions that the photon flux will statistically provide only a single photon at a time incident on anyone detector diode during any clock cycle.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9819E..20P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9819E..20P"><span>Latest developments of 10μm pitch HgCdTe diode array from the legacy to the extrinsic technology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Péré-Laperne, Nicolas; Berthoz, Jocelyn; Taalat, Rachid; Rubaldo, Laurent; Kerlain, Alexandre; Carrère, Emmanuel; Dargent, Loïc.</p> <p>2016-05-01</p> <p>Sofradir recently presented Daphnis, its latest 10 μm pitch product family. Both Daphnis XGA and HD720 are 10μm pitch mid-wave infrared focal plane array. Development of small pixel pitch is opening the way to very compact products with a high spatial resolution. This new product is taking part in the HOT technology competition allowing reductions in size, weight and power of the overall package. This paper presents the recent developments achieved at Sofradir to make the 10μm pitch HgCdTe focal plane array based on the legacy technology. Electrical and electro-optical characterizations are presented to define the appropriate design of 10μm pitch diode array. The technological tradeoffs are explained to lower the dark current, to keep high quantum efficiency with a high operability above 110K, F/4. Also, Sofradir recently achieved outstanding Modulation Transfer Function (MTF) demonstration at this pixel pitch, which clearly demonstrates the benefit to users of adopting 10μm pixel pitch focal plane array based detectors. Furthermore, the HgCdTe technology has demonstrated an increase of the operating temperature, plus 40K, moving from the legacy to the P-on-n one at a 15μm pitch in mid-wave band. The first realizations using the extrinsic P-on-n technology and the characterizations of diodes with a 10μm pitch neighborhood will be presented in both mid-wave and long-wave bands.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.104l1102E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.104l1102E"><span>Enhanced out-coupling efficiency of organic light-emitting diodes using an nanostructure imprinted by an alumina nanohole array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Endo, Kuniaki; Adachi, Chihaya</p> <p>2014-03-01</p> <p>We demonstrate organic light-emitting diodes (OLEDs) with enhanced out-coupling efficiency containing nanostructures imprinted by an alumina nanohole array template that can be applied to large-emitting-area and flexible devices using a roll-to-roll process. The nanostructures are imprinted on a glass substrate by an ultraviolet nanoimprint process using an alumina nanohole array mold and then an OLED is fabricated on the nanostructures. The enhancement of out-coupling efficiency is proportional to the root-mean-square roughness of the nanostructures, and a maximum improvement of external electroluminescence quantum efficiency of 17% is achieved. The electroluminescence spectra of the OLEDs indicate that this improvement is caused by enhancement of the out-coupling of surface plasmon polaritons.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JaJAP..56i2101B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JaJAP..56i2101B"><span>Enhanced light extraction efficiency of micro-ring array AlGaN deep ultraviolet light-emitting diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bekele Fayisa, Gabisa; Lee, Jong Won; Kim, Jungsub; Kim, Yong-Il; Park, Youngsoo; Kim, Jong Kyu</p> <p>2017-09-01</p> <p>An effective approach to overcome inherently poor light extraction efficiency of AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) is presented. We demonstrated the 5 × 5 array micro-ring DUV LED having an inclined sidewall at the outer perimeter and a p-GaN-removed inner circle of the micro-ring, together with MgF2/Al omnidirectional reflectors. The micro-ring array DUV LED shows remarkably higher light output power by 70% than the reference, consistent with the calculated result, as well as comparable turn-on and operational voltages, which are attributed to the effective extraction of strong transverse-magnetic polarized anisotropic emission and the reduction of the absorption loss by the p-GaN contact layer, simultaneously.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6431717','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6431717"><span>Microlens frames for laser diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Skidmore, J.A.; Freitas, B.L.</p> <p>1999-07-13</p> <p>Monolithic microlens frames enable the fabrication of monolithic laser diode arrays and are manufactured inexpensively with high registration, and with inherent focal length compensation for any lens diameter variation. A monolithic substrate is used to fabricate a low-cost microlens array. The substrate is wet-etched or sawed with a series of v-grooves. The v-grooves can be created by wet-etching, by exploiting the large etch-rate selectivity of different crystal planes. The v-grooves provide a support frame for either cylindrical or custom-shaped microlenses. Because the microlens frames are formed by photolithographic semiconductor batch-processing techniques, they can be formed inexpensively over large areas with precise lateral and vertical registration. The v-groove has an important advantage for preserving the correct focus for lenses of varying diameter. 12 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872388','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872388"><span>Microlens frames for laser diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Skidmore, Jay A.; Freitas, Barry L.</p> <p>1999-01-01</p> <p>Monolithic microlens frames enable the fabrication of monolithic laser diode arrays and are manufactured inexpensively with high registration, and with inherent focal length compensation for any lens diameter variation. A monolithic substrate is used to fabricate a low-cost microlens array. The substrate is wet-etched or sawed with a series of v-grooves. The v-grooves can be created by wet-etching, by exploiting the large etch-rate selectivity of different crystal planes. The v-grooves provide a support frame for either cylindrical or custom-shaped microlenses. Because the microlens frames are formed by photolithographic semiconductor batch-processing techniques, they can be formed inexpensively over large areas with precise lateral and vertical registration. The v-groove has an important advantage for preserving the correct focus for lenses of varying diameter.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3260641','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3260641"><span>A CMOS Time-Resolved Fluorescence Lifetime Analysis Micro-System</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rae, Bruce R.; Muir, Keith R.; Gong, Zheng; McKendry, Jonathan; Girkin, John M.; Gu, Erdan; Renshaw, David; Dawson, Martin D.; Henderson, Robert K.</p> <p>2009-01-01</p> <p>We describe a CMOS-based micro-system for time-resolved fluorescence lifetime analysis. It comprises a 16 × 4 array of single-photon avalanche diodes (SPADs) fabricated in 0.35 μm high-voltage CMOS technology with in-pixel time-gated photon counting circuitry and a second device incorporating an 8 × 8 AlInGaN blue micro-pixellated light-emitting diode (micro-LED) array bump-bonded to an equivalent array of LED drivers realized in a standard low-voltage 0.35 μm CMOS technology, capable of producing excitation pulses with a width of 777 ps (FWHM). This system replaces instrumentation based on lasers, photomultiplier tubes, bulk optics and discrete electronics with a PC-based micro-system. Demonstrator lifetime measurements of colloidal quantum dot and Rhodamine samples are presented. PMID:22291564</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012498','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012498"><span>Reverse bias protected solar array with integrated bypass battery</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Landis, Geoffrey A (Inventor)</p> <p>2012-01-01</p> <p>A method for protecting the photovoltaic cells in a photovoltaic (PV) array from reverse bias damage by utilizing a rechargeable battery for bypassing current from a shaded photovoltaic cell or group of cells, avoiding the need for a bypass diode. Further, the method mitigates the voltage degradation of a PV array caused by shaded cells.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1338737-pinning-flux-diodes-ratchets-vortices-interacting-conformal-pinning-arrays','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1338737-pinning-flux-diodes-ratchets-vortices-interacting-conformal-pinning-arrays"><span>Pinning, flux diodes and ratchets for vortices interacting with conformal pinning arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Olson Reichhardt, C. J.; Wang, Y. L.; Xiao, Z. L.; ...</p> <p>2016-05-31</p> <p>A conformal pinning array can be created by conformally transforming a uniform triangular pinning lattice to produce a new structure in which the six-fold ordering of the original lattice is conserved but where there is a spatial gradient in the density of pinning sites. Here we examine several aspects of vortices interacting with conformal pinning arrays and how they can be used to create a flux flow diode effect for driving vortices in different directions across the arrays. Under the application of an ac drive, a pronounced vortex ratchet effect occurs where the vortices flow in the easy direction ofmore » the array asymmetry. When the ac drive is applied perpendicular to the asymmetry direction of the array, it is possible to realize a transverse vortex ratchet effect where there is a generation of a dc flow of vortices perpendicular to the ac drive due to the creation of a noise correlation ratchet by the plastic motion of the vortices. We also examine vortex transport in experiments and compare the pinning effectiveness of conformal arrays to uniform triangular pinning arrays. In conclusion, we find that a triangular array generally pins the vortices more effectively at the first matching field and below, while the conformal array is more effective at higher fields where interstitial vortex flow occurs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/30898','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/30898"><span>LED traffic signal management system : tech summary.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2016-06-01</p> <p>The light source of a signal module is comprised of an array of multiple individual light emitting diodes (LEDs). : Fading of the array over its operational life is a serious concern of traffic engineers throughout the nation. The : Institute of Tran...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22559625','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22559625"><span>Characterization of a novel two dimensional diode array the "magic plate" as a radiation detector for radiation therapy treatment.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wong, J H D; Fuduli, I; Carolan, M; Petasecca, M; Lerch, M L F; Perevertaylo, V L; Metcalfe, P; Rosenfeld, A B</p> <p>2012-05-01</p> <p>Intensity modulated radiation therapy (IMRT) utilizes the technology of multileaf collimators to deliver highly modulated and complex radiation treatment. Dosimetric verification of the IMRT treatment requires the verification of the delivered dose distribution. Two dimensional ion chamber or diode arrays are gaining popularity as a dosimeter of choice due to their real time feedback compared to film dosimetry. This paper describes the characterization of a novel 2D diode array, which has been named the "magic plate" (MP). It was designed to function as a 2D transmission detector as well as a planar detector for dose distribution measurements in a solid water phantom for the dosimetric verification of IMRT treatment delivery. The prototype MP is an 11 × 11 detector array based on thin (50 μm) epitaxial diode technology mounted on a 0.6 mm thick Kapton substrate using a proprietary "drop-in" technology developed by the Centre for Medical Radiation Physics, University of Wollongong. A full characterization of the detector was performed, including radiation damage study, dose per pulse effect, percent depth dose comparison with CC13 ion chamber and build up characteristics with a parallel plane ion chamber measurements, dose linearity, energy response and angular response. Postirradiated magic plate diodes showed a reproducibility of 2.1%. The MP dose per pulse response decreased at higher dose rates while at lower dose rates the MP appears to be dose rate independent. The depth dose measurement of the MP agrees with ion chamber depth dose measurements to within 0.7% while dose linearity was excellent. MP showed angular response dependency due to the anisotropy of the silicon diode with the maximum variation in angular response of 10.8% at gantry angle 180°. Angular dependence was within 3.5% for the gantry angles ± 75°. The field size dependence of the MP at isocenter agrees with ion chamber measurement to within 1.1%. In the beam perturbation study, the surface dose increased by 12.1% for a 30 × 30 cm(2) field size at the source to detector distance (SDD) of 80 cm whilst the transmission for the MP was 99%. The radiation response of the magic plate was successfully characterized. The array of epitaxial silicon based detectors with "drop-in" packaging showed properties suitable to be used as a simplified multipurpose and nonperturbing 2D radiation detector for radiation therapy dosimetric verification.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994stan.reptQ....C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994stan.reptQ....C"><span>Ultra-high aggregate bandwidth two-dimensional multiple-wavelength diode laser arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang-Hasnain, Connie</p> <p>1994-04-01</p> <p>Two-dimensional (2D) multi-wavelength vertical cavity surface emitting laser (VCSEL) arrays is promising for ultrahigh aggregate capacity optical networks. A 2D VCSEL array emitting 140 distinct wavelengths was reported by implementing a spatially graded layer in the VCSEL structure, which in turn creates a wavelength spread. In this program, we concentrated on novel epitaxial growth techniques to make reproducible and repeatable multi-wavelength VCSEL arrays.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9544E..1WO','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9544E..1WO"><span>Stripe-teeth metamaterial Al- and Nb-based rectennas (Presentation Recording)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Osgood, Richard M.; Giardini, Stephen A.; Carlson, Joel B.; Joghee, Prabhuram; O'Hayre, Ryan P.; Diest, Kenneth; Rothschild, Mordechai</p> <p>2015-09-01</p> <p>Unlike a semiconductor, where the absorption is limited by the band gap, a "microrectenna array" could theoretically very efficiently rectify any desired portion of the infrared frequency spectrum (25 - 400 THz). We investigated vertical metal-insulator-metal (MIM) diodes that rectify vertical high-frequency fields produced by a metamaterial planar stripe-teeth Al or Au array (above the diodes), similar to stripe arrays that have demonstrated near-perfect absorption in the infrared due to critical coupling [1]. Using our design rules that maximize asymmetry (and therefore the component of the electric field pointed into the substrate, analogous to Second Harmonic Generation), we designed, fabricated, and analyzed these metamaterial-based microrectenna arrays. NbOx and Al2O3 were produced by anodization and ALD, respectively. Smaller visible-light Pt-NbOx-Nb rectennas have produced output power when illuminated by visible (514 nm) light [2]. The resonances of these new Au/NbOx/Nb and Al/Al2O3/Al microrectenna arrays, with larger dimensions and more complex nanostructures than in Ref. 1, were characterized by microscopic FTIR microscopy and agreed well with FDTD models, once the experimental refractive index values were entered into the model. Current-voltage measurements were carried out, showed that the Al/Al2O3/Al diodes have very large barrier heights and breakdown voltages, and were compared to our model of the MIM diode. We calculate expected THz-rectification using classical [3] and quantum [4] rectification models, and compare to measurements of direct current output, under infrared illumination. [1] C. Wu, et. al., Phys. Rev. B 84 (2011) 075102. [2] R. M. Osgood III, et. al., Proc. SPIE 8096, 809610 (2011). [3] A. Sanchez, et. al., J. Appl. Phys. 49 (1978) 5270. [4] J. R. Tucker and M. J. Feldman, Rev. of Mod. Phys. 57, (1985)1055.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880000219&hterms=Beer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DBeer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880000219&hterms=Beer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DBeer"><span>Multiple-Diode-Laser Gas-Detection Spectrometer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Webster, Christopher R.; Beer, Reinhard; Sander, Stanley P.</p> <p>1988-01-01</p> <p>Small concentrations of selected gases measured automatically. Proposed multiple-laser-diode spectrometer part of system for measuring automatically concentrations of selected gases at part-per-billion level. Array of laser/photodetector pairs measure infrared absorption spectrum of atmosphere along probing laser beams. Adaptable to terrestrial uses as monitoring pollution or control of industrial processes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26669809','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26669809"><span>Increasing Electrochemiluminescence Intensity of a Wireless Electrode Array Chip by Thousands of Times Using a Diode for Sensitive Visual Detection by a Digital Camera.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qi, Liming; Xia, Yong; Qi, Wenjing; Gao, Wenyue; Wu, Fengxia; Xu, Guobao</p> <p>2016-01-19</p> <p>Both a wireless electrochemiluminescence (ECL) electrode microarray chip and the dramatic increase in ECL by embedding a diode in an electromagnetic receiver coil have been first reported. The newly designed device consists of a chip and a transmitter. The chip has an electromagnetic receiver coil, a mini-diode, and a gold electrode array. The mini-diode can rectify alternating current into direct current and thus enhance ECL intensities by 18 thousand times, enabling a sensitive visual detection using common cameras or smart phones as low cost detectors. The detection limit of hydrogen peroxide using a digital camera is comparable to that using photomultiplier tube (PMT)-based detectors. Coupled with a PMT-based detector, the device can detect luminol with higher sensitivity with linear ranges from 10 nM to 1 mM. Because of the advantages including high sensitivity, high throughput, low cost, high portability, and simplicity, it is promising in point of care testing, drug screening, and high throughput analysis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28517664','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28517664"><span>SU-E-I-107: Suitability of Various Radiation Detectors Used in Radiation Therapy for X-Ray Dosimetry in Computed Tomography.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liebmann, M; Poppe, B; von Boetticher, H</p> <p>2012-06-01</p> <p>Assessment of suitability for X-ray dosimetry in computed tomography of various ionization chambers, diodes and two-dimensional detector arrays primarily used in radiation therapy. An Oldelft X-ray simulation unit was used to irradiate PTW 60008, 60012 dosimetry diodes, PTW 23332, 31013, 31010, 31006 axial symmetrical ionization chambers, PTW 23343, 34001 plane parallel ionization chambers and PTW Starcheck and 2D-Array seven29 as well as a prototype Farmer chamber with a copper wall. Peak potential was varied from 50 kV up to 125 kV and beam qualities were quantified through half-value-layer measurements. Energy response was investigated free in air as well as in 2 cm depth in a solid water phantom and refers to a manufacturer calibrated PTW 60004 diode for kV-dosimetry. The thimble ionization chambers PTW 31010, 31013, the uncapsuled diode PTW 60012 and the PTW 2D-Array seven29 exhibit an energy response deviation in the investigated energy region of approximately 10% or lower thus proving good usability in X-ray dosimetry if higher spatial resolution is needed or rotational irradiations occur. It could be shown that in radiation therapy routinely used detectors are usable in a much lower energy region. The rotational symmetry is of advantage in computed tomography dosimetry and enables dose profile as well as point dose measurements in a suitable phantom for estimation of organ doses. Additional the PTW 2D-Array seven29 can give a quick overview of radiation fields in non-rotating tasks. © 2012 American Association of Physicists in Medicine.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23020359','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23020359"><span>A digital optical phase-locked loop for diode lasers based on field programmable gate array.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Zhouxiang; Zhang, Xian; Huang, Kaikai; Lu, Xuanhui</p> <p>2012-09-01</p> <p>We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382∕MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad(2) and transition time of 100 μs under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83i3104X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83i3104X"><span>A digital optical phase-locked loop for diode lasers based on field programmable gate array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Zhouxiang; Zhang, Xian; Huang, Kaikai; Lu, Xuanhui</p> <p>2012-09-01</p> <p>We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat note line width below 1 Hz, residual mean-square phase error of 0.14 rad2 and transition time of 100 μs under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930069060&hterms=John+Kay&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DJohn%2BKay','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930069060&hterms=John+Kay&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DJohn%2BKay"><span>Diode pumped, regenerative Nd:YAG ring amplifier for space application</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coyle, D. B.; Kay, Richard B.; Degnan, John J.; Krebs, Danny J.; Seery, Bernard D.</p> <p>1992-01-01</p> <p>The study reviews the research and development of a prototype laser used to study one possible method of short-pulse production and amplification, in particular, a pulsed Nd:YAG ring laser pumped by laser diode arrays and injected seeded by a 100-ps source. The diode array pumped, regenerative amplifier consists of only five optical elements, two mirrors, one thin film polarizer, one Nd:YAG crystal, and one pockels cell. The pockels cell performed both as a Q-switch and a cavity dumper for amplified pulse ejection through the thin film polarizer. The total optical efficiency was low principally due to the low gain provided by the 2-bar pumped laser head. After comparison with a computer model, a real seed threshold of about 10 exp -15 J was achieved because only about 0.1 percent of the injected energy mode-matched with the ring.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040085703','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040085703"><span>High Power Laser Diode Arrays for 2-Micron Solid State Coherent Lidars Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Amzajerdian, Farzin; Meadows, Byron; Kavaya, Michael J.; Singh, Upendra; Sudesh, Vikas; Baker, Nathaniel</p> <p>2003-01-01</p> <p>Laser diode arrays are critical components of any diode-pumped solid state laser systems, constraining their performance and reliability. Laser diode arrays (LDAs) are used as the pump source for energizing the solid state lasing media to generate an intense coherent laser beam with a high spatial and spectral quality. The solid state laser design and the characteristics of its lasing materials define the operating wavelength, pulse duration, and power of the laser diodes. The pump requirements for high pulse energy 2-micron solid state lasers are substantially different from those of more widely used 1-micron lasers and in many aspects more challenging [1]. Furthermore, the reliability and lifetime demanded by many coherent lidar applications, such as global wind profiling from space and long-range clear air turbulence detection from aircraft, are beyond the capability of currently available LDAs. In addition to the need for more reliable LDAs with longer lifetime, further improvement in the operational parameters of high power quasi-cw LDAs, such as electrical efficiency, brightness, and duty cycle, are also necessary for developing cost-effective 2-micron coherent lidar systems for applications that impose stringent size, heat dissipation, and power constraints. Global wind sounding from space is one of such applications, which is the main driver for this work as part of NASA s Laser Risk Reduction Program. This paper discusses the current state of the 792 nm LDA technology and the technology areas being pursued toward improving their performance. The design and development of a unique characterization facility for addressing the specific issues associated with the LDAs for pumping 2-micron coherent lidar transmitters and identifying areas of technological improvement will be described. Finally, the results of measurements to date on various standard laser diode packages, as well as custom-designed packages with potentially longer lifetime, will be reported.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10513E..0QW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10513E..0QW"><span>High power vertical stacked and horizontal arrayed diode laser bar development based on insulation micro-channel cooling (IMCC) and hard solder bonding technology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Boxue; Jia, Yangtao; Zhang, Haoyu; Jia, Shiyin; Liu, Jindou; Wang, Weifeng; Liu, Xingsheng</p> <p>2018-02-01</p> <p>An insulation micro-channel cooling (IMCC) has been developed for packaging high power bar-based vertical stack and horizontal array diode lasers, which eliminates many issues caused in its congener packaged by commercial copper formed micro-channel cooler(MCC), such as coefficient of thermal expansion (CTE) mismatch between cooler and diode laser bar, high coolant quality requirement (DI water) and channel corrosion and electro-corrosion induced by DI water if the DI-water quality is not well maintained The IMCC cooler separates water flow route and electrical route, which allows tap-water as coolant without electro-corrosion and therefore prolongs cooler lifetime dramatically and escalated the reliability of these diode lasers. The thickness of ceramic and copper in an IMCC cooler is well designed to minimize the CTE mismatch between laser bar and cooler, consequently, a very low "SMILE" of the laser bar can be achieved for small fast axis divergence after collimation. In additional, gold-tin hard solder bonding technology was also developed to minimize the risk of solder electromigration at high current density and thermal fatigue under hard-pulse operation mode. Testing results of IMCC packaged diode lasers are presented in this report.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820016544','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820016544"><span>Test apparatus for locating shorts during assembly of electrical buses</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deboo, G. J.; Devine, D. L. (Inventor)</p> <p>1981-01-01</p> <p>A test apparatus is described for locating electrical shorts that is especially suited for use while an electrical circuit is being fabricated or assembled. A ring counter derives input pulses from a square wave oscillator. The outputs of the counter are fed through transistors to an array of light emitting diodes. Each diode is connected to an electrical conductor, such as a bus bar, that is to be tested. In the absence of a short between the electrical conductors the diodes are sequentially illuminated. When a short occurs, a comparator/multivibrator circuit triggers an alarm and stops the oscillator and the sequential energization of the diodes. The two diodes that remain illuminated identify the electrical conductors that are shorted.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930018549','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930018549"><span>Superlattice barrier varactors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Raman, C.; Sun, J. P.; Chen, W. L.; Munns, G.; East, J.; Haddad, G.</p> <p>1992-01-01</p> <p>SBV (Single Barrier Varactor) diodes have been proposed as alternatives to Schottky barrier diodes for harmonic multiplier applications. However, these show a higher current than expected. The excess current is due to X valley transport in the barrier. We present experimental results showing that the use of a superlattice barrier and doping spikes in the GaAs depletion regions on either side of the barrier can reduce the excess current and improve the control of the capacitance vs. voltage characteristic. The experimental results consist of data taken from two types of device structures. The first test structure was used to study the performance of AlAs/GaAs superlattice barriers. The wafer was fabricated into 90 micron diameter mesa diodes and the resulting current vs. voltage characteristics were measured. A 10 period superlattice structure with a total thickness of approximately 400 A worked well as an electron barrier. The structure had a current density of about one A/sq cm at one volt at room temperature. The capacitance variation of these structures was small because of the design of the GaAs cladding layers. The second test structure was used to study cladding layer designs. These wafers were InGaAs and InAlAs layers lattice matched to an InP substrate. The layers have n(+) doping spikes near the barrier to increase the zero bias capacitance and control the shape of the capacitance vs. voltage characteristic. These structures have a capacitance ratio of 5:1 and an abrupt change from maximum to minimum capacitance. The measurements were made at 80 K. Based on the information obtained from these two structures, we have designed a structure that combines the low current density barrier with the improved cladding layers. The capacitance and current-voltage characteristics from this structure are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24723550','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24723550"><span>Integrating qualitative and quantitative characterization of traditional Chinese medicine injection by high-performance liquid chromatography with diode array detection and tandem mass spectrometry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xie, Yuan-yuan; Xiao, Xue; Luo, Juan-min; Fu, Chan; Wang, Qiao-wei; Wang, Yi-ming; Liang, Qiong-lin; Luo, Guo-an</p> <p>2014-06-01</p> <p>The present study aims to describe and exemplify an integrated strategy of the combination of qualitative and quantitative characterization of a multicomponent mixture for the quality control of traditional Chinese medicine injections with the example of Danhong injection (DHI). The standardized chemical profile of DHI has been established based on liquid chromatography with diode array detection. High-performance liquid chromatography coupled with time-of-flight mass spectrometry and high-performance liquid chromatography with electrospray multistage tandem ion-trap mass spectrometry have been developed to identify the major constituents in DHI. The structures of 26 compounds including nucleotides, phenolic acids, and flavonoid glycosides were identified or tentatively characterized. Meanwhile, the simultaneous determination of seven marker constituents, including uridine, adenosine, danshensu, protocatechuic aldehyde, p-coumaric acid, rosmarinic acid, and salvianolic acid B, in DHI was performed by multiwavelength detection based on high-performance liquid chromatography with diode array detection. The integrated qualitative and quantitative characterization strategy provided an effective and reliable pattern for the comprehensive and systematic characterization of the complex traditional Chinese medicine system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptEn..56g3108H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptEn..56g3108H"><span>Operating scheme for the light-emitting diode array of a volumetric display that exhibits multiple full-color dynamic images</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirayama, Ryuji; Shiraki, Atsushi; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi</p> <p>2017-07-01</p> <p>We designed and developed a control circuit for a three-dimensional (3-D) light-emitting diode (LED) array to be used in volumetric displays exhibiting full-color dynamic 3-D images. The circuit was implemented on a field-programmable gate array; therefore, pulse-width modulation, which requires high-speed processing, could be operated in real time. We experimentally evaluated the developed system by measuring the luminance of an LED with varying input and confirmed that the system works appropriately. In addition, we demonstrated that the volumetric display exhibits different full-color dynamic two-dimensional images in two orthogonal directions. Each of the exhibited images could be obtained only from the prescribed viewpoint. Such directional characteristics of the system are beneficial for applications, including digital signage, security systems, art, and amusement.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19224025','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19224025"><span>Miniaturized high throughput detection system for capillary array electrophoresis on chip with integrated light emitting diode array as addressed ring-shaped light source.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ren, Kangning; Liang, Qionglin; Mu, Xuan; Luo, Guoan; Wang, Yiming</p> <p>2009-03-07</p> <p>A novel miniaturized, portable fluorescence detection system for capillary array electrophoresis (CAE) on a microfluidic chip was developed, consisting of a scanning light-emitting diode (LED) light source and a single point photoelectric sensor. Without charge coupled detector (CCD), lens, fibers and moving parts, the system was extremely simplified. Pulsed driving of the LED significantly increased the sensitivity, and greatly reduced the power consumption and photobleaching effect. The highly integrated system was robust and easy to use. All the advantages realized the concept of a portable micro-total analysis system (micro-TAS), which could work on a single universal serial bus (USB) port. Compared with traditional CAE detecting systems, the current system could scan the radial capillary array with high scanning rate. An 8-channel CAE of fluorescein isothiocyanate (FITC) labeled arginine (Arg) on chip was demonstrated with this system, resulting in a limit of detection (LOD) of 640 amol.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112w1101D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112w1101D"><span>Strong light extraction enhancement using TiO2 nanoparticles-based microcone arrays embossed on III-Nitride light emitting diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Désières, Yohan; Chen, Ding Yuan; Visser, Dennis; Schippers, Casper; Anand, Srinivasan</p> <p>2018-06-01</p> <p>Colloidal TiO2 nanoparticles were used for embossing of composite microcone arrays on III-Nitride vertical-thin-film blue light emitting diodes (LEDs) as well as on silicon, glass, gallium arsenide, and gallium nitride surfaces. Ray tracing simulations were performed to optimize the design of microcones for light extraction and to explain the experimental results. An optical power enhancement of ˜2.08 was measured on III-Nitride blue LEDs embossed with a hexagonal array of TiO2 microcones of ˜1.35 μm in height and ˜2.6 μm in base width, without epoxy encapsulation. A voltage increase in ˜70 mV at an operating current density of ˜35 A/cm2 was measured for the embossed LEDs. The TiO2 microcone arrays were embossed on functioning LEDs, using low pressures (˜100 g/cm2) and temperatures ≤100 °C.