大功率单隧道结半导体激光器的研制简

针对大功率隧道结半导体激光器因光学灾变损伤(COD)而导致输出光功率无法进一步提高的问题,通过优化器件材料结构,提高了其COD阈值.采用标准的半导体激光器制作工艺,制作了发光区条宽为200 μm、腔长为900 μm的单隧道结半导体激光器.在脉冲宽度为200 ns、重复频率为5 kHz的室温下进行测试,器件峰值功率超过70 W,并且无明显COD现象发生.在20 A工作电流下,器件峰值波长为907 nm,光谱宽度为7 nm,斜率效率为1.88,接近相同工作电流下单有源层激光器的两倍.     

1.3微米低阈值隐埋条形双异质结激光器研制成功

据武汉电信器件公司通讯员报道,武汉电信器件公司与北京大学物理系合作,研制成功了1·3微米低阈值隐埋条形双异质结半导体激光器。这次研制成的隐埋条形激光器,是吸收了当前国际上同类激光器的优点,结合该公司的工艺特点制作的。这种隐埋条形激光器,室温连续工作;最低阈值电流小于40mA;线性输出光功率大     

808 nm高功率AlGaAs/GaAs单量子阱远结激光器

设计并研制了一种将p-n结和有源层分开的高功率AlGaAs/GaAs单量子阱远异质结(SQW-RJH)激光器,其发射波长为808 nm,腔长为900 μm,条宽为100μm.其外延结构与通常的808 nm AlGaAs/GaAs单量子阱半导体激光器的结构不同,在p-n结和有源区间多了一层0.3μm厚的p型Al0.3Ga0.7As下波导层.对研制的器件进行了电导数测试,结果显示,与常规AlGaAs/GaAs大功率半导体激光器相比,远结半导体激光器具有阚值电流偏大、导通电压偏高的直流特性.经4 200h的恒流电老化结果表明,器件在老化初期表现出阈值电流随老化时间缓慢下降,输出功率随老化时间缓慢上升的远结特性.     

掩埋异质结激光器的Mesa制备工艺

掩埋异质结结构的半导体激光器具有阈值低、光束质量好的优点。台面（Mesa）制作是掩埋结激光器加工过程中的一步关键工艺，采用传统的全湿法腐蚀工艺制作台面，3英寸圆片内腐蚀深度和器件输出功率水平差异较大。而采用干法刻蚀加湿法腐蚀工艺技术，制备出的台面表面光滑、侧壁连续，腐蚀深度差异为6%，最终器件输出功率水平的差异仅为2%。利用该掩埋结技术制备的1 550 nm大功率激光器均匀性有了较大提升，900μm腔长单管的阈值电流约12 mA,300 mA工作电流时功率输出100 mW。     

半导体激光器电导数及其可靠性的研究

为了探索和验证半导体激光器电导数参数与其可靠性的关系,将12个半导体激光器串联后进行高温加速电老化,直到器件不激射。监测在加速老化过程中半导体激光器电导数参量的变化情况。通过分析老化期间监测的数据,发现电导数曲线在阈值电流处的下沉高度随着老化时间的增加而变小;结特征参量与电导数曲线(在大于阈值电流的工作状态下)在电流I=0处的截距值随着老化过程逐渐变大。并且结特征参量的变化量在早期处于比较小的平稳状态,然后快速增加到一定值并保持一段时间,之后快速下降并最终稳定在比较小的值,这说明器件退化分为3个阶段:在早期退化较慢,之后退化很快并保持一定的退化速度,最后又到了慢速退化期。从实验结果得知电导数参量与器件的寿命和老化程度有密切关系,并且电导数参数可表征半导体激光器的退化状态。     

基于AlxNy绝缘介质膜的新型窗口大功率半导体激光器

提升半导体激光器的腔面抗光学灾变(COD)损伤的能力,改善半导体激光器的工作特性,一直是大功率半导体激光器器件工艺研究的难点.基于薄膜应力使基底半导体材料带隙变化的原理,采用直流磁控溅射方法在不同条件下溅射生成不同内应力的AlxNy绝缘介质膜.通过研究大功率半导体激光器腔面退化机理,借助AlxNy等应力膜设计制作了一种新型非吸收透明窗口结构的宽条形半导体激光器,使器件平均最大输出功率提高46.5%,垂直发散角达到21°,水平发散角达到6.1°,2000 h加速老化试验,其千小时退化速率小于0.091%.     

