Center for Quantum Devices - Most Downloaded Journal Articles

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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.	Reliability in room-temperature negative differential resistance characteristics of low-aluminum contact AlGaN/GaN double-barrier resonant tunneling diodes C. Bayram, Z. Vashaei, and M. Razeghi Applied Physics Letters, Vol. 97, No. 18, p. 181109-1-- November 1, 2010 ...[Visit Journal] AlGaN/GaN resonant tunneling diodes (RTDs), consisting of 20% (10%) aluminum-content in double-barrier (DB) active layer, were grown by metal-organic chemical vapor deposition on freestanding polar (c-plane) and nonpolar (m-plane) GaN substrates. RTDs were fabricated into 35-μm-diameter devices for electrical characterization. Lower aluminum content in the DB active layer and minimization of dislocations and polarization fields increased the reliability and reproducibility of room-temperature negative differential resistance (NDR). Polar RTDs showed decaying NDR behavior, whereas nonpolar ones did not significantly. Averaging over 50 measurements, nonpolar RTDs demonstrated a NDR of 67 Ω, a current-peak-to-valley ratio of 1.08, and an average oscillator output power of 0.52 mW. [reprint (PDF)]
15.	Use of Sacrificial Zinc Oxide Template Layers for Epitaxial Lift-Off of Yttria-Stabilised Zirconia Thin Films D. J. Rogers, T. Maroutian, V. E. Sandana, P. Lecoeur, F. H. Teherani, P. Bove and M. Razeghi Proc. of SPIE 11687, 116872C (2021) ...[Visit Journal] 275 nm-thick Yttria-stabilised zirconia (YSZ) layers were grown on 240 nm-thick epitaxial (0002)-oriented ZnO buffer layers on c-sapphire substrates by pulsed laser deposition (PLD). X-ray diffraction (XRD) studies revealed high quality epitaxial growth with the YSZ having a preferential (111) orientation and a root mean square surface roughness of 1.4 nm over an area of 10 um x 10 um. The YSZ top surface was then temporary bonded to an Apiezon W wax carrier and the sample was immersed in 0.1M HCl so as to preferentially etch/dissolve away the ZnO underlayer and release of the YSZ from the sapphire substrate. XRD revealed only the characteristic (111) peak of YSZ after lift-off and thus confirmed both the dissolution of the ZnO and the preservation of the crystallographic integrity of the YSZ on the wax carrier. Optical and Atomic Force Microscopy revealed some buckling, roughening and cracking of the lifted YSZ, however, which was probably due to tensile epitaxial strain release. [reprint (PDF)]
15.	Ultraviolet Detectors for AstroPhysics Present and Future M. Ulmer, M. Razeghi, and E. Bigan Optoelectronic Integrated Circuit Materials, Physics and Devices, SPIE Conference, San Jose, CA; Proceedings, Vol. 239-- February 6, 1995 ...[Visit Journal] Astronomical instruments for the study of UV astronomy have been developed for NASA missions such as the Hubble Space Telescope. The systems that are `blind to the visible' (`solar-blind') yet sensitive to the UV that have been flown in satellites have detective efficiencies of about 10 to 20%, although typically electron bombardment charge coupled devices are higher at 30 - 40% and ordinary CCDs achieve 1 - 5%. Therefore, there is a large payoff still to be gained by further improvements in the performance of solar blind UV detectors. We provide a brief review of some aspects of UV astronomy, UV detector development, and possible technologies for the future. We suggest that a particularly promising future technology is one based on the ability of investigators to produce high quality films made of wide bandgap III-V semiconductors. [reprint (PDF)]
