低阈值电流、高量子效率脊形波导激光器

研制了低阈值电流、高量子效率670nm压缩应变单量子阱GaInP/AIGalnP脊形波导激光器。测量解理成的激光器条,腔长为300μm时,阈值电流为12．8mA,双面外部量子效率之和达到94．6％。     

量子阱半导体激光器发展动态

综述了近几年来国外在量子阱半导体激光器方面的开发现状，着重阐述了在提高器件性能方面获得低阈值电流，降低α参数和线宽的重要性。     

InGaN量子阱激光器增益和阈值电流的理论计算

根据现有的材料参数，计算了Ｉｎ０．２Ｇａ０．８Ｎ／Ｉｎ０．０５Ｇａ０．９５Ｎ量子阱激光器的增益、阈值电流密度以及阈值与温度的关系。理论分析表明氮化物蓝绿光激光器的阈值电流密度是ＧａＡｓ材料的５倍以上，但其特征温度可接近５００Ｋ。     

大功率量子阱远结半导体激光器

通过将下波导层掺杂为ｐ型,使半导体激光器的有源区与ｐｎ结分离,制作了大功率远结半导体激光器。该器件在老化期间表现出输出功率变大的趋势。理论分析表明,远结半导体激光器特殊的外延结构,决定了器件的阈值比正常器件的高,但是阈值受温度的影响较小,并且器件的退化机制转变为ｐｎ结的退化,这对于制作高可靠性、长寿命、低温度敏感性的半导体激光器具有重要意义。     

低阈值电流密度INGaAs/GaAs/AlGaAs应变量子阱激光器

利用分子束外延技术，生长了极低阈值电流密度、低内损耗、高量子效率的InGaAs／GaAs／AlGaAs应变量子阱激光器．在腔长900μm时，80μm宽接触激光器阈值电流密度是125A／cm2，在腔长为2000μm时是113A／cm2，这样低的阈值电流密度是目前国内报道的最低值．激光器的内损耗和内量子效率分别是2cm－1和84％．     

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。     

量子阱半导体激光器概述

本文主要从量子理论中的电子波函数所满足的薛定锷方程出发,讨论了量子阱理论。进而介绍多量手阱激光器(MQWL)的重要特征之一——阈值电流密度随量子阱的数目变化的情况。     

大功率半导体量子阱激光器及其应用

本文综述了量子阱应变层异质结构的大功率半导体激光器的优化特性，阐述了大功率激光器的一些重要应用，比如用８０８ｎｍ波长的大功率激光器可作为泵浦光源代替庞大的氙灯泵浦系统，还可以用作激光核反应的前级大功率激光漂；大功率半导体激光器发射的波长可以精确地控制在９８０ｎｍ，并能高效率地耗合到光纤中去，有很高的泵浦效率，从而半导体激光泵浦的光纤放大器为光通信技术的发展作了突破性贡献，大功率半导体激光器还在军工     

Threshold current of 670-nm AlGaInP strained quantum well lasers

By means of gain-current calculations we have examined the factors which determine the threshold current of compressively strained Ga_x In_1-xP/AlGaInP quantum well lasers for the various well width/composition (x) combinations which give a transition wavelength of 670 nm. In addition to valence band modifications we find that the increasing depth and decreasing width of the well are important in decreasing the current as the strain increases. We reveal the important role of well width fluctuations in devices with high compressive strain     

中红外可调谐量子级联激光器研究进展

量子级联激光器(QCL)是中红外波段重要的激光光源,其中,可调谐中红外量子级联激光器具有单纵模、频率可调谐的优点,成为目前研究的热点。可调谐中红外量子级联激光器主要通过分布反馈(DFB)光栅、分布布拉格反射(DBR)光栅、外腔衍射光栅等方法实现。本文介绍了中红外量子级联激光器的基本原理,分别归纳、总结了近年来DFB、DBR可调谐量子级联激光器以及外腔可调谐量子级联激光器的研究进展,讨论了各种可调谐方法的优缺点。最后,对可调谐量子级联激光器的发展趋势进行了展望。     

