Page 11 of 30:  Prev << 1 2 3 4 5 6 7 8 9 10 11  12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  >> Next  (738 Items)

16.  High power, continuous wave, room temperature operation of λ ~ 3.4 μm and λ ~ 3.55 μm InP-based quantum cascade lasers
N. Bandyopadhyay, S. Slivken, Y. Bai and M. Razeghi
Applied Physics Letters, Vol. 100, No. 21, p. 212104-1-- May 21, 2012 ...[Visit Journal]
We report two highly strain-balanced InP-based AlInAs/GaInAs quantum cascade lasers emitting near 3.39 and 3.56 . A pulsed threshold current density of only 1.1 kA/cm² has been achieved at room temperature for both lasers with characteristic temperatures (T0) of 166  K and 152  K, respectively. The slope efficiency is also relatively temperature insensitive with characteristic temperatures (T1) of 116 K and 191  K, respectively. Continuous wave powers of 504 mW and 576 mW are obtained at room temperature, respectively. This was accomplished without buried ridge processing. [reprint (PDF)]
 
16.  Quantum Dot Infrared Photodetectors: Comparison Experiment and Theory
H. Lim, W. Zhang, S. Tsao, T. Sills, J. Szafraniec, K. Mi, B. Movaghar, and M. Razeghi
Virtual Journal of Nanoscale Science and Technology 12 (9)-- August 29, 2005 ...[Visit Journal][reprint (PDF)]
 
16.  Electrical Characterization of AlxGa1-xN for UV Photodetector Applications
A. Saxler, M. Ahoujja, W.C. Mitchel, P. Kung, D. Walker, and M. Razeghi
SPIE Conference, San Jose, CA, -- January 27, 1999 ...[Visit Journal]
Ultraviolet photodetectors have many military and commercial applications. However, for many of these applications, the photodetectors must be solar blind. This means that the photodetectors must have a cutoff wavelength of less than about 270 nm. Semiconductor based devices would then need energy gaps of over 4.6 eV. In the AlxGa1-xN system, the aluminum mole fraction, x, required is over 40%. As the energy gap is increased, doping becomes much more difficult, especially p-type doping. This report is a study of the electrical properties of AlxGa1-xN to enable better control of the doping. Magnesium doped p-type AlxGa1-xN has been studied using high-temperature Hall effect measurements. The acceptor ionization energy has been found to increase substantially with the aluminum content. Short-period superlattices consisting of alternating layers of GaN:Mg and AlGaN:Mg were also grown by low-pressure organometallic vapor phase epitaxy. The electrical properties of these superlattices were measured as a function of temperature and compared to conventional AlGaN:Mg layers. It is shown that the optical absorption edge can be shifted to shorter wavelengths while lowering the acceptor ionization energy by using short- period superlattice structures instead of bulk-like AlGaN:Mg. Silicon doped n-type films have also been studied. [reprint (PDF)]
 
16.  Comparison of ZnO nanostructures grown using pulsed laser deposition, metal organic chemical vapor deposition, and physical vapor transport
V.E. Sandana, D.J. Rogers, F. Hosseini Teherani, R. McClintock, C. Bayram, M. Razeghi, H-J Drouhin, M.C. Clochard, V. Sallett, G. Garry, and F. Falyouni
Journal of Vacuum Science and Technology B, Vol. 27, No. 3, May/June, p. 1678-1683-- May 29, 2009 ...[Visit Journal]
This article compares the forms and properties of ZnO nanostructures grown on Si (111) and c-plane sapphire (c-Al2O3) substrates using three different growth processes: metal organic chemical vapor deposition (MOCVD), pulsed laser deposition (PLD), and physical vapor transport (PVT). A very wide range of ZnO nanostructures was observed, including nanorods, nanoneedles, nanocombs, and some novel structures resembelling “bevelled” nanowires. PVT gave the widest family of nanostructures. PLD gave dense regular arrays of nanorods with a preferred orientation perpendicular to the substrate plane on both Si and c-Al2O3 substrates, without the use of a catalyst. X-ray diffraction (XRD) studies confirmed that nanostructures grown by PLD were better crystallized and more highly oriented than those grown by PVT and MOCVD. Samples grown on Si showed relatively poor XRD response but lower wavelength emission and narrower linewidths in PL studies. [reprint (PDF)]
 