15.	Beam Steering in High-Power CW Quantum Cascade Lasers W.W. Bewley, J.R. Lindle, C.S. Kim, I. Vurgaftman, J.R. Meyer, A.J. Evans, J.S. Yu, S. Slivken, and M. Razeghi IEEE Journal of Quantum Electronics, 41 (6)-- June 1, 2005 ...[Visit Journal] We report the light-current (L-I), spectral, and far-field characteristics of quantum cascade lasers (QCLs) with seven different wavelengths in the λ=4.3 to 6.3 μm range. In continuous-wave (CW) mode, the narrow-stripe (≈13 μm) epitaxial- side-up devices operated at temperatures up to 340 K, while at 295 K the CW output power was as high as 640 mW with a wallplug efficiency of 4.5%. All devices with λ≥4.7 μm achieved room-temperature CW operation, and at T=200 K several produced powers exceeding 1 W with ≈10% wallplug efficiency. The data indicated both spectral and spatial instabilities of the optical modes. For example, minor variations of the current often produced nonmonotonic hopping between spectra with envelopes as narrow as 5-10 nm or as broad as 200-250 nm. Bistable beam steering, by far-field angles of up to ±12° from the facet normal, also occurred, although even in extreme cases the beam quality never became worse than twice the diffraction limit. The observed steering is consistent with a theory for interference and beating between the two lowest order lateral modes. We also describe simulations of a wide-stripe photonic-crystal distributed-feedback QCL, which based on the current material quality is projected to emit multiple watts of CW power into a single-mode beam at T=200 K. [reprint (PDF)]
15.	High-Performance Focal Plane Arrays Based on InAs-GaSb Superlattices with a 10-micron Cutoff Wavelegth P.Y. Delaunay, B.M. Nguyen, D. Hoffman and M. Razeghi IEEE Journal of Quantum Electronics, Vol. 44, No. 5, p. 462-467-- May 1, 2008 ...[Visit Journal] We report on the demonstration of a focal plane array based on Type-II InAs/GaSb superlattices grown on N-type GaSb substrate with a 50%-cutoff wavelength at 10 μm. The surface leakage occurring after flip-chip bonding and underfill in the Type-II devices was suppressed using a double heterostructure design. The R₀A of diodes passivated with SiO₂ was 23 Ω·cm² after underfill. A focal plane array hybridized to an Indigo readout integrated circuit demonstrated a noise equivalent temperature difference of 33 mK at 81 K, with an integration time of 0.23 ms. [reprint (PDF)]
15.	Very Long Wavelength GaAs/GaInP Quantum Well Infrared Photodetectors C. Jelen, S. Slivken, G.J. Brown, and M. Razeghi SPIE Conference, San Jose, CA, -- February 12, 1997 ...[Visit Journal] We demonstrate long wavelength quantum well infrared photodetectors with GaAs quantum wells and GaInP barriers grown using gas-source molecular beam epitaxy. Wafers were grown with varying well widths. The optimum well width was 75 angstrom, which resulted in a detection peak at 13 μm and a cutoff wavelength of 15 μm. Dark current measurements of the samples with 15 μm cutoff wavelength show low dark current densities. The dark current characteristics have been investigated as a function of temperature and electron density in the well and compared to a model which takes into account thermionic emission and thermally assisted tunneling. The model is used to extract a saturation velocity of 1.5 x 10⁵ cm/s for electrons. The photoelectron lifetime before recapture has been deduced from this carrier velocity and photoconductive gain measurements. The lifetime is found to be approximately 5 ps. Preliminary focal plane array imaging is demonstrated. [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.	AlGaN ultraviolet photoconductors grown on sapphire D. Walker, X. Zhang, P. Kung, A. Saxler, S. Javadpour, J. Xu, and M. Razeghi Applied Physics Letters 68 (15)-- April 8, 1996 ...[Visit Journal] Al_xGa_1−xN (0≤x≤0.50) ultraviolet photoconductors with a minimum cutoff wavelength shorter than 260 nm have been fabricated and characterized. The AlGaN active layers were grown on (00⋅1) sapphire substrates by metalorganic chemical vapor deposition (MOCVD). The spectral responsivity of the GaN detector at 360 nm is about 1 A/W biased at 8 V at room temperature. The carrier lifetime derived from the voltage‐dependent responsivity is 0.13–0.36 ms. [reprint (PDF)]