Advances in self-assembled semiconductor quantum dot lasers

In the past 20 years the semiconductor laser has become a key device in optical electronics because of its pure output spectrum and high quantum efficiency. As the capabilities of laser diodes have grown, so has the range of applications contemplated for them. A great success in semiconductor lasers has been brought by the ability to artificially structure new materials on an atomic scale by using advanced crystal growth methods such as MBE and MOVPE. The laser performance successes gained using quantum wells in optoelectronic devices can be extended by adopting quantum wire and quantum dot structures. There have been several reports of successful lasing action in semiconductor dot structures within the past few years. In this article I will briefly review the recent progress in the development of quantum dot lasers.     

GaInAs/AlInAs量子阱激光器特性--价带间光吸收对微分量子效率和特征温度的影响

计算和分析了晶格匹配ＧａＩｎＡｓ／ＡｌＩｎＡｓ半导体量子阱激光器（ＱＷＬ）中的价带间光吸收系数及其对微分量子效率（η０）和特征温度（Ｔ０）的影响。结果表明,价带间光吸收系数随带隙增加而减小,随温度和载流子浓度增加而增加,其所引起的阈值和出光微分量子效率的变化趋势虽然与实验观察到的相类似,但数值上却不起明显的作用。因此,价带间光吸收这种温敏光子损耗机制对长波长半导体激光器的温度效应不可能起主要的作用。     

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。     

InGaAs（P）／InP应变量子阱和超晶格的光电性质

利用低压金属有机化合物化学汽相沉积（ＭＯＣＶＤ）生长技术在ＩｎＰ衬底上生长ＩｎＧａＡｓ／ＩｎＰ应变量子阱，超晶格和ＩｎＧａＡｓＰ／ＩｎＰ量子阱结构材料，利用７７Ｋ光荧光（ＰＬ）测量这一应变量了阱和量子阱的光学性质，利用双晶Ｘ光测量应变超晶格的性质。     

半导体量子阱激光器（QWL）及其进展

由于半导体量子阱结构限制电子和空穴到极薄区域的量子尺寸效应,导致了它具有二维台阶状的态密度。因此,用这种结构制备的量子阱激光器(QWL)具有低的阈值电流密度,窄的谱线宽度,宽的波长调谐范围以及高的调制频率响应知易实现大功率、短波长可见光输出等优点。本文在描述了这种结构的台阶状态密度分布的基础上,主要介绍了 QWL 主要优异特性和最近的发展水平。最后对今后的发展方向作了预测。     

Temperature dependence of threshold current of GaAs quantum well lasers

The radiative recombination rate in a quantum well structure is calculated using a constant density of states and the k-selection rule. This calculation shows that the threshold current of a GaAs quantum well laser has low temperature sensitivity (T0 ? 330 K for T > 300 K).     

Threshold current analysis of compressive strain (0-1.8%) inlow-threshold, long-wavelength quantum well lasers

A comprehensive study of the effect of compressive strain on the threshold current performance of long-wavelength (1.5 μm) quantum-well (QW) lasers is presented. Model predictions of threshold currents in such devices identify QW thickness as a parameter that must be considered in optimizing laser performance when Auger currents are present. Experimental comparisons between strained and unstrained devices reveal strain-induced reductions in internal transparency current density per QW from 66 to 40 A/cm², an increase in peak differential modal gain from 0.12 to 0.23 cm/A, and evidence for the elimination of intervalence band absorption as compressive strain increases from 0 to 1.8%. However, most of these improvements arise in the first ~1% of compressive strain. To fabricate low-threshold 1.5-μm buried heterostructure (BH) devices in InP using the strained QW active regions an optimized design which shows that threshold current is at its lowest when the stripe width is approximately 0.6-0.7 μm is derived. Results for uncoated BH lasers are reported