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22642282-su-evaluation-performance-multiple-array-diode-detector-quality-assurance-tests-high-dose-rate-brachytherapy-ir-source','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22642282-su-evaluation-performance-multiple-array-diode-detector-quality-assurance-tests-high-dose-rate-brachytherapy-ir-source"><span>SU-F-T-32: Evaluation of the Performance of a Multiple-Array-Diode Detector for Quality Assurance Tests in High-Dose-Rate Brachytherapy with Ir-192 Source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Harpool, K; De La Fuente Herman, T; Ahmad, S</p> <p></p> <p>Purpose: To evaluate the performance of a two-dimensional (2D) array-diode- detector for geometric and dosimetric quality assurance (QA) tests of high-dose-rate (HDR) brachytherapy with an Ir-192-source. Methods: A phantom setup was designed that encapsulated a two-dimensional (2D) array-diode-detector (MapCheck2) and a catheter for the HDR brachytherapy Ir-192 source. This setup was used to perform both geometric and dosimetric quality assurance for the HDR-Ir192 source. The geometric tests included: (a) measurement of the position of the source and (b) spacing between different dwell positions. The dosimteric tests include: (a) linearity of output with time, (b) end effect and (c) relative dosemore » verification. The 2D-dose distribution measured with MapCheck2 was used to perform the previous tests. The results of MapCheck2 were compared with the corresponding quality assurance testes performed with Gafchromic-film and well-ionization-chamber. Results: The position of the source and the spacing between different dwell-positions were reproducible within 1 mm accuracy by measuring the position of maximal dose using MapCheck2 in contrast to the film which showed a blurred image of the dwell positions due to limited film sensitivity to irradiation. The linearity of the dose with dwell times measured from MapCheck2 was superior to the linearity measured with ionization chamber due to higher signal-to-noise ratio of the diode readings. MapCheck2 provided more accurate measurement of the end effect with uncertainty < 1.5% in comparison with the ionization chamber uncertainty of 3%. Although MapCheck2 did not provide absolute calibration dosimeter for the activity of the source, it provided accurate tool for relative dose verification in HDR-brachytherapy. Conclusion: The 2D-array-diode-detector provides a practical, compact and accurate tool to perform quality assurance for HDR-brachytherapy with an Ir-192 source. The diodes in MapCheck2 have high radiation sensitivity and linearity that is superior to Gafchromic-films and ionization chamber used for geometric and dosimetric QA in HDR-brachytherapy, respectively.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910012121','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910012121"><span>Laterally stacked Schottky diodes for infrared sensor applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lin, True-Lon (Inventor)</p> <p>1991-01-01</p> <p>Laterally stacked Schottky diodes for infrared sensor applications are fabricated utilizing porous silicon having pores. A Schottky metal contract is formed in the pores, such as by electroplating. The sensors may be integrated with silicon circuits on the same chip with a high quantum efficiency, which is ideal for IR focal plane array applications due to uniformity and reproducibility.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=tile&pg=3&id=EJ809230','ERIC'); return false;" href="https://eric.ed.gov/?q=tile&pg=3&id=EJ809230"><span>Cosmic Ray Measurements by Scintillators with Metal Resistor Semiconductor Avalanche Photo Diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Blanco, Francesco; La Rocca, Paola; Riggi, Francesco; Akindinov, Alexandre; Mal'kevich, Dmitry</p> <p>2008-01-01</p> <p>An educational set-up for cosmic ray physics experiments is described. The detector is based on scintillator tiles with a readout through metal resistor semiconductor (MRS) avalanche photo diode (APD) arrays. Typical measurements of the cosmic angular distribution at sea level and a study of the East-West asymmetry obtained by such a device are…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=faraday&pg=3&id=EJ770246','ERIC'); return false;" href="https://eric.ed.gov/?q=faraday&pg=3&id=EJ770246"><span>Exploring Faraday's Law of Electrolysis Using Zinc-Air Batteries with Current Regulative Diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kamata, Masahiro; Paku, Miei</p> <p>2007-01-01</p> <p>Current regulative diodes (CRDs) are applied to develop new educational experiments on Faraday's law by using a zinc-air battery (PR2330) and a resistor to discharge it. The results concluded that the combination of zinc-air batteries and the CRD array is simpler, less expensive, and quantitative and gives accurate data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10085E..04W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10085E..04W"><span>Complete indium-free CW 200W passively cooled high power diode laser array using double-side cooling technology</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Jingwei; Zhu, Pengfei; Liu, Hui; Liang, Xuejie; Wu, Dihai; Liu, Yalong; Yu, Dongshan; Zah, Chung-en; Liu, Xingsheng</p> <p>2017-02-01</p> <p>High power diode lasers have been widely used in many fields. To meet the requirements of high power and high reliability, passively cooled single bar CS-packaged diode lasers must be robust to withstand thermal fatigue and operate long lifetime. In this work, a novel complete indium-free double-side cooling technology has been applied to package passively cooled high power diode lasers. Thermal behavior of hard solder CS-package diode lasers with different packaging structures was simulated and analyzed. Based on these results, the device structure and packaging process of double-side cooled CS-packaged diode lasers were optimized. A series of CW 200W 940nm high power diode lasers were developed and fabricated using hard solder bonding technology. The performance of the CW 200W 940nm high power diode lasers, such as output power, spectrum, thermal resistance, near field, far field, smile, lifetime, etc., is characterized and analyzed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ApPhL..97j3703A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..97j3703A"><span>Photosensitive biosensor array system using optical addressing without an addressing circuit on array biochips</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahn, Chang-Geun; Ah, Chil Seong; Kim, Tae-Youb; Park, Chan Woo; Yang, Jong-Heon; Kim, Ansoon; Sung, Gun Yong</p> <p>2010-09-01</p> <p>This paper introduces a photosensitive biosensor array system with a simple photodiode array that detects photocurrent changes caused by reactions between probe and target molecules. Using optical addressing, the addressing circuit on the array chip is removed for low-cost application, and real cell addressing is achieved using an externally located computer-controllable light-emitting diode array module. The fabricated biosensor array chip shows a good dynamic range of 1-100 ng/mL under prostate-specific antigen detection, with an on-chip resolution of roughly 1 ng/mL.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9649E..0PN','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9649E..0PN"><span>AlGaInN laser diode technology and systems for defence and security applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lujca; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.</p> <p>2015-10-01</p> <p>AlGaInN laser diodes is an emerging technology for defence and security applications such as underwater communications and sensing, atomic clocks and quantum information. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Thus AlGaInN laser diode technology is a key enabler for the development of new disruptive system level applications in displays, telecom, defence and other industries. Ridge waveguide laser diodes are fabricated to achieve single mode operation with optical powers up to 100mW with the 400-440nm wavelength range with high reliability. Visible free-space and underwater communication at frequencies up to 2.5GHz is reported using a directly modulated 422nm GaN laser diode. Low defectivity and highly uniform GaN substrates allow arrays and bars to be fabricated. High power operation operation of AlGaInN laser bars with up to 20 emitters have been demonstrated at optical powers up to 4W in a CS package with common contact configuration. An alternative package configuration for AlGaInN laser arrays allows for each individual laser to be individually addressable allowing complex free-space or optical fibre system integration with a very small form-factor.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009InPhT..52..353C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009InPhT..52..353C"><span>QWIP Status at THALES</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Costard, E.; Nedelcu, A.; Truffer, J. P.; Huet, O.; Dua, L.; Robo, J. A.; Marcadet, X.; Brière de l'Isle, N.; Facoetti, H.; Bois, P.</p> <p>2009-11-01</p> <p>Since 2002, the THALES Group has been manufacturing sensitive arrays using QWIP technology based on GaAs and related III-V compounds, at the Alcatel-Thales-III-V Lab (formerly part of THALES Research and Technology Laboratory). In the past researchers claimed many advantages of QWIPs. Uniformity was one of these and has been the key parameter for the production to start. Another widely claimed advantage for QWIPs was the so-called band-gap engineering and versatility of the III-V processing allowing the custom design of quantum structures to fulfil the requirements of specific applications such as very long wavelength (VLWIR) or multi-spectral detection. In this presentation, we give the status of our LWIR QWIP production line, and also the current status of QWIPs for MWIR (<5 μm) and VLWIR (>15 μm) arrays. As the QWIP technology cannot cover the full electromagnetic spectrum, we develop other semiconductor compounds for SWIR and UV applications. We present here the status of our 320 × 256 SWIR module with InGaAs photodiodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930049455&hterms=Neuron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DNeuron','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930049455&hterms=Neuron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DNeuron"><span>GaAs optoelectronic neuron arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lin, Steven; Grot, Annette; Luo, Jiafu; Psaltis, Demetri</p> <p>1993-01-01</p> <p>A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10,000/sq cm are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA244807','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA244807"><span>Innovative Techniques for the Production of Low Cost 2D Laser Diode Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1991-11-26</p> <p>electrically isolated and liquid cooled. (Deliverables: 5 5-bar arrays.) The following global issues not mentioned above will be investigated...house facet coating station. All global issues mentioned in Section 2.0 will be addressed and continuously investigated during this program. Very</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9300E..2FZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9300E..2FZ"><span>Analysis of low-offset CTIA amplifier for small-size-pixel infrared focal plane array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xue; Huang, Zhangcheng; Shao, Xiumei</p> <p>2014-11-01</p> <p>The design of input stage amplifier becomes more and more difficult as the expansion of format arrays and reduction of pixel size. A design method of low-offset amplifier based on 0.18-μm process used in small-size pixel is analyzed in order to decrease the dark signal of extended wavelength InGaAs infrared focal plane arrays (IRFPA). Based on an example of a cascode operational amplifier (op-amp), the relationship between input offset voltage and size of each transistor is discussed through theoretical analysis and Monte Carlo simulation. The results indicate that input transistors and load transistors have great influence on the input offset voltage while common-gate transistors are negligible. Furthermore, the offset voltage begins to increase slightly when the width and length of transistors decrease along with the diminution of pixel size, and raises rapidly when the size is smaller than a proximate threshold value. The offset voltage of preamplifiers with differential architecture and single-shared architecture in small pitch pixel are studied. After optimization under same conditions, simulation results show that single-shared architecture has smaller offset voltage than differential architecture.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7686E..0GY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7686E..0GY"><span>885-nm laser diode array pumped ceramic Nd:YAG master oscillator power amplifier system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Anthony W.; Li, Steven X.; Stephen, Mark A.; Seas, Antonios; Troupaki, Elisavet; Vasilyev, Aleksey; Conley, Heather; Filemyr, Tim; Kirchner, Cynthia; Rosanova, Alberto</p> <p>2010-04-01</p> <p>The objective of this effort is to develop more reliable, higher efficiency diode pumped Nd:YAG laser systems for space applications by leveraging technology investments from the DoD and other commercial industries. Our goal is to design, build, test and demonstrate the effectiveness of combining 885 nm laser pump diodes and the use of ceramic Nd:YAG for future flight missions. The significant reduction in thermal loading on the gain medium by the use of 885 nm pump lasers will improve system efficiency.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA560393','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA560393"><span>Performance Improvement of Long-Wave Infrared InAs/GaSb Strained-Layer Superlattice Detectors Through Sulfur-Based Passivation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-01-01</p> <p>14]. The detector material was processed into a variable area diode array (VADA) of square and circular mesa diodes with the size of diode mesa sides...processed as single element detectors with 410 lm 410 lm square mesas having circular apertures ranging in diameter from 25 to 300 lm. The processing was...passivations schemes with perimeter-to-area ratio (P/A) of 1600 cm1 ( mesa side size is 25 lm). Fig. 3. Inverse of the dynamic resistance area product (RdA</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002955','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002955"><span>Forward voltage short-pulse technique for measuring high power laser array junction temperature</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meadows, Byron L. (Inventor); Amzajerdian, Frazin (Inventor); Barnes, Bruce W. (Inventor); Baker, Nathaniel R. (Inventor)</p> <p>2012-01-01</p> <p>The present invention relates to a method of measuring the temperature of the P-N junction within the light-emitting region of a quasi-continuous-wave or pulsed semiconductor laser diode device. A series of relatively short and low current monitor pulses are applied to the laser diode in the period between the main drive current pulses necessary to cause the semiconductor to lase. At the sufficiently low current level of the monitor pulses, the laser diode device does not lase and behaves similar to an electronic diode. The voltage across the laser diode resulting from each of these low current monitor pulses is measured with a high degree of precision. The junction temperature is then determined from the measured junction voltage using their known linear relationship.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5563..118H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5563..118H"><span>A customizable commercial miniaturized 320×256 indium gallium arsenide shortwave infrared camera</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Shih-Che; O'Grady, Matthew; Groppe, Joseph V.; Ettenberg, Martin H.; Brubaker, Robert M.</p> <p>2004-10-01</p> <p>The design and performance of a commercial short-wave-infrared (SWIR) InGaAs microcamera engine is presented. The 0.9-to-1.7 micron SWIR imaging system consists of a room-temperature-TEC-stabilized, 320x256 (25 μm pitch) InGaAs focal plane array (FPA) and a high-performance, highly customizable image-processing set of electronics. The detectivity, D*, of the system is greater than 1013 cm-√Hz/W at 1.55 μm, and this sensitivity may be adjusted in real-time over 100 dB. It features snapshot-mode integration with a minimum exposure time of 130 μs. The digital video processor provides real time pixel-to-pixel, 2-point dark-current subtraction and non-uniformity compensation along with defective-pixel substitution. Other features include automatic gain control (AGC), gamma correction, 7 preset configurations, adjustable exposure time, external triggering, and windowing. The windowing feature is highly flexible; the region of interest (ROI) may be placed anywhere on the imager and can be varied at will. Windowing allows for high-speed readout enabling such applications as target acquisition and tracking; for example, a 32x32 ROI window may be read out at over 3500 frames per second (fps). Output video is provided as EIA170-compatible analog, or as 12-bit CameraLink-compatible digital. All the above features are accomplished in a small volume < 28 cm3, weight < 70 g, and with low power consumption < 1.3 W at room temperature using this new microcamera engine. Video processing is based on a field-programmable gate array (FPGA) platform with a soft-embedded processor that allows for ease of integration/addition of customer-specific algorithms, processes, or design requirements. The camera was developed with the high-performance, space-restricted, power-conscious application in mind, such as robotic or UAV deployment.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OptRv..21..599O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OptRv..21..599O"><span>A simple and cost-effective molecular diagnostic system and DNA probes synthesized by light emitting diode photolithography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oleksandrov, Sergiy; Kwon, Jung Ho; Lee, Ki-chang; Sujin-Ku; Paek, Mun Cheol</p> <p>2014-09-01</p> <p>This work introduces a novel chip to be used in the future as a simple and cost-effective method for creating DNA arrays using light emission diode (LED) photolithography. The DNA chip platform contains 24 independent reaction sites, which allows for the testing of a corresponding amount of patients' samples in hospital. An array of commercial UV LEDs and lens systems was combined with a microfluidic flow system to provide patterning of 24 individual reaction sites, each with 64 independent probes. Using the LED array instead of conventional laser exposure systems or micro-mirror systems significantly reduces the cost of equipment. The microfluidic system together with microfluidic flow cells drastically reduces the amount of used reagents, which is important due to the high cost of commercial reagents. The DNA synthesis efficiency was verified by fluorescence labeling and conventional hybridization.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20608711','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20608711"><span>Vertical pillar-superlattice array and graphene hybrid light emitting diodes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Jung Min; Choung, Jae Woong; Yi, Jaeseok; Lee, Dong Hyun; Samal, Monica; Yi, Dong Kee; Lee, Chul-Ho; Yi, Gyu-Chul; Paik, Ungyu; Rogers, John A; Park, Won Il</p> <p>2010-08-11</p> <p>We report a type of device that combines vertical arrays of one-dimensional (1D) pillar-superlattice (PSL) structures with 2D graphene sheets to yield a class of light emitting diode (LED) with interesting mechanical, optical, and electrical characteristics. In this application, graphene sheets coated with very thin metal layers exhibit good mechanical and electrical properties and an ability to mount, in a freely suspended configuration, on the PSL arrays as a top window electrode. Optical characterization demonstrates that graphene exhibits excellent optical transparency even after deposition of the thin metal films. Thermal annealing of the graphene/metal (Gr/M) contact to the GaAs decreases the contact resistance, to provide enhanced carrier injection. The resulting PSL-Gr/M LEDs exhibit bright light emission over large areas. The result suggests the utility of graphene-based materials as electrodes in devices with unusual, nonplanar 3D architectures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016287','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016287"><span>Inverted Three-Junction Tandem Thermophotovoltaic Modules</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wojtczuk, Steven</p> <p>2012-01-01</p> <p>An InGaAs-based three-junction (3J) tandem thermophotovoltaic (TPV) cell has been investigated to utilize more of the blackbody spectrum (from a 1,100 C general purpose heat source GPHS) efficiently. The tandem consists of three vertically stacked subcells, a 0.74-eV InGaAs cell, a 0.6- eV InGaAs cell, and a 0.55-eV InGaAs cell, as well as two interconnecting tunnel junctions. A greater than 20% TPV system efficiency was achieved by another group with a 1,040 C blackbody using a single-bandgap 0.6- eV InGaAs cell MIM (monolithic interconnected module) (30 lateral junctions) that delivered about 12 V/30 or 0.4 V/junction. It is expected that a three-bandgap tandem MIM will eventually have about 3 this voltage (1.15 V) and about half the current. A 4 A/cm2 would be generated by a single-bandgap 0.6-V InGaAs MIM, as opposed to the 2 A/cm2 available from the same spectrum when split among the three series-connected junctions in the tandem stack. This would then be about a 50% increase (3xVoc, 0.5xIsc) in output power if the proposed tandem replaced the single- bandgap MIM. The advantage of the innovation, if successful, would be a 50% increase in power conversion efficiency from radioisotope heat sources using existing thermophotovoltaics. Up to 50% more power would be generated for radioisotope GPHS deep space missions. This type of InGaAs multijunction stack could be used with terrestrial concentrator solar cells to increase efficiency from 41 to 45% or more.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17574558','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17574558"><span>Detection, characterization and identification of phenolic acids in Danshen using high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Ai-Hua; Guo, Hui; Ye, Min; Lin, Yan-Hua; Sun, Jiang-Hao; Xu, Man; Guo, De-An</p> <p>2007-08-17</p> <p>By using HPLC-diode array detection-electrospray ion trap tandem mass spectrometry (HPLC-DAD-ESI-MS(n)) in negative ion mode, we have analyzed the fragmentation pathways of 11 phenolic acids which were isolated from Danshen. Then the extract of Danshen was analyzed, and a total of 42 phenolic acids, including sixteen new minor constituents, were identified or tentatively identified for the first time. A new solid-phase extraction (SPE) method, new HPLC separation method, new liquid chromatography (LC)-MS and LC-MS(n) (n=3-5) data and proposed fragmentation pathways, LC retention time for phenolic acids are reported.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23976789','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23976789"><span>A Single-Photon Avalanche Diode Array for Fluorescence Lifetime Imaging Microscopy.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schwartz, David Eric; Charbon, Edoardo; Shepard, Kenneth L</p> <p>2008-11-21</p> <p>We describe the design, characterization, and demonstration of a fully integrated single-photon avalanche diode (SPAD) imager for use in time-resolved fluorescence imaging. The imager consists of a 64-by-64 array of active SPAD pixels and an on-chip time-to-digital converter (TDC) based on a delay-locked loop (DLL) and calibrated interpolators. The imager can perform both standard time-correlated single-photon counting (TCSPC) and an alternative gated-window detection useful for avoiding pulse pile-up when measuring bright signal levels. To illustrate the use of the imager, we present measurements of the decay lifetimes of fluorescent dyes of several types with a timing resolution of 350 ps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890065106&hterms=947&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%2523947','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890065106&hterms=947&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%2523947"><span>Phase-front measurements of an injection-locked AlGaAs laser-diode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cornwell, Donald M., Jr.; Rall, Jonathan A. R.; Abshire, James B.</p> <p>1989-01-01</p> <p>The phase-front quality of the primary spatial lobe emitted from an injection-locked gain-guided AlGaAs laser-diode array is measured by using an equal-path, phase-shifting Mach-Zehnder interferometer. Root-mean-square phase errors of 0.037 + or - 0.003 wave are measured for the single spatial lobe, which contained 240-mW cw output power in a single longitudinal mode. This phase-front quality corresponds to a Strehl ratio of S = 0.947, which results in a 0.23-dB power loss from the single lobe's ideal diffraction-limited power. These values are comparable with those measured for single-stripe index-guided AlGaAs lasers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3748627','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3748627"><span>A Single-Photon Avalanche Diode Array for Fluorescence Lifetime Imaging Microscopy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schwartz, David Eric; Charbon, Edoardo; Shepard, Kenneth L.</p> <p>2013-01-01</p> <p>We describe the design, characterization, and demonstration of a fully integrated single-photon avalanche diode (SPAD) imager for use in time-resolved fluorescence imaging. The imager consists of a 64-by-64 array of active SPAD pixels and an on-chip time-to-digital converter (TDC) based on a delay-locked loop (DLL) and calibrated interpolators. The imager can perform both standard time-correlated single-photon counting (TCSPC) and an alternative gated-window detection useful for avoiding pulse pile-up when measuring bright signal levels. To illustrate the use of the imager, we present measurements of the decay lifetimes of fluorescent dyes of several types with a timing resolution of 350 ps. PMID:23976789</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA568701','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA568701"><span>MCT Detectors and ROICS for Various Format MWIR and LWIR Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-10-01</p> <p>ABSTRACT Silicon ROICs for MCT LWIR (4x288, 6x576) and MWIR (128x128) diode matrix arrays were designed, manufactured and tested. MCT layers...of polysilicon and two metallization levels. MCT Detectors and ROICs for Various Format MWIR and LWIR Arrays RTO-MP-SET-151 7 - 1...Format MWIR and LWIR Arrays 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA612965','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA612965"><span>A Robust Design Approach to Cost Estimation: Solar Energy for Marine Corps Expeditionary Operations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-07-14</p> <p>solutions in such areas as photovoltaic arrays for power harvesting, light emitting diodes (LED) for decreased energy consumption, and improved battery...generation and conversion system that allows Marines to power systems with solar energy. Each GREENS is comprised of eight photovoltaic array panels...renewable power sources such as photovoltaic arrays and wind turbines. The HOMER model has been utilized for years by organizations and companies</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JCrGr.477..230O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JCrGr.477..230O"><span>Growth of quantum three-dimensional structure of InGaAs emitting at 1 μm applicable for a broadband near-infrared light source</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozaki, Nobuhiko; Kanehira, Shingo; Hayashi, Yuma; Ohkouchi, Shunsuke; Ikeda, Naoki; Sugimoto, Yoshimasa; Hogg, Richard A.</p> <p>2017-11-01</p> <p>We obtained a high-intensity and broadband emission centered at 1 μm from InGaAs quantum three-dimensional (3D) structures grown on a GaAs substrate using molecular beam epitaxy. An InGaAs thin layer grown on GaAs with a thickness close to the critical layer thickness is normally affected by strain as a result of the lattice mismatch and introduced misfit dislocations. However, under certain growth conditions for the In concentration and growth temperature, the growth mode of the InGaAs layer can be transformed from two-dimensional to 3D growth. We found the optimal conditions to obtain a broadband emission from 3D structures with a high intensity and controlled center wavelength at 1 μm. This method offers an alternative approach for fabricating a broadband near-infrared light source for telecommunication and medical imaging systems such as for optical coherence tomography.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SeScT..33e5005D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SeScT..33e5005D"><span>Comprehensive growth and characterization study on highly n-doped InGaAs as a contact layer for quantum cascade laser applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demir, Ilkay; Altuntas, Ismail; Bulut, Baris; Ezzedini, Maher; Ergun, Yuksel; Elagoz, Sezai</p> <p>2018-05-01</p> <p>We present growth and characterization studies of highly n-doped InGaAs epilayers on InP substrate by metal organic vapor phase epitaxy to use as an n-contact layer in quantum cascade laser applications. We have introduced quasi two-dimensional electrons between 10 s pulsed growth n-doped InGaAs epilayers to improve both carrier concentration and mobility of structure by applying pulsed growth and doping methods towards increasing the Si dopant concentration in InGaAs. Additionally, the V/III ratio optimization under fixed group III source flow has been investigated with this new method to understand the effects on both crystalline quality and electrical properties of n-InGaAs epilayers. Finally, we have obtained high crystalline quality of n-InGaAs epilayers grown by 10 s pulsed as a contact layer with 2.8 × 1019 cm‑3 carrier concentration and 1530 cm2 V‑1 s‑1 mobility.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJE...102.1818Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJE...102.1818Z"><span>Experimental study on an S-band near-field microwave magnetron power transmission system on hundred-watt level</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Biao; Jiang, Wan; Yang, Yang; Yu, Chengyang; Huang, Kama; Liu, Changjun</p> <p>2015-11-01</p> <p>A multi-magnetron microwave source, a metamaterial transmitting antenna, and a large power rectenna array are presented to build a near-field 2.45 GHz microwave power transmission system. The square 1 m2 rectenna array consists of sixteen rectennas with 2048 Schottky diodes for large power microwave rectifying. It receives microwave power and converts them into DC power. The design, structure, and measured performance of a unit rectenna as well as the entail rectenna array are presented in detail. The multi-magnetron microwave power source switches between half and full output power levels, i.e. the half-wave and full-wave modes. The transmission antenna is formed by a double-layer metallic hole array, which is applied to combine the output power of each magnetron. The rectenna array DC output power reaches 67.3 W on a 1.2 Ω DC load at a distance of 5.5 m from the transmission antenna. DC output power is affected by the distance, DC load, and the mode of microwave power source. It shows that conventional low power Schottky diodes can be applied to a microwave power transmission system with simple magnetrons to realise large power microwave rectifying.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050111486','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050111486"><span>Simulated Space Environment Effects on the Blocking Force of Silicone Adhesive</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boeder, Paul; Mikatarian, Ron; Koontz, Steve; Albyn, Keith; Finckenor, Miria</p> <p>2005-01-01</p> <p>The International Space Station (ISS) solar arrays utilize MD-944 diode tape to protect the underlying diodes in the solar array panel circuit and also provide thermal conditioning and mechanical support. The diode tape consists of silicone pressure sensitive adhesive (Dow Coming QC-7725) with a protective Kapton over-layer. On-orbit, the Kapton over-layer will erode under exposure to atomic oxygen (AO) and the underlying exposed silicone adhesive will ultimately convert, under additional AO exposure, to a glass like silicate. The current operational plan is to retract ISS solar array P6 and leave it stored under load for a long duration (6 months or more) during ISS assembly. With the Kapton over-layer eroded away, the exposed silicone adhesive must not cause the solar array to stick to itself or cause the solar array to fail during redeployment. Previous testing by Lockheed-Martin Space Systems (LMSS) characterized silicone blocking following exposure to low energy atomic oxygen (AO) in an asher facility, but this is believed to be conservative. An additional series of tests was performed by the Environmental Effects Group at MSFC under direction from the ISS Program Office Environments Team. This test series included high energy AO (5 eV), near ultraviolet (NUV) radiation and ionizing radiation, singly and in combination. Additional samples were exposed to thermal energy AO (<0.1 ev) for comparison to the LMSS tests. Diode tape samples were exposed to each environment constituent individually, put under preload for seven days and then the resulting blocking force was measured using a tensile machine. Additional samples were exposed to AO, NUV and electrons in series and then put under long term (three to ten months) preload to determine the effect of preload duration on the resulting blocking force of the silicone-to-silicone bond. Test results indicate that high energy AO, ultraviolet radiation and electron ionizing radiation exposure all reduce the blocking force for a silicone-to-silicone bond. AO exposure produces the most significant reduction in blocking force.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22093725-digital-optical-phase-locked-loop-diode-lasers-based-field-programmable-gate-array','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22093725-digital-optical-phase-locked-loop-diode-lasers-based-field-programmable-gate-array"><span>A digital optical phase-locked loop for diode lasers based on field programmable gate array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Xu Zhouxiang; Zhang Xian; Huang Kaikai</p> <p>2012-09-15</p> <p>We have designed and implemented a highly digital optical phase-locked loop (OPLL) for diode lasers in atom interferometry. The three parts of controlling circuit in this OPLL, including phase and frequency detector (PFD), loop filter and proportional integral derivative (PID) controller, are implemented in a single field programmable gate array chip. A structure type compatible with the model MAX9382/MCH12140 is chosen for PFD and pipeline and parallelism technology have been adapted in PID controller. Especially, high speed clock and twisted ring counter have been integrated in the most crucial part, the loop filter. This OPLL has the narrow beat notemore » line width below 1 Hz, residual mean-square phase error of 0.14 rad{sup 2} and transition time of 100 {mu}s under 10 MHz frequency step. A main innovation of this design is the completely digitalization of the whole controlling circuit in OPLL for diode lasers.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SeScT..32h5009W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SeScT..32h5009W"><span>Nanoscale cross-point diode array accessing embedded high density PCM</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Heng; Liu, Yan; Liu, Bo; Gao, Dan; Xu, Zhen; Zhan, Yipeng; Song, Zhitang; Feng, Songlin</p> <p>2017-08-01</p> <p>The main bottlenecks in the development of current embedded phase change memory (PCM) technology are the current density and data storage density. In this paper, we present a PCM with 4F2 cross-point diode selector and blade-type bottom electrode contact (BEC). A blade TiN BEC with a cross-sectional area of 630 nm2 (10 nm × 63 nm) reduces the reset current down to about 750 μA. The optimized diode array could supply this 750 μA reset current at about 1.7 V and low off-current 1 × 10-4 μA at about -5.05 V. The on-off ratio of this device is 7.5 × 106. The proposed nanoscale PCM device simultaneously exhibits an operation voltage as low as 3 V and a high density drive current with an ultra small cell size of 4F2 (108 nm × 108 nm). Over 106 cycling endurance properties guarantee that it can work effectively on the embedded memory.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720038304&hterms=Types+Integration+Their+Measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DTypes%2BIntegration%2BTheir%2BMeasurement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720038304&hterms=Types+Integration+Their+Measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DTypes%2BIntegration%2BTheir%2BMeasurement"><span>The silicon vidicon: Integration, storage and slow scan capability - Experimental observation of a secondary mode of operation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ando, K. J.