15.	Low pressure metalorganic chemical vapor deposition of high quality AlN and GaN thin films on sapphire and silicon substrates P. Kung, X. Zhang, E. Bigan, and M. Razeghi Optoelectronic Integrated Circuit Materials, Physics and Devices, SPIE Conference, San Jose, CA; Proceedings, Vol. 2397-- February 6, 1995 ...[Visit Journal] High quality AlN and GaN epilayers have been grown on basal plane sapphire by low pressure metalorganic chemical vapor deposition. The X-ray rocking curve linewidth of the AlN and GaN films were about 100 and 30 arcsecs respectively. Sharp absorption edges were determined at 6.1 and 3.4 eV respectively. Successful donor-bound excitonic luminescence emissions were detected for GaN films grown on sapphire and silicon. Two additional lines at 3.37 and 3.31 eV were observed on GaN on sapphire and assumed to be impurity-related. Doping of GaN layers was achieved with magnesium. Mg-related photoluminescence emissions were successfully detected on as-grown samples, without any post-growth treatment. [reprint (PDF)]
15.	High performance terahertz quantum cascade laser sources based on intracavity difference frequency generation Q.Y. Lu, N. Bandyopadhyay, S. Slivken, Y. Bai and M. Razeghi Optics Express, Vol. 21, No. 1, p. 968-- January 14, 2013 ...[Visit Journal] We demonstrate high power, room temperature, single-mode THz emissions based on intracavity difference frequency generation from mid-infrared quantum cascade lasers. Dual active regions both featuring giant nonlinear susceptibilities are used to enhance the THz power and conversion efficiency. The THz frequency is lithographically tuned by integrated dual-period distributed feedback gratings with different grating periods. Single mode emissions from 3.3 to 4.6 THz with side-mode suppression ratio and output power up to 40 dB and 65 µW are obtained, with a narrow linewidth of 5 GHz. [reprint (PDF)]
15.	Recent advances in InAs/InAs1- xSbx/AlAs1-xSbx gap-engineered Type-II superlattice-based photodetectors Manijeh Razeghi, Abbas Haddadi, Arash Dehzangi, Romain Chevallier, Thomas Yang Proc. SPIE 10177, Infrared Technology and Applications XLIII, 1017705 -- May 9, 2017 ...[Visit Journal] InAs/InAs1-xSbx/AlAs1-xSbx type-II superlattices (T2SLs) is a system of multi-interacting quantum wells. Since its introduction, this material system has drawn a lot of attention especially for infrared detection. In recent years, InAs/InAs1- xSbx/AlAs1-xSbx T2SL material system has experienced incredible improvements in material quality, device structure designs and device fabrication process which elevated the performances of T2SL-based photodetectors to a comparable level to the state-of-the-art material systems for infrared detection such as Mercury Cadmium Telluride (MCT). In this paper, we will present the current status of InAs/InAs1-xSbx/AlAs1-xSbx T2SL-based photodetectors for detection in different infrared regions, from short-wavelength (SWIR) to long-wavelength (LWIR) infrared, and the future outlook of this material system. [reprint (PDF)]
15.	Bias-selectable dual-band mid-/long-wavelength infrared photodetectors based on InAs/InAs_1−xSb_x type-II superlattices A. Haddadi, R. Chevallier, G. Chen, A. M. Hoang, and M. Razeghi Applied Physics Letters 106 , 011104-- January 8, 2015 ...[Visit Journal] A high performance bias-selectable mid-/long-wavelength infrared photodetector based on InAs/InAs_1−xSb_x type-II superlattices on GaSb substrate has been demonstrated. The mid- and long-wavelength channels' 50% cut-off wavelengths were ∼5.1 and ∼9.5 μm at 77 K. The mid-wavelength channel exhibited a quantum efficiency of 45% at 100 mV bias voltage under front-side illumination and without any anti-reflection coating. With a dark current density of 1 × 10⁻⁷ A/cm² under 100 mV applied bias, the mid-wavelength channel exhibited a specific detectivity of 8.2 × 10¹² cm·Hz^½·W^-1 at 77 K. The long-wavelength channel exhibited a quantum efficiency of 40%, a dark current density of 5.7 × 10⁻⁴ A/cm² under −150 mV applied bias at 77 K, providing a specific detectivity value of 1.64 × 10¹¹ cm·Hz^½·W^-1. [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)]
