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

• Main Authors: 李翔 Li, Xiang, 汪宏 Wang, Hong, 乔忠良 Qiao, Zhongliang, 张宇 Zhang, Yu, 牛智川 Niu, Zhichuan, 佟存柱 Tong, Cunzhu, 刘重阳 Liu, Chongyang
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: Chinese
• Published: 2021
• Subjects: Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics; 半导体锁模激光器 Mode-Locked Semiconductor Lasers; 重复频率 Repetition Frequency; GaSb基材料 GaSb-Based Material System; 2 μm波段 2 μm Wavelength Band
• Online Access: https://hdl.handle.net/10356/147471
• Institution: Nanyang Technological University

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 a