16.  Room temperature continuous wave operation of quantum cascade lasers with watt-level optical power
Y. Bai, S.R. Darvish, S. Slivken, W. Zhang, A. Evans, J. Nguyen and M. Razeghi
Applied Physics Letters, Vol. 92, No. 10, p. 101105-1-- March 10, 2008 ...[Visit Journal]
We demonstrate quantum cascade lasers at an emitting wavelength of 4.6 µm, which are capable of room temperature, high power continuous wave (cw) operation. Buried ridge geometry with a width of 9.8 µm was utilized. A device with a 3 mm cavity length that was epilayer-down bonded on a diamond submount exhibited a maximum output power of 1.3 W at room temperature in cw operation. The maximum output power at 80 K was measured to be 4 W, with a wall plug efficiency of 27%. [reprint (PDF)]
 
16.  Quantum Dot Intersubband Photodetectors
C. Jelen, M. Erdtmann, S. Kim, and M. Razeghi
SPIE Conference, San Jose, CA, -- January 22, 2001 ...[Visit Journal]
Quantum dots are recognized as very promising candidates for the fabrication of intersubband photodetectors in the infrared spectral range. At present, material quality is making rapid progress and some devices have been demonstrated. Examples of mid-infrared quantum dot intersubband photodetectors are presented along with device design and data analysis. Nonetheless, the performance of these devices remains less than comparable quantum well intersubband photodetectors due to difficulties in controlling the quantum dot size and distribution during epitaxy. [reprint (PDF)]
 
16.  High-power, room-temperature and continuous-wave operation of distributed-feedback quantum-cascade lasers at λ = 4.8 µm
J.S. Yu, S. Slivken, S.R. Darvish, A. Evans, B. Gokden and M. Razeghi
Applied Physics Letters, 87 (4)-- July 25, 2005 ...[Visit Journal]
The authors present high-power continuous-wave (cw) operation of distributed-feedback quantum-cascade lasers. Continuous-wave output powers of 56 mW at 25 °C and 15 mW at 40 °C are obtained. Single-mode emission near 7.8 µm with a side-mode suppression ratio of >=30 dB and a tuning range of 2.83 cm−1 was obtained between 15 and 40 °C. The device exhibits no beam steering with a full width at half maximum of 27.4° at 25 °C in cw mode. [reprint (PDF)]
 
15.  High Power, Room Temperature, Continuous-Wave Operation of Quantum Cascade Lasers Grown by GasMBE
A. Evans, J. David, L. Doris, J.S. Yu, S. Slivken and M. Razeghi
SPIE Conference, Jose, CA, Vol. 5359, pp. 188-- January 25, 2004 ...[Visit Journal]
Very high power continuous-wave quantum cascade lasers are demonstrated in the mid-infrared (3 - 6 µm) wavelength range. λ~6 µm high-reflectivity coated QCLs are demonstrated producing over 370 mW continuous-wave power at room temperature with continuous-wave operation up to 333 K. Advanced heterostructure geometries, including the use of a thick electroplated gold, epilayer-side heat sink and a buried-ridge heterostructure are demonstrated to improve laser performance significantly when combined with narrow laser ridges. Recent significant improvements in CW operation are presented and include the development if narrow (9 µm-wide) ridges for high temperature CW operation. GasMBE growth of the strain-balanced λ~6 µm QCL heterostructure is discussed. X-ray diffraction measurements are presented and compared to computer simulations that indicate excellent layer and compositional uniformity of the structure. [reprint (PDF)]
 
15.  High Quality Type-II InAs/GaSb Superlattices with Cutoff Wavelength ~3.7 µm Using Interface Engineering
Y. Wei, J. Bae, A. Gin, A. Hood, M. Razeghi, G.J. Brown, and M. Tidrow
Journal of Applied Physics, 94 (7)-- October 1, 2003 ...[Visit Journal]
We report the most recent advance in the area of Type-II InAs/GaSb superlattices that have cutoff wavelength of ~3.7 µm. With GaxIn1–x type interface engineering techniques, the mismatch between the superlattices and the GaSb (001) substrate has been reduced to <0.1%. There is no evidence of dislocations using the best examination tools of x-ray, atomic force microscopy, and transmission electron microscopy. The full width half maximum of the photoluminescence peak at 11 K was ~4.5 meV using an Ar+ ion laser (514 nm) at fluent power of 140 mW. The integrated photoluminescence intensity was linearly dependent on the fluent laser power from 2.2 to 140 mW at 11 K. The temperature-dependent photoluminescence measurement revealed a characteristic temperature of one T1 = 245 K at sample temperatures below 160 K with fluent power of 70 mW, and T1 = 203 K for sample temperatures above 180 K with fluent power of 70 and 420 mW. [reprint (PDF)]
 