15.	Negative and positive luminescence in mid-wavelength infrared InAs/GaSb superlattice photodiodes D. Hoffman, A. Gin, Y. Wei, A. Hood, F. Fuchs, and M. Razeghi IEEE Journal of Quantum Electronics, 41 (12)-- December 1, 2005 ...[Visit Journal] The quantum efficiency of negative and positive luminescence in binary type-II InAs-GaSb superlattice photodiodes has been investigated in the midinfrared spectral range around the 5-μm wavelength. The negative luminescence efficiency is nearly independent on temperature in the entire range from 220 to 325 K. For infrared diodes with a 2-μm absorbing layer, processed without anti-reflection coating, a negative luminescence efficiency of 45% is found, indicating very efficient minority carrier extraction. The temperature dependent measurements of the quantum efficiency of the positive luminescence enables for the determination of the capture cross section of the Shockley-Read-Hall centers involved in the competing nonradiative recombination. [reprint (PDF)]
15.	Very high wall plug efficiency of quantum cascade lasers Y. Bai, S. Slivken, S.R. Darvish, and M. Razeghi SPIE Proceedings, San Francisco, CA (January 22-28, 2010), Vol. 7608, p. 76080F-1-- January 22, 2010 ...[Visit Journal] We demonstrate very high wall plug efficiency (WPE) of mid-infrared quantum cascade lasers (QCLs) in low temperature pulsed mode operation (53%), room temperature pulsed mode operation (23%), and room temperature continuous wave operation (18%). All of these values are the highest to date for any QCLs. The optimization of WPE takes the route of understanding the limiting factors of each sub-efficiency, exploring new designs to overcome the limiting factor, and constantly improving the material quality. [reprint (PDF)]
15.	Beryllium compensation doping of InAs/GaSb infrared superlattice photodiodes D. Hoffman, B.M. Nguyen, P.Y. Delaunay, A. Hood, M. Razeghi and J. Pellegrino Applied Physics Letters, Vol. 91, No. 14, p. 143507-1-- October 1, 2007 ...[Visit Journal] Capacitance-voltage measurements in conjunction with dark current measurements on InAs/GaSb long wavelength infrared superlattice photodiodes grown by molecular-beam epitaxy on GaSb substrates are reported. By varying the beryllium concentration in the InAs layer of the active region, the residually n-type superlattice is compensated to become slightly p-type. By adjusting the doping, the dominant dark current mechanism can be varied from diffusion to Zener tunneling. Minimization of the dark current leads to an increase of the zero-bias differential resistance from less than 4 to 32 cm² for a 100% cutoff of 12.05 µm [reprint (PDF)]
15.	Fabrication of nanostructured heterojunction LEDs using self-forming Moth-Eye Arrays of n-ZnO Nanocones Grown on p-Si (111) by PLD D.J. Rogers; V.E. Sandana; F. Hosseini Teherani; M. Razeghi; H.-J. Drouhin Proc. SPIE 7217, Zinc Oxide Materials and Devices IV, 721708 (February 17, 2009)-- February 17, 2009 ...[Visit Journal] ZnO nanostructures were grown on Si (111) substrates using Pulsed Laser Deposition. The impact of growth temperature (T_s) and Ar pressure (P_Ar) on the morphology, crystal structure and photoluminescence was investigated. Various types of ZnO nanostructures were obtained. Self-forming arrays of vertically-aligned nanorods and nanocones with strong c-axis crystallographic orientation and good optical response were obtained at higher T_s. The nanocone, or "moth-eye" type structures were selected for LED development because of their graded effective refractive index, which could facilitate improved light extraction at the LED/air interface. Such moth-eye arrays were grown on p-type Si (111) substrates to form heteroj unction LEDs with the n-type ZnO nanocones acting as an active component of the device. These nanostructured LEDs gave rectifying I/V characteristics with a threshold voltage of about 6V and a blueish-white electroluminescence, which was clearly visible to the naked eye. [reprint (PDF)]
