高温(T=80℃)连续激射的2μm InGaSb/AlGaAsSb量子阱激光器

研制了激射波长为2μm的InGaSb/AlGaAsSb应变量子阱激光器。室温连续工作时,电流为1.2A时,出光功率为82.2mW。激光器连续工作温度可高达80℃,出光功率为63.7mW。     

High-temperature (T=80℃) operation of a 2 μm InGaSb-AlGaAsSb quantum well laser

An InGaSb/AlGaAsSb compressively strained quantum well laser emitting at 2 μm has been fabricated. An output power of 82.2 mW was obtained in continuous wave (CW) mode at room temperature. The laser can operate at high temperature (T=80℃), with a maximum output power of 63.7 mW in CW mode.     

Room temperature continuous wave operation of quantum cascade laser at λ～ 9.4μm

Continuous wave (CW) operation of long wave infrared (LWIR) quantum cascade lasers (QCLs) is achieved up to a temperature of 303 K.For room temperature CW operation,the wafer with 35 stages was processed into buried heterostructure lasers.For a 2-mm-long and 10-μm-wide laser with high-reflectivity (HR) coating on the rear facet,CW output power of 45 mW at 283 K and 9 mW at 303 K is obtained.The lasing wavelength is around 9.4μm locating in the LWIR spectrum range.     

Holographic fabricated continuous wave operation of distributed feedback quantum cascade lasers atλ≈8.5μm

The fabrication and characterization of distributed feedback（DFB） quantum cascade lasers emitting atλ≈8.5μm are reported.The first-order DFB grating structure was defined using the holographic lithography technique.Reliable dynamic single-mode emission with a side-mode suppression ratio of 20 dB and a tuning coefficient of-0.277 cm^-1/K from 93 to 210 K is obtained in continuous wave mode by using high-reflectivity coating on the rear facet.The output power is over 100 mW at a temperature of 80 K.     

Internal quantum efficiency of stimulated emission of (λ=1.55 µm) InGaAsP/InP laser diodes

The stimulated emission (η _i ^st ) of InGaAsP/InP separate-confinement double heterostructure lasers operating at λ=1.5–1.6 μm has been studied experimentally and theoretically. Laser heterostructures with a varied design of the waveguide layer were grown by MOCVD. The maximum internal quantum efficiency η _i ^st ≈97% was obtained in a structure with a double-step waveguide characterized by minimum leakage into the p-emitter above the generation threshold. The high value of η _i ^st is provided by low threshold and nonequilibrium carrier concentrations at the interface between the waveguide and p-emitter. The calculation yields η _i ^st values correlating well with the experimental data. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 37, No. 2, 2003, pp. 243–248. Original Russian Text Copyright ? 2003 by Skrynnikov, Zegrya, Pikhtin, Slipchenko, Shamakhov, Tarasov.     

Study of heterostructures with a combined In(Ga)As/GaAs quantum dot/quantum well layer and a Mn δ layer

Using high-resolution transmission electron microscopy and photoelectric spectroscopy methods, the effect of Mn δ layer embedding and GaAs coating layer growth techniques in structures with In(Ga)As/GaAs quantum dots and wells on their structural and optoelectronic characteristics is studied. It is shown that the low-temperature GaAs coating layer in a structure with a Mn δ layer is structurally inhomogeneous and can cause a decrease in the quantum-dot photosensitivity.     

Contribution of Auger recombination to saturation of the light-current characteristics in high-power laser diodes (λ = 1.0–1.9 m m)

Spectral and light-current characteristics of lasers based on the asymmetric separate-confinement heterostructures InGaAs/InGaAsAl/InP and InGaAs/GaAs/AlGaAs/GaAs were studied in the pulsed mode of lasing. It is shown that, at high levels of current pumping, the charge-carrier concentration in the active region of semiconductor lasers for the near-infrared optical region increases beyond the oscillation threshold; drastic saturation of the light-current characteristics is observed. Processes occurring in lasers as the charge-carrier concentration increases beyond the lasing threshold are studied theoretically. It is established that, at high pump levels, the rate of stimulated recombination decreases, the lifetime of charge carriers increases, and both the concentration of emitted photons and the quantum yield of stimulated radiation decrease. It is shown that variations in stimulated recombination, the decrease in the quantum efficiency, and saturation of the light-current characteristic in semiconductor lasers at high levels of current pumping are caused by the contribution of the nonradiative Auger recombination.     