15.  Demonstration of type-II superlattice MWIR minority carrier unipolar imager for high operation temperature application
Guanxi Chen, Abbas Haddadi, Anh-Minh Hoang, Romain Chevallier, and Manijeh Razeghi
Optics Letters Vol. 40, Iss. 1, pp. 29–32-- December 18, 2014 ...[Visit Journal]
An InAs/GaSb type-II superlattice-based mid-wavelength infrared (MWIR) 320×256 unipolar focal plane array (FPA) using pMp architecture exhibited excellent infrared image from 81 to 150 K and ∼98% operability, which illustrated the possibility for high operation temperature application. At 150 K and −50  mV operation bias, the 27 μm pixels exhibited dark current density to be 1.2×10−5  A/cm², with 50% cutoff wavelength of 4.9 μm, quantum efficiency of 67% at peak responsivity (4.6 μm), and specific detectivity of 1.2×1012 Jones. At 90 K and below, the 27 μm pixels exhibited system limited dark current density, which is below 1×10−9  A/cm², and specific detectivity of 1.5×1014 Jones. From 81 to 100 K, the FPA showed ∼11  mK NEDT by using F/2.3 optics and a 9.69 ms integration time. [reprint (PDF)]
 
15.  Development of Quantum Cascade Lasers for High Peak Output Power and Low Threshold Current Density
S. Slivken and M. Razeghi
Solid State Electronics 46-- January 1, 2002 ...[Visit Journal]
Design and material optimization are used to both decrease the threshold current density and increase the output power for quantum cascade lasers. Waveguides are designed to try and minimize free-carrier and surface-plasmon absorption. Excellent material characterization is also presented, showing excellent control over layer thickness, interface quality, and doping level. Experiments are done to both optimize the injector doping level and to maximize the output power from a single aperture. At 300 K, a threshold current density as low as 1.8 kA/cm² is reported, along with peak powers of approximately 2.5 W. Strain-balanced lasers are also demonstrated at λnot, vert, similar5 μm, exhibiting threshold current densities<300 A/cm² at 80 K. These values represent the state-of-the-art for mid-infrared lasers with λ>4 μm [reprint (PDF)]
 
15.  Room temperature neagtive differential resistance characteristics of polar III-nitride resonant tunneling diodes
C. Bayram, Z. Vashaei, and M. Razeghi
Applied Physics Letters, Vol. 97, No. 9, p. 092104-1-- August 30, 2010 ...[Visit Journal]
III-nitride resonant tunneling diodes (RTDs), consisting Al0.2Ga0.8N/GaN double-barrier (DB) active layers, were grown on c-plane lateral epitaxial overgrowth (LEO) GaN/sapphire and c-plane freestanding (FS) GaN. RTDs on both templates, fabricated into mesa diameters ranging from 5 to 35 μm, showed negative differential resistance (NDR) at room temperature. NDR characteristics (voltage and current density at NDR onset and current-peak-to-valley ratio) were analyzed and reported as a function of device size and substrate choice. Our results show that LEO RTDs perform as well as FS ones and DB active layer design and quality have been the bottlenecks in III-nitride RTDs. [reprint (PDF)]
 
15.  Solar-Blind Deep UV Avalanche Photodetectors Using Reduced Area Epitaxy
Lakshay Gautam , Junhee Lee, Michael Richards, and Manijeh Razeghi ,
Lakshay Gautam, Manijeh Razeghi, IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 59, NO. 6, 10.1109/JQE.2023.3325254 ...[Visit Journal]
We report high gain avalanche photodetectors operating in the deep UV wavelength regime. The high gain was leveraged through reduced area epitaxy by patterning AlN on Sapphire substrate. This helps in a substantial reduction of crack formation due to overgrowth on individually isolated AlN mesas. Reproducible gain on the order of 105 was reported for multiple diodes in different areas of 320 × 256 focal plane array. [reprint (PDF)]
 
