High-power diffraction-limited phase-locked GaAs/GaAlAs semiconductor laser array

High-power diffraction-limited phase-locked gallium-arsenide (GaAs)/ gallium-aluminum-arsenide (GaAlAs) semiconductor laser arrays have been fabricated using the LPE technique, the standard photolithographic technique, wet etching, and proton bombardment. The tailored gain-guided arrays are made by varying the width of the channels of the lasers while keeping the spacing between them constant. The array consists of six lasers. Its optical output power per facet is 300 mW at 2.71_th with single-mode continuous wave (CW) operation and single lobe far-field pattern with full width at half maximum (FWHM) of 1.90°.     

High-power diffraction-limited phase-locked GaAs/GaAlAs semiconductor laser array

High-power diffraction-limited phase-locked gallium-arsenide (GaAs)/ gallium-aluminum-arsenide (GaAlAs) semiconductor laser arrays have been fabricated using the LPE technique, the standard photolithographic technique, wet etching, and proton bombardment. The tailored gain-guided arrays are made by varying the width of the channels of the lasers while keeping the spacing between them constant. The array consists of six lasers. Its optical output power per facet is 300 mW at 2.71_th with single-mode continuous wave (CW) operation and single lobe far-field pattern with full width at half maximum (FWHM) of 1.90°.     

GaAs/GaAlAs traveling wave type laser amplifier with tilted facets

GaAs/GaAlAs traveling wave type laser amplifiers with different tilted angle facets are defined by proton bombardment. Some characters are measured. Maximum single-pass gains of 27.8 dB are reached with an optical fiber coupling system.     

GaAs/GaAlAs traveling wave type laser amplifier with tilted facets

GaAs/GaAlAs traveling wave type laser amplifiers with different tilted angle facets are defined by proton bombardment. Some characters are measured. Maximum single-pass gains of 27.8 dB are reached with an optical fiber coupling system.     

The radiant characteristics of quantum-dimensional laser structures in the GaAs/GaAlAs system

It is shown that allowance for the dependence of the intraband relaxation time on the laser operation regime in the model of the burning-out of a spectral hole makes it possible to obtain a better agreement between experimental and theoretical spectral characteristics. Reported at the 3rd Belarusian-Russian Seminar “Semiconductor Lasers and Systems Based on Them,” Minsk, June 22–24, 1999. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 536–538, July–August, 2000.     

GaAs／GaAlAs透射式光电阴极的分辨力特性分析

从简化的二维扩散方程出发，推导GaAs/GaAlAs透射式阴极的调制传递函数表达式，计算2μm厚GaAs阴极层的GaAs/GaAlAs透射阴极的理论分辨力特性曲线，并讨论它与若干参数的关系。     

高功率单模GaAlAs/GaAs激光器

本文报告了隐埋双脊衬底大光腔结构GaAlAs/GaAs激光器的制备和特性,获得CW光输出的最高功率可达80mW。     

GaAlAs／GaAs量子阱结构的光致发光研究

阐述了用ＭＯＣＶＤ生长的ＧａＡｌＡｓ／ＧａＡｓ梯度折射率分别限制量子阱结构及其光学性质。样品经高分辨率光致发光（ＰＬ）测试显示,在１０Ｋ下对于８ｎｍ的单量子阱,通过激发产生的荧光谱半峰宽（ＦＷＨＭ）为６．２ｎｍ,同时具有较高的强度。表明量子阱结构具有陡峭的界面;另外还观察到,Ｘ（ｅ－ｈｈ）峰值位置相对于激发能级的移动。测试结果表明,样品质量符合设计要求,结果令人满意。     

Monte Carlo study of electron velocity variance in GaAlAs/GaAs/GaAlAs quantum well

The ensemble Monte Carlo method is used to study electron transport in a GaAlAs/GaAs/GaAlAs 1000 Å long quantum well. The rejection method is applied to calculate electron scattering probabilities between 2D and 3D states. The concentration of 2D electrons, the valleys' occupancies and the electron velocity variance along the simulated structure are calculated.     

X-ray double-crystal rocking curves in GaAlAs/GaAs heterostructures

Summary X-ray double-crystal rocking curves of Ga_1−x Al _x As/GaAs heterostructures have been calculated using a dynamical diffraction model for the general case of Bragg reflection geometry. Different experimental configurations have been considered and the possibility of studying both slightly mismatched and relatively thin layers has been investigated. Experimental rocking curves have been measured using the CuKα ₁ radiation, the 004 symmetric reflection and a perfect crystal as the monochromator. An excellent agreement between calculated and experimental rocking curves has been found and this demonstrates the reliability of both the experimental procedure and the theoretical approach.     

GaAs／GaAlAs脊型波导交变式Δβ耦合器

研制了具有肖特基势垒电极的ＧａＡｓ／ＧａＡｌＡｓ双异质结脊型波导交变式Δβ耦合器．通过合理设计器件结构，降低波导层中载流子浓度和上、下包层中Ａｌ的含量，以及采用反应离子刻蚀和剥离等技术，使器件总损耗降为１０ｄＢ，消光比为２６．８ｄＢ，器件在１．３μｍ下实现单模工作．     

GaAs/GaAlAs多量子阱的光致荧光诊断

利用光致荧光技术对GaAs/GaAlAs多量子阱质量进行了诊断。讨论了量子阱厚度涨落,铝成份涨落,各种缺陷和非故意掺杂等对量子阱光致荧光谱的影响,并反过来,又由光致荧光谱来推断引起量子阱质量退化的原因。在一定程度上为分子束外延工艺的改进提供了依据。 关键词：     

Channeled substrate window twin stripe GaAs/GaAlAs visible laser: Fabrication and steady state analysis

GaAs/GaAlAs high power window stripe lasers are developed with straight ac-tive layer in region adjacent to facet and curved active layer in central part.Only one-step liq-uid-phase epitaxy(LPE)growth is used in the fabvrication to from two internal current patheslaterally,allowing of a very simple fabrication process.Optical coupling from two stimulatingregions makes less beam divergence.The steady state analysis of such laser structure agreewell with experimental results.     

