基于背向曝光的GaN基脊型LD制备工艺改进

GaN基脊型激光二极管（LD）的制备工艺中,面临的一个主要困难是p电极和窄脊结构的制备受到光刻对准精度的严重制约。设计和验证了一种基于背向曝光技术的激光器制备工艺。通过预先沉积一层200nm的铝作为挡光掩模和牺牲层,利用ICP蚀刻制备出宽为2.5μm的脊型结构,并使用PECVD沉积SiO2绝缘层。随后采用背向曝光实现二次光刻,将脊型图形精确地转移到电极窗口,继而采用湿法腐蚀SiO2绝缘层打开窗口,借助对的铝掩模腐蚀实现对残余绝缘层的辅助剥离,从而同时解决了目前脊型激光器电极窗口对准困难和绝缘层侧向腐蚀条件难于把握的问题。     

InAs/InP量子点激光器制备工艺研究

报道了通过化学湿刻蚀制备窄脊条InAs/InP量子点激光器的方法。激光器脊条主要是由半导体材料InGaAs和InP构成,通过选择合适配比的H2SO4∶H2O2∶H2O和H3PO4∶HCl腐蚀溶液和InP的腐蚀方向,在室温下选择性地腐蚀了InGaAs和InP,获得了窄脊条宽为6μm的量子点激光器。此激光器能够在室温连续波模式下工作,激射波长在光纤通信重要窗口1.55μm,单面最大输出功率超过12mW。     

以红宝石激光泵浦砷化镓激光器

为研究各种物质的激励和发射,用电子束作光泵的方法已得到发展。最近,已利用砷化镓二极管激光在锑化铟和砷化铟晶体中实现光抽运。以液氮温度下的Q开关红宝石激光器作激励源,获得了型砷化镓晶体的激光作用。     

灵敏度达10—16焦耳的砷化镓激光接收器

1969年10月,美帝通用电气公司介绍了一种高灵敏度激光接收器。此种新型“激光眼”接收器（GR-102型）是一种特别适用于0.9微米砷化镓激光器波长的低能量水平光脉冲接收器。68年,该公司还制造了适用于1.065微米波长的掺钕钇铝石榴石和玻璃激光器的类似接收机（NR-101型）。     

砷化镓激光器具有众多应用

砷化镓激光器具有众多应用砷化镓是第一种用于二极管激光器的化合物半导体，是发展最好的二极管激光材料。用铝代替其中的某些镓，可制造出在７５０～８７０ｍｍ发射的长寿命激光器。采用不同的内部结构，可制成多种形式的镓砷铝（Ｇａ１－ｘＡｌｘＡｓ）激光器。简单的双...     

湿法腐蚀DFB半导体激光器的均匀光栅的研究

论述了用湿法腐蚀电子束光刻的均匀光栅DFB激光器亚微米光栅的过程,研究了几种腐蚀液对半导体激光器外延材料中InP的腐蚀过程.用扫描电子显微镜(SEM)对其腐蚀情况进行了分析,通过调节腐蚀液HB1:HNO3:H2O的体积比,找到了对InP腐蚀的最佳配比(1:1:30)以及合适的腐蚀条件(室温23℃).利用这种腐蚀液得到的光栅图形可以满足DFB激光器的要求.     

808nm DFB半导体激光器的光栅制备

实验优化设计了808nm DFB半导体激光器的二级布拉格光栅结构,介绍了808 nm分布反馈（DFB）半导体激光器光栅制备的工艺过程。采用全息光刻方法和湿法腐蚀技术在GaAs衬底片上制备了周期为240nm的光栅图形,全息光刻系统采用条纹锁定技术降低条纹抖动和提高干涉稳定性,腐蚀液采用H3PO4 : H2O2 : H2O (1 : 1 : 10),腐蚀时间为30s。光学显微镜、扫描电子显微镜（SEM）和原子力显微镜（AFM）测试显示,光栅周期为240nm,占空比为0.25,深度为80nm,具有完美的表面形貌,及良好的连续性和均匀性。     

半导体激光器阵列隔离槽的湿法腐蚀

研究了几种腐蚀液对半导体激光器阵列外延材料的腐蚀过程,其中HF(40%)/CrO3(33wt%)腐蚀液比较适合,用扫描电子显微镜(SEM)对其腐蚀情况进行了分析,并给出了利用这种腐蚀液进行腐蚀的半导体激光器阵列隔离槽的图像.通过调节HF/CrO3腐蚀液的体积比(从0.02到0.2),确定了AlxGa1-xAs组分渐变材料的腐蚀条件(室温23℃,腐蚀时间4min)以及最佳配比(体积比为0.1).利用这种腐蚀液得到的腐蚀图形可以满足激光器阵列的要求.     