15.	Comparison of chemical and laser lift-off for the transfer of InGaN-based p-i-n junctions from sapphire to glass substrates D. J. Rogers ; P. Bove ; F. Hosseini Teherani ; K. Pantzas ; T. Moudakir ; G. Orsal ; G. Patriarche ; S. Gautier ; A. Ougazzaden ; V. E. Sandana ; R. McClintock ; M. Razeghi Proc. SPIE 8626, Oxide-based Materials and Devices IV, 862611 (March 18, 2013)-- March 18, 2013 ...[Visit Journal] InGaN-based p-i-n structures were transferred from sapphire to soda-lime glass substrates using two approaches: (1) laser-lift-off (LLO) and thermo-metallic bonding and (2) chemical lift-off (LLO) by means sacrificial ZnO templates and direct wafer bonding. Both processes were found to function at RT and allow reclaim of the expensive single crystal substrate. Both approaches have also already been demonstrated to work for the wafer-scale transfer of III/V semiconductors. Compared with the industry-standard LLO, the CLO offers the added advantages of a lattice match to InGaN with higher indium contents, no need for an interfacial adhesive layer (which facilitates electrical, optical and thermal coupling), no damaged/contaminated GaN surface layer, simplified sapphire reclaim (GaN residue after LLO may complicate reclaim) and cost savings linked to elimination of the expensive LLO process. [reprint (PDF)]
15.	Growth of AlGaN on silicon substrates: a novel way to make back-illuminated ultraviolet photodetectors Ryan McClintock ; Manijeh Razeghi Proc. SPIE 9555, Optical Sensing, Imaging, and Photon Counting: Nanostructured Devices and Applications, 95550U-- August 28, 2015 ...[Visit Journal] AlGaN, with its tunable wide-bandgap is a good choice for the realization of ultraviolet photodetectors. AlGaN films tend to be grown on foreign substrates such as sapphire, which is the most common choice for back-illuminated devices. However, even ultraviolet opaque substrates like silicon holds promise because, silicon can be removed by chemical treatment to allow back-illumination,1 and it is a very low-cost substrate which is available in large diameters up to 300 mm. However, Implementation of silicon as the solar-blind PD substrates requires overcoming the lattice-mismatch (17%) with the AlxGa1-xN that leads to high density of dislocation and crack-initiating stress. In this talk, we report the growth of thick crack-free AlGaN films on (111) silicon substrates through the use of a substrate patterning and mask-less selective area regrowth. This technique is critical as it decouples the epilayers and the substrate and allows for crack-free growth; however, the masking also helps to reduce the dislocation density by inclining the growth direction and encouraging dislocations to annihilate. A back-illuminated p-i-n PD structure is subsequently grown on this high quality template layer. After processing and hybridizing the device we use a chemical process to selectively remove the silicon substrate. This removal has minimal effect on the device, but it removes the UV-opaque silicon and allows back-illumination of the photodetector. We report our latest results of back-illuminated solar-blind photodetectors growth on silicon. [reprint (PDF)]
15.	Semiconductor ultraviolet detectors M. Razeghi and A. Rogalski Journal of Applied Physics Applied Physics Review 79 (10)-- May 15, 1996 ...[Visit Journal] In this review article a comprehensive analysis of the developments in ultraviolet (UV) detector technology is described. At the beginning, the classification of UV detectors and general requirements imposed on these detectors are presented. Further considerations are restricted to modern semiconductor UV detectors, so the basic theory of photoconductive and photovoltaic detectors is presented in a uniform way convenient for various detector materials. Next, the current state of the art of different types of semiconductor UV detectors is presented. Hitherto, the semiconductor UV detectors have been mainly fabricated using Si. Industries such as the aerospace, automotive, petroleum, and others have continuously provided the impetus pushing the development of fringe technologies which are tolerant of increasingly high temperatures and hostile environments. As a result, the main efforts are currently directed to a new generation of UV detectors fabricated from wide band-gap semiconductors the most promising of which are diamond and AlGaN. The latest progress in development of AlGaN UV detectors is finally described in detail. [reprint (PDF)]