</p> <p>1971-01-01</p> <p>Description of the performance of the silicon diode array vidicon - an imaging sensor which possesses wide spectral response, high quantum efficiency, and linear response. These characteristics, in addition to its inherent ruggedness, simplicity, and long-term stability and operating life make this device potentially of great usefulness for ground-base and spaceborne planetary and stellar imaging applications. However, integration and charged storage for periods greater than approximately five seconds are not possible at room temperature because of diode saturation from dark current buildup. Since dark current can be reduced by cooling, measurements were made in the range from -65 to 25 C. Results are presented on the extension of integration, storage, and slow scan capabilities achievable by cooling. Integration times in excess of 20 minutes were achieved at the lowest temperatures. The measured results are compared with results obtained with other types of sensors and the advantages of the silicon diode array vidicon for imaging applications are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9832E..04U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9832E..04U"><span>Linear LIDAR versus Geiger-mode LIDAR: impact on data properties and data quality</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ullrich, A.; Pfennigbauer, M.</p> <p>2016-05-01</p> <p>LIDAR has become the inevitable technology to provide accurate 3D data fast and reliably even in adverse measurement situations and harsh environments. It provides highly accurate point clouds with a significant number of additional valuable attributes per point. LIDAR systems based on Geiger-mode avalanche photo diode arrays, also called single photon avalanche photo diode arrays, earlier employed for military applications, now seek to enter the commercial market of 3D data acquisition, advertising higher point acquisition speeds from longer ranges compared to conventional techniques. Publications pointing out the advantages of these new systems refer to the other category of LIDAR as "linear LIDAR", as the prime receiver element for detecting the laser echo pulses - avalanche photo diodes - are used in a linear mode of operation. We analyze the differences between the two LIDAR technologies and the fundamental differences in the data they provide. The limitations imposed by physics on both approaches to LIDAR are also addressed and advantages of linear LIDAR over the photon counting approach are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26328920','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26328920"><span>Hybrid InGaAs quantum well-dots nanostructures for light-emitting and photo-voltaic applications.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mintairov, S A; Kalyuzhnyy, N A; Lantratov, V M; Maximov, M V; Nadtochiy, A M; Rouvimov, Sergei; Zhukov, A E</p> <p>2015-09-25</p> <p>Hybrid quantum well-dots (QWD) nanostructures have been formed by deposition of 7-10 monolayers of In0.4Ga0.6As on a vicinal GaAs surface using metal-organic chemical vapor deposition. Transmission electron microscopy, photoluminescence and photocurrent analysis have shown that such structures represent quantum wells comprising three-dimensional (quantum dot-like) regions of two kinds. At least 20 QWD layers can be deposited defect-free providing high gain/absorption in the 0.9-1.1 spectral interval. Use of QWD media in a GaAs solar cell resulted in a photocurrent increment of 3.7 mA cm(-2) for the terrestrial spectrum and by 4.1 mA cm(-2) for the space spectrum. Diode lasers based on QWD emitting around 1.1 μm revealed high saturated gain and low transparency current density of about 15 cm(-1) and 37 A cm(-2) per layer, respectively.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptEn..54b6103A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptEn..54b6103A"><span>Beam uniformity analysis of infrared laser illuminators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allik, Toomas H.; Dixon, Roberta E.; Proffitt, R. Patrick; Fung, Susan; Ramboyong, Len; Soyka, Thomas J.</p> <p>2015-02-01</p> <p>Uniform near-infrared (NIR) and short-wave infrared (SWIR) illuminators are desired in low ambient light detection, recognition, and identification of military applications. Factors that contribute to laser illumination image degradation are high frequency, coherent laser speckle and low frequency nonuniformities created by the laser or external laser cavity optics. Laser speckle analysis and beam uniformity improvements have been independently studied by numerous authors, but analysis to separate these two effects from a single measurement technique has not been published. In this study, profiles of compact, diode laser NIR and SWIR illuminators were measured and evaluated. Digital 12-bit images were recorded with a flat-field calibrated InGaAs camera with measurements at F/1.4 and F/16. Separating beam uniformity components from laser speckle was approximated by filtering the original image. The goal of this paper is to identify and quantify the beam quality variation of illumination prototypes, draw awareness to its impact on range performance modeling, and develop measurement techniques and methodologies for military, industry, and vendors of active sources.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150003402','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150003402"><span>High Efficiency Quantum Well Waveguide Solar Cells and Methods for Constructing the Same</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sood, Ashok K. (Inventor); Welser, Roger E. (Inventor)</p> <p>2014-01-01</p> <p>Photon absorption, and thus current generation, is hindered in conventional thin-film solar cell designs, including quantum well structures, by the limited path length of incident light passing vertically through the device. Optical scattering into lateral waveguide structures provides a physical mechanism to increase photocurrent generation through in-plane light trapping. However, the insertion of wells of high refractive index material with lower energy gap into the device structure often results in lower voltage operation, and hence lower photovoltaic power conversion efficiency. The voltage output of an InGaAs quantum well waveguide photovoltaic device can be increased by employing a III-V material structure with an extended wide band gap emitter heterojunction. Analysis of the light IV characteristics reveals that non-radiative recombination components of the underlying dark diode current have been reduced, exposing the limiting radiative recombination component and providing a pathway for realizing solar-electric conversion efficiency of 30% or more in single junction cells.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22314357','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22314357"><span>Generation and control of polarization-entangled photons from GaAs island quantum dots by an electric field.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghali, Mohsen; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo</p> <p>2012-02-07</p> <p>Semiconductor quantum dots are potential sources for generating polarization-entangled photons efficiently. The main prerequisite for such generation based on biexciton-exciton cascaded emission is to control the exciton fine-structure splitting. Among various techniques investigated for this purpose, an electric field is a promising means to facilitate the integration into optoelectronic devices. Here we demonstrate the generation of polarization-entangled photons from single GaAs quantum dots by an electric field. In contrast to previous studies, which were limited to In(Ga)As quantum dots, GaAs island quantum dots formed by a thickness fluctuation were used because they exhibit a larger oscillator strength and emit light with a shorter wavelength. A forward voltage was applied to a Schottky diode to control the fine-structure splitting. We observed a decrease and suppression in the fine-structure splitting of the studied single quantum dot with the field, which enabled us to generate polarization-entangled photons with a high fidelity of 0.72 ± 0.05.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960025070','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960025070"><span>Macroscopic Violation of Three Cauchy-Schwarz Inequalities Using Correlated Light Beams From an Infra-Red Emitting Semiconductor Diode Array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edwards, P. J.; Huang, X.; Li, Y. Q. (Editor); Wang, Y. Z. (Editor)</p> <p>1996-01-01</p> <p>We briefly review quantum mechanical and semi-classical descriptions of experiments which demonstrate the macroscopic violation of the three Cauchy-Schwarz inequalities: g(sup 2)(sub 11)(0) greater than or equal to 1; g(sup 2)(sub 11)(0) greater than or equal to g(sup 2)(sub 11)(t), (t approaches infinity); (the absolute value of g(sup 2)(sub 11)(0))(exp 2) less than or equal to g(sup 2)(sub 11)(0) g(sup 2)(sub 11)(0). Our measurements demonstrate the violation, at macroscopic intensities, of each of these inequalities. We show that their violation, although weak, can be demonstrated through photodetector current covariance measurements on correlated sub-Poissonian Poissonian, and super Poissonian light beams. Such beams are readily generated by a tandem array of infrared-emitting semiconductor junction diodes. Our measurements utilize an electrically coupled array of one or more infrared-emitting diodes, optically coupled to a detector array. The emitting array is operated in such a way as to generate highly correlated beams of variable photon Fano Factor. Because the measurements are made on time scales long compared with the first order coherence time and with detector areas large compared with the corresponding coherence areas, first order interference effects are negligible. The first and second inequalities are violated, as expected, when a sub-Poissonian light beam is split and the intensity fluctuations of the two split beams are measured by two photodetectors and subsequently cross-correlated. The third inequality is violated by bunched (as well as anti-bunched) beams of equal intensity provided the measured cross correlation coefficient exceeds (F - 1)/F, where F is the measured Fano Factor of each beam. We also investigate the violation for the case of unequal beams.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SeScT..29i5022G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SeScT..29i5022G"><span>Temperature dependent current transport of Pd/ZnO nanowire Schottky diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gayen, R. N.; Bhattacharyya, S. R.; Jana, P.</p> <p>2014-09-01</p> <p>Zinc oxide (ZnO) nanowire based Schottky barrier diodes are fabricated by depositing Pd metal contact on top of vertically well-aligned ZnO nanowire arrays. A vertical array of ZnO nanowires on indium tin oxide (ITO) coated glass substrates is synthesized by hybrid wet chemical route. Scanning electron microscopy (SEM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) measurement confirm the formation of stoichiometric well-aligned hexagonal (h-ZnO) nanowire arrays with wurtzite structure. Temperature dependent current-voltage (I-V) measurements on palladium-ZnO (Pd/ZnO) nanowire Schottky junctions in the temperature range 303-383 K exhibit excellent rectifying character. From these nonlinear I-V plots, different electrical parameters of diode-like reverse saturation current, barrier height and ideality factor are determined as a function of temperature assuming pure thermionic emission model. The ideality factor is found to decrease while the barrier height increases with the increase in temperature. The series resistance values calculated from Cheung’s functions also show temperature dependency. Such behavior can be attributed to the presence of defects that traps carriers, and barrier height inhomogeneity at the interface of the barrier junction. After barrier height inhomogeneity correction, considering a Gaussian distributed barrier height fluctuation across the Pd/ZnO interface, the estimated values of mean barrier height and modified Richardson constant are more closely matched to the theoretically predicted value for Pd/ZnO Schottky barrier diodes. The variation of density of interface states as a function of interface state energy is also calculated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JPhCS..28...66M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JPhCS..28...66M"><span>Simultaneous Determination of Iron, Copper and Cobalt in Food Samples by CCD-diode Array Detection-Flow Injection Analysis with Partial Least Squares Calibration Model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mi, Jiaping; Li, Yuanqian; Zhou, Xiaoli; Zheng, Bo; Zhou, Ying</p> <p>2006-01-01</p> <p>A flow injection-CCD diode array detection spectrophotometry with partial least squares (PLS) program for simultaneous determination of iron, copper and cobalt in food samples has been established. The method was based on the chromogenic reaction of the three metal ions and 2- (5-Bromo-2-pyridylazo)-5-diethylaminophenol, 5-Br-PADAP in acetic acid - sodium acetate buffer solution (pH5) with Triton X-100 and ascorbic acid. The overlapped spectra of the colored complexes were collected by charge-coupled device (CCD) - diode array detector and the multi-wavelength absorbance data was processed using partial least squares (PLS) algorithm. Optimum reaction conditions and parameters of flow injection analysis were investigated. The samples of tea, sesame, laver, millet, cornmeal, mung bean and soybean powder were determined by the proposed method. The average recoveries of spiked samples were 91.80%~100.9% for Iron, 92.50%~108.0% for Copper, 93.00%~110.5% for Cobalt, respectively with relative standard deviation (R.S.D) of 1.1%~12.1%. The sampling rate is 45 samples h-1. The determination results of the food samples were in good agreement between the proposed method and ICP-AES.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.7280E..2FZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.7280E..2FZ"><span>Design of a portable noninvasive photoacoustic glucose monitoring system integrated laser diode excitation with annular array detection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zeng, Lvming; Liu, Guodong; Yang, Diwu; Ren, Zhong; Huang, Zhen</p> <p>2008-12-01</p> <p>A near-infrared photoacoustic glucose monitoring system, which is integrated dual-wavelength pulsed laser diode excitation with eight-element planar annular array detection technique, is designed and fabricated during this study. It has the characteristics of nonivasive, inexpensive, portable, accurate location, and high signal-to-noise ratio. In the system, the exciting source is based on two laser diodes with wavelengths of 905 nm and 1550 nm, respectively, with optical pulse energy of 20 μJ and 6 μJ. The laser beam is optically focused and jointly projected to a confocal point with a diameter of 0.7 mm approximately. A 7.5 MHz 8-element annular array transducer with a hollow structure is machined to capture photoacoustic signal in backward mode. The captured signals excitated from blood glucose are processed with a synthetic focusing algorithm to obtain high signal-to-noise ratio and accurate location over a range of axial detection depth. The custom-made transducer with equal area elements is coaxially collimated with the laser source to improve the photoacoustic excite/receive efficiency. In the paper, we introduce the photoacoustic theory, receive/process technique, and design method of the portable noninvasive photoacoustic glucose monitoring system, which can potentially be developed as a powerful diagnosis and treatment tool for diabetes mellitus.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25521818','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25521818"><span>Liquid chromatography with diode array detection combined with spectral deconvolution for the analysis of some diterpene esters in Arabica coffee brew.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Erny, Guillaume L; Moeenfard, Marzieh; Alves, Arminda</p> <p>2015-02-01</p> <p>In this manuscript, the separation of kahweol and cafestol esters from Arabica coffee brews was investigated using liquid chromatography with a diode array detector. When detected in conjunction, cafestol, and kahweol esters were eluted together, but, after optimization, the kahweol esters could be selectively detected by setting the wavelength at 290 nm to allow their quantification. Such an approach was not possible for the cafestol esters, and spectral deconvolution was used to obtain deconvoluted chromatograms. In each of those chromatograms, the four esters were baseline separated allowing for the quantification of the eight targeted compounds. Because kahweol esters could be quantified either using the chromatogram obtained by setting the wavelength at 290 nm or using the deconvoluted chromatogram, those compounds were used to compare the analytical performances. Slightly better limits of detection were obtained using the deconvoluted chromatogram. Identical concentrations were found in a real sample with both approaches. The peak areas in the deconvoluted chromatograms were repeatable (intraday repeatability of 0.8%, interday repeatability of 1.0%). This work demonstrates the accuracy of spectral deconvolution when using liquid chromatography to mathematically separate coeluting compounds using the full spectra recorded by a diode array detector. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070018233&hterms=Diode&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DDiode','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070018233&hterms=Diode&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DDiode"><span>An Initiative Toward Reliable Long-Duration Operation of Diode Lasers in Space</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tratt, David M.; Amzajerdian, Farzin; Stephen, Mark A.; Shapiro, Andrew A.</p> <p>2006-01-01</p> <p>This viewgraph presentation reviews the workings of the Laser Diode Arrays (LDA) working group. The group facilitates focused interaction between the LDA user and provider communities and it will author standards document for the specification and qualification of LDA's for operation in the space environment. It also reviews the NASA test and evaluation facilities that are available to the community.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990SPIE.1201..469A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990SPIE.1201..469A"><span>Development of a drug assay using surface-enhanced Raman spectroscopy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Angel, S. M.; Roe, Jeffrey N.; Andresen, Brian D.; Myrick, Michael L.; Milanovich, Fred P.</p> <p>1990-07-01</p> <p>Surface-enhanced Raman spectroscopy has been used to detect low levels of several chemical compounds, including the drugs of abuse -cocaine hydrochloride and methamphetamme hydrochloride. Raman spectra of these substances have also been taken over optical fibers using red-wavelength excitation. These measurements demonstrate the feasibility of the remote determination of various target chemicals using diode laser excitation and diode array detection.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18542353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18542353"><span>Real-time near IR (1310 nm) imaging of CO2 laser ablation of enamel.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Darling, Cynthia L; Fried, Daniel</p> <p>2008-02-18</p> <p>The high-transparency of dental enamel in the near-IR (NIR) can be exploited for real-time imaging of ablation crater formation during drilling with lasers. NIR images were acquired with an InGaAs focal plane array and a NIR zoom microscope during drilling incisions in human enamel samples with a lambda=9.3-microm CO(2) laser operating at repetition rates of 50-300-Hz with and without a water spray. Crack formation, dehydration and thermal changes were observed during ablation. These initial images demonstrate the potential of NIR imaging to monitor laser-ablation events in real-time to provide information about the mechanism of ablation and to evaluate the potential for peripheral thermal and mechanical damage.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2386..174S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2386..174S"><span>Transcutaneous analyte measuring method (TAMM): a reflective, noninvasive, near-infrared blood chemistry analyzer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schlager, Kenneth J.; Ruchti, Timothy L.</p> <p>1995-04-01</p> <p>TAMM for Transcutaneous Analyte Measuring Method is a near infrared spectroscopic technique for the noninvasive measurement of human blood chemistry. A near infrared indium gallium arsenide (InGaAs) photodiode array spectrometer has been developed and tested on over 1,000 patients as a part of an SBIR program sponsored by the Naval Medical Research and Development Command. Nine (9) blood analytes have been measured and evaluated during pre-clinical testing: sodium, chloride, calcium, potassium, bicarbonate, BUN, glucose, hematocrit and hemoglobin. A reflective rather than a transmissive invasive approach to measurement has been taken to avoid variations resulting from skin color and sensor positioning. The current status of the instrumentation, neural network pattern recognition algorithms and test results will be discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAP...123p1593K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAP...123p1593K"><span>Effects of a GaSb buffer layer on an InGaAs overlayer grown on Ge(111) substrates: Strain, twin generation, and surface roughness</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kajikawa, Y.; Nishigaichi, M.; Tenma, S.; Kato, K.; Katsube, S.</p> <p>2018-04-01</p> <p>InGaAs layers were grown by molecular-beam epitaxy on nominal and vicinal Ge(111) substrates with inserting GaSb buffer layers. High-resolution X-ray diffraction using symmetric 333 and asymmetric 224 reflections was employed to analyze the crystallographic properties of the grown layers. By using the two reflections, we determined the lattice constants (the unit cell length a and the angle α between axes) of the grown layers with taking into account the rhombohedral distortion of the lattices of the grown layers. This allowed us the independent determination of the strain components (perpendicular and parallel components to the substrate surface, ε⊥ and ε//) and the composition x of the InxGa1-xAs layers by assuming the distortion coefficient D, which is defined as the ratio of ε⊥ against ε//. Furthermore, the twin ratios were determined for the GaSb and the InGaAs layers by comparing asymmetric 224 reflections from the twin domain with that from the normal domain of the layers. As a result, it has been shown that the twin ratio in the InGaAs layer can be decreased to be less than 0.1% by the use of the vicinal substrate together with annealing the GaSb buffer layer during the growth interruption before the InGaAs overgrowth.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-8337893.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-8337893.html"><span>Around Marshall</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1983-08-10</p> <p>One of the main components of the Hubble Space Telescope (HST) is the Solar Array Drive Electronics (SADE) system. This system interfaces with the Support System Module (SSM) for exchange of operational commands and telemetry data. SADE operates and controls the Solar Array Drive Mechanisms (SADM) for the orientation of the Solar Array Drive (SAD). It also monitors the position of the arrays and the temperature of the SADM. During the first HST servicing mission, the astronauts replaced the SADE component because of some malfunctions. This turned out to be a very challenging extravehicular activity (EVA). Two transistors and two diodes had been thermally stressed with the conformal coating discolored and charred. Soldered cornections became molten and reflowed between the two diodes. The failed transistors gave no indication of defective construction. All repairs were made and the HST was redeposited into orbit. Prior to undertaking this challenging mission, the orbiter's crew trained at Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS) to prepare themselves for working in a low gravity environment. They also practiced replacing HST parts and exercised maneuverability and equipment handling. Pictured are crew members practicing on a space platform.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9819E..07A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9819E..07A"><span>A 400 KHz line rate 2048-pixel stitched SWIR linear array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anchlia, Ankur; Vinella, Rosa M.; Gielen, Daphne; Wouters, Kristof; Vervenne, Vincent; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; De Gaspari, Danny; Das, Jo; Merken, Patrick</p> <p>2016-05-01</p> <p>Xenics has developed a family of stitched SWIR long linear arrays that operate up to 400 KHz of line rate. These arrays serve medical and industrial applications that require high line rates as well as space applications that require long linear arrays. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long array to run at a high line rates irrespective of the array length, which limits the line rate in a traditional linear array. The ROIC is flip-chipped with InGaAs detector arrays. The FPA has a pixel pitch of 12.5μm and has two pixel flavors: square (12.5μm) and rectangular (250μm). The frontend circuit is based on Capacitive Trans-impedance Amplifier (CTIA) to attain stable detector bias, and good linearity and signal integrity, especially at high speeds. The CTIA has an input auto-zero mechanism that allows to have low detector bias (<20mV). An on-chip Correlated Double Sample (CDS) facilitates removal of CTIA KTC and 1/f noise, and other offsets, achieving low noise performance. There are five gain modes in the FPA giving the full well range from 85Ke- to 40Me-. The measured input referred noise is 35e-rms in the highest gain mode. The FPA operates in Integrate While Read mode and, at a master clock rate of 60MHz and a minimum integration time of 1.4μs, achieves the highest line rate of 400 KHz. In this paper, design details and measurements results are presented in order to demonstrate the array performance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9482E..15D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9482E..15D"><span>Low SWaP multispectral sensors using dichroic filter arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dougherty, John; Varghese, Ron</p> <p>2015-06-01</p> <p>The benefits of multispectral imaging are well established in a variety of applications including remote sensing, authentication, satellite and aerial surveillance, machine vision, biomedical, and other scientific and industrial uses. However, many of the potential solutions require more compact, robust, and cost-effective cameras to realize these benefits. The next generation of multispectral sensors and cameras needs to deliver improvements in size, weight, power, portability, and spectral band customization to support widespread deployment for a variety of purpose-built aerial, unmanned, and scientific applications. A novel implementation uses micro-patterning of dichroic filters1 into Bayer and custom mosaics, enabling true real-time multispectral imaging with simultaneous multi-band image acquisition. Consistent with color image processing, individual spectral channels are de-mosaiced with each channel providing an image of the field of view. This approach can be implemented across a variety of wavelength ranges and on a variety of detector types including linear, area, silicon, and InGaAs. This dichroic filter array approach can also reduce payloads and increase range for unmanned systems, with the capability to support both handheld and autonomous systems. Recent examples and results of 4 band RGB + NIR dichroic filter arrays in multispectral cameras are discussed. Benefits and tradeoffs of multispectral sensors using dichroic filter arrays are compared with alternative approaches - including their passivity, spectral range, customization options, and scalable production.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22223371','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22223371"><span>Comparative study of fourteen alkaloids from Uncaria rhynchophylla hooks and leaves using HPLC-diode array detection-atmospheric pressure chemical ionization/MS method.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qu, Jialin; Gong, Tianxing; Ma, Bin; Zhang, Lin; Kano, Yoshihiro; Yuan, Dan</p> <p>2012-01-01</p> <p>The purpose of the study is to compare alkaloid profile of Uncaria rhynchophylla hooks and leaves. Ten oxindole alkaloids and four glycosidic indole alkaloids were identified using HPLC-diode array detection (DAD) or LC-atmospheric pressure chemical ionization (APCI)-MS method, and a HPLC-UV method for simultaneous quantification of major alkaloids was validated. The hooks are characterized by high levels of four oxindole alkaloids rhynchophylline (R), isorhynchophylline (IR), corynoxeine (C) and isocorynoxeine (IC), while the leaves contained high level of two glycosidic indole alkaloids vincoside lactam (VL) and strictosidine (S). The presented methods have proven its usefulness in chemical characterization of U. rhynchophylla hooks and leaves.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApPhL.101c2103L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApPhL.101c2103L"><span>Nitrogen-polar core-shell GaN light-emitting diodes grown by selective area metalorganic vapor phase epitaxy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Shunfeng; Wang, Xue; Fündling, Sönke; Erenburg, Milena; Ledig, Johannes; Wei, Jiandong; Wehmann, Hergo H.; Waag, Andreas; Bergbauer, Werner; Mandl, Martin; Strassburg, Martin; Trampert, Achim; Jahn, Uwe; Riechert, Henning; Jönen, Holger; Hangleiter, Andreas</p> <p>2012-07-01</p> <p>Homogeneous nitrogen-polar GaN core-shell light emitting diode (LED) arrays were fabricated by selective area growth on patterned substrates. Transmission electron microscopy measurements prove the core-shell structure of the rod LEDs. Depending on the growth facets, the InGaN/GaN multi-quantum wells (MQWs) show different dimensions and morphology. Cathodoluminescence (CL) measurements reveal a MQWs emission centered at about 415 nm on sidewalls and another emission at 460 nm from top surfaces. CL line scans on cleaved rod also indicate the core-shell morphology. Finally, an internal quantum efficiency of about 28% at room temperature was determined by an all-optical method on a LED array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820023785','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820023785"><span>Radiation effects studies for the high-resolution spectrograph</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, L. C.; Becher, J.</p> <p>1982-01-01</p> <p>The generation and collection of charge carriers created during the passage of energetic protons through a silicon photodiode array are modeled. Pulse height distributions of noise charge collected during exposure of a digicon type diode array to 21 and 75 MeV protons were obtained. The magnitude of charge collected by a diode from each proton event is determined not only by diffusion, but by statistical considerations involving the ionization process itself. Utilizing analytical solutions to the diffusion equation for transport of minority carriers, together with the Vavilov theory of energy loss fluctuations in thin absorbers, simulations of the pulse height spectra which follow the experimental distributions fairly well are presented and an estimate for the minority carrier diffusion length L sub d is provided.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920054564&hterms=Neodymium+phosphate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DNeodymium%2Bphosphate','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920054564&hterms=Neodymium+phosphate&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DNeodymium%2Bphosphate"><span>One joule output from a diode-array-pumped Nd:YAG laser with side-pumped rod geometry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kasinski, Jeffrey J.; Hughes, Will; Dibiase, Don; Bournes, Patrick; Burnham, Ralph</p> <p>1992-01-01</p> <p>Output of 1.25 J per pulse (1.064 micron) with an absolute optical efficiency of 28 percent and corresponding electrical efficiency of 10 percent was demonstrated in a diode-array-pumped Nd:YAG laser using a side-pumped rod geometry in a master-oscillator/power-amplifier configuration. In Q-switched operation, an output of 0.75 J in a 17-ns pulse was obtained. The fundamental laser output was frequency doubled in KTP with 60 percent conversion efficiency to obtain 0.45 J in a 16-ns pulse at 532 nm. The output beam had high spatial quality with pointing stability better than 40 microrad and a shot-to-shot pulse energy fluctuation of less than +/-3 percent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA635128','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA635128"><span>Bremsstrahlung Diode Performance on Mercury MIV A</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2005-06-01</p> <p>generator, experiments are performed utilizing both carbon (C) and tantalum (Ta) converters. An array of CaF2 thermoluminescent dosimeters ( TLDs ...an Al cylinder of 4-mm wall thickness; this thickness is sufficient to isolate the TLDs from externally produced Compton electrons . The measured PD...production of Mercury, a series of large-area electron -beam (e-beam) diode experiments are performed in which the e-beam is deposited onto either a</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA406568','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA406568"><span>Biophysical Characterization of an Bifunctional Iron Regulating Enzyme</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2002-05-01</p> <p>of the direct assay 29 Citrate, cis- aconitate and d- isocitrate all absorb light in the UV-Vis region, a fact which was confirmed...experimentally using a Hewlard-Packard 8452 Diode UV-Vis Diode Array Spectrophotometer. The maximum absorbance of cis- aconitate was determined to be 240 nm...and isocitrate was 212 nm. The preponderance of cis- aconitate concentration versus the formation of isocitrate concentration made tracking a</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100036562','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100036562"><span>InGaP Heterojunction Barrier Solar Cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Welser, Roger E.</p> <p>2010-01-01</p> <p>A new solar-cell structure utilizes a single, ultra-wide well of either gallium arsenide (GaAs) or indium-gallium-phosphide (InGaP) in the depletion region of a wide bandgap matrix, instead of the usual multiple quantum well layers. These InGaP barrier layers are effective at reducing diode dark current, and photogenerated carrier escape is maximized by the proper design of the electric field and barrier profile. With the new material, open-circuit voltage enhancements of 40 and 100 mV (versus PIN control systems) are possible without any degradation in short-circuit current. Basic tenets of quantum-well and quantum- dot solar cells are utilized, but instead of using multiple thin layers, a single wide well works better. InGaP is used as a barrier material, which increases open current, while simultaneously lowering dark current, reducing both hole diffusion from the base, and space charge recombination within the depletion region. Both the built-in field and the barrier profile are tailored to enhance thermionic emissions, which maximizes the photocurrent at forward bias, with a demonstrated voltage increase. An InGaP heterojunction barrier solar cell consists of a single, ultra-wide GaAs, aluminum-gallium-arsenide (AlGaAs), or lower-energy-gap InGaP absorber well placed within the depletion region of an otherwise wide bandgap PIN diode. Photogenerated electron collection is unencumbered in this structure. InGaAs wells can be added to the thick GaAs absorber layer to capture lower-energy photons.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5059435','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5059435"><span>A 17 GHz molecular rectifier</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Trasobares, J.; Vuillaume, D.; Théron, D.; Clément, N.