半导体激光器阵列隔离槽的湿法腐蚀

研究了几种腐蚀液对半导体激光器阵列外延材料的腐蚀过程,其中HF(40 %) /CrO3 (33wt%)腐蚀液比较适合,用扫描电子显微镜(SEM)对其腐蚀情况进行了分析,并给出了利用这种腐蚀液进行腐蚀的半导体激光器阵列隔离槽的图像.通过调节HF/CrO3 腐蚀液的体积比(从0 0 2到0 2 ) ,确定了AlxGa1-xAs组分渐变材料的腐蚀条件(室温2 3℃,腐蚀时间4min)以及最佳配比(体积比为0 1) .利用这种腐蚀液得到的腐蚀图形可以满足激光器阵列的要求.     

GaN基蓝光激光器光场特性模拟

采用有限差分法对GaN基多量子阱(MQWs)脊形激光器进行二维光场模拟.InGaN和AlGaN材料的折射率分别由修正的Brunner以及Bergmann方法得到.分析了激光器单模特性和远场发散角同器件的脊形刻蚀深度和脊形条宽的关系.研究了在脊形上用Si/SiO2膜取代传统SiO2介质膜这种新的脊形设计对激光器结构参数的影响.模拟结果发现,脊形条宽越窄,脊形刻蚀深度越深,平行结平面方向的发散角越大,但由此会引起单模特性不稳定,两者之间有一个折衷值.通过引入新的脊形设计,可以降低对器件刻蚀深度精度的要求,同时有很好的单模稳定性.     

GaInP/AlGaInP脊形波导激光器器件结构的优化研究

通过优化脊形波导的结构参数可以降低脊形波导激光器的阈值电流,提出了实现亚微米脊宽,从而降低阈值电流的方法。针对脊形波导制作过程中蚀刻深度不易控制的问题,对GaInP/AlGaInP材料中加入蚀刻阻挡层进行了研究。     

离子束刻蚀法制备大功率高效率650nm AlGaInP可见光激光器

用纯Ar离子束刻蚀方法制备出大功率高效率650nm实折射率AlGaInP压应变量子阱激光器.对偏角衬底,干法刻蚀可得到湿法腐蚀不能得到的高垂直度和对称台面.制备的激光器条宽腔长分别为4μm和600μm,前后端面镀膜条件为10%/90%.室温下阈值电流的典型值为46mA,输出功率为40mW时仍可保持基横模.10mW,40mW时的斜率效率分别为1.4W/A和1.1W/A.     

650-nm InGaP Broad Area Lasers With 5000-h Reliable Operation at 600 mW

Reliable operation of 650-nm broad area laser diodes with InGaP quantum-wells embedded in AlGaInP waveguide layers and n-AlInP and p-AlGaAs cladding layers is reported. Mounted on chemical vapor deposition (CVD)-diamond heat spreader and standard C-mounts, the 100-mum stripe width lasers showed reliable operation over 5000 h at 15 degC and 600 mW     

5.6-W Broad-Area Lasers With a Vertical Far-Field Angle of 31$^{circ}$ Emitting at 670 nm

Highly efficient 670-nm high-power broad-area laser diodes with a single InGaP quantum-well embedded in AlGaInP waveguide layers and n-AlInP and p-AlGaAs cladding layers are presented. The developed vertical layer structure leads to a vertical far-field angle of 31deg. At 15degC, 100 mu-m-wide broad-area lasers reach an output power of 5.6 W limited by thermal rollover. The conversion efficiency was 41% at 1.5 W. A 7600-h reliable operation at 1.5 W and a mean time to failure of about 37550 h will be reported.     