15.  High performance Zn-diffused planar mid-wavelength infrared type-II InAs/InAs1-xSbx superlattice photodetector by MOCVD
Donghai Wu, Arash Dehzangi, Jiakai Li, and Manijeh Razeghi
Appl. Phys. Lett. 116, 161108-- April 21, 2020 ...[Visit Journal]
We report a Zn-diffused planar mid-wavelength infrared photodetector based on type-II InAs/InAs1-xSbx superlattices. Both the superlattice growth and Zn diffusion were performed in a metal-organic chemical vapor deposition system. At 77K, the photodetector exhibits a peak responsivity of 0.70A/W at 3.65λ, corresponding to a quantum efficiency of 24% at zero bias without anti-reflection coating, with a 50% cutoff wavelength of 4.28λ. With an R0A value of 3.2x105 Ω·cm2 and a dark current density of 9.6x10-8 A/cm² bias of -20mV at 77K, the photodetector exhibits a specific detectivity of 2.9x1012cm·Hz½/W. At 150K, the photodetector exhibits a dark current density of 9.1x10-6 A/cm² and a quantum efficiency of 25%, resulting in a detectivity of 3.4x1011cm·Hz/W. [reprint (PDF)]
 
15.  Mid-wavelength infrared high operating temperature pBn photodetectors based on type-II InAs/InAsSb superlattice
Donghai Wu, Jiakai Li, Arash Dehzangi, and Manijeh Razeghi
AIP Advances 10, 025018-- February 11, 2020 ...[Visit Journal]
A high operating temperature mid-wavelength infrared pBn photodetector based on the type-II InAs/InAsSb superlattice on a GaSb substrate has been demonstrated. At 150 K, the photodetector exhibits a peak responsivity of 1.48 A/W, corresponding to a quantum efficiency of 47% at −50 mV applied bias under front-side illumination, with a 50% cutoff wavelength of 4.4 μm. With an R×A of 12,783 Ω·cm² and a dark current density of 1.16×10−5A/cm² under −50 mV applied bias, the photodetector exhibits a specific detectivity of 7.1×1011 cm·Hz½/W. At 300 K, the photodetector exhibits a dark current density of 0.44 A/cm²and a quantum efficiency of 39%, resultingin a specific detectivity of 2.5×109 cm·Hz½/W. [reprint (PDF)]
 
15.  High-responsivity GaInAs/InP Quantum Well Infrared Photodetectors Grown by Low-Pressure Metalorganic Chemical Vapor Deposition
M. Erdtmann, A. Matlis, C. Jelen, M. Razeghi, and G. Brown
SPIE Conference, San Jose, CA, -- January 26, 2000 ...[Visit Journal]
We have studied the dependence of the well doping density in n-type GaInAs/InP quantum well IR photodetectors (QWIPs) grown by low-pressure metalorganic chemical vapor deposition. Three identical GaInAs/InP QWIP structures were grown with well sheet carrier densities of 1x1011 cm-2, 3x1011 cm-2, and 10x1011 cm-2; all three samples had very sharp spectral response at λ equals 9.0 μm. We find that there is a large sensitivity of responsivity, dark current, noise current, and detectivity with the well doping density. Measurements revealed that the lowest-doped samples had an extremely low responsivity relative to the doping concentration while the highest-doped sample had an excessively high dark current relative to doping. The middle-doped sample yielded the optimal results. This QWIP had a responsivity of 33.2 A/W and operated with a detectivity of 3.5x1010 cm·Hz½·W-1 at a bias of 0.75 V and temperature of 80 K. This responsivity is the highest value reported for any QWIP in the (lambda) equals 8-9 &mus;m range. Analysis is also presented explaining the dependence of the measured QWIP parameters to well doping density. [reprint (PDF)]
 
