基于三层速率方程的单量子阱激光器电路模型

量子阱激光器以其优良的性能,成为光通信领域的一种重要光源.在量子阱激光器模型中引入中间过渡态,能更完整地描述阱中载流子的输运过程.对基于三层速率方程的单量子阱激光器电路模型进行模拟分析,探讨了过渡态在载流子输运过程中的作用.其模型仿真的结果对器件设计及不同模型的选用具有十分重要的参考价值.     

小发散角量子阱激光器研究

使用三层平板波导理论分析了半导体量子阱激光器远场分布。针对大功率激光器讨论了极窄和模式扩展波导结构方法减小垂直方向远场发散角,得到了极窄波导结构量子阱激光器远场分布的简化模型,获得了垂直发散角的理论值,垂直方向远场发散角减小为28.6°;使用传输矩阵方法模拟了模式扩展波导结构量子阱激光器的近场光斑及远场分布,垂直方向远场发散角减小为16°。实验测试了极窄和模式扩展波导结构量子阱激光器的垂直发散角,理论结果与实验测试获得的发散角基本一致,实现了降低发散角的要求,获得了小发散角量子阱激光器。     

GaN基激光器多量子阱结构的性能表征与结构优化

研究了包括四元合金在内的三种多量子阱结构,对以此为有源层的激光器进行了性能表征和比较分析.通过对阈值电流和外微分量子效率的测量以及增益分布的模拟分析,证实了四元合金用于量子阱结构生长对提高激光器性能的作用.此外对优化的量子阱结构激光器的漏电流和增益饱和带来的影响进行了研究.     

GaN基激光器多量子阱结构的性能表征与结构优化

研究了包括四元合金在内的三种多量子阱结构,对以此为有源层的激光器进行了性能表征和比较分析.通过对阈值电流和外微分量子效率的测量以及增益分布的模拟分析,证实了四元合金用于量子阱结构生长对提高激光器性能的作用.此外对优化的量子阱结构激光器的漏电流和增益饱和带来的影响进行了研究.     

基于三层模型的多量子阱激光器调制特性的SPICE模拟

从三层速率方程推导出多量子阱激光器的等效电路模型 ,并用数量而不是密度来描述载流子及光子行为 ,避开了传统方法中处处都要涉及到的体积参量 ,解释了传统的二层模型所不能解释的多量子阱 (MQW )激光器中多量子阱内载流子不均匀分布问题 ,用SPICE进行了调制特性的模拟及讨论。激光器件的模拟以层次性的方式实现 ,对使用EDA工具进行集成光学器件和系统仿真进行了探索。     

应变多量子阱激光器的结构稳定性

通过计算应变多量子阱中的净应力和应变弛豫,讨论了激光器结构中应变多量子阱的稳定性。净应力是失配位错增殖的驱动力,是应变多量子阱稳定的重要判据。因此,用单结点模型计算了应变多量子阱结构中的净应力。计算结果表明,净应力的最大值在应变多量子阱结构中的位置与阱层和垒层的厚度以及阱层的失配有关,非应变垒层和盖层能在一定程度上稀释净应力。在此基础上,利用动力学模型计算了应变多量子阱的应变弛豫。     

量子阱激光器超晶格缓冲层的研究

在量子阱半导体激光器结构中采用优化超晶格缓冲层来掩埋衬底缺陷，获得了性能优良的激光器。对超晶格缓冲层所具有的“量子阱陷阱效应”进行了理论分析。     

2 μm半导体激光器有源区量子阱数的优化设计

利用LASTIP软件理论分析了有源区量子阱数目对不同组分的InGaAsSb/AlGaAsSb 2 m半导体激光器能带、电子与空穴浓度分布以及辐射复合率等性能参数的影响。研究表明: 量子阱的个数是影响激光器件性能的关键参数, 需要综合分析和优化。量子阱数太少时, 量子阱对电子束缚能力弱, 电子在p层中泄漏明显, 辐射复合率低。量子阱数过多时, 载流子在阱内分配不均匀, p型层中电子浓度升高, 器件内损耗加大, 辐射复合率下降。结合对外延材料质量的分析, InGaAsSb/AlGaAsSb 半导体激光器有源区最优量子阱数目为2~3。该研究结果可合理地解释已有实验报道, 并为2 m半导体激光器结构设计提供理论依据。     

预应变InGaN/GaN多量子阱发光特性调控研究

为了减弱InGaN/GaN量子阱内的压电极化场,在蓝紫光InGaN/GaN多量子阱激光器结构中采用了预应变InGaN插入层,通过变温电致发光和高分辨X射线衍射测量研究了预应变插入层对量子阱晶体质量和发光特性的影响。实验结果显示,常温下有预应变层的量子阱电致发光谱积分强度显著提高。模拟计算进一步表明,预应变层对量子阱内压电极化场有调制效果,有利于量子阱中的应力弛豫,可以有效减弱量子限制斯塔克效应,有助于提高量子阱的发光效率。     

GaAs/AlGaAs环形激光器的量子阱结构优化

为了研究量子阱结构对半导体环形激光器阈值电流的影响,从F-P腔激光器的振荡条件出发,分析了半导体环形激光器的阈值电流密度与量子阱结构参量的函数关系,并推导出最佳量子阱数的表达式。利用器件仿真软件ATLAS建立环形激光器的等效模型,仿真、分析了不同工作温度下,量子阱数、阱厚及势垒厚度对阈值电流的影响。结果表明,阈值电流随量子阱数和阱厚的增加先减小后增大,存在一组最佳值;在确定合适的量子阱数和阱厚后,相对较窄的势垒厚度有助于进一步降低阈值电流;采用GaAs/AlGaAs材料体系和器件结构,其最佳量子阱结构参量为M=3,dw=20nm及db=10nm。     

Investigation of InGaAs/GaAs Quantum Well Lasers with Slightly Doped Tunnel Junction

Semiconductors - We experimentally investigate and analyze the electrical and optical characteristics of InGaAs/GaAs conventional quantum well laser diode and the quantum well laser diode with...     