</p> <p>2016-01-01</p> <p>Molecular electronics originally proposed that small molecules sandwiched between electrodes would accomplish electronic functions and enable ultimate scaling to be reached. However, so far, functional molecular devices have only been demonstrated at low frequency. Here, we demonstrate molecular diodes operating up to 17.8 GHz. Direct current and radio frequency (RF) properties were simultaneously measured on a large array of molecular junctions composed of gold nanocrystal electrodes, ferrocenyl undecanethiol molecules and the tip of an interferometric scanning microwave microscope. The present nanometre-scale molecular diodes offer a current density increase by several orders of magnitude compared with that of micrometre-scale molecular diodes, allowing RF operation. The measured S11 parameters show a diode rectification ratio of 12 dB which is linked to the rectification behaviour of the direct current conductance. From the RF measurements, we extrapolate a cut-off frequency of 520 GHz. A comparison with the silicon RF-Schottky diodes, architecture suggests that the RF-molecular diodes are extremely attractive for scaling and high-frequency operation. PMID:27694833</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22303890-low-defect-ingaas-quantum-well-selectively-grown-metal-organic-chemical-vapor-deposition-si-wafers-next-generation-non-planar-devices','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22303890-low-defect-ingaas-quantum-well-selectively-grown-metal-organic-chemical-vapor-deposition-si-wafers-next-generation-non-planar-devices"><span>Low defect InGaAs quantum well selectively grown by metal organic chemical vapor deposition on Si(100) 300 mm wafers for next generation non planar devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cipro, R.; Gorbenko, V.; Univ. Grenoble Alpes, F-38000, France CEA-LETI, MINATEC Campus, F-38054 Grenoble</p> <p>2014-06-30</p> <p>Metal organic chemical vapor deposition of GaAs, InGaAs, and AlGaAs on nominal 300 mm Si(100) at temperatures below 550 °C was studied using the selective aspect ratio trapping method. We clearly show that growing directly GaAs on a flat Si surface in a SiO{sub 2} cavity with an aspect ratio as low as 1.3 is efficient to completely annihilate the anti-phase boundary domains. InGaAs quantum wells were grown on a GaAs buffer and exhibit room temperature micro-photoluminescence. Cathodoluminescence reveals the presence of dark spots which could be associated with the presence of emerging dislocation in a direction parallel to the cavity. Themore » InGaAs layers obtained with no antiphase boundaries are perfect candidates for being integrated as channels in n-type metal oxide semiconductor field effect transistor (MOSFET), while the low temperatures used allow the co-integration of p-type MOSFET.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JCrGr.164..339S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JCrGr.164..339S"><span>MOMBE selective infill growth of InP:Si and InGaAs:Si and large area MOMBE regrowth</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schelhase, S.; Böttcher, J.; Gibis, R.; Künzel, H.; Paraskevopoulos, A.</p> <p>1996-07-01</p> <p>MOMBE selective infill growth (SIG) of silicon-doped InP and InGaAs was investigated by variation of the principal growth parameters, i.e. temperature, {V}/{III}- ratio and rate. Excellent surface morphology in conjunction with perfect selectivity and defect-free vertical interfaces between the grown layer and the etched substrate sidewall was achieved by an appropriate optimization of the selective growth conditions for InP as well as, for the first time, InGaAs. In the case of SIG of InP, smooth growth boundaries were obtained in the [01¯1] direction, whereas in the [01¯1¯] direction minor growth perturbations occur, which are related to a strong orientation dependent diffusion behavior of the growth species on the growth front. In the case of SIG of InGaAs, slight perturbations accompanied by facet formation at the edges of the selectively grown windows were observed. In the perspective of device application, homogeneous large area MOMBE InGaAs regrowth of the embedded structures was successfully achieved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27635787','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27635787"><span>Self-Positioned Nanosized Mask for Transparent and Flexible Ferroelectric Polymer Nanodiodes Array.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hyun, Seung; Kwon, Owoong; Choi, Chungryong; Vincent Joseph, Kanniyambatti L; Kim, Yunseok; Kim, Jin Kon</p> <p>2016-10-12</p> <p>High density arrays of ferroelectric polymer nanodiodes have gained strong attention for next-generation transparent and flexible nonvolatile resistive memory. Here, we introduce a facile and innovative method to fabricate ferroelectric polymer nanodiode array on an ITO-coated poly(ethylene terephthalate) (PET) substrate by using block copolymer self-assembly and oxygen plasma etching. First, polystyrene-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) micelles were spin-coated on poly(vinylidene fluoride-ran-trifluoroethylene) copolymer (P(VDF-TrFE)) film/ITO-coated PET substrate. After the sample was immersed in a gold precursor (HAuCl 4 ) containing solution, which strongly coordinates with nitrogen group in P2VP, oxygen plasma etching was performed. During the plasma etching, coordinated gold precursors became gold nanoparticles (GNPs), which successfully acted as self-positioned etching mask to fabricate a high density array of P(VDF-TrFE)) nanoislands with GNP at the top. Each nanoisland shows clearly individual diode property, as confirmed by current-voltage (I-V) curve. Furthermore, due to the transparent and flexible nature of P(VDF-TrFE)) nanoisland as well as the substrate, the P(VDF-TrFE) nanodiode array was highly tranparent, and the diode property was maintained even after a large number of bendings (for instance, 1000 times). The array could be used as the next-generation tranparent and flexible nonvolatile memory device.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980001018','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980001018"><span>Electrical and Optical Performance Characteristics of 0.74-eV p/n InGaAs Monolithic Interconnected Modules</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilt, David M.; Fatemi, Navid S.; Jenkins, Phillip P.; Weizer, Victor G.; Hoffman, Richard W., Jr.; Jain, Raj K.; Murray, Christopher S.; Riley, David R.</p> <p>1997-01-01</p> <p>There has been a traditional trade-off in thermophotovoltaic (TPV) energy conversion development between system efficiency and power density. This trade-off originates from the use of front surface spectral controls such as selective emitters and various types of filters. A monolithic interconnected module (MIM) structure has been developed which allows for both high power densities and high system efficiencies. The MIM device consists of many individual indium gallium arsenide (InGaAs) cells series-connected on a single semi-insulating indium phosphide (InP) substrate. The MIM is exposed to the entire emitter output, thereby maximizing output power density. An infrared (IR) reflector placed on the rear surface of the substrate returns the unused portion of the emitter output spectrum back to the emitter for recycling, thereby providing for high system efficiencies. Initial MIM development has focused on a 1 sq cm device consisting of eight (8) series interconnected cells. MIM devices, produced from 0.74-eV InGaAs, have demonstrated V(sub oc) = 3.2 volts, J(sub sc) = 70 mA/sq cm, and a fill factor of 66% under flashlamp testing. Infrared (IR) reflectance measurements (greater than 2 micron) of these devices indicate a reflectivity of greater than 82%. MIM devices produced from 0.55-eV InGaAs have also been demonstrated. In addition, conventional p/n InGaAs devices with record efficiencies (11.7% AM0) have been demonstrated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26070022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26070022"><span>Passivation of InGaAs(001)-(2 × 4) by Self-Limiting Chemical Vapor Deposition of a Silicon Hydride Control Layer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Edmonds, Mary; Kent, Tyler; Chagarov, Evgueni; Sardashti, Kasra; Droopad, Ravi; Chang, Mei; Kachian, Jessica; Park, Jun Hong; Kummel, Andrew</p> <p>2015-07-08</p> <p>A saturated Si-Hx seed layer for gate oxide or contact conductor ALD has been deposited via two separate self-limiting and saturating CVD processes on InGaAs(001)-(2 × 4) at substrate temperatures of 250 and 350 °C. For the first self-limiting process, a single silicon precursor, Si3H8, was dosed at a substrate temperature of 250 °C, and XPS results show the deposited silicon hydride layer saturated at about 4 monolayers of silicon coverage with hydrogen termination. STS results show the surface Fermi level remains unpinned following the deposition of the saturated silicon hydride layer, indicating the InGaAs surface dangling bonds are electrically passivated by Si-Hx. For the second self-limiting process, Si2Cl6 was dosed at a substrate temperature of 350 °C, and XPS results show the deposited silicon chloride layer saturated at about 2.5 monolayers of silicon coverage with chlorine termination. Atomic hydrogen produced by a thermal gas cracker was subsequently dosed at 350 °C to remove the Si-Cl termination by replacing with Si-H termination as confirmed by XPS, and STS results confirm the saturated Si-Hx bilayer leaves the InGaAs(001)-(2 × 4) surface Fermi level unpinned. Density function theory modeling of silicon hydride surface passivation shows an Si-Hx monolayer can remove all the dangling bonds and leave a charge balanced surface on InGaAs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......133T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......133T"><span>Spectral gain measurements of quantum confined emitters, and design and fabrication of intersubband quantum box laser structures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsvid, Gene</p> <p></p> <p>Semiconductor laser active regions are commonly characterized by photo- and electro-luminescence (PL, EL) and cavity length analysis. However quantitative spectral information is not readily extracted from PL and EL data and comparison of different active region materials can be difficult. More quantifiable spectral information is contained in the optical gain spectra. This work reports on spectral gain studies, using multi-segmented interband devices, of InGaAs quantum well and quantum dot active regions grown by metalorganic chemical vapor deposition (MOCVD). Using the fundamental connection between gain and spontaneous emission spectra, the spontaneous radiative current and spontaneous radiative efficiency is evaluated for these active regions. The spectral gain and spontaneous radiative efficiency measurements of 980 nm emitting InGaAs quantum well (QW) material provides a benchmark comparison to previous results obtained on highly-strained, 1200 nm emitting InGaAs QW material. These studies provide insight into carrier recombination and the role of the current injection efficiency in InGaAs QW lasers. The spectral gain of self-assembled MOCVD grown InGaAs quantum dots (QD) active regions are also investigated, allowing for comparison to InGaAs QW material. The second part of my talk will cover intersubband-transition QW and quantum-box (QB) lasers. Quantum cascade (QC) lasers have emerged as compact and technologically important light sources in the mid-infrared (IR) and far-IR wavelength ranges infringing on the near-IR and terahertz spectral regions respectively. However, the overall power conversion efficiency, so-called wallplug efficiency, of the best QC lasers, emitting around 5 microns, is ˜9% in CW operation and very unlikely to exceed 15%. In order to dramatically improve the wallplug efficiency of mid-IR lasers (i.e., to about 50%), intersubband QB (IQB) lasers have been proposed. The basic idea, the optimal design and the progress towards the fabrication of IQB lasers will be presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......172A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......172A"><span>Continuum modelling of silicon diffusion in indium gallium arsenide</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aldridge, Henry Lee, Jr.</p> <p></p> <p>A possible method to overcome the physical limitations experienced by continued transistor scaling and continue improvements in performance and power consumption is integration of III-V semiconductors as alternative channel materials for logic devices. Indium Gallium Arsenide (InGaAs) is such a material from the III-V semiconductor family, which exhibit superior electron mobilities and injection velocities than that of silicon. In order for InGaAs integration to be realized, contact resistances must be minimized through maximizing activation of dopants in this material. Additionally, redistribution of dopants during processing must be clearly understood and ultimately controlled at the nanometer-scale. In this work, the activation and diffusion behavior of silicon, a prominent n-type dopant in InGaAs, has been characterized and subsequently modelled using the Florida Object Oriented Process and Device Simulator (FLOOPS). In contrast to previous reports, silicon exhibits non-negligible diffusion in InGaAs, even for smaller thermal budget rapid thermal anneals (RTAs). Its diffusion is heavily concentration-dependent, with broadening "shoulder-like" profiles when doping levels exceed 1-3x1019cm -3, for both ion-implanted and Molecular Beam Epitaxy (MBE)-grown cases. Likewise a max net-activation value of ˜1.7x1019cm -3 is consistently reached with enough thermal processing, regardless of doping method. In line with experimental results and several ab-initio calculation results, rapid concentration-dependent diffusion of Si in InGaAs and the upper limits of its activation is believed to be governed by cation vacancies that serve as compensating defects in heavily n-type regions of InGaAs. These results are ultimately in line with an amphoteric defect model, where the activation limits of dopants are an intrinsic limitation of the material, rather than governed by individual dopant species or their methods of incorporation. As a result a Fermi level dependent point defect diffusion model and activation limit model were subsequently developed in FLOOPS with outputs in good agreement with experimental results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5089..238H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5089..238H"><span>Laser diode arrays for naval reconnaissance</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holloway, John H., Jr.; Crosby, Frank J.; Petee, Danny A.; Suiter, Harold R.; Witherspoon, Ned H.</p> <p>2003-09-01</p> <p>The Airborne Littoral Reconnaissance Technologies (ALRT) Project has demonstrated a nighttime operational minefield detection capability using commercial off-the-shelf high-power Laser Diode Arrays (LDAs). Historically, optical aerial detection of minefields has primarily been limited to daytime operations but LDAs promise compact and efficient lighting to allow for enhanced reconnaissance operations for future mine detection systems. When combined with high-resolution intensified imaging systems, LDAs can illuminate otherwise unseen areas. Future wavelength options will open the way for active multispectral imaging with LDAs. The Coastal Systems Station working for the Office of Naval Research on the ALRT project has designed, developed, integrated, and tested both prototype and commercial arrays from a Cessna airborne platform. Detailed test results show the ability to detect several targets of interest in a variety of background conditions. Initial testing of the prototype arrays, reported on last year, was completed and further investigations of the commercial versions were performed. Polarization-state detection studies were performed, and advantageous properties of the source-target-sensor geometry noted. Current project plans are to expand the field-of-view coverage for Naval exercises in the summer of 2003. This paper describes the test collection, data library products, array information, on-going test analysis results, and future planned testing of the LDAs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhB...50u4003K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhB...50u4003K"><span>High intensity click statistics from a 10 × 10 avalanche photodiode array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kröger, Johannes; Ahrens, Thomas; Sperling, Jan; Vogel, Werner; Stolz, Heinrich; Hage, Boris</p> <p>2017-11-01</p> <p>Photon-number measurements are a fundamental technique for the discrimination and characterization of quantum states of light. Beyond the abilities of state-of-the-art devices, we present measurements with an array of 100 avalanche photodiodes exposed to photon-numbers ranging from well below to significantly above one photon per diode. Despite each single diode only discriminating between zero and non-zero photon-numbers we were able to extract a second order moment, which acts as a nonclassicality indicator. We demonstrate a vast enhancement of the applicable intensity range by two orders of magnitude relative to the standard application of such devices. It turns out that the probabilistic mapping of arbitrary photon-numbers on a finite number of registered clicks is not per se a disadvantage compared with true photon counters. Such detector arrays can bridge the gap between single-photon and linear detection, by investigation of the click statistics, without the necessity of photon statistics reconstruction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23188359','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23188359"><span>Analysis of light emitting diode array lighting system based on human vision: normal and abnormal uniformity condition.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qin, Zong; Ji, Chuangang; Wang, Kai; Liu, Sheng</p> <p>2012-10-08</p> <p>In this paper, condition for uniform lighting generated by light emitting diode (LED) array was systematically studied. To take human vision effect into consideration, contrast sensitivity function (CSF) was novelly adopted as critical criterion for uniform lighting instead of conventionally used Sparrow's Criterion (SC). Through CSF method, design parameters including system thickness, LED pitch, LED's spatial radiation distribution and viewing condition can be analytically combined. In a specific LED array lighting system (LALS) with foursquare LED arrangement, different types of LEDs (Lambertian and Batwing type) and given viewing condition, optimum system thicknesses and LED pitches were calculated and compared with those got through SC method. Results show that CSF method can achieve more appropriate optimum parameters than SC method. Additionally, an abnormal phenomenon that uniformity varies with structural parameters non-monotonically in LALS with non-Lambertian LEDs was found and analyzed. Based on the analysis, a design method of LALS that can bring about better practicability, lower cost and more attractive appearance was summarized.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29714286','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29714286"><span>Morphologies and optical and electrical properties of InGaN/GaN micro-square array light-emitting diode chips.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Han, Dan; Ma, Shufang; Jia, Zhigang; Liu, Peizhi; Jia, Wei; Shang, Lin; Zhai, Guangmei; Xu, Bingshe</p> <p>2018-04-10</p> <p>InGaN/GaN micro-square array light-emitting diode (LED) chips (micro-chips) have been prepared via the focused ion beam (FIB) etching technique, which can not only reduce ohmic contact degradation but also control the aspect ratio precisely in three-dimensional (3D) structure LED (3D-LED) device fabrication. The effects of FIB beam current and micro-square array depth on morphologies and optical and electrical properties of the micro-chips have been studied. Our results show that sidewall surface morphology and optical and electrical properties of the micro-chips degrade with increased beam current. After potassium hydroxide etching with different times, an optimal current-voltage and luminescence performance can be obtained. Combining the results of cathodoluminescence mappings and light output-current characteristics, the light extraction efficiency of the micro-chips is reduced as FIB etch depth increases. The mechanisms of micro-square depth on light extraction have been revealed by 3D finite difference time domain.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22634781-su-proton-computed-tomography-using-silicon-diode-array','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22634781-su-proton-computed-tomography-using-silicon-diode-array"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wang, P; Cammin, J; Solberg, T</p> <p></p> <p>Purpose: Proton radiography and proton computed tomography (PCT) can be used to measure proton stopping power directly. However, practical and cost effective proton imaging detectors are not widely available. In this study, the authors investigated the feasibility of proton imaging using a silicon diode array. Methods: A one-dimensional silicon-diode detector array (1DSDA) was aligned with the central axis (CAX) of the proton beam. Polymethyl methacrylate (PMMA) slabs were used to find the correspondence between the water equivalent thickness (WET) and 1DSDA channel number. 2D proton radiographs (PR) were obtained by translation and rotation of a phantom relative to CAX whilemore » the proton nozzle and 1DSDA were kept stationary. A PCT image of one slice of the phantom was reconstructed using filtered backprojection. Results: PR and PCT images of the PMMA cube were successfully acquired using the 1DSDA. The WET of the phantom was measured using PR data with an accuracy of 4.2% or better. Structures down to 1 mm in size could be resolved. Reconstruction of a PCT image showed very good agreement with simulation. Limitations in spatial resolution are attributed to limited spatial sampling, beam collimation, and proton scatter. Conclusion: The results demonstrate the feasibility of using silicon diode arrays for proton imaging. Such a device can potentially offer fast image acquisition, high spatial and energy resolution for PR and PCT.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23070832','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23070832"><span>Metabolic profile of glyburide in human liver microsomes using LC-DAD-Q-TRAP-MS/MS.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ravindran, Selvan; Basu, Sudipta; Gorti, Santosh Kapil Kumar; Surve, Prashant; Sloka, Navya</p> <p>2013-05-01</p> <p>The sulfonylurea urea drug glyburide (glibenclamide) is widely used for the treatment of diabetes milletus and gestational diabetes. In previous studies monohydroxylated metabolites were identified and characterized for glyburide in different species, but the metabolite owing to the loss of cyclohexyl ring was identified only in mouse. Glyburide upon incubation with hepatic microsomes resulted in 10 metabolites for human. The current study identifies new metabolites of glyburide along with the hydroxylated metabolites that were reported earlier. The newly identified drug metabolites are dihydroxylated metabolites, a metabolite owing to the loss of cyclohexyl ring and one owing to hydroxylation with dehydrogenation. Among the 10 identified metabolites, there were six monohydroxylated metabolites, one dihydroxylated metabolite, two metabolites owing to hydroxylation and dehydrogenation, and one metabolite owing to the loss of cyclohexyl ring. New metabolites of glyburide were identified and characterized using liquid chromatography-diode array detector-quadruple-ion trap-mass spectrometry/mass spectrometry (LC-DAD-Q-TRAP-MS/MS). An enhanced mass scan-enhanced product ion scan with information-dependent acquisition mode in a Q-TRAP-MS/MS system was used to characterize the metabolites. Liquid chromatography with diode array detection was used as a complimentary technique to confirm and identify the metabolites. Metabolites formed in higher amounts were detected in both diode array detection and mass spectrometry detection. Copyright © 2012 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97s5303S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97s5303S"><span>Direct extraction of electron parameters from magnetoconductance analysis in mesoscopic ring array structures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sawada, A.; Faniel, S.; Mineshige, S.; Kawabata, S.; Saito, K.; Kobayashi, K.; Sekine, Y.; Sugiyama, H.; Koga, T.</p> <p>2018-05-01</p> <p>We report an approach for examining electron properties using information about the shape and size of a nanostructure as a measurement reference. This approach quantifies the spin precession angles per unit length directly by considering the time-reversal interferences on chaotic return trajectories within mesoscopic ring arrays (MRAs). Experimentally, we fabricated MRAs using nanolithography in InGaAs quantum wells which had a gate-controllable spin-orbit interaction (SOI). As a result, we observed an Onsager symmetry related to relativistic magnetic fields, which provided us with indispensable information for the semiclassical billiard ball simulation. Our simulations, developed based on the real-space formalism of the weak localization/antilocalization effect including the degree of freedom for electronic spin, reproduced the experimental magnetoconductivity (MC) curves with high fidelity. The values of five distinct electron parameters (Fermi wavelength, spin precession angles per unit length for two different SOIs, impurity scattering length, and phase coherence length) were thereby extracted from a single MC curve. The methodology developed here is applicable to wide ranges of nanomaterials and devices, providing a diagnostic tool for exotic properties of two-dimensional electron systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867574','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867574"><span>Semiconductor laser devices having lateral refractive index tailoring</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ashby, Carol I. H.; Hadley, G. Ronald; Hohimer, John P.; Owyoung, Adelbert</p> <p>1990-01-01</p> <p>A broad-area semiconductor laser diode includes an active lasing region interposed between an upper and a lower cladding layer, the laser diode further comprising structure for controllably varying a lateral refractive index profile of the diode to substantially compensate for an effect of junction heating during operation. In embodiments disclosed the controlling structure comprises resistive heating strips or non-radiative linear junctions disposed parallel to the active region. Another embodiment discloses a multi-layered upper cladding region selectively disordered by implanted or diffused dopant impurities. Still another embodiment discloses an upper cladding layer of variable thickness that is convex in shape and symmetrically disposed about a central axis of the active region. The teaching of the invention is also shown to be applicable to arrays of semiconductor laser diodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22482647-edge-multi-energy-soft-ray-diagnostic-experimental-advanced-superconducting-tokamak','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22482647-edge-multi-energy-soft-ray-diagnostic-experimental-advanced-superconducting-tokamak"><span>Edge multi-energy soft x-ray diagnostic in Experimental Advanced Superconducting Tokamak</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Li, Y. L.; Xu, G. S.; Wan, B. N.</p> <p></p> <p>A multi-energy soft x-ray (ME-SXR) diagnostic has been built for electron temperature profile in the edge plasma region in Experimental Advanced Superconducting Tokamak (EAST) after two rounds of campaigns. Originally, five preamplifiers were mounted inside the EAST vacuum vessel chamber attached to five vertically stacked compact diode arrays. A custom mechanical structure was designed to protect the detectors and electronics under constraints of the tangential field of view for plasma edge and the allocation of space. In the next experiment, the mechanical structure was redesigned with a barrel structure to absolutely isolate it from the vacuum vessel. Multiple shielding structuresmore » were mounted at the pinhole head to protect the metal foils from lithium coating. The pre-amplifiers were moved to the outside of the vacuum chamber to avoid introducing interference. Twisted copper cooling tube was embedded into the back-shell near the diode to limit the temperature of the preamplifiers and diode arrays during vacuum vessel baking when the temperature reached 150 °C. Electron temperature profiles were reconstructed from ME-SXR measurements using neural networks.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1953c0233C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1953c0233C"><span>Growth of indium gallium arsenide thin film on silicon substrate by MOCVD technique</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chowdhury, Sisir; Das, Anish; Banerji, Pallab</p> <p>2018-05-01</p> <p>Indium gallium arsenide (InGaAs) thin film with indium phosphide (InP) buffer has been grown on p-type silicon (100) by Metal Organic Chemical Vapor Deposition (MOCVD) technique. To get a lattice matched substrate an Indium Phosphide buffer thin film is deposited onto Si substrate prior to InGaAs growth. The grown films have been investigated by UV-Vis-NIR reflectance spectroscopy. The band gap energy of the grown InGaAs thin films determined to be 0.82 eV from reflectance spectrum and the films are found to have same thickness for growth between 600 °C and 650 °C. Crystalline quality of the grown films has been studied by grazing incidence X-ray diffractometry (GIXRD).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OExpr..2530388S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OExpr..2530388S"><span>Breakdown flash at telecom wavelengths in InGaAs avalanche photodiodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Yicheng; Lim, Janet Zheng Jie; Poh, Hou Shun; Tan, Peng Kian; Tan, Peiyu Amelia; Ling, Alexander; Kurtsiefer, Christian</p> <p>2017-11-01</p> <p>Quantum key distribution (QKD) at telecom wavelengths (1260-1625nm) has the potential for fast deployment due to existing optical fibre infrastructure and mature telecom technologies. At these wavelengths, indium gallium arsenide (InGaAs) avalanche photodiode (APD) based detectors are the preferred choice for photon detection. Similar to their silicon counterparts used at shorter wavelengths, they exhibit fluorescence from recombination of electron-hole pairs generated in the avalanche breakdown process. This fluorescence may open side channels for attacks on QKD systems. Here, we characterize the breakdown fluorescence from two commercial InGaAs single photon counting modules, and find a spectral distribution between 1000nm and 1600nm. We also show that by spectral filtering, this side channel can be efficiently suppressed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29221068','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29221068"><span>Breakdown flash at telecom wavelengths in InGaAs avalanche photodiodes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shi, Yicheng; Lim, Janet Zheng Jie; Poh, Hou Shun; Tan, Peng Kian; Tan, Peiyu Amelia; Ling, Alexander; Kurtsiefer, Christian</p> <p>2017-11-27</p> <p>Quantum key distribution (QKD) at telecom wavelengths (1260 - 1625 nm) has the potential for fast deployment due to existing optical fibre infrastructure and mature telecom technologies. At these wavelengths, Indium Gallium Arsenide (InGaAs) avalanche photodiode (APD) based detectors are the preferred choice for photon detection. Similar to their Silicon counterparts used at shorter wavelengths, they exhibit fluorescence from recombination of electron-hole pairs generated in the avalanche breakdown process. This fluorescence may open side channels for attacks on QKD systems. Here, we characterize the breakdown fluorescence from two commercial InGaAs single photon counting modules, and find a spectral distribution between 1000 nm and 1600 nm. We also show that by spectral filtering, this side channel can be efficiently suppressed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10590E..1NM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10590E..1NM"><span>Sequential, progressive, equal-power, reflective beam-splitter arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manhart, Paul K.</p> <p>2017-11-01</p> <p>The equations to calculate equal-power reflectivity of a sequential series of beam splitters is presented. Non-sequential optical design examples are offered for uniform illumination using diode lasers. Objects created using Boolean operators and Swept Surfaces can create objects capable of reflecting light into predefined elevation and azimuth angles. Analysis of the illumination patterns for the array are also presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110004362','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110004362"><span>Technique for Radiometer and Antenna Array Calibration with Two Antenna Noise Diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Srinivasan, Karthik; Limaye, Ashutosh; Laymon, Charles; Meyer, Paul</p> <p>2011-01-01</p> <p>This paper presents a new technique to calibrate a microwave radiometer and phased array antenna system. This calibration technique uses a radiated noise source in addition to an injected noise sources for calibration. The plane of reference for this calibration technique is the face of the antenna and therefore can effectively calibration the gain fluctuations in the active phased array antennas. This paper gives the mathematical formulation for the technique and discusses the improvements brought by the method over the existing calibration techniques.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1366953-use-priori-spectral-information-measurement-ray-flux-filtered-diode-arrays','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1366953-use-priori-spectral-information-measurement-ray-flux-filtered-diode-arrays"><span>Use of a priori spectral information in the measurement of x-ray flux with filtered diode arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Marrs, R. E.; Widmann, K.; Brown, G. V.; ...</p> <p>2015-10-29</p> <p>Filtered x-ray diode (XRD) arrays are often used to measure x-ray spectra vs. time from spectrally continuous x-ray sources such as hohlraums. A priori models of the incident x-ray spectrum enable a more accurate unfolding of the x-ray flux as compared to the standard technique of modifying a thermal Planckian with spectral peaks or dips at the response energy of each filtered XRD channel. A model x-ray spectrum consisting of a thermal Planckian, a Gaussian at higher energy, and (in some cases) a high energy background provides an excellent fit to XRD-array measurements of x-ray emission from laser heated hohlraums.more » If high-resolution measurements of part of the x-ray emission spectrum are available, that information can be included in the a priori model. In cases where the x-ray emission spectrum is not Planckian, candidate x-ray spectra can be allowed or excluded by fitting them to measured XRD voltages. Here, examples are presented from the filtered XRD arrays, named Dante, at the National Ignition Facility and the Laboratory for Laser Energetics.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10641E..0OF','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10641E..0OF"><span>The performance of Geiger mode avalanche photo-diodes in free space laser communication links</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farrell, Thomas C.</p> <p>2018-05-01</p> <p>Geiger mode avalanche photo-diode (APD) arrays, when used as detectors in laser communication (lasercom) receivers, promise better performance at lower signal levels than APDs operated in the linear mode. In this paper, we describe the basic operation of the Geiger mode APD array as a lasercom detector, concentrating on aspects relevant to the link design engineer (rather than, for example, describing the details of the physics of the basic device operation itself). Equations are developed that describe the effects of defocus and hold-off time on the relation between the number of photons detected by the array and the output of photo-electron counts. We show how to incorporate these equations into a link budget. The resulting predictions are validated by comparison against simulation results. Finally, we compare the performance of linear mode APD based receivers and Geiger mode APD array based receivers. Results show the Geiger mode receivers yield better performance, in terms of probability of bit error, at lower signal levels, except on links where there is an exceptionally large amount of background noise. Under those conditions, not surprisingly, the hold-off time degrades performance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://images.nasa.gov/#/details-8337884.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-8337884.html"><span>Around Marshall</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1983-08-10</p> <p>One of the main components of the Hubble Space Telescope (HST) is the Solar Array Drive Electronics (SADE) system. This system interfaces with the Support System Module (SSM) for exchange of operational commands and telemetry data. SADE operates and controls the Solar Array Drive Mechanisms (SADM) for the orientation of the Solar Array Drive (SAD). It also monitors the position of the arrays and the temperature of the SADM. During the first HST servicing mission, the astronauts replaced the SADE component because of some malfunctions. This turned out to be a very challenging extravehicular activity (EVA). Two transistors and two diodes had been thermally stressed with the conformal coating discolored and charred. Soldered cornections became molten and reflowed between the two diodes. The failed transistors gave no indication of defective construction. All repairs were made and the HST was redeposited into orbit. Prior to undertaking this challenging mission, the orbiter's crew trained at Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS) to prepare themselves for working in a low gravity environment. They also practiced replacing HST parts and exercised maneuverability and equipment handling. Pictured is an astronaut practicing climbing a space platform that was necessary in making repairs on the HST.