15.  Bias–selectable nBn dual–band long–/very long–wavelength infrared photodetectors based on InAs/InAsSb/AlAsSb type–II superlattices
Abbas Haddadi, Arash Dehzangi, Romain Chevallier, Sourav Adhikary, & Manijeh Razeghi
Nature Scientific Reports 7, Article number: 3379-- June 13, 2017 ...[Visit Journal]
Type–II superlattices (T2SLs) are a class of artificial semiconductors that have demonstrated themselves as a viable candidate to compete with the state–of–the–art mercury–cadmium–telluride material system in the field of infrared detection and imaging. Within type–II superlattices, InAs/InAs1−xSbx T2SLs have been shown to have a significantly longer minority carrier lifetime. However, demonstration of high–performance dual–band photodetectors based on InAs/InAs1−xSbx T2SLs in the long and very long wavelength infrared (LWIR & VLWIR) regimes remains challenging. We report the demonstration of high–performance bias–selectable dual–band long–wavelength infrared photodetectors based on new InAs/InAsSb/AlAsSb type–II superlattice design. Our design uses two different bandgap absorption regions separated by an electron barrier that blocks the transport of majority carriers to reduce the dark current density of the device. As the applied bias is varied, the device exhibits well–defined cut–off wavelengths of either ∼8.7 or ∼12.5 μm at 77 K. This bias–selectable dual–band photodetector is compact, with no moving parts, and will open new opportunities for multi–spectral LWIR and VLWIR imaging and detection. [reprint (PDF)]
 
15.  Defects in Organometallic Vapor-Phase Epitaxy-Grown GaInP Layers
Feng S.L., Bourgoin J.C., Omnes F., and Razeghi M.
Applied Physics Letters 59 (8), p. 941-- May 28, 1991 ...[Visit Journal]
Non-intentionally doped metalorganic vapor‐phase epitaxy Ga1−x InxP layers, having an alloy composition (x = 0.49) corresponding to a lattice matched to GaAs, grown by metalorganic chemical vapor deposition, have been studied by capacitance‐voltage and deep-level transient spectroscopy techniques. They are found to exhibit a free‐carrier concentration at room temperature of the order of 1015 cm−3. Two electron traps have been detected. The first one, at 75 meV below the conduction band, is in small concentration (∼1013 cm−3) while the other, at about 0.9 eV and emitting electrons above room temperature, has a concentration in the range 1014–1015 cm−3. [reprint (PDF)]
 
15.  High Quality Aluminum Nitride Epitaxial Layers Grown on Sapphire Substrates
A. Saxler, P. Kung, C.J. Sun, E. Bigan and M. Razeghi
Applied Physics Letters 64 (3)-- January 17, 1994 ...[Visit Journal]
In this letter we report the growth of high quality AlN epitaxial layers on sapphire substrates. The AlN grown on (00·1) sapphire exhibited a better crystalline quality than that grown on (01·2) sapphire. An x-ray rocking curve of AlN on (00·1) Al2O3 yielded a full width at half-maximum of 97.2 arcsec, which is the narrowest value reported to our knowledge. The AlN peak on (01·2) Al2O3 was about 30 times wider. The absorption edge measured by ultraviolet transmission spectroscopy for AlN grown on (00·1) Al2O3 was about 197 nm. [reprint (PDF)]
 
15.  The Molecular Beam Epitaxial Growth of InSb on (111) GaAs
E. Michel, J. Kim, J. Xu, S. Javadpour, I. Ferguson, and M. Razeghi
Applied Physics Letters 69 (2)-- July 8, 1996 ...[Visit Journal]
The molecular beam epitaxial growth of InSb on (111)B GaAs has been investigated. It was found that for a given Sb/In ratio, a higher growth temperature was required for the growth of InSb on (111)B GaAs compared to that on (001) GaAs. This difference has been attributed to the bonding characteristics of the (111)B and (001) surface. Once growth had been optimized, it was found that the material characteristics of (111)B InSb were almost identical to that of (001) InSb, i.e., independent of orientation. For example, the x-ray full width at half-maximum and 300 K mobility had the same absolute values for (111) InSb and (001)InSb and followed the same dependence with the sample thickness. Te was found to be a well-behaved n-type dopant for (111)B InSb. [reprint (PDF)]
 
15.  Transport properties in n-type InSb films grown by metalorganic chemical vapor deposition
S.N. Song, J.B. Ketterson, Y.H. Choi, R. Sudharsanan, and M. Razeghi
Applied Physics Letters 63 (7)-- August 16, 1993 ...[Visit Journal]
We have measured the temperature and magnetic field dependence of the Hall mobility and transverse magnetoresistance in n-type InSb films epitaxially grown on GaAs substrates by metalorganic chemical vapor deposition. The films show a giant magnetoresistance: e.g., at 240 K the resistivity increases over 20 times at a magnetic field of 5 T; the low field coefficient of resistivity at 77 K is as high as 47.5 μ·Ω· cm/G. The Hall mobility decreases with magnetic field and saturates at higher fields. By taking the interface carrier transport into account, the observed field dependence of the Hall mobility and magnetoresistance may be understood based on a two-layer model. [reprint (PDF)]
 