Improvement of GaAs/AlGaAs quantum well laser diodes by rapid thermal annealing

Post-growth annealing is shown to improve the laser diode quality of GaAs/AlGaAs graded-index separate confinement heterostructure quantum well laser diode structures grown at a nonoptimal substrate temperature lower than 680°C by molecular beam epitaxy. Reduction by a factor of up to three in the threshold current was accompanied by a reduction in the interface trap density. The reduced threshold current is still higher than that of laser diodes grown at the optimal temperatures which are between 680 and 695°C. The improvement in laser diode performance is ascribed to the reduction of interface nonradiative recombination centers.     

High-power single-mode 2.0 μm laser diodes

Data are presented on high-power single-mode index-guided laser diodes fabricated from a strained-layer InGaAs-InGaAsP double quantum well heterostructure epitaxial design. The total maximum power and external efficiency achieved are 50 mW and 43%, respectively. The far-field is measured to be 31° by 46° in the parallel and perpendicular directions, yielding an aspect ratio of 1.5 for the single-mode laser diode. The optical output of the laser diode is a multi-longitudinal mode spectrum spanning 1.98-2.00 μm at an output power of 50 mW CW. The characteristic temperature of the laser diode is 48 K     

1.06μm大功率连续半导体激光器

利用金属有机化学气相淀积(MOCVD)技术,生长了InGaAs/AlGaAs分别限制压应变双量子阱和单量子阱两种材料结构,通过对不同腔长单管激光器的LIV测试获得内部参数,对单、双阱两种材料结构器件参数进行对比分析,确定了单量子阱结构作为1.06μm大功率半导体激光器的材料结构。通过研究单管激光器的电光转换效率与腔长、注入电流的关系,获得了最高达到57.5%的电光转换效率。对1mm腔长单管激光器进行了大电流高温加速老化测试,结果显示研制出的单管激光器室温下在1.5A工作电流下寿命远大于104h。     

CW room-temperature visible single quantum well Ga0.73Al0.27As diode lasers grown by metalorganic chemical vapour deposition

Room-temperature CW laser operation at 7125 ? has been achieved in a (Ga1?xAlxAs, x?0.27) single quantum well double heterostructure (SQW-DH) diode laser. The laser consists of a 9 ?m-wide delineated shallow proton stripe. The pulsed threshold current for a 250 ?m long device is 115 mA whereas the CW threshold current is 140 mA. The CW external differential quantum efficiency is 60%.     

Low threshold current density 1.5 mu m GaInAs/AlGaInAs graded-index separate-confinement-heterostructure quantum well laser diodes grown by metal organic chemical vapour deposition

A low threshold current density of 640 A/cm/sup 2/ was obtained in a 1.5 Gmm GaInAs/AlGaInAs multiple quantum well laser diode, grown by metal organic chemical vapour deposition, with continuously graded-index separate-confinement heterostructure. An internal waveguide loss of 14 cm/sup -1/ and internal quantum efficiency of 59% were obtained, which are comparable to those of GaInAs/GaInAsP quantum well laser diodes.<>     

GaInAsN/GaAs laser diodes operating at 1.52 μm

GaInAsN/GaAs double quantum well (DQW) lasers have been grown by solid source molecular beam epitaxy (MBE). Room-temperature pulsed operation is demonstrated for a ridge waveguide laser diode at a wavelength of 1517 nm. This is the first report of room-temperature laser emission in the 1.5 μm range based on GaAs     

Optimization of GaAsP/AlGaAs-based QW laser structures for high power 800 nm operation

We present a detailed study of the MOVPE growth of 800 nm diode laser structures based on the combination of a GaAsP quantum well with well-established AlGaAs waveguide structures. By optimizing the strain and thickness of the quantum well highly-reliable diode lasers with low threshold current and high efficiency were demonstrated. 100 μm aperture “broad area” devices mounted epi-side up achieve a CW output power of 8.9 W with a wall-plug efficiency of 50%. These output powers represent record values for diode lasers in this wavelength range. Reliability measurements at 1.5 W and 50°C ambient temperature suggest lifetimes >10 000 h.     

808nm无Al量子阱激光器mini阵列的研制

通过分析激光器的结构,优化设计了非对称宽波导激光器结构及外延生长条件。利用低压金属有机化合物气相淀积技术(LP-MOCVD)生长了高质量的InGaAsP/GaInP无铝应变量子阱外延材料,制作成808 nm高功率半导体激光器mini阵列,将其应用到1 064 nm全固态激光器中。20℃下,制作的808 nm,0.5 cm半导体激光器mini阵列,连续驱动电流50 A时输出功率达到50 W,最高光电转换效率达到53%。将该808 nm激光器mini阵列应用到全固态1 064 nm激光模组中,50 W,1 064 nm激光输出时,工作电流只有15 A。经过多于500 h老化以后,1 064 nm全固态激光器的功率衰减小于2%。     

All-optical active switch using a multiple quantum well nonlinearetalon as a laser diode mirror

A GaAs/AlGaAs multiple quantum well nonlinear etalon with a Bragg reflector was used as a feedback mirror of an external cavity laser diode. The laser oscillation was switched on/off by an external control light with high contrast ratio of 30:1