GaAs-GaAlAs DH激光器暗线(DLD)的观察

<正> 一、引 言 GaAs-GaAlAs双异质结激光器(以下简称 GaAlAs DH激光器)的退化是人们很关心的问题.现在看来,器件退化主要有二种形式:快退化和慢退化.GaAlAs DH激光器有源区暗线的增长是器件快退化的主要原因之一.暗线的形成一般在几分钟到几十小时,因此在器件短期老化后如能方便地对器件内部发光情况进行观察并结合进行如阈值、微分量子效率、热阻、伏安特性等测试,将有助于器件退化原因的分析,有利于改进外延与制     

大功率半导体激光器的腔面钝化

大功率半导体激光器的腔面退化是影响其寿命和可靠性的重要因素,长期以来一直是人们关注和研究的重点。本文利用离子铣结合腔面钝化还原层的方法对大功率半导体激光器的腔面进行处理。结果显示,离子铣腔面钝化能够在一定程度上减少半导体激光器的功率退化,168h加速老化后退化幅度降低4.5%;同时该技术对老化过程中COD阈值降低有明显的抑制作用,可有效减少使用中的突然失效。结果表明,该技术能够改善半导体激光器的腔面特性,器件的可靠性和使用寿命可望得到提高。     

中子辐照下的6H-SiCpn结电特性分析

用中子辐照在６Ｈ－ＳｉＣｐｎ结中引入的复合中心和深能级陷阱解释了ＳｉＣｐｎ结辐照后电特性退化的现象,并推导了辐照后ＳｉＣｐｎ结理想因子与外加电压的关系,给出了ＳｉＣｐｎ结中子辐照电特性退化的模型,模拟结果和实验数据的对比说明关于ＳｉＣｐｎ结电特性退化的理论解释是正确的。     

高质量半导体激光晶片液相外延研究

以GaAs单晶为衬底的GaAlAs三元系红外光短波长双异质结半导体激光器,目前已走上实用化阶段.这种激光器的各种特性参数已基本上能满足应用系统的需求,它的应用开发领域正在越来越广.但是,这种半导体激光器目前还相当昂贵,价格远高于象晶体管之类的半导体器件,主要是因为制造的成品率很低,重复性和均匀性很差.为使这种半导体激光器更广泛地走向实用化,必须找出高可靠性高成品率和重复性好的器件制造方法,其中关键的技术是激光晶片的制造.我们采用液相外延技术制作这种激     

Recombination enhanced annealing effect in AlGaAs/GaAs remote junction heterostructure lasers

New structure lasers, the remote junction heterostructure (RJH) lasers, are made to obtain information about slow degradation of AlGaAs/GaAs DH lasers. The RJH laser is characterized by the presence of a thin clad layer between the active layer and the p-n junction. During the LD and LED mode aging process, the RJH lasers showed a marked reduction of threshold current. This reduction was accompanied by increased spontaneous lifetime and pileup of defects at the p-n junction. From these observations, a model was proposed in which point defect generation in the active layer and defect motion toward the p-n junction during the aging are assumed. The rate equation was derived for concentration of the point defect, and the solution of this equation was compared with the experimental results with reasonable agreement. The parameters relating to the slow degradation were determined, and the ultimate life of conventional DH lasers was discussed using these parameters.     

Higher power InGaAs-GaAs-InGaP distributed feedback buried heterostructure strained quantum well lasers grown by three step MOVPE

The first demonstration of distributed feedback InGaAs-GaAs buried heterostructure strained quantum well lasers with In/sub 0.49/Ga/sub 0.51/P cladding layers entirely grown by a three step MOVPE process is reported. Uncoated distributed feedback buried heterostructure lasers with a pn InGaP current blocking junction on a p/sup +/-GaAs substrate show a low laser threshold of 3.2 mA and a high output power of 45 mW both measured CW at RT.<>     

Characteristics of GaAs lasers near room temperature

The efficiency and threshold of GaAs lasers can be affected by a delay occurring between the application of a current pulse and the laser output. The delays may be some tenths of a microsecond in certain diffused junction lasers when operated near room temperature, e.g., when the donor substrate dopant is selenium with a concentration of the order of 10¹⁸atoms per cm³. No such delays are observed in diodes in which the substrate dopant is silicon. In the case of selenium, the delay depends on the doping level, decreasing as the concentration increases. The delay is also very sensitive to injection current, decreasing rapidly with increasing current from its maximum at threshold. During the pulse, after lasing commences, the output continues to increase. A similar effect has also been observed with spontaneous emission. Operation of these devices below room temperature shows that the delay is also dependent on temperature. The delay decreases over a fairly narrow temperature range and in all cases is no longer observed ( < 20 n/s) below -70°C. These observations are explained by considering the effect of impurity trapping levels which may be associated with the     

平面型InGaAs探测结构中p型杂质的二维扩散行为研究

在平面型InGaAs P-i-N短波红外探测结构中,p型杂质在材料中纵向和横向的扩散是决定pn结位置及其光电性能的主要因素,本文采用扫描电容显微方法(SCM)获得了扩散成结InGaAs/InAlAs像元剖面的二维载流子分布,从而实现对不同扩散条件下pn电场结的精确定位和分析.此外,对于InGaAs/InP探测器,SCM...     