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=MSFC-8337884&hterms=sad&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsad','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=MSFC-8337884&hterms=sad&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsad"><span>Neutral Buoyancy Simulator - SADE NBS Test</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1983-01-01</p> <p>One of the main components of the Hubble Space Telescope (HST) is the Solar Array Drive Electronics (SADE) system. This system interfaces with the Support System Module (SSM) for exchange of operational commands and telemetry data. SADE operates and controls the Solar Array Drive Mechanisms (SADM) for the orientation of the Solar Array Drive (SAD). It also monitors the position of the arrays and the temperature of the SADM. During the first HST servicing mission, the astronauts replaced the SADE component because of some malfunctions. This turned out to be a very challenging extravehicular activity (EVA). Two transistors and two diodes had been thermally stressed with the conformal coating discolored and charred. Soldered cornections became molten and reflowed between the two diodes. The failed transistors gave no indication of defective construction. All repairs were made and the HST was redeposited into orbit. Prior to undertaking this challenging mission, the orbiter's crew trained at Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS) to prepare themselves for working in a low gravity environment. They also practiced replacing HST parts and exercised maneuverability and equipment handling. Pictured is an astronaut practicing climbing a space platform that was necessary in making repairs on the HST.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=MSFC-8337893&hterms=sad&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsad','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=MSFC-8337893&hterms=sad&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsad"><span>Neutral Buoyancy Simulator-NB50B-SADE Training Exercises</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1983-01-01</p> <p>One of the main components of the Hubble Space Telescope (HST) is the Solar Array Drive Electronics (SADE) system. This system interfaces with the Support System Module (SSM) for exchange of operational commands and telemetry data. SADE operates and controls the Solar Array Drive Mechanisms (SADM) for the orientation of the Solar Array Drive (SAD). It also monitors the position of the arrays and the temperature of the SADM. During the first HST servicing mission, the astronauts replaced the SADE component because of some malfunctions. This turned out to be a very challenging extravehicular activity (EVA). Two transistors and two diodes had been thermally stressed with the conformal coating discolored and charred. Soldered cornections became molten and reflowed between the two diodes. The failed transistors gave no indication of defective construction. All repairs were made and the HST was redeposited into orbit. Prior to undertaking this challenging mission, the orbiter's crew trained at Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS) to prepare themselves for working in a low gravity environment. They also practiced replacing HST parts and exercised maneuverability and equipment handling. Pictured are crew members practicing on a space platform.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22002699','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22002699"><span>Structural characterization of phenolics and betacyanins in Gomphrena globosa by high-performance liquid chromatography-diode array detection/electrospray ionization multi-stage mass spectrometry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferreres, Federico; Gil-Izquierdo, Angel; Valentão, Patrícia; Andrade, Paula B</p> <p>2011-11-30</p> <p>The metabolite profiling of Gomphrena globosa inflorescences was performed by high-performance liquid chromatography-diode array detection/electrospray ionization multi-stage mass spectrometry (HPLC-DAD/ESI-MS(n)). Based on the fragmentation patterns, 24 phenolic compounds were characterized. The identified phenolics include p-coumaric and ferulic acids, quercetin, kaempferol, isorhamnetin, and hydroxylated 6,7-methylenedioxyflavone derivatives, as well as their aglycones, none of them reported before in the species. This is also the first time that tetrahydroxy-methylenedioxyflavone derivatives and acetylglycosides are described in nature. Betacyanins were also found. This study significantly extends the knowledge of the G. globosa metabolome, by providing further insights into its phenolic composition. Copyright © 2011 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11093641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11093641"><span>Separation and quantitation of colour pigments of chili powder (Capsicum frutescens) by high-performance liquid chromatography-diode array detection.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cserháti, T; Forgács, E; Morais, M H; Mota, T; Ramos, A</p> <p>2000-10-27</p> <p>The performance of reversed-phase thin-layer (RP-TLC) and reversed-phase high-performance liquid chromatography (RP-HPLC) was compared for the separation and determination of the colour pigments of chili (Capsicum frutescens) powder using a wide variety of eluent systems. No separation of pigments was achieved in RP-TLC, however, it was established that tetrahydrofuran shows an unusually high solvent strength. RP-HPLC using water-methanol-acetonitrile gradient elution separated the chili pigments in many fractions. Diode array detection (DAD) indicated that yellow pigments are eluted earlier than the red ones and chili powder contains more yellow pigments than common paprika powders. It was established that the very different absorption spectra of pigments make the use of DAD necessary.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871241','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871241"><span>High efficiency 2 micrometer laser utilizing wing-pumped Tm.sup.3+ and a laser diode array end-pumping architecture</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Beach, Raymond J.</p> <p>1997-01-01</p> <p>Wing pumping a Tm.sup.3+ doped, end pumped solid state laser generates 2 .mu.m laser radiation at high average powers with high efficiency. Using laser diode arrays to end-pump the laser rod or slab in the wing of the Tm.sup.3+ absorption band near 785 nm results in 2-for-1 quantum efficiency in Tm.sup.3+ because high Tm.sup.3+ concentrations can be used. Wing pumping allows the thermal power generated in the rod or slab to be distributed over a large enough volume to make thermal management practical in the laser gain medium even at high average power operation. The approach is applicable to CW, Q-switched, and rep-pulsed free-laser operation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/563709','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/563709"><span>High efficiency 2 micrometer laser utilizing wing-pumped Tm{sup 3+} and a laser diode array end-pumping architecture</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Beach, R.J.</p> <p>1997-11-18</p> <p>Wing pumping a Tm{sup 3+} doped, end pumped solid state laser generates 2 {micro}m laser radiation at high average powers with high efficiency. Using laser diode arrays to end-pump the laser rod or slab in the wing of the Tm{sup 3+} absorption band near 785 nm results in 2-for-1 quantum efficiency in Tm{sup 3+} because high Tm{sup 3+} concentrations can be used. Wing pumping allows the thermal power generated in the rod or slab to be distributed over a large enough volume to make thermal management practical in the laser gain medium even at high average power operation. The approach is applicable to CW, Q-switched, and rep-pulsed free-laser operation. 7 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27824490','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27824490"><span>Cost-effective elimination of lipofuscin fluorescence from formalin-fixed brain tissue by white phosphor light emitting diode array.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Yulong; Chakrabartty, Avi</p> <p>2016-12-01</p> <p>Autofluorescence of aldehyde-fixed tissues greatly hinders fluorescence microscopy. In particular, lipofuscin, an autofluorescent component of aged brain tissue, complicates fluorescence imaging of tissue in neurodegenerative diseases. Background and lipofuscin fluorescence can be reduced by greater than 90% through photobleaching using white phosphor light emitting diode arrays prior to treatment with fluorescent probes. We compared the effect of photobleaching versus established chemical quenchers on the quality of fluorescent staining in formalin-fixed brain tissue of frontotemporal dementia with tau-positive inclusions. Unlike chemical quenchers, which reduced fluorescent probe signals as well as background, photobleaching treatment had no effect on probe fluorescence intensity while it effectively reduced background and lipofuscin fluorescence. The advantages and versatility of photobleaching over established methods are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27036399','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27036399"><span>A Portable Diode Array Spectrophotometer.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stephenson, David</p> <p>2016-05-01</p> <p>A cheap portable visible light spectrometer is presented. The spectrometer uses readily sourced items and could be constructed by anyone with a knowledge of electronics. The spectrometer covers the wavelength range 450-725 nm with a resolution better than 5 nm. The spectrometer uses a diffraction grating to separate wavelengths, which are detected using a 128-element diode array, the output of which is analyzed using a microprocessor. The spectrum is displayed on a small liquid crystal display screen and can be saved to a micro SD card for later analysis. Battery life (2 × AAA) is estimated to be 200 hours. The overall dimensions of the unit are 120 × 65 × 60 mm, and it weighs about 200 g. © The Author(s) 2016.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10526E..1IS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10526E..1IS"><span>Numerical simulation of the modulation transfer function (MTF) in infrared focal plane arrays: simulation methodology and MTF optimization</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schuster, J.</p> <p>2018-02-01</p> <p>Military requirements demand both single and dual-color infrared (IR) imaging systems with both high resolution and sharp contrast. To quantify the performance of these imaging systems, a key measure of performance, the modulation transfer function (MTF), describes how well an optical system reproduces an objects contrast in the image plane at different spatial frequencies. At the center of an IR imaging system is the focal plane array (FPA). IR FPAs are hybrid structures consisting of a semiconductor detector pixel array, typically fabricated from HgCdTe, InGaAs or III-V superlattice materials, hybridized with heat/pressure to a silicon read-out integrated circuit (ROIC) with indium bumps on each pixel providing the mechanical and electrical connection. Due to the growing sophistication of the pixel arrays in these FPAs, sophisticated modeling techniques are required to predict, understand, and benchmark the pixel array MTF that contributes to the total imaging system MTF. To model the pixel array MTF, computationally exhaustive 2D and 3D numerical simulation approaches are required to correctly account for complex architectures and effects such as lateral diffusion from the pixel corners. It is paramount to accurately model the lateral di_usion (pixel crosstalk) as it can become the dominant mechanism limiting the detector MTF if not properly mitigated. Once the detector MTF has been simulated, it is directly decomposed into its constituent contributions to reveal exactly what is limiting the total detector MTF, providing a path for optimization. An overview of the MTF will be given and the simulation approach will be discussed in detail, along with how different simulation parameters effect the MTF calculation. Finally, MTF optimization strategies (crosstalk mitigation) will be discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050206375','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050206375"><span>Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jain, Raj K.</p> <p>2005-01-01</p> <p>Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110016795','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110016795"><span>Growing High-Quality InAs Quantum Dots for Infrared Lasers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Qiu, Yueming; Uhl, David</p> <p>2004-01-01</p> <p>An improved method of growing high-quality InAs quantum dots embedded in lattice-matched InGaAs quantum wells on InP substrates has been developed. InAs/InGaAs/InP quantum dot semiconductor lasers fabricated by this method are capable of operating at room temperature at wavelengths greater than or equal to 1.8 mm. Previously, InAs quantum dot lasers based on InP substrates have been reported only at low temperature of 77 K at a wavelength of 1.9 micrometers. In the present method, as in the prior method, one utilizes metalorganic vapor phase epitaxy to grow the aforementioned semiconductor structures. The development of the present method was prompted in part by the observation that when InAs quantum dots are deposited on an InGaAs layer, some of the InAs in the InGaAs layer becomes segregated from the layer and contributes to the formation of the InAs quantum dots. As a result, the quantum dots become highly nonuniform; some even exceed a critical thickness, beyond which they relax. In the present method, one covers the InGaAs layer with a thin layer of GaAs before depositing the InAs quantum dots. The purpose and effect of this thin GaAs layer is to suppress the segregation of InAs from the InGaAs layer, thereby enabling the InAs quantum dots to become nearly uniform (see figure). Devices fabricated by this method have shown near-room-temperature performance.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22854778','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22854778"><span>A III-V nanowire channel on silicon for high-performance vertical transistors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi</p> <p>2012-08-09</p> <p>Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994JCrGr.136...78J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994JCrGr.136...78J"><span>Reflection high energy electron diffraction and reflectance difference studies of surface anisotropy in InGaAs chemical beam epitaxy on flat and vicinal (001) GaAs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Junno, B.; Paulsson, G.; Miller, M.; Samuelson, L.</p> <p>1994-03-01</p> <p>InGaAs quantum wells (QWs) were grown in a chemical beam epitaxy (CBE) machine with trimethylindium (TMI), triethylgallium (TEG) and tertiarybutylarsine (TBA) as precursors. Growth was monitored in-situ by reflectance difference (RD) and reflection high energy electron diffraction (RHEED), on both flat and vicinal (2° off in the <111> A direction) (001)GaAs substrates. The RD was monitored at 632.8 nm. At this wavelength the RD signal from a GaAs surface is primarily related to the absorption by Ga dimers. When InGaAs had been grown, both the average RD signal and the amplitude of the RD oscillations for the subsequent growth of GaAs increased significantly, compared to GaAs growth on GaAs. This In influence was found to persist even after the growth of 20-30 ML of pure GaAs. As a result we were able to monitor growth oscillations with RD and RHEED simultaneously during growth of quantum wells of InGaAs in GaAs. As a conclusion to these observations we suggest that the group III dimer bond concentration, detected in the RD signal, increases.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA591547','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA591547"><span>Leveraging Crystal Anisotropy for Deterministic Growth of InAs Quantum Dots with Narrow Optical Linewidths</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-08-29</p> <p>similar layer thicknesses. This offset indicates that the electric field profile of our Schottky diode is different than for unpatterned samples, implying...sacrificing uniformity by further optimizing the substrate Figure 3. (a) Schematic of the Schottky diode heterostructure, indicating the patterned substrate...and negative (X−) trions are indicated . (c) Distribution of linewidths for 80 PL lines from dots grown in high density arrays such as those in Figure 2b</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1149612','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1149612"><span>Amber light-emitting diode comprising a group III-nitride nanowire active region</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Wang, George T.; Li, Qiming; Wierer, Jr., Jonathan J.; Koleske, Daniel</p> <p>2014-07-22</p> <p>A temperature stable (color and efficiency) III-nitride based amber (585 nm) light-emitting diode is based on a novel hybrid nanowire-planar structure. The arrays of GaN nanowires enable radial InGaN/GaN quantum well LED structures with high indium content and high material quality. The high efficiency and temperature stable direct yellow and red phosphor-free emitters enable high efficiency white LEDs based on the RGYB color-mixing approach.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA154255','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA154255"><span>Wide-Band Monolithic Acoustoelectric Memory Correlators.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1982-11-01</p> <p>piezoelectric and non- earlier analysis of thin- oxide varactors . The new analysis ex- conducting. Tapped structures which satisfy this criterion are plains...for tapped LiNbO3/metal- oxide - important realization. The logical consequence is that only silicon [26] structures is, in fact, not applicable here. It...Clarke, "The GaAs SAW depletion layer of’ the diode array. A more complex structure, diode storage correlalor," in 1980 Ultrasonics Synp. Proc., pp a GaAs</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6814563-development-drug-assay-using-surface-enhanced-raman-spectroscopy','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6814563-development-drug-assay-using-surface-enhanced-raman-spectroscopy"><span>Development of a drug assay using surface-enhanced Raman spectroscopy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Angel, S.M.; Roe, J.N.; Andresen, B.D.</p> <p>1990-05-01</p> <p>Surface-enhanced Raman spectroscopy has been used to detect low levels of several chemical compounds, including the drugs of abuse -- cocaine hydrochloride and methamphetamine hydrochloride. Raman spectra of these substances have also been taken over optical fibers using red-wavelength excitation. These measurements demonstrate the feasibility of the remote red-wavelength excitation. These measurements demonstrate the feasibility of the remote determination of various target chemicals using diode excitation and diode array detection. 5 refs., 5 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25366228','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25366228"><span>Label-free specific detection of femtomolar cardiac troponin using an integrated nanoslit array fluidic diode.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Yifan; Yobas, Levent</p> <p>2014-12-10</p> <p>We demonstrate here for the first time the utility of an integrated nanofluidic diode for detecting and quantifying physiologically relevant macromolecules. Troponin T, a key human cardiac protein biomarker, was selectively and rapidly detected free of labels for concentrations down to 10 fg/mL (∼ 0.3 fM) in buffer as well as 10 pg/mL (∼ 300 fM) in untreated human serum. This ultrasensitive detection arises from monolithic integration of a unique nanofluidic diode structure that is highly robust and amenable to site-specific surface modification. The structure features a planar nanoslit array where each nanoslit is defined at a nominal width of 70 nm over a micrometer-scale silicon trench without the use of high-resolution patterning techniques. Through vapor deposition, a glass layer is placed at a nonuniform thickness, tapering the trench profile upward and contributing to the triangular nanoslit structure. This asymmetric profile is essential for ionic current rectification noted here at various pH values, ionic strengths, and captured target species, which modulate the surface-charge density within the sensitive region of the nanoslit. The nanoslit, unlike nanopores, offers only 1D confinement, which appears to be adequate for reasonable rectification. The measurements are found in quantitative agreement with the diode simulations for the first time based on a pH- and salt-dependent surface-charge model.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.106h1103S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.106h1103S"><span>Growth and properties of rare-earth arsenide InGaAs nanocomposites for terahertz generation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salas, R.; Guchhait, S.; Sifferman, S. D.; McNicholas, K. M.; Dasika, V. D.; Krivoy, E. M.; Jung, D.; Lee, M. L.; Bank, S. R.</p> <p>2015-02-01</p> <p>We explore the electrical, optical, and structural properties of fast photoconductors of In0.53Ga0.47As containing a number of different rare-earth arsenide nanostructures. The rare-earth species provides a route to tailor the properties of the photoconductive materials. LuAs, GdAs, and LaAs nanostructures were embedded into InGaAs in a superlattice structure and compared to the relatively well-studied ErAs:InGaAs system. LaAs:InGaAs was found to have the highest dark resistivities, while GdAs:InGaAs had the lowest carrier lifetimes and highest carrier mobility at moderate depositions. The quality of the InGaAs overgrowth appears to have the most significant effect on the properties of these candidate fast photoconductors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JaJAP..46L.138H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JaJAP..46L.138H"><span>830-nm Polarization Controlled Lasing of InGaAs Quantum Wire Vertical-Cavity Surface-Emitting Lasers Grown on (775)B GaAs Substrates by Molecular Beam Epitaxy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Higuchi, Yu; Osaki, Shinji; Sasahata, Yoshifumi; Kitada, Takahiro; Shimomura, Satoshi; Ogura, Mutsuo; Hiyamizu, Satoshi</p> <p>2007-02-01</p> <p>We report the first demonstration of room temperature (RT) current injection lasing of vertical-cavity surface-emitting lasers (VCSELs), with self-organized InGaAs/(GaAs)6(AlAs)1 quantum wires (QWRs) in their active region, grown on (775)B-oriented GaAs substrates by molecular beam epitaxy. A (775)B InGaAs QWR-VCSEL with an aperture diameter of 4 μm lased at a wavelength of 829.7 nm and a threshold current of 0.7 mA at RT. The light output was linearly polarized in the direction parallel to the QWRs due to optical anisotropy of the self-organized (775)B InGaAs QWRs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3081869','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3081869"><span>Water equivalent path length measurement in proton radiotherapy using time resolved diode dosimetry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gottschalk, B.; Tang, S.; Bentefour, E. H.; Cascio, E. W.; Prieels, D.; Lu, H.-M.</p> <p>2011-01-01</p> <p>Purpose: To verify water equivalent path length (WEPL) before treatment in proton radiotherapy using time resolved in vivo diode dosimetry. Methods: Using a passively scattered range modulated proton beam, the output of a diode driving a fast current-to-voltage amplifier is recorded at a number of depths in a water tank. At each depth, a burst of overlapping single proton pulses is observed. The rms duration of the burst is computed and the resulting data set is fitted with a cubic polynomial. Results: When the diode is subsequently set to an arbitrary depth and the polynomial is used as a calibration curve, the “unknown” depth is determined within 0.3 mm rms. Conclusions: A diode or a diode array, placed (for instance) in the rectum in conjunction with a rectal balloon, can potentially determine the WEPL at that point, just prior to treatment, with submillimeter accuracy, allowing the beam energy to be adjusted. The associated unwanted dose is about 0.2% of a typical single fraction treatment dose. PMID:21626963</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1133638','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1133638"><span>Soft lithography microlens fabrication and array for enhanced light extraction from organic light emitting diodes (OLEDs)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Leung, Wai Y.; Park, Joong-Mok; Gan, Zhengqing; Constant, Kristen P.; Shinar, Joseph; Shinar, Ruth; ho, Kai-Ming</p> <p>2014-06-03</p> <p>Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850052856&hterms=fundamentals+characteristics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dfundamentals%2Bcharacteristics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850052856&hterms=fundamentals+characteristics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dfundamentals%2Bcharacteristics"><span>Coupled-mode analysis of gain and wavelength oscillation characteristics of diode laser phased arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Butler, J. K.; Ettenberg, M.; Ackley, D. E.</p> <p>1985-01-01</p> <p>The lasing wavelengths and gain characteristics of the modes of phase-locked arrays of channel-substrate-planar (CSP) lasers are presented. The gain values for the array modes are determined from complex coupling coefficients calculated using the fields of neighboring elements of the array. The computations show that, for index guided lasers which have nearly planar phase fronts, the highest order array mode will be preferred. The 'in-phase' or fundamental mode, which produces only one major lobe in the far-field radiation pattern, has the lowest modal gain of all array modes. The modal gain differential between the highest order and fundamental modes is less than 10/cm for weak coupling between the elements.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940017251','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940017251"><span>Bit-systolic arithmetic arrays using dynamic differential gallium arsenide circuits</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beagles, Grant; Winters, Kel; Eldin, A. G.</p> <p>1992-01-01</p> <p>A new family of gallium arsenide circuits for fine grained bit-systolic arithmetic arrays is introduced. This scheme combines features of two recent techniques of dynamic gallium arsenide FET logic and differential dynamic single-clock CMOS logic. The resulting circuits are fast and compact, with tightly constrained series FET propagation paths, low fanout, no dc power dissipation, and depletion FET implementation without level shifting diodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8353E..0DE','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8353E..0DE"><span>MT6425CA: a 640 X 512-25μm CTIA ROIC for SWIR InGaAs detector arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eminoglu, Selim; Mahsereci, Yigit Uygar; Altiner, Caglar; Akin, Tayfun</p> <p>2012-06-01</p> <p>This paper reports the development of a new CTIA ROIC (MT6425CA) suitable for SWIR InGaAs detector arrays. MT6425CA has a format of 640 × 512 with a pixel pitch of 25 μm and has a system-on-chip architecture, where all the critical timing and biasing for this ROIC are generated by programmable blocks on-chip. MT6425CA is a highly configurable and flexible ROIC, where many of its features can be programmed through a 3-wire serial interface allowing on-the-fly configuration of many ROIC features. The ROIC runs on 3.3V supply voltage at nominal clock speed of 10 MHz clock. It performs snapshot operation both using Integrate-Then-Read (ITR) and Integrate-While- Read (IWR) modes. The CTIA type pixel input circuitry has a full-well-capacity (FWC) of about 320,000e-, with an input referred read noise of less than 110e- at 300K. MT6425CA has programmable number of outputs, where 4, 2, or 1 output can be selected along with an analog reference for pseudo-differential operation. The integration time can be programmed up to 1s in steps of 0.1μs. The gain and offset in the ROIC can be programmed to adjust the output offset and voltage swing. ROIC dissipates less than 130mW from a 3.3V supply at full speed and full frame size with 4 outputs, providing both low-power and low-noise operation. MT6425CA is fabricated using a modern mixed-signal CMOS process on 200mm CMOS wafers with a high yield above 75%, yielding more than 50 working parts per wafer. It has been silicon verified, and tested parts are available either in wafer and die levels with a complete documentation including test reports and wafer maps. A USB based camera electronics and camera development platform with software are available to help customers to evaluate the imaging performance of MT6425CA in a fast and efficient way.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5792...88G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5792...88G"><span>Resonantly diode laser pumped 1.6-μm Er:YAG laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garbuzov, Dmitri; Kudryashov, Igor; Dubinskii, Mark</p> <p>2005-06-01</p> <p>We report what is believed to be the first demonstration of direct resonant diode pumping of a 1.6-mm Er3+-doped bulk solid-state laser (DPSSL). The most of the results is obtained with pumping Er:YAG by the single mode diode laser packaged in fibered modules. The fibered modules, emitting at 1470 nm and 1530 nm wavelength with and without fiber grating (FBG) stabilization, have been used in pumping experiments. The very first results on high power DPSSL operation achieved with diode array pumping also will be presented. The highest absorbed photon conversion efficiency of 26% has been obtained for Er:YAG DPSSL using the 1470-nm single-mode module. Analysis of the DPSSL input-output characteristics suggests that the obtained slope efficiency can be increased at least up to 40% through the reduction of intracavity losses and pumping efficiency improvement. Diode pumped SSL (DPSSL) operates at a wavelength of 1617 nm and 1645 nm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910005238','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910005238"><span>Millimeter-wave monolithic diode-grid frequency multiplier</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maserjian, Joseph (Inventor)</p> <p>1990-01-01</p> <p>A semiconductor diode structure useful for harmonic generation of millimeter or submillimeter wave radiation from a fundamental input wave is fabricated on a GaAs substrate. A heavily doped layer of n(sup ++) GaAs is produced on the substrate and then a layer of intrinsic GaAs on said heavily doped layer on top of which a sheet of heavy doping (++) is produced. A thin layer of intrinsic GaAs grown over the sheet is capped with two metal contacts separated by a gap to produce two diodes connected back to back through the n(sup ++) layer for multiplication of frequency by an odd multiple. If only one metal contact caps the thin layer of intrinsic GaAs, the second diode contact is produced to connect to the n(sup ++) layer for multiplication of frequency by an even number. The odd or even frequency multiple is selected by a filter. A phased array of diodes in a grid will increase the power of the higher frequency generated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23126931','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23126931"><span>Compact "diode-based" multi-energy soft x-ray diagnostic for NSTX.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tritz, K; Clayton, D J; Stutman, D; Finkenthal, M</p> <p>2012-10-01</p> <p>A novel and compact, diode-based, multi-energy soft x-ray (ME-SXR) diagnostic has been developed for the National Spherical Tokamak Experiment. The new edge ME-SXR system tested on NSTX consists of a set of vertically stacked diode arrays, each viewing the plasma tangentially through independent pinholes and filters providing an overlapping view of the plasma midplane which allows simultaneous SXR measurements with coarse sub-sampling of the x-ray spectrum. Using computed x-ray spectral emission data, combinations of filters can provide fast (>10 kHz) measurements of changes in the electron temperature and density profiles providing a method to "fill-in" the gaps of the multi-point Thomson scattering system.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.647a2056T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.647a2056T"><span>Monte Carlo model for the analysis and development of III-V Tunnel-FETs and Impact Ionization-MOSFETs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Talbo, V.; Mateos, J.; González, T.; Lechaux, Y.; Wichmann, N.; Bollaert, S.; Vasallo, B. G.</p> <p>2015-10-01</p> <p>Impact-ionization metal-oxide-semiconductor FETs (I-MOSFETs) are in competition with tunnel FETs (TFETs) in order to achieve the best behaviour for low power logic circuits. Concretely, III-V I-MOSFETs are being explored as promising devices due to the proper reliability, since the impact ionization events happen away from the gate oxide, and the high cutoff frequency, due to high electron mobility. To facilitate the design process from the physical point of view, a Monte Carlo (MC) model which includes both impact ionization and band-to-band tunnel is presented. Two ungated InGaAs and InAlAs/InGaAs 100 nm PIN diodes have been simulated. In both devices, the tunnel processes are more frequent than impact ionizations, so that they are found to be appropriate for TFET structures and not for I- MOSFETs. According to our simulations, other narrow bandgap candidates for the III-V heterostructure, such as InAs or GaSb, and/or PININ structures must be considered for a correct I-MOSFET design.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3293408','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3293408"><span>Generation and control of polarization-entangled photons from GaAs island quantum dots by an electric field</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ghali, Mohsen; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo</p> <p>2012-01-01</p> <p>Semiconductor quantum dots are potential sources for generating polarization-entangled photons efficiently. The main prerequisite for such generation based on biexciton–exciton cascaded emission is to control the exciton fine-structure splitting. Among various techniques investigated for this purpose, an electric field is a promising means to facilitate the integration into optoelectronic devices. Here we demonstrate the generation of polarization-entangled photons from single GaAs quantum dots by an electric field. In contrast to previous studies, which were limited to In(Ga)As quantum dots, GaAs island quantum dots formed by a thickness fluctuation were used because they exhibit a larger oscillator strength and emit light with a shorter wavelength. A forward voltage was applied to a Schottky diode to control the fine-structure splitting. We observed a decrease and suppression in the fine-structure splitting of the studied single quantum dot with the field, which enabled us to generate polarization-entangled photons with a high fidelity of 0.72±0.05. PMID:22314357</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARA29003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARA29003B"><span>High-speed single-photon signaling for daytime QKD</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bienfang, Joshua; Restelli, Alessandro; Clark, Charles</p> <p>2011-03-01</p> <p>The distribution of quantum-generated cryptographic key at high throughputs can be critically limited by the performance of the systems' single-photon detectors. While noise and afterpulsing are considerations for all single-photon QKD systems, high-transmission rate systems also have critical detector timing-resolution and recovery time requirements. We present experimental results exploiting the high timing resolution and count-rate stability of modified single-photon avalanche diodes (SPADs) in our GHz QKD system operating over a 1.5 km free-space link that demonstrate the ability to apply extremely short temporal gates, enabling daytime free-space QKD with a 4% QBER. We also discuss recent advances in gating techniques for InGaAs SPADs that are suitable for high-speed fiber-based QKD. We present afterpulse-probability measurements that demonstrate the ability to support single-photon count rates above 100 MHz with low afterpulse probability. These results will benefit the design and characterization of free-space and fiber QKD systems. A. Restelli, J.C. Bienfang A. Mink, and C.W. Clark, IEEE J. Sel. Topics in Quant. Electron 16, 1084 (2010).