相干光通信中平衡探测器的研究与测试

Analysis and Test of Balanced Detector in Coherent Optical Communication

在高速相干光通信系统中,平衡光电探测器是其核心器件。通过对相干探测原理的分析,得出了一致性系数与平衡探测信噪比的关系,给出了平衡探测器的组成结构,设计了相干探测的测试方案。当通信速率为5 Gbps时,该平衡探测器的共模抑制比高于27d B,采用平衡探测实现相干解调的最小信号光功率比单管探测改善了8 d B,验证了该平衡探测器用于高速相干光通信的可行性。

Balanced photodetector is the core component in the high-speed coherent optical communication system. According to the analysis of coherent detection principle,the relationship between consistency coefficient and signal-to-noise ratio of the balanced detection is obtained,the structure of the balanced detector is presented,and the test scheme about coherent detection is designed. Under the communication rate of 5 Gbps,the common mode rejection ratio of the balanced detector is more than 27 d B,and the minimum optical signal power using balanced detection to realize coherent demodulation than single tube detection＇s is improved by 8 d B,which verifies the feasibility of the balanced detector used for high speed coherent optical communication.