为了研究光注入半导体激光器(SL)产生的光子微波信号的性能, 基于SL的速率方程和光纤布喇格光栅(FBG)滤波理论, 采用数值仿真的方法进行了理论分析, 得到了各种注入参量下的光谱、功率谱和线宽, 并讨论了反馈参量对微波线宽的影响, 考虑到光注入下产生的微波线宽较宽, 进一步引入FBG光反馈窄化了微波信号的线宽。结果表明, 当SL仅在光注入作用下时, 通过改变注入参量, 可实现微波频率连续可调谐和微波强度最大化; 微波线宽随着反馈强度的增加逐渐变窄, 通过适当调节反馈参量可将微波线宽压缩到10kHz以下。该研究结果可为半导体激光器在光生微波中的应用提供一定的理论参考。

In order to study the performance of the photonic microwave signal generated by a semiconductor laser (SL) under optical injection, based on the rate equation of SL and the fiber Bragg grating (FBG) filter theory, the optical spectra, power spectra, and linewidth under different injection parameters were obtained by numerical simulation and theoretical analysis, and the effect of the feedback parameters on the microwave linewidth was also studied. Considering that the generated microwave signal has wide linewidth, a FBG optical feedback was further introduced to narrow the microwave linewidth. The results show that, for the SL subject to optical injection only, the microwave frequency can be continuously tuned and the microwave intensity can be maximized by changing the injection parameters; the microwave linewidth gradually decreases with the increase of feedback strength. Through properly adjusting the feedback parameters, the microwave linewidth can be compressed below 10kHz. The results can provide a theoretical reference for the application of semiconductor laser in the photonic microwave signals generation.