15.  Optical Investigations of GaAs-GaInP Quantum Wells Grown on the GaAs, InP, and Si Substrates
H. Xiaoguang, M. Razeghi
Applied Physics Letters 61 (14)-- October 5, 1992 ...[Visit Journal]
We report the first photoluminescence investigation of GaAs‐Ga0.51In0.49P lattice matched multiquantum wells grown by the low pressure metalorganic chemical vapor deposition simultaneously in the same run on GaAs, Si, and InP substrates. The sharp photoluminescence peaks indicate the high quality of the samples on three different substrates. The temperature dependence of the photoluminescence indicates that the intrinsic excitonic transitions dominate at low temperature and free‐carrier recombinations at room temperature. The photoluminescence peaks of the samples grown on Si and InP substrates shift about 15 meV from the corresponding peaks of the sample grown on the GaAs substrate. Two possible interpretations are provided for the observed energy shift. One is the diffusion of In along the dislocation threads from GaInP to GaAs and another is the localized strain induced by defects and In segregations. [reprint (PDF)]
 
15.  Thermal characteristics and analysis of quantum cascade lasers for biochemical sensing applications
J.S. Yu, H.K. Lee, S. Slivken, and M. Razeghi
SPIE Proceedings, Biosensing II, San Diego, CA (August 2-6, 2009), Vol. 7397, p. 739705-1-- August 2, 2009 ...[Visit Journal]
We studied the thermal characteristics and analysis of InGaAs/InAlAs quantum cascade lasers (QCLs) in terms of internal temperature distribution, heat flux, and thermal conductance from the heat transfer simulation. The heat source densities were obtained from threshold power densities measured experimentally for QCLs under room-temperature continuous-wave operation. The use of a thick electroplated Au around the laser ridges helps increase the heat removal from devices. The two-dimensional anisotropic heat dissipation model was used to analyze the thermal behaviors inside the device. The simulation results were also compared with those estimated from experimental data. [reprint (PDF)]
 
15.  Pulsed metalorganic chemical vapor deposition of high quality AlN/GaN superlattices for intersubband transitions
C. Bayram, B. Fain, N. Pere-Laperne, R. McClintock and M. Razeghi
SPIE Proceedings, San Jose, CA Volume 7222-12-- January 26, 2009 ...[Visit Journal]
A pulsed metalorganic chemical vapor deposition (MOCVD) technique, specifically designed for high quality AlN/GaN superlattices (SLs) is introduced. Optical quality and precise controllability over layer thicknesses are investigated. Indium is shown to improve interface and surface quality. An AlN/GaN SL designed for intersubband transition at a telecommunication wavelength of ~1.5 µm, is grown, and processed for intersubband (ISB) absorption measurements. Room temperature measurements show intersubband absorption centered at 1.49 µm. Minimal (n-type) silicon doping of the well is shown to be crucial for good ISB absorption characteristics. The potential to extend this technology into the far infrared and even the terahertz (THz) region is also discussed. [reprint (PDF)]
 
15.  Low-Threshold 7.3 μm Quantum Cascade Lasers Grown by Gas-Source Molecular Beam Epitaxy
S. Slivken, A. Matlis, A. Rybaltowski, Z. Wu and M. Razeghi
Applied Physics Letters 74 (19)-- May 19, 1999 ...[Visit Journal]
We report low-threshold 7.3 μm superlattice-based quantum cascade lasers. The threshold current density is 3.4 kA/cm² at 300 K and 1.25 kA/cm² at 79 K in pulsed mode for narrow (∼20 μm), 2 mm-long laser diodes. The characteristic temperature (T0) is 210 K. The slope efficiencies are 153 and 650 mW/A at 300 and 100 K, respectively. Power output is in excess of 100 mW at 300 K. Laser far-field intensity measurements give divergence angles of 64° and 29° in the growth direction and in the plane of the quantum wells, respectively. Far-field simulations show excellent agreement with the measured results. [reprint (PDF)]
 

Page 11 of 30:  Prev << 1 2 3 4 5 6 7 8 9 10 11  12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30  >> Next  (738 Items)