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28957252','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28957252"><span>Microchip Yb:CaLnAlO4 lasers with up to 91% slope efficiency.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loiko, Pavel; Serres, Josep Maria; Mateos, Xavier; Xu, Xiaodong; Xu, Jun; Jambunathan, Venkatesan; Navratil, Petr; Lucianetti, Antonio; Mocek, Tomas; Zhang, Xuzhao; Griebner, Uwe; Petrov, Valentin; Aguiló, Magdalena; Díaz, Francesc; Major, Arkady</p> <p>2017-07-01</p> <p>Multi-watt continuous-wave (CW) operation of tetragonal rare-earth calcium aluminate Yb:CaLnAlO 4 (Ln=Gd,Y)) crystals in plano-plano microchip lasers was demonstrated with an almost quantum-defect-limited slope efficiency. Pumped at 978 nm by an InGaAs laser diode, a 3.4 mm long 8 at. % Yb:CaGdAlO 4 laser generated 7.79 W at 1057-1065 nm with a slope efficiency of η=84% (with respect to the absorbed pump power). An even higher η=91% was achieved with a 2.5 mm long 3 at. % Yb:CaYAlO 4 laser, from which 5.06 W were extracted at 1048-1056 nm. Both lasers produced linearly polarized output (σ-polarization) with an almost circular diffraction-limited beam (Mx,y2<1.1). The output performance of the developed lasers was modeled, yielding an internal loss coefficient as low as 0.004-0.007  cm -1 . In addition, their spectroscopic properties were revisited.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22594286-reverse-bias-driven-dichromatic-electroluminescence-zno-wire-arrays-gan-film-heterojunction-light-emitting-diodes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22594286-reverse-bias-driven-dichromatic-electroluminescence-zno-wire-arrays-gan-film-heterojunction-light-emitting-diodes"><span>Reverse-bias-driven dichromatic electroluminescence of n-ZnO wire arrays/p-GaN film heterojunction light-emitting diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jeong, Junseok; Choi, Ji Eun; Hong, Young Joon, E-mail: yjhong@sejong.ac.kr</p> <p></p> <p>Position-controlled n-ZnO microwire (MW) and nanowire-bundle (NW-B) arrays were fabricated using hydrothermal growth of ZnO on a patterned p-GaN film. Both the wire/film p–n heterojunctions showed electrical rectification features at reverse-bias (rb) voltages, analogous to backward diodes. Dichromatic electroluminescence (EL) emissions with 445- and 560-nm-wavelength peaks displayed whitish-blue and greenish-yellow light from MW- and NW-B-based heterojunctions at rb voltages, respectively. The different dichromatic EL emission colors were studied based on photoluminescence spectra and the dichromatic EL peak intensity ratios as a function of the rb voltage. The different EL colors are discussed with respect to depletion thickness and electron tunnelingmore » probability determined by wire/film junction geometry and size.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109j1103J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109j1103J"><span>Reverse-bias-driven dichromatic electroluminescence of n-ZnO wire arrays/p-GaN film heterojunction light-emitting diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeong, Junseok; Choi, Ji Eun; Kim, Yong-Jin; Hwang, Sunyong; Kim, Sung Kyu; Kim, Jong Kyu; Jeong, Hu Young; Hong, Young Joon</p> <p>2016-09-01</p> <p>Position-controlled n-ZnO microwire (MW) and nanowire-bundle (NW-B) arrays were fabricated using hydrothermal growth of ZnO on a patterned p-GaN film. Both the wire/film p-n heterojunctions showed electrical rectification features at reverse-bias (rb) voltages, analogous to backward diodes. Dichromatic electroluminescence (EL) emissions with 445- and 560-nm-wavelength peaks displayed whitish-blue and greenish-yellow light from MW- and NW-B-based heterojunctions at rb voltages, respectively. The different dichromatic EL emission colors were studied based on photoluminescence spectra and the dichromatic EL peak intensity ratios as a function of the rb voltage. The different EL colors are discussed with respect to depletion thickness and electron tunneling probability determined by wire/film junction geometry and size.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptLT..78...34B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptLT..78...34B"><span>Design and fabrication of AlGaInP-based micro-light-emitting-diode array devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bao, Xingzhen; Liang, Jingqiu; Liang, Zhongzhu; Wang, Weibiao; Tian, Chao; Qin, Yuxin; Lü, Jinguang</p> <p>2016-04-01</p> <p>An integrated high-resolution (individual pixel size 80 μm×80 μm) solid-state self-emissive active matrix programmed with 320×240 micro-light-emitting-diode arrays structure was designed and fabricated on an AlGaInP semiconductor chip using micro electro-mechanical systems, microstructure and semiconductor fabricating techniques. Row pixels share a p-electrode and line pixels share an n-electrode. We experimentally investigated GaAs substrate thickness affects the electrical and optical characteristics of the pixels. For a 150-μm-thick GaAs substrate, the single pixel output power was 167.4 μW at 5 mA, and increased to 326.4 μW when current increase to 10 mA. The device investigated potentially plays an important role in many fields.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29071784','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29071784"><span>Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sel, Sabriye; Öztürk Er, Elif; Bakırdere, Sezgin</p> <p>2017-12-01</p> <p>A highly sensitive and simple diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water, and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time-of-flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg/L for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high-performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg/L, respectively. Recovery studies were also performed to show the applicability of the developed methods, and percentage recovery values were found to be 90-105% in tap water and 94-97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23455517','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23455517"><span>Vertically p-n-junctioned GaN nano-wire array diode fabricated on Si(111) using MOCVD.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Ji-Hyeon; Kim, Min-Hee; Kissinger, Suthan; Lee, Cheul-Ro</p> <p>2013-04-07</p> <p>We demonstrate the fabrication of n-GaN:Si/p-GaN:Mg nanowire arrays on (111) silicon substrate by metal organic chemical vapor deposition (MOCVD) method .The nanowires were grown by a newly developed two-step growth process. The diameter of as-grown nanowires ranges from 300-400 nm with a density of 6-7 × 10(7) cm(-2). The p- and n-type doping of the nanowires is achieved with Mg and Si dopant species. Structural characterization by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) indicates that the nanowires are relatively defect-free. The room-temperature photoluminescence emission with a strong peak at 370 nm indicates that the n-GaN:Si/p-GaN:Mg nanowire arrays have potential application in light-emitting nanodevices. The cathodoluminscence (CL) spectrum clearly shows a distinct optical transition of GaN nanodiodes. The nano-n-GaN:Si/p-GaN:Mg diodes were further completed using a sputter coating approach to deposit Au/Ni metal contacts. The polysilazane filler has been etched by a wet chemical etching process. The n-GaN:Si/p-GaN:Mg nanowire diode was fabricated for different Mg source flow rates. The current-voltage (I-V) measurements reveal excellent rectifying properties with an obvious turn-on voltage at 1.6 V for a Mg flow rate of 5 sccm (standard cubic centimeters per minute).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Nanos...5.2959P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Nanos...5.2959P"><span>Vertically p-n-junctioned GaN nano-wire array diode fabricated on Si(111) using MOCVD</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Ji-Hyeon; Kim, Min-Hee; Kissinger, Suthan; Lee, Cheul-Ro</p> <p>2013-03-01</p> <p>We demonstrate the fabrication of n-GaN:Si/p-GaN:Mg nanowire arrays on (111) silicon substrate by metal organic chemical vapor deposition (MOCVD) method .The nanowires were grown by a newly developed two-step growth process. The diameter of as-grown nanowires ranges from 300-400 nm with a density of 6-7 × 107 cm-2. The p- and n-type doping of the nanowires is achieved with Mg and Si dopant species. Structural characterization by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) indicates that the nanowires are relatively defect-free. The room-temperature photoluminescence emission with a strong peak at 370 nm indicates that the n-GaN:Si/p-GaN:Mg nanowire arrays have potential application in light-emitting nanodevices. The cathodoluminscence (CL) spectrum clearly shows a distinct optical transition of GaN nanodiodes. The nano-n-GaN:Si/p-GaN:Mg diodes were further completed using a sputter coating approach to deposit Au/Ni metal contacts. The polysilazane filler has been etched by a wet chemical etching process. The n-GaN:Si/p-GaN:Mg nanowire diode was fabricated for different Mg source flow rates. The current-voltage (I-V) measurements reveal excellent rectifying properties with an obvious turn-on voltage at 1.6 V for a Mg flow rate of 5 sccm (standard cubic centimeters per minute).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26888213','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26888213"><span>Classification of the medicinal plants of the genus Atractylodes using high-performance liquid chromatography with diode array and tandem mass spectrometry detection combined with multivariate statistical analysis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cho, Hyun-Deok; Kim, Unyong; Suh, Joon Hyuk; Eom, Han Young; Kim, Junghyun; Lee, Seul Gi; Choi, Yong Seok; Han, Sang Beom</p> <p>2016-04-01</p> <p>Analytical methods using high-performance liquid chromatography with diode array and tandem mass spectrometry detection were developed for the discrimination of the rhizomes of four Atractylodes medicinal plants: A. japonica, A. macrocephala, A. chinensis, and A. lancea. A quantitative study was performed, selecting five bioactive components, including atractylenolide I, II, III, eudesma-4(14),7(11)-dien-8-one and atractylodin, on twenty-six Atractylodes samples of various origins. Sample extraction was optimized to sonication with 80% methanol for 40 min at room temperature. High-performance liquid chromatography with diode array detection was established using a C18 column with a water/acetonitrile gradient system at a flow rate of 1.0 mL/min, and the detection wavelength was set at 236 nm. Liquid chromatography with tandem mass spectrometry was applied to certify the reliability of the quantitative results. The developed methods were validated by ensuring specificity, linearity, limit of quantification, accuracy, precision, recovery, robustness, and stability. Results showed that cangzhu contained higher amounts of atractylenolide I and atractylodin than baizhu, and especially atractylodin contents showed the greatest variation between baizhu and cangzhu. Multivariate statistical analysis, such as principal component analysis and hierarchical cluster analysis, were also employed for further classification of the Atractylodes plants. The established method was suitable for quality control of the Atractylodes plants. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010072609&hterms=gallium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dgallium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010072609&hterms=gallium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dgallium"><span>An Indium Gallium Arsenide Visible/SWIR Focal Plane Array for Low Light Level Imaging</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cohen, Marshall J.; Ettenberg, Martin H.; Lange, Michael J.; Olsen, Gregory H.</p> <p>1999-01-01</p> <p>PIN photodiodes fabricated from indium gallium arsenide lattice-matched to indium phosphide substrates (In(.53)Ga(.47)As/InP) exhibit low reverse saturation current densities (JD < 10(exp -8) A/sq cm), and high shunt resistance-area products (RoA > 10(exp 6) omega-sq cm) at T=290K. Backside-illuminated, hybrid-integrated InGaAs FPAs are sensitive from 0.9 micrometers to 1.7 micrometers. 290K detectivities, D(*), greater than 10(exp 14) cm-(square root of Hz/W) are demonstrated. This represents the highest room temperature detectivity of any infrared material. The long wavelength cutoff (1.7 micrometers) makes In(.53)Ga(.47)As an idea match to the available airglow that has major peaks at 1.3 micrometers and 1.6 micrometers. The short wavelength 'cut-on' at 0.9 micrometers is due to absorption in the InP substrate. We will report on new InGaAs FPA epitaxial structures and processing techniques. These have resulted in improved performance in the form of a 10 x increase in detectivity and visible response via removal of the InP substrate. The resulting device features visible and SWIR response with greater than 15% quantum efficiency at 0.5 micrometers while maintaining the long wavelength cutoff. Imaging has been demonstrated under overcast starlight/urban glow conditions with cooling provided by a single stage thermoelectric cooler. Details on the material structure and device fabrication, quantitative characterization of spectral response and detectivity, as well as examples of night vision imagery are presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22220530-performance-parameters-liquid-filled-ionization-chamber-array','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22220530-performance-parameters-liquid-filled-ionization-chamber-array"><span>Performance parameters of a liquid filled ionization chamber array</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Poppe, B.; Stelljes, T. S.; Looe, H. K.</p> <p>2013-08-15</p> <p>Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluatedmore » using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The σ-values of the Gaussian dose response function for a single detector of the array were found to be (0.72 ± 0.25) mm at 6 MV and (0.74 ± 0.25) mm at 15 MV and the corresponding low pass cutoff frequencies are 0.22 and 0.21 mm{sup −1}, respectively. For the inner 5 × 5 cm{sup 2} region and the outer 11 × 11 cm{sup 2} region of the array the Nyquist theorem is fulfilled for maximum sampling frequencies of 0.2 and 0.1 mm{sup −1}, respectively. An IMRT field verification with a Gamma-Index analysis yielded a passing rate of 95.2% for a 3 mm/3% criterion with a TPS calculation as reference.Conclusions: This study shows the applicability of the Octavius 1000SRS in modern dosimetry. Output factor and dose profile measurements illustrated the applicability of the array in small field and stereotactic dosimetry. The high spatial resolution ensures adequate measurements of dose profiles in regular and intensity modulated photon-beam fields.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990ElL....26..307H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990ElL....26..307H"><span>Low threshold distributed Bragg reflector surface emitting laser diode with semiconductor air-bridge-supported top mirror</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsin, W.; Du, G.; Gamelin, J. K.; Malloy, K. J.; Wang, S.</p> <p>1990-03-01</p> <p>A surface emitting laser diode (SELD) with two distributed Bragg reflectors (DBR) and semiconductor multilayer air-bridge-supported top mirror is fabricated. A low threshold current of 1.5 mA is achieved under room temperature CW operation. The spectrum shows a strong peak at 891 nm with a FWHM of 10 A. With light emission from the top Bragg reflector instead of from the back side of the substrate, laser arrays are easily formed with this novel structure.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA015880','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA015880"><span>Reverse Current Blocking Diodes for Flexible Solar Array Protection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1975-04-01</p> <p>the general ’ Tic, ici~cjluir; foreign nations. T1->*.:. ti~c!chnical report has been reviewed and is approved for L .D. Man i c/GS - 3 :P’rojcct nm r...To generate the figures, a set of thermal radiative properties for the diodes and substrate had to be assumed. A second surface mirror made of...simulated nuclear weapon generated gamma pulses. Dose rates of varying levels were delivered by "two radiation effects machines. Lower dose rate</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhTea..55..374L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhTea..55..374L"><span>Visual Electricity Demonstrator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lincoln, James</p> <p>2017-09-01</p> <p>The Visual Electricity Demonstrator (VED) is a linear diode array that serves as a dynamic alternative to an ammeter. A string of 48 red light-emitting diodes (LEDs) blink one after another to create the illusion of a moving current. Having the current represented visually builds an intuitive and qualitative understanding about what is happening in a circuit. In this article, I describe several activities for this device and explain how using this technology in the classroom can enhance the understanding and appreciation of physics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004OExpr..12.3765A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004OExpr..12.3765A"><span>1-mJ Q-switched diode-pumped Nd:BaY2F8 laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Agnesi, Antonio; Carraro, Giovanni; Guandalini, Annalisa; Reali, Giancarlo; Sani, Elisa; Toncelli, Alessandra; Tonelli, Mauro</p> <p>2004-08-01</p> <p>We report what is to our knowledge the first high repetition rate Q-switched Nd:BaY2F8 (Nd:BaYF) laser pumped with a multiwatt fiber-coupled diode array tuned at 806 nm. As much as 2.42 W of average power and up to 1.05 mJ of pulse energy were obtained with 6.1 W of absorbed pump power, with excellent beam quality (M2<1.2) and linear polarization.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAP...119t5702W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAP...119t5702W"><span>Numerical study of the intrinsic recombination carriers lifetime in extended short-wavelength infrared detector materials: A comparison between InGaAs and HgCdTe</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wen, Hanqing; Bellotti, Enrico</p> <p>2016-05-01</p> <p>Intrinsic carrier lifetime due to radiative and Auger recombination in HgCdTe and strained InGaAs has been computed in the extended short-wavelength infrared (ESWIR) spectrum from 1.7 μm to 2.7 μm. Using the Green's function theory, both direct and phonon-assisted indirect Auger recombination rates as well as the radiative recombination rates are calculated for different cutoff wavelengths at 300 K with full band structures of the materials. In order to properly model the full band structures of strained InGaAs, an empirical pseudo-potential model for the alloy is fitted using the virtual crystal approximation with spin-orbit coupling included. The results showed that for InxGa1-xAs grown on InP substrate, the compressive strain, which presents in the film when the cutoff wavelength is longer than 1.7 μm, leads to decrease of Auger recombination rate and increase of radiative recombination rate. Since the dominant intrinsic recombination mechanism in this spectral range is radiative recombination, the overall intrinsic carrier lifetime in the strained InGaAs alloys is shorter than that in the relaxed material. When compared to the relaxed HgCdTe, both relaxed and compressively strained InGaAs alloys show shorter intrinsic carrier lifetime at the same cutoff wavelength in room temperature which confirms the potential advantage of HgCdTe as wide-band infrared detector material. While HgCdTe offers superior performance, ultimately the material of choice for ESWIR application will also depend on material quality and cost.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900017367','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900017367"><span>Dielectric function of InGaAs in the visible</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alterovitz, S. A.; Sieg, R. E.; Yao, H. D.; Snyder, P. G.; Woollam, J. A.; Pamulapati, J.; Bhattacharya, P. K.; Sekula-Moise, P. A.</p> <p>1990-01-01</p> <p>Measurements are reported of the dielectric function of thermodynamically stable In(x)Ga(1-x)As in the composition range 0.3 equal to or less than X = to or less than 0.7. The optically thick samples of InGaAs were made by molecular beam epitaxy (MBE) in the range 0.4 = to or less than X = to or less than 0.7 and by metal-organic chemical vapor deposition (MOCVD) for X = 0.3. The MBE made samples, usually 1 micron thick, were grown on semi-insulating InP and included a strain release structure. The MOCVD sample was grown on GaAs and was 2 microns thick. The dielectric functions were measured by variable angle spectroscopic ellipsometry in the range 1.55 to 4.4 eV. The data was analyzed assuming an optically thick InGaAs material with an oxide layer on top. The thickness of this layer was estimated by comparing the results for the InP lattice matched material, i.e., X = 0.53, with results published in the literature. The top oxide layer mathematically for X = 0.3 and X = 0.53 was removed to get the dielectric function of the bare InGaAs. In addition, the dielectric function of GaAs in vacuum, after a protective arsenic layer was removed. The dielectric functions for X = 0, 0.3, and 0.53 together with the X = 1 result from the literature to evaluate an algorithm for calculating the dielectric function of InGaAs for an arbitrary value of X(0 = to or less than X = to or less than 1) were used. Results of the dielectric function calculated using the algorithm were compared with experimental data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910068613&hterms=arsenic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Darsenic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910068613&hterms=arsenic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Darsenic"><span>Dielectric function of InGaAs in the visible</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alterovitz, S. A.; Yao, H. D.; Snyder, P. G.; Woolam, J. A.; Pamulapati, J.; Bhattacharya, P. K.; Sekula-Moise, P. A.; Sieg, R. E.</p> <p>1990-01-01</p> <p>Measurements are reported of the dielectric function of thermodynamically stable In(x)Ga(1-x)As in the composition range 0.3 equal to or less than X = to or less than 0.7. The optically thick samples of InGaAs were made by molecular beam epitaxy (MBE) in the range 0.4 = to or less than X = to or less than 0.7 and by metal-organic chemical vapor deposition (MOCVD) for X = 0.3. The MBE made samples, usually 1 micron thick, were grown on semi-insulating InP and included a strain release structure. The MOCVD sample was grown on GaAs and was 2 microns thick. The dielectric functions were measured by variable angle spectroscopic ellipsometry in the range 1.55 to 4.4 eV. The data was analyzed assuming an optically thick InGaAs material with an oxide layer on top. The thickness of this layer was estimated by comparing the results for the InP lattice matched material, i.e., X = 0.53, with results published in the literature. The top oxide layer mathematically for X = 0.3 and X = 0.53 was removed to get the dielectric function of the bare InGaAs. In addition, the dielectric function of GaAs in vacuum, after a protective arsenic layer was removed. The dielectric functions for X = 0, 0.3, and 0.53 together with the X = 1 result from the literature to evaluate an algorithm for calculating the dielectric function of InGaAs for an arbitrary value of X (0 = to or less than X = to or less than 1) were used. Results of the dielectric function calculated using the algorithm were compared with experimental data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22596734-numerical-study-intrinsic-recombination-carriers-lifetime-extended-short-wavelength-infrared-detector-materials-comparison-between-ingaas-hgcdte','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22596734-numerical-study-intrinsic-recombination-carriers-lifetime-extended-short-wavelength-infrared-detector-materials-comparison-between-ingaas-hgcdte"><span>Numerical study of the intrinsic recombination carriers lifetime in extended short-wavelength infrared detector materials: A comparison between InGaAs and HgCdTe</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wen, Hanqing; Bellotti, Enrico, E-mail: bellotti@bu.edu</p> <p>2016-05-28</p> <p>Intrinsic carrier lifetime due to radiative and Auger recombination in HgCdTe and strained InGaAs has been computed in the extended short-wavelength infrared (ESWIR) spectrum from 1.7 μm to 2.7 μm. Using the Green's function theory, both direct and phonon-assisted indirect Auger recombination rates as well as the radiative recombination rates are calculated for different cutoff wavelengths at 300 K with full band structures of the materials. In order to properly model the full band structures of strained InGaAs, an empirical pseudo-potential model for the alloy is fitted using the virtual crystal approximation with spin-orbit coupling included. The results showed that for In{sub x}Ga{submore » 1−x}As grown on InP substrate, the compressive strain, which presents in the film when the cutoff wavelength is longer than 1.7 μm, leads to decrease of Auger recombination rate and increase of radiative recombination rate. Since the dominant intrinsic recombination mechanism in this spectral range is radiative recombination, the overall intrinsic carrier lifetime in the strained InGaAs alloys is shorter than that in the relaxed material. When compared to the relaxed HgCdTe, both relaxed and compressively strained InGaAs alloys show shorter intrinsic carrier lifetime at the same cutoff wavelength in room temperature which confirms the potential advantage of HgCdTe as wide-band infrared detector material. While HgCdTe offers superior performance, ultimately the material of choice for ESWIR application will also depend on material quality and cost.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22300071-nanospherical-lens-lithographical-ag-nanodisk-arrays-embedded-gan-localized-surface-plasmon-enhanced-blue-light-emitting-diodes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22300071-nanospherical-lens-lithographical-ag-nanodisk-arrays-embedded-gan-localized-surface-plasmon-enhanced-blue-light-emitting-diodes"><span>Nanospherical-lens lithographical Ag nanodisk arrays embedded in p-GaN for localized surface plasmon-enhanced blue light emitting diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wei, Tongbo, E-mail: tbwei@semi.ac.cn; Wu, Kui; Sun, Bo</p> <p>2014-06-15</p> <p>Large-scale Ag nanodisks (NDs) arrays fabricated using nanospherical-lens lithography (NLL) are embedded in p-GaN layer of an InGaN/GaN light-emitting diode (LED) for generating localized surface plasmon (LSP) coupling with the radiating dipoles in the quantum-well (QWs). Based on the Ag NDs with the controlled surface coverage, LSP leads to the improved crystalline quality of regrowth p-GaN, increased photoluminescence (PL) intensity, reduced PL decay time, and enhanced output power of LED. Compared with the LED without Ag NDs, the optical output power at a current of 350 mA of the LSP-enhanced LEDs with Ag NDs having a distance of 20 andmore » 35 nm to QWs is increased by 26.7% and 31.1%, respectively. The electrical characteristics and optical properties of LEDs with embedded Ag NPs are dependent on the distance of between Ag NPs and QWs region. The LED with Ag NDs array structure is also found to exhibit reduced emission divergence, compared to that without Ag NDs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22141918','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22141918"><span>A functional hybrid memristor crossbar-array/CMOS system for data storage and neuromorphic applications.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Kuk-Hwan; Gaba, Siddharth; Wheeler, Dana; Cruz-Albrecht, Jose M; Hussain, Tahir; Srinivasa, Narayan; Lu, Wei</p> <p>2012-01-11</p> <p>Crossbar arrays based on two-terminal resistive switches have been proposed as a leading candidate for future memory and logic applications. Here we demonstrate a high-density, fully operational hybrid crossbar/CMOS system composed of a transistor- and diode-less memristor crossbar array vertically integrated on top of a CMOS chip by taking advantage of the intrinsic nonlinear characteristics of the memristor element. The hybrid crossbar/CMOS system can reliably store complex binary and multilevel 1600 pixel bitmap images using a new programming scheme. © 2011 American Chemical Society</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26099108','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26099108"><span>Enhancing Light Emission of ZnO-Nanofilm/Si-Micropillar Heterostructure Arrays by Piezo-Phototronic Effect.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiaoyi; Chen, Mengxiao; Yu, Ruomeng; Zhang, Taiping; Song, Dongsheng; Liang, Renrong; Zhang, Qinglin; Cheng, Shaobo; Dong, Lin; Pan, Anlian; Wang, Zhong Lin; Zhu, Jing; Pan, Caofeng</p> <p>2015-06-22</p> <p>n-ZnO nanofilm/p-Si micropillar heterostructure light-emitting diode (LED) arrays for white light emissions are achieved and the light emission intensity of LED array is enhanced by 120% under -0.05% compressive strains. These results indicate a promising approach to fabricate Si-based light-emitting components with high performances enhanced by piezo-phototronic effect, with potential applications in touchpad technology, personalized signatures, smart skin, and silicon-based photonic integrated circuits. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JaJAP..47.2868Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JaJAP..47.2868Y"><span>High Performance 50 nm InAlAs/In0.75GaAs Metamorphic High Electron Mobility Transistors with Si3N4 Passivation on Thin InGaAs Layer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yeon, Seongjin; Seo, Kwangseok</p> <p>2008-04-01</p> <p>We fabricated 50 nm InAlAs/InGaAs metamorphic high electron mobility transistors (HEMTs) with a very thin barrier. Through the reduction of the gate-channel distance (dGC) in the epitaxial structure, a channel aspect ratio (ARC) of over three was achieved when Lg was 50 nm. We inserted a thin InGaAs layer as a protective layer, and tested various gate structures to reduce surface problems induced by barrier shrinkage and to optimize the device characteristics. Through the optimization of the gate structure with the thin InGaAs layer, the fabricated 50 nm metamorphic HEMT exhibited high DC and RF characteristics, Gm of 1.5 S/mm, and fT of 490 GHz.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97s5202E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97s5202E"><span>Bond-strength inversion in (In,Ga)As semiconductor alloys</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eckner, Stefanie; Ritter, Konrad; Schöppe, Philipp; Haubold, Erik; Eckner, Erich; Rensberg, Jura; Röder, Robert; Ridgway, Mark C.; Schnohr, Claudia S.</p> <p>2018-05-01</p> <p>The atomic-scale structure and vibrational properties of semiconductor alloys are determined by the energy required for stretching and bending the individual bonds. Using temperature-dependent extended x-ray absorption fine-structure spectroscopy, we have determined the element-specific In-As and Ga-As effective bond-stretching force constants in (In,Ga)As as a function of the alloy composition. The results reveal a striking inversion of the bond strength where the originally stiffer bond in the parent materials becomes the softer bond in the alloy and vice versa. Our findings clearly demonstrate that changes of both the individual bond length and the surrounding matrix affect the bond-stretching force constants. We thus show that the previously used common assumptions about the element-specific force constants in semiconductor alloys do not reproduce the composition dependence determined experimentally for (In,Ga)As.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10619E..0WY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10619E..0WY"><span>Analyses of absorption distribution of a rubidium cell side-pumped by a Laser-Diode-Array (LDA)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Hang; Han, Juhong; Rong, Kepeng; Wang, Shunyan; Cai, He; An, Guofei; Zhang, Wei; Yu, Qiang; Wu, Peng; Wang, Hongyuan; Wang, You</p> <p>2018-01-01</p> <p>A diode-pumped alkali laser (DPAL) has been regarded as one of the most potential candidates to achieve high power performances of next generation. In this paper, we investigate the physical properties of a rubidium cell side-pumped by a Laser-Diode-Array (LDA) in this study. As the saturated concentration of a gain medium inside a vapor cell is extremely sensitive to the temperature, the populations of every energy-level of the atomic alkali are strongly relying on the vapor temperature. Thus, the absorption characteristics of a DPAL are mainly dominated by the temperature distribution. In this paper, the temperature, absorption, and lasing distributions in the cross-section of a rubidium cell side-pumped by a LDA are obtained by means of a complicated mathematic procedure. Based on the original end-pumped mode we constructed before, a novel one-direction side-pumped theoretical mode has been established to explore the distribution properties in the transverse section of a rubidium vapor cell by combining the procedures of heat transfer and laser kinetics together. It has been thought the results might be helpful for design of a side-pumped configuration in a high-powered DPAL.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29775490','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29775490"><span>Monolithic Flexible Vertical GaN Light-Emitting Diodes for a Transparent Wireless Brain Optical Stimulator.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Han Eol; Choi, JeHyuk; Lee, Seung Hyun; Jeong, Minju; Shin, Jung Ho; Joe, Daniel J; Kim, DoHyun; Kim, Chang Wan; Park, Jung Hwan; Lee, Jae Hee; Kim, Daesoo; Shin, Chan-Soo; Lee, Keon Jae</p> <p>2018-05-18</p> <p>Flexible inorganic-based micro light-emitting diodes (µLEDs) are emerging as a significant technology for flexible displays, which is an important area for bilateral visual communication in the upcoming Internet of Things era. Conventional flexible lateral µLEDs have been investigated by several researchers, but still have significant issues of power consumption, thermal stability, lifetime, and light-extraction efficiency on plastics. Here, high-performance flexible vertical GaN light-emitting diodes (LEDs) are demonstrated by silver nanowire networks and monolithic fabrication. Transparent, ultrathin GaN LED arrays adhere to a human fingernail and stably glow without any mechanical deformation. Experimental studies provide outstanding characteristics of the flexible vertical μLEDs (f-VLEDs) with high optical power (30 mW mm -2 ), long lifetime (≈12 years), and good thermal/mechanical stability (100 000 bending/unbending cycles). The wireless light-emitting system on the human skin is successfully realized by transferring the electrical power f-VLED. Finally, the high-density GaN f-VLED arrays are inserted onto a living mouse cortex and operated without significant histological damage of brain. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050210081','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050210081"><span>Space Qualification of Laser Diode Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Troupaki, Elisavet; Kashem, Nasir B.; Allan, Graham R.; Vasilyev, Aleksey; Stephen, Mark</p> <p>2005-01-01</p> <p>Laser instruments have great potential in enabling a new generation of remote-sensing scientific instruments. NASA s desire to employ laser instruments aboard satellites, imposes stringent reliability requirements under severe conditions. As a result of these requirements, NASA has a research program to understand, quantify and reduce the risk of failure to these instruments when deployed on satellites. Most of NASA s proposed laser missions have base-lined diode-pumped Nd:YAG lasers that generally use quasi-constant wave (QCW), 808 nm Laser Diode Arrays (LDAs). Our group has an on-going test program to measure the performance of these LDAs when operated in conditions replicating launch and orbit. In this paper, we report on the results of tests designed to measure the effect of vibration loads simulating launch into space and the radiation environment encountered on orbit. Our primary objective is to quantify the performance of the LDAs in conditions replicating those of a satellite instrument, determine their limitations and strengths which will enable better and more robust designs. To this end we have developed a systematic testing strategy to quantify the effect of environmental stresses on the optical and electrical properties of the LDA.