量子点激光器瞬态响应及调制特性分析

基于二能级系统建立量子点激光器的载流子-光子速率方程模型,分析量子点激光器的瞬态响应和调制特性,获得其动态特性.同时分析了注入电流对量子点激光器输出光子密度的影响,随着注入电流的增大,激光器光电延迟时间缩短,弛豫过程缩短,弛豫振荡频率增大,且输出光子峰值和稳态功率增加,适当增加注入电流可拓宽量子点激光器调制带宽.通过小信号调制分析,发现量子点激光器上限调制频率比普通激光器高一个数量级,证明了其具有良好的高频调制特性.

Simulation and Analysis of Transient Response and Modulation Characteristics of Quantum Dot Laser

The carrier-photon rate equation model of quantum dot laser was derived based on the two energy states system. By analyzing the transient response and modulation characteristics of quantum dot laser, its dynamic characteristics were obtained. The dependence of quantum dot laser output photon density on the inject current was discussed. With increasing the injection current, both the delay time and the relaxation process were shorten, but both the relaxation oscillation frequency and the peak and steady-state power of output photon increased, which means that the modulation bandwidth of quantum dot laser can be broaden by appropriately increasing the inject current. Based on the small-signal modulation analysis, it is found that the maximum modulation frequency of quantum dot laser is an order of magnitude higher than that of the conventional semiconductor laser. Then it is proved that the quantum dot laser has much better high frequency modulation characteristics.