A5069054262- Semiconductor Lasers and Optical Devices
- Semiconductor Quantum Structures and Devices
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Advanced Semiconductor Detectors and Materials
- solar cell performance optimization
- Astro and Planetary Science
- Solid State Laser Technologies
- Semiconductor materials and devices
- Laser Design and Applications
- Silicon and Solar Cell Technologies
- Atmospheric Ozone and Climate
- Chalcogenide Semiconductor Thin Films
- Astronomical Observations and Instrumentation
- Social Work Education and Practice
- Advanced Fiber Laser Technologies
- Astrophysics and Cosmic Phenomena
- GaN-based semiconductor devices and materials
- Thermal Radiation and Cooling Technologies
- Planetary Science and Exploration
- Distributed and Parallel Computing Systems
- Astrophysical Phenomena and Observations
- Semiconductor materials and interfaces
- Stellar, planetary, and galactic studies
- Scientific Computing and Data Management
MIT Lincoln Laboratory
2010-2024
Massachusetts Institute of Technology
2008-2024
Western Sydney University
2018-2024
Goddard Space Flight Center
2023
Indiana University Bloomington
1998-2020
Auburn University
2020
University of Hohenheim
1982-2019
NuVasive (United States)
2018
Turner Consulting Group (United States)
2017
University of Kansas
2016
The outputs from an 11-element, linear diode laser array with broad stripes have been beam combined into a single quality of ∼20× diffraction limited in the plane junction. This combining was achieved by use common external cavity containing grating, which simultaneously forces each element to operate at different, but controlled, wavelength and beams all elements overlap propagate same direction. power 50% output bare array.
Jetstream will be the first production cloud resource supporting general science and engineering research within XD ecosystem. In this report we describe motivation for proposing Jetstream, configuration of system as funded by NSF, team that is implementing communities expect to use new system. Our hope plan which become available in 2016, aid thousands researchers who need modest amounts computing power interactively. The implementation should increase size disciplinary diversity US...
Abstract The James Webb Space Telescope (JWST) is NASA’s flagship mission successor to the highly successful Hubble Telescope. It an infrared observatory featuring a cryogenic 6.6 m aperture, deployable Optical Element (OTE) with payload of four science instruments (SIs) assembled into Integrated Science Instrument Module (ISIM) that provide imagery and spectroscopy in near-infrared band between 0.6 5 μ mid-infrared 28.1 m. JWST was successfully launched on 2021 December 25 aboard Ariane...
In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Ga xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> As xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> Sb xmlns:xlink="http://www.w3.org/1999/xlink">1-y</sub> thermophotovoltaic (TPV) diodes were grown lattice matched to GaSb substrates by metal-organic vapor phase epitaxy in the bandgap range of EG = 0.5 0.6 eV. InGaAsSb TPV diodes, utilizing front-surface spectral control...
Strained single-quantum-well, broadened-waveguide GaInAsSb/AlGaAsSb diode lasers have exhibited room-temperature threshold current densities as low 50 A/cm2, one of the lowest values reported for at room temperature. These lasers, grown by molecular beam epitaxy, emission wavelengths ∼2.05 μm, characteristic temperature 65 K, internal quantum efficiency 95%, and loss coefficient 7 cm−1. Single-ended cw power 1 W is obtained a 100-μm aperture.
An ArF excimer laser has been used to form p-n junctions in Si. The produces dopant molecules by gas-phase photolysis of an organometallic molecule and simultaneously heats the substrate allow incorporation dopant. Solar cells having conversion efficiencies 9.6% at AM1 without use antireflection coatings have fabricated from these junctions.
The purpose of this qualitative case study research was to explore how adults with mild intellectual disabilities (ID) live out their social-sexual lives. Findings revealed the importance both physical and emotional pleasure five ID. Research educational efforts population have focused largely on reproduction abuse prevention, emphasizing safety over possibilities human connectedness. Data sources included observations a series interviews. in areas – sensuality, intimacy, sexual experience,...
Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-95 are presented. The broad-band fluxes (B, V, R, and I), the spectrophotometric continuum flux F(5177) integrated emission-line Ha, Hb, Hg, HeI, HeII all show nearly monotonic increase with episodes milder short-term variations superposed. amplitude increases decreasing wavelength (4400-9000 A). follow ultraviolet X-ray time delays, measured from centroids cross- correlation functions, typically around 5 days, but...