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25401669','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25401669"><span>Handheld probe integrating laser diode and ultrasound transducer array for ultrasound/photoacoustic dual modality imaging.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daoudi, K; van den Berg, P J; Rabot, O; Kohl, A; Tisserand, S; Brands, P; Steenbergen, W</p> <p>2014-10-20</p> <p>Ultrasound and photoacoustics can be utilized as complementary imaging techniques to improve clinical diagnoses. Photoacoustics provides optical contrast and functional information while ultrasound provides structural and anatomical information. As of yet, photoacoustic imaging uses large and expensive systems, which limits their clinical application and makes the combination costly and impracticable. In this work we present and evaluate a compact and ergonomically designed handheld probe, connected to a portable ultrasound system for inexpensive, real-time dual-modality ultrasound/photoacoustic imaging. The probe integrates an ultrasound transducer array and a highly efficient diode stack laser emitting 130 ns pulses at 805 nm wavelength and a pulse energy of 0.56 mJ, with a high pulse repetition frequency of up to 10 kHz. The diodes are driven by a customized laser driver, which can be triggered externally with a high temporal stability necessary to synchronize the ultrasound detection and laser pulsing. The emitted beam is collimated with cylindrical micro-lenses and shaped using a diffractive optical element, delivering a homogenized rectangular light intensity distribution. The system performance was tested in vitro and in vivo by imaging a human finger joint.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9991E..0AW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9991E..0AW"><span>High speed visible light communication using blue GaN laser diodes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watson, S.; Viola, S.; Giuliano, G.; Najda, S. P.; Perlin, P.; Suski, T.; Marona, L.; Leszczyński, M.; Wisniewski, P.; Czernecki, R.; Targowski, G.; Watson, M. A.; White, H.; Rowe, D.; Laycock, L.; Kelly, A. E.</p> <p>2016-10-01</p> <p>GaN-based laser diodes have been developed over the last 20 years making them desirable for many security and defence applications, in particular, free space laser communications. Unlike their LED counterparts, laser diodes are not limited by their carrier lifetime which makes them attractive for high speed communication, whether in free space, through fiber or underwater. Gigabit data transmission can be achieved in free space by modulating the visible light from the laser with a pseudo-random bit sequence (PRBS), with recent results approaching 5 Gbit/s error free data transmission. By exploiting the low-loss in the blue part of the spectrum through water, data transmission experiments have also been conducted to show rates of 2.5 Gbit/s underwater. Different water types have been tested to monitor the effect of scattering and to see how this affects the overall transmission rate and distance. This is of great interest for communication with unmanned underwater vehicles (UUV) as the current method using acoustics is much slower and vulnerable to interception. These types of laser diodes can typically reach 50-100 mW of power which increases the length at which the data can be transmitted. This distance could be further improved by making use of high power laser arrays. Highly uniform GaN substrates with low defectivity allow individually addressable laser bars to be fabricated. This could ultimately increase optical power levels to 4 W for a 20-emitter array. Overall, the development of GaN laser diodes will play an important part in free space optical communications and will be vital in the advancement of security and defence applications.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/510667','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/510667"><span>Analysis of Sr{sub 5{minus}x}Ba{sub x}(PO{sub 4}){sub 3}F:Yb{sup 3+} crystals for improved laser performance with diode-pumping</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Schaffers, K.I.; Bayramian, A.J.; Marshall, C.D.</p> <p></p> <p>Crystals of Yb{sup 3+}:Sr{sub 1-x}Ba{sub x}(PO{sub 4}){sub 3}F (0 < x < 5) have been investigated as a means to obtain broader absorption bands than are currently available with Yb{sup 3+}:S-FAP [Yb{sup 3+}: Sr{sub 5}(PO{sub 4}){sub 3}F], thereby improving diode-pumping efficiency for high peak power applications. Large diode-arrays have a FWHM pump band of >5 nm while the FWHM of the 900 nm absorption band for Yb:S-FAP is 5.5 nm; therefore, a significant amount of pump power can be wasted due to the nonideal overlap. Spectroscopic analysis of Yb:Sr{sub 5-x}Ba{sub x}-FAP crystals indicates that adding barium to the lattice increasesmore » the pump band to 13-16 run which more than compensates for the diode-array pump source without a detrimental reduction in absorption cross section. However, the emission cross section decreases by approximately half with relatively no effect on the emission lifetime. The small signal gain has also been measured and compared to the parent material Yb:S-FAP and emission cross sections have been determined by the method of reciprocity, the Filchtbauer-Ladenburg method, and small signal gain. Overall, Yb{sup 3+}:Sr{sub 5-x}Ba{sub x}(PO{sub 4}){sub 3}F crystals appear to achieve the goal of nearly matching the favorable thermal and laser performance properties of Yb:S-FAP while having a broader absorption band to better accommodate diode pumping.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6456E..0TH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6456E..0TH"><span>Novel high-brightness fiber coupled diode laser device</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haag, Matthias; Köhler, Bernd; Biesenbach, Jens; Brand, Thomas</p> <p>2007-02-01</p> <p>High brightness becomes more and more important in diode laser applications for fiber laser pumping and materials processing. For OEM customers fiber coupled devices have great advantages over direct beam modules: the fiber exit is a standardized interface, beam guiding is easy with nearly unlimited flexibility. In addition to the transport function the fiber serves as homogenizer: the beam profile of the laser radiation emitted from a fiber is symmetrical with highly repeatable beam quality and pointing stability. However, efficient fiber coupling requires an adaption of the slow-axis beam quality to the fiber requirements. Diode laser systems based on standard 10mm bars usually employ beam transformation systems to rearrange the highly asymmetrical beam of the laser bar or laser stack. These beam transformation systems (prism arrays, lens arrays, fiber bundles etc.) are expensive and become inefficient with increasing complexity. This is especially true for high power devices with small fiber diameters. On the other hand, systems based on single emitters are claimed to have good potential in cost reduction. Brightness of the inevitable fiber bundles, though, is limited due to inherent fill-factor losses. At DILAS a novel diode laser device has been developed combining the advantages of diode bars and single emitters: high brightness at high reliability with single emitter cost structure. Heart of the device is a specially tailored laser bar (T-Bar), which epitaxial and lateral structure was designed such that only standard fast- and slow-axis collimator lenses are required to couple the beam into a 200μm fiber. Up to 30 of these T-Bars of one wavelength can be combined to reach a total of > 500W ex fiber in the first step. Going to a power level of today's single emitter diodes even 1kW ex 200μm fiber can be expected.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830000008&hterms=silicon+detector+electrons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsilicon%2Bdetector%2Belectrons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830000008&hterms=silicon+detector+electrons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsilicon%2Bdetector%2Belectrons"><span>X-Ray Detector for 1 to 30 keV</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alcorn, G.; Jackson, J., Jr; Grant, P.; Marshall, F.</p> <p>1983-01-01</p> <p>Array of silicon X-ray detecting diodes measures photon energy and provides image of X-ray pattern. Regardless of thickness of new X-ray detector, depletion region extends through it. Impinging X-rays generate electrons in quantities proportional to X-ray energy. X-ray detector is mated to chargecoupled-device array for image generation and processing. Useful in industrial part inspection, pulsed-plasma research and medical application.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10513E..1RZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10513E..1RZ"><span>Study on the near-field non-linearity (SMILE) of high power diode laser arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Hongyou; Jia, Yangtao; Li, Changxuan; Zah, Chung-en; Liu, Xingsheng</p> <p>2018-02-01</p> <p>High power laser diodes have been found a wide range of industrial, space, medical applications, characterized by high conversion efficiency, small size, light weight and a long lifetime. However, due to thermal induced stress, each emitter in a semiconductor laser bar or array is displaced along p-n junction, resulting of each emitter is not in a line, called Near-field Non-linearity. Near-field Non-linearity along laser bar (also known as "SMILE") determines the outcome of optical coupling and beam shaping [1]. The SMILE of a laser array is the main obstacle to obtain good optical coupling efficiency and beam shaping from a laser array. Larger SMILE value causes a larger divergence angle and a wider line after collimation and focusing, respectively. In this letter, we simulate two different package structures based on MCC (Micro Channel Cooler) with Indium and AuSn solders, including the distribution of normal stress and the SMILE value. According to the theoretical results, we found the distribution of normal stress on laser bar shows the largest in the middle and drops rapidly near both ends. At last, we did another experiment to prove that the SMILE value of a laser bar was mainly affected by the die bonding process, rather than the operating condition.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29529726','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29529726"><span>Multi-frame linear regressive filter for the measurement of infrared pixel spatial response and MTF from sparse data.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huard, Edouard; Derelle, Sophie; Jaeck, Julien; Nghiem, Jean; Haïdar, Riad; Primot, Jérôme</p> <p>2018-03-05</p> <p>A challenging point in the prediction of the image quality of infrared imaging systems is the evaluation of the detector modulation transfer function (MTF). In this paper, we present a linear method to get a 2D continuous MTF from sparse spectral data. Within the method, an object with a predictable sparse spatial spectrum is imaged by the focal plane array. The sparse data is then treated to return the 2D continuous MTF with the hypothesis that all the pixels have an identical spatial response. The linearity of the treatment is a key point to estimate directly the error bars of the resulting detector MTF. The test bench will be presented along with measurement tests on a 25 μm pitch InGaAs detector.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26901448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26901448"><span>Monolithically Integrated InGaAs Nanowires on 3D Structured Silicon-on-Insulator as a New Platform for Full Optical Links.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Hyunseok; Farrell, Alan C; Senanayake, Pradeep; Lee, Wook-Jae; Huffaker, Diana L</p> <p>2016-03-09</p> <p>Monolithically integrated III-V semiconductors on a silicon-on-insulator (SOI) platform can be used as a building block for energy-efficient on-chip optical links. Epitaxial growth of III-V semiconductors on silicon, however, has been challenged by the large mismatches in lattice constants and thermal expansion coefficients between epitaxial layers and silicon substrates. Here, we demonstrate for the first time the monolithic integration of InGaAs nanowires on the SOI platform and its feasibility for photonics and optoelectronic applications. InGaAs nanowires are grown not only on a planar SOI layer but also on a 3D structured SOI layer by catalyst-free metal-organic chemical vapor deposition. The precise positioning of nanowires on 3D structures, including waveguides and gratings, reveals the versatility and practicality of the proposed platform. Photoluminescence measurements exhibit that the composition of ternary InGaAs nanowires grown on the SOI layer has wide tunability covering all telecommunication wavelengths from 1.2 to 1.8 μm. We also show that the emission from an optically pumped single nanowire is effectively coupled and transmitted through an SOI waveguide, explicitly showing that this work lays the foundation for a new platform toward energy-efficient optical links.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24988280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24988280"><span>Metastable growth of pure wurtzite InGaAs microstructures.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ng, Kar Wei; Ko, Wai Son; Lu, Fanglu; Chang-Hasnain, Connie J</p> <p>2014-08-13</p> <p>III-V compound semiconductors can exist in two major crystal phases, namely, zincblende (ZB) and wurtzite (WZ). While ZB is thermodynamically favorable in conventional III-V epitaxy, the pure WZ phase can be stable in nanowires with diameters smaller than certain critical values. However, thin nanowires are more vulnerable to surface recombination, and this can ultimately limit their performances as practical devices. In this work, we study a metastable growth mechanism that can yield purely WZ-phased InGaAs microstructures on silicon. InGaAs nucleates as sharp nanoneedles and expand along both axial and radial directions simultaneously in a core-shell fashion. While the base can scale from tens of nanometers to over a micron, the tip can remain sharp over the entire growth. The sharpness maintains a high local surface-to-volume ratio, favoring hexagonal lattice to grow axially. These unique features lead to the formation of microsized pure WZ InGaAs structures on silicon. To verify that the WZ microstructures are truly metastable, we demonstrate, for the first time, the in situ transformation from WZ to the energy-favorable ZB phase inside a transmission electron microscope. This unconventional core-shell growth mechanism can potentially be applied to other III-V materials systems, enabling the effective utilization of the extraordinary properties of the metastable wurtzite crystals.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940006922','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940006922"><span>InGaAs concentrator cells for laser power converters and tandem cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wojtczuk, S.; Vernon, S.; Gagnon, E.</p> <p>1993-01-01</p> <p>In(0.53)Ga(0.47)As N-on-P concentrator cells were made as part of an effort to develop 1.315 micron laser power converters. The 1.315 micron laser power conversion efficiency was estimated as 29.4 percent (at 5.57 W/cm(sup 2)) based on an 86 percent measured external quantum efficiency at 1.315 microns, and a measured open circuit voltage (484 mV), and fill-factor (67 percent) at the equivalent AM0 short-circuit photocurrent (5.07 A/cm(sup 2)). A 13.5 percent percent AMO efficiency was achieved at 89 suns and 25 C. Measured one-sun and 100-sun AMO efficiency, log I-V analysis, and quantum efficiency are presented for InGaAs cells with and without InP windows to passivate the front surface. Windowed cells performed better at concentration than windowless cells. Lattice mismatch between InGaAs epilayers and InP substrate was less than 800 ppm. Theoretical efficiency is estimated for 1.315 microns laser power converters versus the bandgap energy. Adding aluminum to InGaAs to form In(x)Al(y)Ga(1-x-y)As is presented as a way to achieve an optimal bandgap for 1.315 microns laser power conversion.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27607696','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27607696"><span>Exciton localization and ultralow onset ultraviolet emission in ZnO nanopencils-based heterojunction diodes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiang, Junyan; Zhang, Yuantao; Chi, Chen; Long, Yan; Han, Xu; Wu, Bin; Zhang, Baolin; Du, Guotong</p> <p>2016-09-05</p> <p>n-GaN/i-ZnO/p-GaN double heterojunction diodes were constructed by vertically binding p-GaN wafer on the tip of ZnO nanopencil arrays grown on n-GaN/sapphire substrates. An increased quantum confinement in the tip of ZnO nanopencils has been verified by photoluminescence measurements combined with quantitative analyses. Under forward bias, a sharp ultraviolet emission at ~375 nm due to localized excitons recombination can be observed in ZnO. The electroluminescence mechanism of the studied diode is tentatively elucidated using a simplified quantum confinement model. Additionally, the improved performance of the studied diode featuring an ultralow emission onset, a good operation stability and an enhanced ultraviolet emission shows the potential of our approach. This work provides a new route for the design and development of ZnO-based excitonic optoelectronic devices.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22109497','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22109497"><span>Propagation of a radial phased-locked Lorentz beam array in turbulent atmosphere.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Guoquan</p> <p>2011-11-21</p> <p>A radial phased-locked (PL) Lorentz beam array provides an appropriate theoretical model to describe a coherent diode laser array, which is an efficient radiation source for high-power beaming use. The propagation of a radial PL Lorentz beam array in turbulent atmosphere is investigated. Based on the extended Huygens-Fresnel integral and some mathematical techniques, analytical formulae for the average intensity and the effective beam size of a radial PL Lorentz beam array are derived in turbulent atmosphere. The average intensity distribution and the spreading properties of a radial PL Lorentz beam array in turbulent atmosphere are numerically calculated. The influences of the beam parameters and the structure constant of the atmospheric turbulence on the propagation of a radial PL Lorentz beam array in turbulent atmosphere are discussed in detail. © 2011 Optical Society of America</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9639E..0TA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9639E..0TA"><span>A 400 KHz line rate 2048 pixel modular SWIR linear array for earth observation applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anchlia, Ankur; Vinella, Rosa M.; Wouters, Kristof; Gielen, Daphne; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; van der Zanden, Koen; Vermeiren, Jan; Merken, Patrick</p> <p>2015-10-01</p> <p>In this paper, we report about a family of linear imaging FPAs sensitive in the [0.9 - 1.7um] band, developed for high speed applications such as LIDAR, wavelength references and OCT analyzers and also for earth observation applications. Fast linear FPAs can also be used in a wide variety of terrestrial applications, including high speed sorting, electro- and photo-luminesce and medical applications. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. In principle, this concept can be extended to any multiple of 512 pixels, the limiting factor being the pixel yield of long InGaAs arrays and the CTE differences in the hybrid setup. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long-linear array to run at a high line rate of 400 KHz irrespective of the array length, which limits the line rate in a traditional linear array. The pixel has a pitch of 12.5um. The detector frontend is based on CTIA (Capacitor Trans-impedance Amplifier), having 5 selectable integration capacitors giving full well from 62x103e- (gain0) to 40x106e- (gain4). An auto-zero circuit limits the detector bias non-uniformity to 5-10mV across broad intensity levels, limiting the input referred dark signal noise to 20e-rms for Tint=3ms at room temperature. An on-chip CDS that follows the CTIA facilitates removal of Reset/KTC noise, CTIA offsets and most of the 1/f noise. The measured noise of the ROIC is 35e-rms in gain0. At a master clock rate of 60MHz and a minimum integration time of 1.4us, the FPAs reach the highest line rate of 400 KHz.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22648932-su-diode-array-transmission-detector-systems-evaluation','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22648932-su-diode-array-transmission-detector-systems-evaluation"><span>SU-F-T-326: Diode Array Transmission Detector Systems Evaluation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hoffman, D; Dyer, B; Kumaran Nair, C</p> <p>2016-06-15</p> <p>Purpose: A new transmission detector, Delta4 Discover, developed by Scandidos (Uppsala, Sweden) was evaluated for external photon beam verification and quality assurance. The device is an array of 4040 diodes designed to be mounted on the linac accessory tray to measure photon field shape, position and fluence during patient treatment. Interfractional measurements are compared to a baseline measurement made during delivery quality assurance. The aim of this work is to evaluate the stability of the device and its effect on the shape and magnitude of the treatment beam. Methods: Beam profiles, percent depth dose, and beam attenuation was measured formore » 6, 10, and 15 MV photon beams with and without the device in place for 1×1 and 30×30 cm2 fields. Changes in profile and percent depth dose was quantified to evaluate the need to recommission the treatment beam, or account for the device with a tray factor. The stability of the radiation measurements was evaluated by measuring the deviation of each diode measurement during repeated prostate VMAT treatment delivery. Results: Photon beam profiles changed by < 1.25% in the nonpenumbra regions of the 30×30 cm2 beam. Percent depth dose curves show a 5–7% increased dose at depths < 2.5cm, but agreed within 1% at depths > 2.5cm. This indicates increased skin dose, similar to the use of a physical beam wedge. The device attenuated 6, 10, and 15 MV photon beams by 1.71±0.02%, 1.36±0.03%, and 1.17±0.03%, respectively. The diode array reproduced dosimetric measurements within 0.5% standard deviation for repeated prostate VMAT measurement. Conclusion: The device demonstrated stabile radiation measurements, while not changing the treatment beam shape in a clinically significantly manner. Use of this device can be accounted for with a tray factor, as opposed to recommissioning the treatment beam.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002STIN...0287584.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002STIN...0287584."><span>STS-109 Mission Highlights Resource Tape</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>2002-05-01</p> <p>This video, Part 2 of 4, shows the activities of the STS-109 crew (Scott Altman, Commander; Duane Carey, Pilot; John Grunsfeld, Payload Commander; Nancy Currie, James Newman, Richard Linnehan, Michael Massimino, Mission Specialists) during flight days 4 and 5. The activities from other flights days can be seen on 'STS-109 Mission Highlights Resource Tape' Part 1 of 4 (internal ID 2002139471), 'STS-109 Mission Highlights Resource Tape' Part 3 of 4 (internal ID 2002139476), and 'STS-109 Mission Highlights Resource Tape' Part 4 of 4 (internal ID 2002137577). The primary activities during these days were EVAs (extravehicular activities) to replace two solar arrays on the HST (Hubble Space Telescope). Footage from flight day 4 records an EVA by Grunsfeld and Linnehan, including their exit from Columbia's payload bay airlock, their stowing of the old HST starboard rigid array on the rigid array carrier in Columbia's payload bay, their attachment of the new array on HST, the installation of a new starboard diode box, and the unfolding of the new array. The pistol grip space tool used to fasten the old array in its new location is shown in use. The video also includes several shots of the HST with Earth in the background. On flight day 5 Newman and Massimino conduct an EVA to change the port side array and diode box on HST. This EVA is very similar to the one on flight day 4, and is covered similarly in the video. A hand operated ratchet is shown in use. In addition to a repeat of the previous tasks, the astronauts change HST's reaction wheel assembly, and because they are ahead of schedule, install installation and lubricate an instrument door on the telescope. The Earth views include a view of Egypt and Israel, with the Nile River, Red Sea, and Mediterranean Sea.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8702E..0BS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8702E..0BS"><span>Improving the beam quality of high-power laser diodes by introducing lateral periodicity into waveguides</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sobczak, Grzegorz; DÄ browska, ElŻbieta; Teodorczyk, Marian; Kalbarczyk, Joanna; MalÄ g, Andrzej</p> <p>2013-01-01</p> <p>Low quality of the optical beam emitted by high-power laser diodes is the main disadvantage of these devices. The two most important reasons are highly non-Gaussian beam profile with relatively wide divergence in the junction plane and the filamentation effect. Designing laser diode as an array of narrow, close to each other single-mode waveguides is one of the solutions to this problem. In such devices called phase locked arrays (PLA) there is no room for filaments formation. The consequence of optical coupling of many single-mode waveguides is the device emission in the form of few almost diffraction limited beams. Because of losses in regions between active stripes the PLA devices have, however, somewhat higher threshold current and lower slope efficiencies compared to wide-stripe devices of similar geometry. In this work the concept of the high-power laser diode resonator consisted of joined PLA and wide stripe segments is proposed. Resulting changes of electro-optical characteristics of PLA are discussed. The devices are based on the asymmetric heterostructure designed for improvement of the catastrophic optical damage threshold as well as thermal and electrical resistances. Due to reduced distance from the active layer to surface in this heterostructure, better stability of current (and gain) distribution with changing drive level is expected. This could lead to better stability of optical field distribution and supermodes control. The beam divergence reduction in the direction perpendicular of the junction plane has been also achieved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100033583','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100033583"><span>Qualification and Selection of Flight Diode Lasers for Space Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebe, Carl C.; Dillon, Robert P.; Gontijo, Ivair; Forouhar, Siamak; Shapiro, Andrew A.; Cooper, Mark S.; Meras, Patrick L.</p> <p>2010-01-01</p> <p>The reliability and lifetime of laser diodes is critical to space missions. The Nuclear Spectroscopic Telescope Array (NuSTAR) mission includes a metrology system that is based upon laser diodes. An operational test facility has been developed to qualify and select, by mission standards, laser diodes that will survive the intended space environment and mission lifetime. The facility is situated in an electrostatic discharge (ESD) certified clean-room and consist of an enclosed temperature-controlled stage that can accommodate up to 20 laser diodes. The facility is designed to characterize a single laser diode, in addition to conducting laser lifetime testing on up to 20 laser diodes simultaneously. A standard laser current driver is used to drive a single laser diode. Laser diode current, voltage, power, and wavelength are measured for each laser diode, and a method of selecting the most adequate laser diodes for space deployment is implemented. The method consists of creating histograms of laser threshold currents, powers at a designated current, and wavelengths at designated power. From these histograms, the laser diodes that illustrate a performance that is outside the normal are rejected and the remaining lasers are considered spaceborne candidates. To perform laser lifetime testing, the facility is equipped with 20 custom laser drivers that were designed and built by California Institute of Technology specifically to drive NuSTAR metrology lasers. The laser drivers can be operated in constant-current mode or alternating-current mode. Situated inside the enclosure, in front of the laser diodes, are 20 power-meter heads to record laser power throughout the duration of lifetime testing. Prior to connecting a laser diode to the current source for characterization and lifetime testing, a background program is initiated to collect current, voltage, and resistance. This backstage data collection enables the operational test facility to have full laser diode traceablity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830019800','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830019800"><span>A new strategy for efficient solar energy conversion: Parallel-processing with surface plasmons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, L. M.</p> <p>1982-01-01</p> <p>This paper introduces an advanced concept for direct conversion of sunlight to electricity, which aims at high efficiency by tailoring the conversion process to separate energy bands within the broad solar spectrum. The objective is to obtain a high level of spectrum-splitting without sequential losses or unique materials for each frequency band. In this concept, sunlight excites a spectrum of surface plasma waves which are processed in parallel on the same metal film. The surface plasmons transport energy to an array of metal-barrier-semiconductor diodes, where energy is extracted by inelastic tunneling. Diodes are tuned to different frequency bands by selecting the operating voltage and geometry, but all diodes share the same materials.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991SPIE.1400.....L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991SPIE.1400.....L"><span>Optical fabrication and testing; Proceedings of the Meeting, Singapore, Oct. 22-27, 1990</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lorenzen, Manfred; Campbell, Duncan R.; Johnson, Craig W.</p> <p>1991-03-01</p> <p>Various papers on optical fabrication and testing are presented. Individual topics addressed include: interferometry with laser diodes, new methods for economic production of prisms and lenses, interferometer accuracy and precision, optical testing with wavelength scanning interferometer, digital Talbot interferometer, high-sensitivity interferometric technique for strain measurements, absolute interferometric testing of spherical surfaces, contouring using gratings created on an LCD panel, three-dimensional inspection using laser-based dynamic fringe projection, noncontact optical microtopography, laser scan microscope and infrared laser scan microscope, photon scanning tunneling microscopy. Also discussed are: combination-matching problems in the layout design of minilaser rangefinder, design and testing of a cube-corner array for laser ranging, mode and far-field pattern of diode laser-phased arrays, new glasses for optics and optoelectronics, optical properties of Li-doped ZnO films, application and machining of Zerodur for optical purposes, finish machining of optical components in mass production.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19750503','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19750503"><span>Direct characterization of aqueous extract of Hibiscus sabdariffa using HPLC with diode array detection coupled to ESI and ion trap MS.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rodríguez-Medina, Inmaculada C; Beltrán-Debón, Raúl; Molina, Vicente Micol; Alonso-Villaverde, Carlos; Joven, Jorge; Menéndez, Javier A; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto</p> <p>2009-10-01</p> <p>The phenolic fraction and other polar compounds of the Hibiscus sabdariffa were separated and identified by HPLC with diode array detection coupled to electrospray TOF and IT tandem MS (DAD-HPLC-ESI-TOF-MS and IT-MS). The H. sabdariffa aqueous extract was filtered and directly injected into the LC system. The analysis of the compounds was carried out by RP HPLC coupled to DAD and TOF-MS in order to obtain molecular formula and exact mass. Posterior analyses with IT-MS were performed and the fragmentation pattern and confirmation of the structures were achieved. The H. sabdariffa samples were successfully analyzed in positive and negative ionization modes with two optimized linear gradients. In positive mode, the two most representative anthocyanins and other compounds were identified whereas the phenolic fraction, hydroxycitric acid and its lactone were identified using the negative ionization mode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25466282','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25466282"><span>Identification and quantification of flavonoids and chromes in Baeckea frutescens by using HPLC coupled with diode-array detection and quadruple time-of-flight mass spectrometry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jia, Bei-Xi; Huangfu, Qian-Qian; Ren, Feng-Xiao; Jia, Lu; Zhang, Yan-Bing; Liu, Hong-Min; Yang, Jie; Wang, Qiang</p> <p>2015-01-01</p> <p>This article marks the first report on high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD) and quadruple time-of-flight mass spectrometry (Q-TOF/MS) for the identification and quantification of main bioactive constituents in Baeckea frutescens. In total, 24 compounds were identified or tentatively characterised based on their retention behaviours, UV profiles and MS fragment information. Furthermore, a validated method with good linearity, sensitivity, precision, stability, repeatability and accuracy was successfully applied for simultaneous determination of five flavonoids and one chromone in different plant parts of B. frutescens collected at different harvest times, and their dynamic contents revealed the appropriate harvest times. The established HPLC-DAD-Q-TOF/MS using multi-bioactive markers was proved to be a validated strategy for the quality evaluation on both raw materials and related products of B. frutescens.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22078305','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22078305"><span>The offline combination of thin-layer chromatography and high-performance liquid chromatography with diode array detection and micrOTOF-Q mass spectrometry for the separation and identification of spinochromes from sea urchin (Strongylocentrotus droebachiensis) shells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shikov, Alexander N; Ossipov, Vladimir I; Martiskainen, Olli; Pozharitskaya, Olga N; Ivanova, Svetlana A; Makarov, Valery G</p> <p>2011-12-16</p> <p>Thin-layer chromatography (TLC) with off-line high-performance liquid chromatography coupled to diode array detection and micrOTOF-Q mass spectrometry (HPLC-DAD-MS) resulted in the successful fractionation, separation and identification of spinochrome pigments from sea urchin (Strongylocentrotus droebachiensis) shells. Two fractions of pigments were separated by TLC and eluted with methanol using a TLC-MS interface. HPLC-DAD-MS analysis of the fractions indicated the presence of six sea urchin pigments: spinochrome monomers B and D, three spinochrome dimers (anhydroethylidene-6,6'-bis(2,3,7-trihydroxynaphthazarin) and its isomer and ethylidene-6,6'-bis(2,3,7-trihydroxynaphthazarin)), and one pigment that was preliminary identified as a spinochrome dimer with the structural formula C(22)H(16)O(16). Copyright © 2011 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApPhL.112t1902Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApPhL.112t1902Z"><span>Light beam shaping for collimated emission from white organic light-emitting diodes using customized lenticular microlens arrays structure</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Lei; Bai, Gui-Lin; Guo, Xin; Shen, Su; Ou, Qing-Dong; Fan, Yuan-Yuan</p> <p>2018-05-01</p> <p>We present a design approach to realizing a desired collimated planar incoherent light source (CPILS) by incorporating lenticular microlens arrays (LMLAs) onto the substrates of discrete white organic light-emitting diode (WOLED) light sources and demonstrate the effectiveness of this method in collimated light beam shaping and luminance enhancement simultaneously. The obtained collimated WOLED light source shows enhanced luminance by a factor of 2.7 compared with that of the flat conventional device at the normal polar angle and, more importantly, exhibits a narrowed angular emission with a full-width at half-maximum (FWHM) of ˜33.6°. We anticipate that the presented strategy could provide an alternative way for achieving the desired large scale CPILS, thereby opening the door to many potential applications, including LCD backlights, three-dimensional displays, car headlights, and so forth.