Y_3Al_5O_(12):Er~(3 )激光器的稳态振荡(λ=2.94μm,T=300K)

实验和理论都证明,在~4I_(11/2)→~4I_(13/2)“自发”跃迁和~4I_(13/2)交叉弛豫低能级(~4I_(13/2))工作的掺铒钇铝石榴石激光器可获得稳态振荡。     

Cathodoluminescence investigations of vertically stacked,sub-μm arrays of sidewall quantum wires on patterned GaAs (311)A substrates

Vertically stacked arrays of GaAs/(AlGa)As sidewall quantum wires (Qwires) were successfully fabricated on GaAs (311)A substrates patterned with 0.5 μm-pitch gratings. The Qwires exhibit a lateral confinement potential as large as 210 meV and high luminescence efficiency up to 300 K. The distinct carrier transfer and loss mechanisms are studied by temperature dependent, spectrally and spatially resolved cathodoluminescence. Despite the almost perfect carrier capture in the Qwires, non-radiative recombination within the connecting quantum well (Qwell) regions usually cannot be neglected even at low temperatures. For temperatures approaching 300 K, reemission of carriers out of the Qwell into the vertical (AlGa)As barriers contributes increasingly to the reduction of the carrier transfer and luminescence efficiency of the Qwires without notable repopulation of the connecting Qwells.     

Independent operation time of photodetectors of the (3—5)-μm spectral band based on InSb and CdHgTe heteroepitaxial structures

The time of independent operation t _ind of indium antimonide photoresistors and photodiodes and photoresistors based on Cd _х Hg_1–х Te (х ~ 0.3) heterostructures deeply cooled with a Joule–Thomson throttling system is investigated. The largest independent operation time (taut ≥ 28 s) was obtained for Cd _х Hg_1–х Te (х ~ 0.3) photoresistors. Time t _ind of the photoresistors and photodiodes is found to be related to the temperature of transition of the semiconductor materials from the impurity region to the intrinsic region. The possibility of increasing time t _ind of the photodetectors by optimizing the requirements for the characteristics of InSb and Cd _х Hg_1–х Te is discussed.     

Growth of Space Ordered 1.3μm InAs Quantum Dots on GaAs(100) Vicinal Substrates by MOCVD

用MOCVD技术在偏(1100)GaAs衬底上生长了发光波长在1.3μm的线状空间规则排列InAs量子点.光致发光实验表明,相对于正(100)衬底,偏(100)GaAs衬底上生长的InAs量子点具有更好的材料质量,光谱有更大的强度和更窄的线宽.为了得到发光波长为1.3μm的量子点,对比研究了不同In含量的InGaAs应力缓冲层(SBL)和应力盖层(SCL)的应力缓冲作用.结果表明,增加SCL中In含量能有效延伸量子点发光波长到1. 3μm,但是随着SBL中In的增加,发光波长变化不明显,并且材料质量明显下降.     

铷原子4D_(5/2)态双光子偏振光谱及其在1.5μm激光稳频中的应用

介绍了基于87 Rb原子5S1/2-5P3/2-4D5/2阶梯型能级系统中的双光子偏振光谱。与其他跃迁相比,循环跃迁的信噪比最好。研究了双光子偏振光谱循环跃迁线信号强度随抽运光光强的变化情况。利用双光子偏振光谱,将1529nm半导体激光器的频率锁定于87 Rb原子的5P3/2(F′=3)-4D5/2(F″=4)跃迁线上,当取样时间τ=100s时阿仑方差最小,为σy(τ)=1.3×10-11。与自由运转相比,该方法显著地改善了1529nm激光器长期频率稳定度。     

Photodeposition of silver at the interface of a heterojunction based on a solid electrolyte: The case of CdSe-As<Subscript>2</Subscript>S<Subscript>3</Subscript>:Ag<Subscript>x</Subscript> (<Emphasis Type="Italic">x</Emphasis>=0.9–2.4) heterojunctions

The phenomenon of photodeposition of silver has been detected in CdSe-As₂S₃:Ag_x (x=0.9–2.4) heterojunctions. The mass transfer of silver ions to the interface is caused by an electric field arising due to separation of electron-hole pairs in the space-charge regions of the heterojunction upon photovoltage generation. The migration of ions is also stimulated by their entrainment by the electron flow. Recombination of electrons with ions at the interface causes photodeposition of clusters of a chemical element responsible for ionic conduction in the solid electrolyte. A new method is suggested for preparing materials for optical data storage. The method is based on the phenomenon of photostimulated transport of ions and photodeposition of a metal at the interfaces of heterojunctions based on solid electrolytes.