Dependence of output properties on ridge structures and asymmetricfacet reflectivity in 0.98-μm InGaAs-InGaAsP-InGaP SQW FP-LDs

The dependence of output performances on the waveguide structures and the facet reflectivity of 0.98-μm Al-free InGaAs-InGaAsP-InGaP ridge waveguide single-quantum-well Fabry-Perot laser diodes are investigated theoretically and experimentally. In our analysis, lateral and longitudinal spatial hole-burning, carrier-density-dependent optical loss in the well, and gain saturation are considered simultaneously. Permissible ranges of the ridge width, the InGaP cladding thickness, and the front facet reflectivity are presented in conjunction with the desired performance parameters such as maximum kink-free output power, beam divergence, and peak light density at the front facet     

Characteristics of native-oxide-confined InGaP-(AlxGa1-x)0.5In0.5P quantum-well ridgewaveguide lasers

We report 670-nm native-oxide confined GaInP-(Al_xGa_1-x)_0.5In_0.5P quantum-well ridge waveguide laser diodes. The devices are fabricated from a compressively strained GaInP-(Al_xGa_1-x)_0.5In_0.5P quantum-well separate confinement heterostructure laser structure. Wet chemical etching and wet oxidation process are used to form native oxide confined ridge waveguides. The oxidation process converts the p-Al_0.5In_0.5P cladding layer into AlO_x after ridge etch. Laser diodes of 3.5-μm-wide ridge waveguide operate with threshold currents below 13.5 mA and differential quantum efficiencies over 35%/facet     

Low-threshold, highly reliable 630 nm-band AlGaIP visible laserdiodes with AlInP buried waveguide

Low-threshold, highly reliable 630 nm-band AlGaInP visible laser diodes have been developed by employing a low-loss optical waveguide buried in the AlInP layer. A low-threshold current of 19 mA at 25°C is obtained with a cavity length of 310 μm. This current is the lowest value for 630 nm-band AlGaInP visible laser diodes, to our knowledge. Our AlInP-buried laser diodes with a cavity length of 500 μm operated over 7000 h without significant degradation at 60°C and 5 mW     

GaInP/AlGaInP index waveguide-type visible laser diodes with dry-etched mesa stripes

GaInP/AlGaInP index waveguide-type visible-light laser diodes with dry-etched mesa stripes have been fabricated by Cl/sub 2/ reactive ion beam etching for the first time. The AlGaInP cladding layer, which is normally very difficult to dry etch due to problems with Al oxidation and the low volatility of In and its reaction products, was etched smoothly with high depth accuracy. The etched mesa stripes were buried by metal organic vapour-phase epitaxy without crystal discontinuity at the regrown surface. The threshold current under room-temperature pulsed operation is 35 mA (L=300 mu m), which is almost the same value as that for wet-etched lasers.<>     

Nonlinearity in power-current Characteristics of narrow-pulse-driven AlGaInP laser diodes

In this paper, a simple yet effective model is developed to analyze the nonlinearity in power-current characteristics, also known as "kinks", observed in AlGaInP selectively-buried-ridge (SBR) laser diodes driven by narrow pulses (/spl sim/10/sup -7/s). The model takes the temperature-induced waveguide as well as the carrier distribution into account, and the simulation results show good agreement with the experiments. The main factors influencing the kink behavior of SBR lasers are investigated based on this model, and it is believed to be of great help for the optimization AlGaInP laser structure for high-power applications.     

Dependently addressable dual-spot native-oxide-confined GaInP-(AlxGa1-x)0.5In0.5Pquantum-well lasers

We describe the fabrication and characteristics of 15-μm spaced dual-spot, 670-nm native-oxide confined GaInP-(Al_xGa_1-x )_0.5In_0.5P quantum-well ridge waveguide laser diodes. The devices are fabricated from a compressively strained GaInP-(Al_xGa_1-x)_0.5In_0.5P quantum-well separate confinement heterostructure laser structure. Wet oxidation of Al_0.5In_0.5P is used to form native-oxide-confined dual-ridge waveguides. The oxidation process converts part of the p-Al_0.5In_0.5P cladding layer into AlO_x after ridge etching. These diodes show excellent performance: uniform low threshold currents of 15 mA and differential quantum efficiencies over 35%/facet. The diodes show crosstalk less than 2%