15.	High-Performance InP-Based Mid-IR Quantum Cascade Lasers M. Razeghi IEEE Journal of Selected Topics in Quantum Electronics, Vol. 15, No. 3, May-June 2009, p. 941-951.-- June 5, 2009 ...[Visit Journal] Quantum cascade lasers (QCLs) were once considered as inefficient devices, as the wall-plug efficiency (WPE) was merely a few percent at room temperature. But this situation has changed in the past few years, as dramatic enhancements to the output power andWPE have been made for InP-based mid-IR QCLs. Room temperature continuous-wave (CW) output power as high as 2.8 W and WPE as high as 15% have now been demonstrated for individual devices. Along with the fundamental exploration of refining the design and improving the material quality, a consistent determination of important device performance parameters allows for strategically addressing each component that can be improved potentially. In this paper, we present quantitative experimental evidence backing up the strategies we have adopted to improve the WPE for QCLs with room temperature CW operation. [reprint (PDF)]
15.	High power broad area quantum cascade lasers Y. Bai, S. Slivken, S.R. Darvish, A. Haddadi, B. Gokden and M. Razeghi Applied Physics Letters, Vol. 95, No. 22, p. 221104-1-- November 30, 2009 ...[Visit Journal] Broad area quantum cascade lasers (QCLs) are studied with ridge widths up to 400 µm, in room temperature pulsed mode operation at an emission wavelength around 4.45 µm. The peak output power scales linearly with the ridge width. A maximum total peak output power of 120 W is obtained from a single 400-µm-wide device with a cavity length of 3 mm. A stable far field emission characteristic is observed with dual lobes at ±38° for all tested devices, which suggests that these broad area QCLs are highly resistant to filamentation. [reprint (PDF)]
15.	Very high quality p-type Al_xGa_1-xN/GaN superlattice A. Yasan and M. Razeghi special ISDRS issue of Solid State Electronics Journal, 47-- January 1, 2003 ...[Visit Journal] Very high quality p-type Al_xGa_1−xN/GaN superlattice has been achieved through optimization of Mg flow and period of superlattice. Theoretical model was used to optimize the structure of superlattice by choosing suitable Al compositions and superlattice periods. The experiments show that for x=0.26, the resistivity is as low as 0.19 Ω cm and hole concentration is as high as 4.2×10¹⁸ cm⁻³, the highest values ever reported for p-type AlGaN/GaN superlattices. Hall effect measurement and admittance spectroscopy on the samples confirm the high quality of the superlattices. The activation energy calculated for p-type GaN and p-type A_0.1Ga_0.9N/GaN superlattice is estimated to be not, vert, similar 125 and 3 meV respectively. [reprint (PDF)]
15.	Long-term reliability of Al-free InGaAsP/GaAs λ = 808 nm) lasers at high-power high-temperature operation J. Diaz, H. Yi, M. Razeghi and G.T. Burnham Applied Physics Letters 71 (21)-- November 24, 1997 ...[Visit Journal] We report the long-term reliability measurement on uncoated Al-free InGaAsP/GaAs (λ = 808 nm) lasers at high-power and high-temperature operation. No degradation in laser performance has been observed for over 30 ,000 h of lifetime testing in any of randomly selected several 100 μm-wide uncoated lasers operated at 60 °C with 1 W continuous wave output power. This is the first and the most conclusive evidence ever reported that directly shows the high long-term reliability of uncoated Al-free lasers. [reprint (PDF)]

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