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27870291','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27870291"><span>Simultaneous quantitation of 14 active components in Yinchenhao decoction with an ultrahigh performance liquid chromatography-diode array detector: Method development and ingredient analysis of different commonly prepared samples.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yi, YaXiong; Zhang, Yong; Ding, Yue; Lu, Lu; Zhang, Tong; Zhao, Yuan; Xu, XiaoJun; Zhang, YuXin</p> <p>2016-11-01</p> <p>J. Sep. Sci. 2016, 39, 4147-4157 DOI: 10.1002/jssc.201600284 Yinchenhao decoction (YCHD) is a famous Chinese herbal formula recorded in the Shang Han Lun which was prescribed by Zhongjing Zhang during 150-219 AD. A novel quantitative analysis method was developed, based on ultrahigh performance liquid chromatography coupled with a diode array detector for the simultaneous determination of 14 main active components in Yinchenhao decoction. Furthermore, the method has been applied for compositional difference analysis of the 14 components in eight normal extraction samples of Yinchenhao decoction, with the aid of hierarchical clustering analysis and similarity analysis. The present research could help hospital, factory and lab choose the best way to make Yinchenhao decoction with better efficacy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26832299','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26832299"><span>Fabrication, characterization and applications of flexible vertical InGaN micro-light emitting diode arrays.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tian, Pengfei; McKendry, Jonathan J D; Gu, Erdan; Chen, Zhizhong; Sun, Yongjian; Zhang, Guoyi; Dawson, Martin D; Liu, Ran</p> <p>2016-01-11</p> <p>Flexible vertical InGaN micro-light emitting diode (micro-LED) arrays have been fabricated and characterized for potential applications in flexible micro-displays and visible light communication. The LED epitaxial layers were transferred from initial sapphire substrates to flexible AuSn substrates by metal bonding and laser lift off techniques. The current versus voltage characteristics of flexible micro-LEDs degraded after bending the devices, but the electroluminescence spectra show little shift even under a very small bending radius 3 mm. The high thermal conductivity of flexible metal substrates enables high thermal saturation current density and high light output power of the flexible micro-LEDs, benefiting the potential applications in flexible high-brightness micro-displays and high-speed visible light communication. We have achieved ~40 MHz modulation bandwidth and 120 Mbit/s data transmission speed for a typical flexible micro-LED.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950007767','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950007767"><span>Wavelength-division multiplexed optical integrated circuit with vertical diffraction grating</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lang, Robert J. (Inventor); Forouhar, Siamak (Inventor)</p> <p>1994-01-01</p> <p>A semiconductor optical integrated circuit for wave division multiplexing has a semiconductor waveguide layer, a succession of diffraction grating points in the waveguide layer along a predetermined diffraction grating contour, a semiconductor diode array in the waveguide layer having plural optical ports facing the succession of diffraction grating points along a first direction, respective semiconductor diodes in the array corresponding to respective ones of a predetermined succession of wavelengths, an optical fiber having one end thereof terminated at the waveguide layer, the one end of the optical fiber facing the succession of diffraction grating points along a second direction, wherein the diffraction grating points are spatially distributed along the predetermined contour in such a manner that the succession of diffraction grating points diffracts light of respective ones of the succession of wavelengths between the one end of the optical fiber and corresponding ones of the optical ports.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ApPhL..97a3101L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..97a3101L"><span>Color tunable light-emitting diodes based on p+-Si/p-CuAlO2/n-ZnO nanorod array heterojunctions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ling, Bo; Zhao, Jun Liang; Sun, Xiao Wei; Tan, Swee Tiam; Kyaw, Aung Ko Ko; Divayana, Yoga; Dong, Zhi Li</p> <p>2010-07-01</p> <p>Wide-range color tuning from red to blue was achieved in phosphor-free p+-Si/p-CuAlO2/n-ZnO nanorod light-emitting diodes at room temperature. CuAlO2 films were deposited on p+-Si substrates by sputtering followed by annealing. ZnO nanorods were further grown on the annealed p+-Si/p-CuAlO2 substrates by vapor phase transport. The color of the p-CuAlO2/n-ZnO nanorod array heterojunction electroluminescence depended on the annealing temperature of the CuAlO2 film. With the increase of the annealing temperature from 900 to 1050 °C, the emission showed a blueshift under the same forward bias. The origin of the blueshift is related to the amount of Cu concentration diffused into ZnO.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26836075','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26836075"><span>Miniaturized time-resolved Raman spectrometer for planetary science based on a fast single photon avalanche diode detector array.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blacksberg, Jordana; Alerstam, Erik; Maruyama, Yuki; Cochrane, Corey J; Rossman, George R</p> <p>2016-02-01</p> <p>We present recent developments in time-resolved Raman spectroscopy instrumentation and measurement techniques for in situ planetary surface exploration, leading to improved performance and identification of minerals and organics. The time-resolved Raman spectrometer uses a 532 nm pulsed microchip laser source synchronized with a single photon avalanche diode array to achieve sub-nanosecond time resolution. This instrument can detect Raman spectral signatures from a wide variety of minerals and organics relevant to planetary science while eliminating pervasive background interference caused by fluorescence. We present an overview of the instrument design and operation and demonstrate high signal-to-noise ratio Raman spectra for several relevant samples of sulfates, clays, and polycyclic aromatic hydrocarbons. Finally, we present an instrument design suitable for operation on a rover or lander and discuss future directions that promise great advancement in capability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JSemi..36j2006H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JSemi..36j2006H"><span>Design and simulation of a novel high-efficiency cooling heat-sink structure using fluid-thermodynamics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hongqi, Jing; Li, Zhong; Yuxi, Ni; Junjie, Zhang; Suping, Liu; Xiaoyu, Ma</p> <p>2015-10-01</p> <p>A novel high-efficiency cooling mini-channel heat-sink structure has been designed to meet the package technology demands of high power density laser diode array stacks. Thermal and water flowing characteristics have been simulated using the Ansys-Fluent software. Owing to the increased effective cooling area, this mini-channel heat-sink structure has a better cooling effect when compared with the traditional macro-channel heat-sinks. Owing to the lower flow velocity in this novel high efficient cooling structure, the chillers' water-pressure requirement is reduced. Meanwhile, the machining process of this high-efficiency cooling mini-channel heat-sink structure is simple and the cost is relatively low, it also has advantages in terms of high durability and long lifetime. This heat-sink is an ideal choice for the package of high power density laser diode array stacks. Project supported by the Defense Industrial Technology Development Program (No. B1320133033).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24492347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24492347"><span>Aqueous photochemical reactions of chloride, bromide, and iodide ions in a diode-array spectrophotometer. Autoinhibition in the photolysis of iodide ions.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalmár, József; Dóka, Éva; Lente, Gábor; Fábián, István</p> <p>2014-03-28</p> <p>The aqueous photoreactions of three halide ions (chloride, bromide and iodide) were studied using a diode array spectrophotometer to drive and detect the process at the same time. The concentration and pH dependences of the halogen formation rates were studied in detail. The experimental data were interpreted by improving earlier models where the cage complex of a halogen atom and an electron has a central role. The triiodide ion was shown to exert a strong inhibiting effect on the reaction sequence leading to its own formation. An assumed chemical reaction between the triiodide ion and the cage complex interpreted the strong autoinhibition effect. It is shown that there is a real danger of unwanted interference from the photoreactions of halide ions when halide salts are used as supporting electrolytes in spectrophotometric experiments using a relatively high intensity UV light source.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2548024','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2548024"><span>Signal-to-noise optimization and evaluation of a home-made visible diode-array spectrophotometer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Raimundo, Jr., Ivo M.; Pasquini, Celio</p> <p>1993-01-01</p> <p>This paper describes a simple low-cost multichannel visible spectrophotometer built with an RL512G EGG-Reticon photodiode array. A symmetric Czerny-Turner optical design was employed; instrument control was via a single-board microcomputer based on the 8085 Intel microprocessor. Spectral intensity data are stored in the single-board's RAM and then transferred to an IBM-AT 3865X compatible microcomputer through a RS-232C interface. This external microcomputer processes the data to recover transmittance, absorbance or relative intensity of the spectra. The signal-to-noise ratio and dynamic range were improved by using variable integration times, which increase during the same scan; and by the use of either weighted or unweighted sliding average of consecutive diodes. The instrument is suitable for automatic methods requiring quasi-simultaneous multiwavelength detections, such as multivariative calibration and flow-injection gradient scan techniques. PMID:18924979</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16019828','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16019828"><span>Screening of grapes and wine for azoxystrobin, kresoxim-methyl and trifloxystrobin fungicides by HPLC with diode array detection.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Melo Abreu, Susana; Correia, Manuela; Herbert, Paulo; Santos, Lúcia; Alves, Arminda</p> <p>2005-06-01</p> <p>The Quinone outside Inhibitors (QoI) are one of the most important and recent fungicide groups used in viticulture and also allowed by Integrated Pest Management. Azoxystrobin, kresoxim-methyl and trifloxystrobin are the main active ingredients for treating downy and powdery mildews that can be present in grapes and wines. In this paper, a method is reported for the analysis of these three QoI-fungicides in grapes and wine. After liquid-liquid extraction and a clean-up on commercial silica cartridges, analysis was by isocratic HPLC with diode array detection (DAD) with a run time of 13 min. Confirmation was by solid-phase micro-extraction (SPME), followed by GC/MS determination. The main validation parameters for the three compounds in grapes and wine were a limit of detection up to 0.073 mg kg(-1), a precision not exceeding 10.0% and an average recovery of 93% +/- 38.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28094849','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28094849"><span>The "collimator monitoring fill factor" of a two-dimensional detector array, a measure of its ability to detect collimation errors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stelljes, Tenzin Sonam; Looe, Hui Khee; Harder, Dietrich; Poppe, Björn</p> <p>2017-03-01</p> <p>Two-dimensional detector arrays are routinely used for constancy checks and treatment plan verification in photon-beam radiotherapy. In addition to the spatial resolution of the dose profiles, the "coverage" of the radiation field with respect to the detection of any beam collimation deficiency appears as the second characteristic feature of a detector array. The here proposed "collimator monitoring fill factor" (CM fill factor) has been conceived to serve as a quantitative characteristic of this "coverage". The CM fill factor is defined as the probability of a 2D array to detect any collimator position error. Therefore, it is represented by the ratio of the "sensitive area" of a single detector, in which collimator position errors are detectable, and the geometrical "cell area" associated with this detector within the array. Numerical values of the CM fill factor have been Monte Carlo simulated for 2D detector arrays equipped with air-vented ionization chambers, liquid-filled ionization chambers and diode detectors and were compared with the "FWHM fill factor" defined by Gago-Arias et al. (2012). For arrays with vented ionization chambers, the differences between the CM fill factor and the FWHM fill factor are moderate, but occasionally the latter exceeds unity. For narrower detectors such as liquid-filled ionization chambers and Si diodes and for small sampling distances, large differences between the FWHM fill factor and the CM fill factor have been observed. These differences can be explained by the shapes of the fluence response functions of these narrow detectors. A new parameter "collimator monitoring fill factor" (CM fill factor), applicable to quantitate the collimator position error detection probability of a 2D detector array, has been proposed. It is designed as a help in classifying the clinical performance of two-dimensional detector arrays in photon-beam radiotherapy. © 2017 American Association of Physicists in Medicine.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060030469&hterms=InP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DInP','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060030469&hterms=InP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DInP"><span>Improved dot size uniformity and luminescense of InAs quantum dots on InP substrate</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Qiu, Y.; Uhl, D.</p> <p>2002-01-01</p> <p>InAs self-organized quantum dots have been grown in InGaAs quantum well on InP substrates by metalorganic vapor phase epitaxy. Atomic Force Microscopy confirmed of quantum dot formation with dot density of 3X10(sup 10) cm(sup -2). Improved dot size uniformity and strong room temperature photoluminescence up to 2 micron were observed after modifying the InGaAs well.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApPhL.100q3508K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApPhL.100q3508K"><span>Experimental evidence for the correlation between the weak inversion hump and near midgap states in dielectric/InGaAs interfaces</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krylov, Igor; Kornblum, Lior; Gavrilov, Arkady; Ritter, Dan; Eizenberg, Moshe</p> <p>2012-04-01</p> <p>Temperature dependent capacitance-voltage (C-V) and conductance-voltage (G-V) measurements were performed to obtain activation energies (EA) for weak inversion C-V humps and parallel conductance peaks in Al2O3/InGaAs and Si3N4/InGaAs gate stacks. Values of 0.48 eV (slightly more than half of the band gap of the studied In0.53Ga0.47As) were obtained for EA of both phenomena for both gate dielectrics studied. This indicates an universal InGaAs behavior and shows that both phenomena are due to generation-recombination of minority carriers through near midgap located interface states. The C-V hump correlates with the interface states density (Dit) and can be used as a characterization tool for dielectric/InGaAs systems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22261912-comparative-optical-study-epitaxial-ingaas-quantum-rods-grown-sub-sub-sources','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22261912-comparative-optical-study-epitaxial-ingaas-quantum-rods-grown-sub-sub-sources"><span>Comparative optical study of epitaxial InGaAs quantum rods grown with As{sub 2} and As{sub 4} sources</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nedzinskas, Ramūnas; Čechavičius, Bronislovas; Kavaliauskas, Julius</p> <p>2013-12-04</p> <p>Photoreflectance and photoluminescence (PL) spectroscopies are used to examine the optical properties and electronic structure of InGaAs quantum rods (QRs), embedded within InGaAs quantum well (QW). The nanostructures studied were grown by molecular beam epitaxy using As{sub 2} or As{sub 4} sources. The impact of As source on spectral features associated with interband optical transitions in the QRs and the surrounding QW are demonstrated. A red shift of the QR- and a blue shift of the QW-related optical transitions, along with a significant increase in PL intensity, have been observed if an As{sub 4} source is used. The changes inmore » optical properties are attributed mainly to carrier confinement effects caused by variation of In content contrast between the QR material and the surrounding well.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920000067&hterms=laser+spot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dlaser%2Bspot','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920000067&hterms=laser+spot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dlaser%2Bspot"><span>50 Mb/s, 220-mW Laser-Array Transmitter</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cornwell, Donald M., Jr.</p> <p>1992-01-01</p> <p>Laser transmitter based on injection locking produces single-wavelength, diffraction-limited, single-lobe beam. Output stage is array of laser diodes producing non-diffraction-limited, multi-mode beam in absence of injection locking. Suitable for both free-space and optical-fiber communication systems. Because beam from transmitter focused to spot as small as 5 micrometers, devices usable for reading and writing optical disks at increased information densities. Application also in remote sensing and ranging.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA612938','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA612938"><span>A Robust Design Approach to Cost Estimation: Solar Energy for Marine Corps Expeditionary Operations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-04-30</p> <p>areas as photovoltaic arrays for power harvesting, light emitting diodes (LED) for decreased energy consumption, and improved battery and smart power ...conversion system that allows Marines to power systems with solar energy. Each GREENS is comprised of eight photovoltaic array panels, four high-energy...Brandon Newell conducted an experiment where he assessed the capabilities of the HOMER model in forecasting the power output of a solar panel at the</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10086E..0OS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10086E..0OS"><span>Coherent beam combining architectures for high power tapered laser arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schimmel, G.; Janicot, S.; Hanna, M.; Decker, J.; Crump, P.; Erbert, G.; Witte, U.; Traub, M.; Georges, P.; Lucas-Leclin, G.</p> <p>2017-02-01</p> <p>Coherent beam combining (CBC) aims at increasing the spatial brightness of lasers. It consists in maintaining a constant phase relationship between different emitters, in order to combine them constructively in one single beam. We have investigated the CBC of an array of five individually-addressable high-power tapered laser diodes at λ = 976 nm, in two architectures: the first one utilizes the self-organization of the lasers in an interferometric extended-cavity, which ensures their mutual coherence; the second one relies on the injection of the emitters by a single-frequency laser diode. In both cases, the coherent combining of the phase-locked beams is ensured on the front side of the array by a transmission diffractive grating with 98% efficiency. The passive phase-locking of the laser bar is obtained up to 5 A (per emitter). An optimization algorithm is implemented to find the proper currents in the five ridge sections that ensured the maximum combined power on the front side. Under these conditions we achieve a maximum combined power of 7.5 W. In the active MOPA configuration, we can increase the currents in the tapered sections up to 6 A and get a combined power of 11.5 W, corresponding to a combining efficiency of 76%. It is limited by the beam quality of the tapered emitters and by fast phase fluctuations between emitters. Still, these results confirm the potential of CBC approaches with tapered lasers to provide a high-power and high-brightness beam, and compare with the current state-of-the-art with laser diodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994OptEn..33.2408D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994OptEn..33.2408D"><span>Review of infrared scene projector technology-1993</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Driggers, Ronald G.; Barnard, Kenneth J.; Burroughs, E. E.; Deep, Raymond G.; Williams, Owen M.</p> <p>1994-07-01</p> <p>The importance of testing IR imagers and missile seekers with realistic IR scenes warrants a review of the current technologies used in dynamic infrared scene projection. These technologies include resistive arrays, deformable mirror arrays, mirror membrane devices, liquid crystal light valves, laser writers, laser diode arrays, and CRTs. Other methods include frustrated total internal reflection, thermoelectric devices, galvanic cells, Bly cells, and vanadium dioxide. A description of each technology is presented along with a discussion of their relative benefits and disadvantages. The current state of each methodology is also summarized. Finally, the methods are compared and contrasted in terms of their performance parameters.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23853385','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23853385"><span>A New Individually Addressable Micro-LED Array for Photogenetic Neural Stimulation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McGovern, B; Berlinguer Palmini, R; Grossman, N; Drakakis, E; Poher, V; Neil, M A A; Degenaar, P</p> <p>2010-12-01</p> <p>Here, we demonstrate the use of a micro light emitting diode (LED) array as a powerful tool for complex spatiotemporal control of photosensitized neurons. The array can generate arbitrary, 2-D, excitation patterns with millisecond and micrometer resolution. In particular, we describe an active matrix control address system to allow simultaneous control of 256 individual micro LEDs. We present the system optically integrated into a microscope environment and patch clamp electrophysiology. The results show that the emitters have sufficient radiance at the required wavelength to stimulate neurons expressing channelrhodopsin-2 (ChR2).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010004353','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010004353"><span>Boiling Heat Transfer Measurements on Highly Conductive Surfaces Using Microscale Heater and Temperature Arrays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, J.; Bae, S. W.; Whitten, M. W.; Mullen, J. D.; Quine, R. W.; Kalkur, T. S.</p> <p>1999-01-01</p> <p>Two systems have been developed to study boiling heat transfer on the microscale. The first system utilizes a 32 x 32 array of diodes to measure the local temperature fluctuations during boiling on a silicon wafer heated from below. The second system utilizes an array of 96 microscale heaters each maintained at constant surface temperature using electronic feedback loops. The power required to keep each heater at constant temperature is measured, enabling the local heat transfer coefficient to be determined. Both of these systems as well as some preliminary results are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999SPIE.3829..135A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999SPIE.3829..135A"><span>UV diode-pumped solid state laser for medical applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Apollonov, Victor V.; Konstantinov, K. V.; Sirotkin, A. A.</p> <p>1999-07-01</p> <p>A compact, solid-state, high-efficiency, and safe UV laser medical system with optical fiber output was created for treatment of destructive forms of pulmonary tuberculosis. A frequency-quadruped quasi-CW Nd:YVO4 laser system pumped by laser-diode array is investigated with various resonator configurations. A longitudinal end-pumping scheme was used in a compact acousto-optical Q-switched laser for producing stable pulses of UV radiation at the repetition frequency 10-20 kHz and the duration 7-10 ns with the fiber-guide output power exceeding 10 mW.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003OExpr..11.1149A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003OExpr..11.1149A"><span>Medium-power diode-pumped Nd:BaY2F8 laser</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Agnesi, Antonio; Guandalini, Annalisa; Lucca, Andrea; Sani, Elisa; Toncelli, Alessandra; Tonelli, Mauro; dell'Acqua, Stefano</p> <p>2003-05-01</p> <p>We report what is to our knowledge the first Nd:BaY2F8 (Nd:BaYF) laser pumped with a multiwatt fiber-coupled diode array tuned at approximately 804 nm. As much as 2.4 W were obtained with 6.2 W of absorbed pump power, showing efficient operation (51% slope efficiency), excellent beam quality (M2=1.1), and weak thermal lensing. Small intracavity losses (<1%) were measured, indicating both reduced thermally induced aberrations and good optical quality of the laser crystal.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930018563','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930018563"><span>Quasi-optical antenna-mixer-array design for terahertz frequencies</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Guo, Yong; Potter, Kent A.; Rutledge, David B.</p> <p>1992-01-01</p> <p>A new quasi-optical antenna-mixer-array design for terahertz frequencies is presented. In the design, antenna and mixer are combined into an entity, based on the technology in which millimeter-wave horn antenna arrays have been fabricated in silicon wafers. It consists of a set of forward- and backward-looking horns made with a set of silicon wafers. The front side is used to receive incoming signal, and the back side is used to feed local oscillator signal. Intermediate frequency is led out from the side of the array. Signal received by the horn array is picked up by antenna probes suspended on thin silicon-oxynitride membranes inside the horns. Mixer diodes will be located on the membranes inside the horns. Modeling of such an antenna-mixer-array design is done on a scaled model at microwave frequencies. The impedance matching, RF and LO isolation, and patterns of the array have been tested and analyzed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......189H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......189H"><span>III-V Ultra-Thin-Body InGaAs/InAs MOSFETs for Low Standby Power Logic Applications</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Cheng-Ying</p> <p></p> <p>As device scaling continues to sub-10-nm regime, III-V InGaAs/InAs metal- oxide-semiconductor ?eld-e?ect transistors (MOSFETs) are promising candidates for replacing Si-based MOSFETs for future very-large-scale integration (VLSI) logic applications. III-V InGaAs materials have low electron effective mass and high electron velocity, allowing higher on-state current at lower VDD and reducing the switching power consumption. However, III-V InGaAs materials have a narrower band gap and higher permittivity, leading to large band-to-band tunneling (BTBT) leakage or gate-induced drain leakage (GIDL) at the drain end of the channel, and large subthreshold leakage due to worse electrostatic integrity. To utilize III-V MOSFETs in future logic circuits, III-V MOSFETs must have high on-state performance over Si MOSFETs as well as very low leakage current and low standby power consumption. In this dissertation, we will report InGaAs/InAs ultra-thin-body MOSFETs. Three techniques for reducing the leakage currents in InGaAs/InAs MOSFETs are reported as described below. 1) Wide band-gap barriers: We developed AlAs0.44Sb0.56 barriers lattice-match to InP by molecular beam epitaxy (MBE), and studied the electron transport in In0.53Ga0.47As/AlAs 0.44Sb0.56 heterostructures. The InGaAs channel MOSFETs using AlAs0.44Sb0.56 bottom barriers or p-doped In0.52 Al0.48As barriers were demonstrated, showing significant suppression on the back barrier leakage. 2) Ultra-thin channels: We investigated the electron transport in InGaAs and InAs ultra-thin quantum wells and ultra-thin body MOSFETs (t ch ~ 2-4 nm). For high performance logic, InAs channels enable higher on-state current, while for low power logic, InGaAs channels allow lower BTBT leakage current. 3) Source/Drain engineering: We developed raised InGaAs and recessed InP source/drain spacers. The raised InGaAs source/drain spacers improve electrostatics, reducing subthreshold leakage, and smooth the electric field near drain, reducing BTBT leakage. With further replacement of raised InGaAs spacers by recessed, doping-graded InP spacers at high field regions, BTBT leakage can be reduced ~100:1. Using the above-mentioned techniques, record high performance InAs MOSFETs with a 2.7 nm InAs channel and a ZrO2 gate dielectric were demonstrated with Ion = 500 microA/microm at Ioff = 100 nA/microm and VDS =0.5 V, showing the highest on-state performance among all the III-V MOSFETs and comparable performance to 22 nm Si FinFETs. Record low leakage InGaAs MOSFETs with recessed InP source/drain spacers were also demonstrated with minimum I off = 60 pA/microm at 30 nm-Lg , and Ion = 150 microA/microm at I off = 1 nA/microm and VDS =0.5 V. This recessed InP source/drain spacer technique improves device scalability and enables III-V MOSFETs for low standby power logic applications. Furthermore, ultra-thin InAs channel MOSFETs were fabricated on Si substrates, exhibiting high yield and high transconductance gm ~2.0 mS/microm at 20 nm- Lg and VDS =0.5 V. With further scaling of gate lengths, a 12 nm-Lg III-V MOSFET has shown maximum Ion/Ioff ratio ~8.3x105 , confirming that III-V MOSFETs are scalable to sub-10-nm technology nodes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA486091','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA486091"><span>Implementing a Multiplexed System of Detectors for Higher Photon Counting Rates</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-01-01</p> <p>D1 D2 Fig. 3. (a) Setup for testing different arrangements of InGaAs SPAD assemblies; (b) three different InGaAs SPAD assemblies; ( c ) schematic of...presently available, either commercial or prototype, the deadtimes range from ≈50 ns for actively quenched single photon avalanche detectors ( SPADs ...to ≈10 µs for passively quenched SPADs , although even actively quenched SPADs sometimes employ µs deadtimes to avoid excessive afterpulsing rates. In</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA474922','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA474922"><span>Large Diameter, High Speed InGaAs Receivers for Free-Space Lasercom</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-01-01</p> <p>appropriate transimpedance amplifier and limiting amplifier . Development and testing of the APD receivers will be described below. 15. SUBJECT TERMS 16...available transimpedance amplifiers (TIA) from Maxim of Dallas. There have also been several devices built in house by NRL in 8-pin TO-39 headers...manufacture a large area, high speed InGaAs APD with an effective ionization ratio of < 0.2 and by matching the APD device with an appropriate transimpedance</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22303483-three-dimensional-whispering-gallery-modes-ingaas-nanoneedle-lasers-silicon','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22303483-three-dimensional-whispering-gallery-modes-ingaas-nanoneedle-lasers-silicon"><span>Three-dimensional whispering gallery modes in InGaAs nanoneedle lasers on silicon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Tran, T.-T. D.; Chen, R.; Ng, K. W.</p> <p>2014-09-15</p> <p>As-grown InGaAs nanoneedle lasers, synthesized at complementary metal–oxide–semiconductor compatible temperatures on polycrystalline and crystalline silicon substrates, were studied in photoluminescence experiments. Radiation patterns of three-dimensional whispering gallery modes were observed upon optically pumping the needles above the lasing threshold. Using the radiation patterns as well as finite-difference-time-domain simulations and polarization measurements, all modal numbers of the three-dimensional whispering gallery modes could be identified.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840012333','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840012333"><span>Material growth and characterization for solid state devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stefanakos, E. K.; Collis, W. J.; Abul-Fadl, A.; Iyer, S.</p> <p>1984-01-01</p> <p>During the reporting period, InGaAs was grown on Fe-doped (semi-insulating) (100) InP substrates by current controlled liquid phase epitaxy (CCLPE) at 640 C and current densities of 2.5A sq/cm to 5 A/sq cm for periods from 5 to 30 minutes. Special efforts were made to reduce the background carrier concentration in the grown layers as much as possible. The best layers exhibited carrier concentrations in the mid-10 to the 15th power/cu cm range and up to 10,900 sq cm/V-sec room temperature mobility. InGaAsP quaternary layers of energy gap corresponding to wavelengths of approximately 1.5 microns and 1.3 microns were grown on (100) InP substrates by CCLPE. In the device fabrication area, work was directed toward processing MISFET's using InGaAs. SiO2, Si3N4 and Al2O3 were deposited by ion beam sputtering, electron beam evaporation and chemical vapor reaction on Si, GaAs, and InGaAs substrates. SiO2 and Si3N4 sputtered layers were found to possess a high density of pinhole defects that precluded capacitance-voltage analysis. Chemical vapor deposited Al2O3 layers on Si, GaAs and InGaAs substrates also exhibited a large number of pinhole defects. This prevented achieving good MIS devices over most of the substrate surface area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Nanot..28K5201K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Nanot..28K5201K"><span>Charge carrier relaxation in InGaAs-GaAs quantum wire modulation-doped heterostructures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kondratenko, S. V.; Iliash, S. A.; Mazur, Yu I.; Kunets, V. P.; Benamara, M.; Salamo, G. J.</p> <p>2017-09-01</p> <p>The time dependencies of the carrier relaxation in modulation-doped InGaAs-GaAs low-dimensional structures with quantum wires have been studied as functions of temperature and light excitation levels. The photoconductivity (PC) relaxation follows a stretched exponent with decay constant, which depends on the morphology of InGaAs epitaxial layers, presence of deep traps, and energy disorder due to inhomogeneous distribution of size and composition. A hopping model, where electron tunnels between bands of localized states, gives appropriate interpretation for temperature-independent PC decay across the temperature range 150-290 K. At low temperatures (T < 150 K), multiple trapping-retrapping via 1D states of InGaAs quantum wires (QWRs), sub-bands of two-dimensional electron gas of modulation-doped n-GaAs spacers, as well as defect states in the GaAs environment are the dominant relaxation mechanism. The PC and photoluminescence transients for samples with different morphologies of the InGaAs nanostructures are compared. The relaxation rates are found to be largely dependent on energy disorder due to inhomogeneous distribution of strain, nanostructure size and composition, and piezoelectric fields in and around nanostructures, which have a strong impact on efficiency of carrier exchange between bands of the InGaAs QWRs, GaAs spacers, or wetting layers; presence of local electric fields; and deep traps.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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