为产生高性能微波频率梳(MFC),基于级联马赫-曾德尔调制器(MZM)光学回路系统,提出一种利用光梳外差法产生可调谐MFC的方案。将连续光通过耦合器注入到级联MZM光学回路中调制,最终产生光学频率梳(OFC),再将生成的OFC在光电探测器中拍频获得MFC。对该方案建立了理论模型,利用光通信系统设计软件Optisystem研究了光源功率、光源线宽和射频驱动信号(RF)频率等参数对输出MFC的性能的影响。结果表明,合理地调节光源、RF等器件参数,可以获得带宽为300 GHz、平坦度为0.12 dB、功率达22.49 dBm的MFC。该方案结构简单,易于实现,通过调节RF信号的频率,就可以得到梳距可调谐的MFC。

To produce a high-performance microwave frequency comb (MFC), a tunable MFC generating scheme using optical comb heterodyning is proposed based on a cascaded Mach-Zehnder modulator (MZM) optical loop system. Continuous light injected through the coupler into the cascade MZM optical loop for modulation can generate an optical frequency comb (OFC), which beats in the photoelectric detector to produce MFC. A theoretical model is created to simulate the system. The influences of the light source power, light source line width, radio frequency driving signal (RF) frequency, and other parameters on the final MFC performance are studied with the optical communication system design software Optisystem. Results show that the output MFC generated by properly adjusting the parameters of the light source, RF, and other devices has a 300-GHz bandwidth, with flatness of 0.12 dB and power reaching up to 22.49 dBm. The scheme is structurally simple and easy to implement, while additionally obtaining a comb-tunable MFC when the RF signal frequency is adjusted.