质子注入平面掩埋条形高频DFB激光器

报道了采用质子注入制作平面掩埋条形高频ＤＦＢ激光器。质子注入提高了限制层对电流的限制作用,并减小了限制层的寄生电容;ＤＦＢ激光器的斜率效率由注入前的０．１４７ｍＷ／ｍＡ提高到０．２１６ｍＷ／ｍＡ;电容测试结果表明：质子注入使ｐｎｐｎ结构的势垒电容明显减小,激光器的寄生电容由注入前的约１００ｐＦ降至注入后的６ｐＦ;激光器的３ｄＢ调制宽带由注入前的５００ＭＨｚ提高到５．６６ＧＨｚ。高温老化筛选结果表明     

Influence of Zn doping profiles on excitation dependence of photoluminescence intensity in InGaAsP heterostructures

It is known that the Zn doping profile in strained multi-quantum-well (MQW) InGaAsP lasers strongly affects the electro-optical characteristics of these devices and their temperature sensitivity. A systematic investigation of the excitation dependence of the active layer photoluminescence (PL) intensity from compressively strained InGaAsP MQW pin laser material with different Zn doping profiles is described. When the pn junction lies within the active region, the excitation dependence of the PL intensity is superlinear at low excitation and linear at higher excitation. As the Zn profile is set back from the heterointerface creating a displaced pn junction from the active region, the excitation dependence is superlinear and linear at 300 K but becomes linear for all excitation powers at 77 K. The implications of these observations are discussed.     

New structures of GaAlAs lateral-injection laser for low-threshold and single-mode operation

Two new structures of lateral-injection transverse junction stripe (TJS) lasers, in which the stripe geometry is formed by the double heterojunctions, have been developed. These lasers, the homojunction type and the single-heterojunction type, have a self-reverse-biased p-n junction for concentrating current into the narrow active region. The temperature dependence of the threshold current has been very much improved in one of the new structures, the homojunction type, and is fair compared with those of good conventional broad-contact lasers. The threshold current does not increase rapidly up to 350 K in the homojunction lasers. These lasers exhibit improved characteristics of low threshold, the single longitudinal mode oscillation as well as the single fundamental transverse-mode oscillation, and "kink-free" behavior in the current depedence of the light-output power.     

L-band DFB laser diodes with output power of 106 mW at 1625 nm

For the first time, distributed-feedback lasers emitting at 1625 nm with high output power and low operation current are fabricated. Temperature-induced performance degradation is minimised by optimising carrier and optical confinement. Consequently, these L-band lasers show no additional degradation in threshold current with rising temperature compared to C-band lasers.     

GSMBE生长In_(0.49)Ga_(0.51)P/GaAs HBT微结构材料及器件研究

采用 GSMBE技术 ,在材料表征和分析的基础上 ,通过优化生长条件 ,生长出高性能In0 .4 9Ga0 .51P/ Ga As异质结双极晶体管 (HBT)微结构材料 ,并制备出器件。材料结构中采用了厚度为 6 0 nm、掺杂浓度为 3× 10 19cm-3的掺 Be Ga As基区和 5nm非掺杂隔离层 ,器件流片中采用湿法化学腐蚀制作台面结构。测试结果表明该类器件具有良好的结特性 ,在集电极电流密度 2 80 A/cm2时其共发射极电流增益达 32 0。由此说明非掺杂隔离层的引入有效地抑制了由于基区 Be扩散导致的 pn结与异质结偏位及其所引起的器件性能劣化。     

高温CMOS数字集成电路直流传输特性的分析

分析了高温CMOS倒相器和门电路的直流传输特性,建立了相应的解析模型。根据分析,高温MOSFET阈值电压和载流子迁移率的降低,以及MOSFET漏端pn结泄漏电流的增加引起了CMOS倒相器和门电路直流传输特性劣化。在MOSFET漏端pn结泄漏电流的影响下,高温CMOS倒相器和门电路的输出高电平下降,低电平上升,导致了电路的功能失效。给出的理论模型和实验结果一致。