GaAlAs／GaAs量子阱结构的实验研究

利用分子束外延生长法生长出了ＧａＡｌＡｓ／ＧａＡｓ梯度折射率分别限制单量子阱结构材料，对样品进行了光荧光谱、双晶Ｘ射线衍射和电化学电容－电压分布测量。实验结果表明，样品质量达到了设计要求，利用该材料制作的激光二极管获得了初步结果。     

GaAs/GaAlAs异质NIPI超晶格的光荧光谱

异质NIPI超晶格结构的基本单元是由n型和p型的宽禁带材料薄层及插在它们中间的不掺杂窄禁带材料层组成,如nGaAlAs-不掺杂GaAs-pGaAlAs-不掺杂GaAs四层结构,其中Ⅰ代表不掺杂层.它是组分超晶格和掺杂超晶格结合,因而具有许多新的性质,例如空间电荷分离,载流子局域在未掺杂区内等.这个结构最早是由德国的Dõhler等所研究.     

Electronic and Optical Properties of GaAlAs/GaAs Thin Films

Technical Physics - It has been shown that the formation of GaAlAs nanofilms on a GaAs surface leads to an increase in the emission coefficient of true secondary electrons and in the quantum yield...     

Photoluminescence studies of GaAs/GaAlAs multiple quantum well heterostructures

The photoluminescence excited by He:Ne and Nd:YAG lasers of GaAs/Ga_0.75Al_0.25As multiple quantum well heterostructures grown by MBE was measured as a function of temperature from 4.2 K up to room temperature and for different pumping powers at constant temperature. The excitonic transitions associated with carriers confined in the quantum wells as well as other transitions associated with impurities either already present in the substrates or introduced into the samples during growth are identified in the spectra and fully characterized. From Arrhenius plots of the photoluminescence peak integrated intensities versus inverse temperature, activation energies are estimated for acceptor defects in the samples as well as for quantum well related excitonic transitions. Photoluminescence polarization experiments demonstrate a dramatic manifestation of the selection rules governing heavy hole and light hole optical transitions in quantum wells.     

GaAlAs/GaAs非均匀阱宽多量子阱超辐射发光管材料制备及表征

超辐射发光二极管(SLD)具有不同于半导体激光器和普通发光二极管的优异性能。为了制备高功率半导体超辐射发光管,并且得到比较大的光谱宽度、大的单程增益和抑制电流饱和,我们研究设计了具有850nm辐射波长的GaAlAs/GaAs非均匀阱宽多量子阱超辐射发光二极管结构,采用分子束外延(MBE)方法进行了材料制备。同时利用X射线双晶衍射,变温(10～300K)光致发光(PL)等方法检测分析了外延薄膜的结构和光电特性。在光致发光谱线中我们得到了发射波长850nm的谱峰,谱峰范围跨跃800～880nm,双晶回摆曲线结果显示了设计的结构得到实现。在注入电流140mA时,器件输出光谱的半峰全宽可以达到26nm,室温下连续输出功率达到6mW。     

GaAs/GaAlAs双异质结发光管退化特性的研究

本文研究了GaAs/GaAlAs双异质结发光管的退化特性。有快、慢二种退化类型。器件的慢退化是由于有源区有暗缺陷(DSD)产生和长大,引起光功率下降。文中研究了老化过程中I-V特性和I-P特性与EL图象的变化规律,并与相同结构的InP/InGaAsP双异质结发光管的退化特性进行了比较,结果表明:它们有着不同的退化机理。     

Modulation transfer function characteristic of uniform-doping transmission-mode GaAs/GaAlAs photocathode

The resolution characteristic can be obtained by the modulation transfer function (MTF) of a GaAs/GaAlAs photocathode.After establishing the theoretical model of GaAs(100)-oriented atomic configuration and the formula for the ionized impurity scattering of the non-equilibrium carriers,this paper calculates the trajectories of photoelectrons in a photocathode.Thus the distribution of photoelectron spots on the emit-face is obtained,which is namely the point spread function.The MTF is obtained by Fourier transfer of the line spread function obtained from the point spread function.The MTF obtained from these calculations is shown to depend heavily on the electron diffusion length,and enhanced considerably by decreasing the electron diffusion length and increasing the doping concentration.Furthermore,the resolution is enhanced considerably by increasing the active-layer thickness,especially at high spatial frequencies.The best spatial resolution is 860 lp/mm,for the GaAs photocathode of doping concentration 1 × 10 19 cm 3,electron diffusion length 3.6 μm and the active-layer thickness 2 μm,under the 633-nm light irradiated.This research will contribute to the future improvement of the cathode’s resolution for preparing a high performance GaAs photocathode,and improve the resolution of a low light level image intensifier.