Multiple quantum-well diode lasers incorporating compressively strained InAs0.935Sb0.065 wells and tensile-strained In0.15Al0.85As0.9Sb0.1 barriers are reported. These lasers, grown on InAs substrates by molecular beam epitaxy, have emission wavelengths between 3.2 3.55 μm. Broad-stripe exhibited pulsed threshold current density as low 30 A/cm2 at 80 K the characteristic temperatures 40 K. The maximum operating temperature is 225 Ridge-waveguide cw of 12 mA 100 K, 175
We demonstrate 35 W output peak power with M2 approximately 1.35 in both dimensions from a 100 element, microm pitch slab-coupled optical waveguide laser diode array using wavelength beam combining.
Solar cells with conversion efficiencies of 12% (AM1) have been fabricated from single-crystal GaAs epilayers grown by CVD on Ge-coated Si substrates. The utilize an n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> /p/p shallow-homo junction structure a thin (<0.2 µm) epitaxial Ge layer. These solar are the first reported devices
We have demonstrated active coherent beam combination (CBC) of up to 218 semiconductor amplifiers with 38.5 W cw output using eleven one-dimensional 21-element individually addressable diode amplifier arrays operating at 960 nm. The array elements are slab-coupled-optical-waveguide (SCOWAs) set in a master-oscillator–power-amplifier configuration. Diffractive optical divide the master-oscillator seed multiple SCOWAs. A SCOWA was phase actuated by adjusting drive current each element and...
The methodology for a heterodyned laser-induced transient thermal grating technique non-contact, non-destructive measurements of transport in opaque material is presented. Phase-controlled heterodyne detection allows us to isolate pure phase or amplitude signal contributions by varying the relative between reference and probe beams. includes components associated with both reflectivity surface displacement whereas contribution governed alone. By analyzing latter two-dimensional diffusion...
High-power diode lasers emitting at /spl sim/1.9 μm have been fabricated from a quantum-well heterostructure having an active region consisting of five GaInAsSb wells and six AlGaAsSb barriers. For devices 300 wide 1000 long, single-ended output power as high 1.3 W cw has obtained with initial differential quantum efficiency 47%. The pulsed threshold current density is low 143 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for...
We call attention to a small group of cataclysmic variable stars (whose prototype might be considered RZ LMi) that have complex light curves fo similar shape which repeat with typical periods few weeks. The predictability the time each superoutburst and stability curve is unexpectedly high for variables, are well-known erratic variations in both timing their outbursts. phenomenon appears closely related SU Ursae Majoris-type superoutbursts, especially since superhumps appear these stars....
We report the wavelength beam combining of an array high-power high-brightness 970-nm slab-coupled optical waveguide lasers. A 50-W peak power under quasi-continuous-wave (CW) operation was measured in output with a quality M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x,y</sub> <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> =1.2, and 30 W CW xmlns:xlink="http://www.w3.org/1999/xlink">x,y </sub> =2
We describe how cross-sectional scanning tunneling microscopy (STM) may be used to image the interfacial bonding across nearly lattice-matched, non-common-atom GaSb/InAs heterojunction with atomic-scale precision. The method, which takes advantage of length difference between and bulk bonds, appears equally applicable AlSb/InAs suggests one might recover complete structure either from atomic-resolution STM data.
Historically, 3C 66A has been considered a relative quiescent blazar. For that reason, was selected as comparison source for OJ 287 in the OJ-94 project. However, after more detailed observation it turns out variability of itself is very interesting. We have analyzed entire project data set from fall 1993 to spring 1998 by using structure function analysis, Deeming periodograms, Scargle and folded light curves. Here we present first preliminary evidence 65 day period observed during bright...
Strained quantum-well diode lasers emitting at 3.9 μm have been fabricated. The laser structure, grown on a GaSb substrate by molecular beam epitaxy, consists of compressively strained InAsSb active layers and tensile-strained InAlAsSb barrier layers, surrounded AlAsSb cladding layers. Broad-stripe exhibited pulsed operation up to 165 K, with threshold current density 78 A/cm2 80 K. characteristic temperature is 30 K 120 devices operated cw 123 the maximum power mW/facet. Ridge-waveguide 128 35 mA.
Double-heterostructure diode lasers emitting at 3 μm have exhibited pulsed operation temperatures up to 255 K and cw 170 K, with output power of 45 mW/facet 100 K. The laser structure, grown on GaSb substrates by molecular beam epitaxy, has a metastable GaInAsSb active layer AlGaAsSb cladding layers. lowest threshold current density is 9 A/cm2 obtained 40 characteristic temperature 35 low 28 above 120