1.3μm GaAs基量子点垂直腔面发射激光器结构设计与分析

结合垂直腔面发射激光器(VCSEL)原理以及量子点增益特点,计算了不同结构VCSEL的腔内损耗和量子点的模式增益.分析了激光器阈值特性以及氧化限制层对光损耗的影响.设计了含氧化限制层的1.3 μm量子点VCSEL结构

氧化限制型垂直腔面发射激光器串联电阻分

含氧化限制孔的VCSEL具有低的阈值电流,但氧化孔的存在也会加大串联电阻.本文采用理论模型,详细计算了氧化限制型VCSEL的串联电阻.把串联电阻分解为垂直方向电阻和横向电阻,分析了串联电阻与氧化孔半径的关系,提出了降低VCSEL串联电阻的具体方法

1064nm RCE探测器光电响应特性分析

对1064nm谐振腔增强型（RCE）光电探测器（PD）的光电响应特性进行了分析研究．利用MBE生长技术得到有源区分别为量子阱和量子点的1064nm RCE探测器的外延片，并对制作的探测器进行了各种光电特性测试．结果表明量子阱结构的RCE探测器量子效率峰值达到57％，谱线半宽6～7nm，峰值波长1059nm；而量子点结构的RCE探测器量子效率峰值达到30％，谱线半宽5nm，峰值波长1056nm．通过分析量子效率和吸收系数之间的关系，对两种结构器件的吸收进行了比较，发现虽然量子点探测器的吸收小，但通过合理设计共振腔等方法也可以达到较高的量子效率．两种结构的器件都有很好的I-V特性

2 微米GaSb 基被动锁模激光器重复频率变化的研究 = Repetition frequency variation of a 2 μm GaSb-based passively mode-locked laser

半导体锁模激光器产生的高重复频率的光脉冲序列在众多领域都有着广泛的应用，而对于绝大多数应用，一个固定而准确的重复频率是必须的。由于此种激光器的重复频率主要由激光器波导的有效折射率和腔长来确定，激光器制成以及解理时的不确定性就可能会给其重复频率带来偏差。为了弄清此种激光器的各种工作条件会怎样影响其重复频率从而对上述的偏差进行补偿，设计并制成了一种2 μm GaSb基单量子阱锁模激光器。激光器采用两段式结构（增益区，饱和吸收体区）并可以在高达60 ℃实现稳定的锁模工作模式。系统地记录了此激光器重复频率随偏置条件（增益区电流，饱和吸收体区电压）以及工作温度的变化规律，并且对产生这些变化的原因进行了分析。这些工作能够让人们更加清楚地认识锁模激光器的特性，从而更好地达到各种应用所需要的重复频率。Multi-gigahertz optical pulse trains generated from mode-locked semiconductor lasers are promising for a number of applications in many areas. For most of these applications, a fixed and stable pulse repetition frequency is necessary. Since the repetition frequency of such lasers is primarily determined by the effective refractive index of the laser waveguide and the laser cavity length, uncertainties during device fabrication as well as cleaving process may bring deviations to the repetition frequency. To gain better knowledge of how working conditions of such lasers effect their repetition frequency and thus compensate the above-mentioned deviations, a novel 2 µm InGaSb/AlGaAsSb single quantum well (SQW) mode-locked laser (MLL) was presented in this work. It has a two-section configuration (gain section and saturable absorber section separated by an electrical isolation region) and stable mode locking was achieved in this laser under a variety of bias conditions up to 60 ℃. Repetition frequency variations of this mode-locked laser with bias condition (gain section current I , absorber section voltage V ) and working temperature (T) were systematically recorded, and the mechanisms behind these variations were analyzed. It is believed that this work enables us to have a better understanding of passively mode-locked semiconductor lasers and is of interest to better meet the application-required frequencies. g aNational Research Foundation (NRF)Accepted version新加坡国家研究基金会（NRF-CRP12-2013-04）；中国国家自然科学基金（61964007，61790583）；广东省重点领域研发计划项目（2020B0303020001

2μm InGaSb/AlGaAsSb 量子阱激光器理想因子的研究 = Investigation on ideality factor of 2 µm InGaSb/AlGaAsSb quantum well laser

展示了一种低阈值(~131 A/cm2)2 μm InGaSb/AlGaAsSb单量子阱(Single Quantum Well, SQW)激光器, 并对该激光器的理想因子n进行了研究。激光器的总体理想因子n由中央pn结的理想因子n和n型GaSb衬底与n型金属之间形成的整流结的理想因子n两部分组成。当温度从20 ℃升高到80 ℃时, 激光器的总体理想因子n从4.0降低至3.3。该结果与所使用的理论模型以及独立的GaSb材料整流结(pn结、GaSb/金属结等)理想因子n的数值是相吻合的。2 µm InGaSb/AlGaAsSb single quantum well(SQW) laser with low threshold current density of ~131 A/cm and its ideality factor n was presented. The ideality factors n of the central p-n junction and the n-GaSb/metal junction sum up to be the total ideality factor n of the laser. The total ideality factor n decreases from 4.0 to 3.3 when the temperature was increased from 20 to 80℃. The results are in good agreement with the applied theoretical model as well as the ideality factor n of the individual GaSb -based junctions(p-n junction, GaSb/metal junction etc. ). 2National Research Foundation (NRF)Published version新加坡国家研究基金会（NRF-CRP12-2013-04）;国家自然科学基金（61790581，61790582，61435012，61308051