基于相干自混频原理的马赫-曾德尔调制器偏置点的监测

Monitoring Bias Offset Drift of Mach-Zehnder Modulator Based on Coherent Hybrid Scheme

提出并实现了用相干自混频方法监测马赫-曾德尔调制器(MZM)零偏置点漂移,将同一光源所产生的部分未调制光和调制后的光进行混频,利用混频光功率的最大最小值之比作为监测量监测。相比于监测信号光平均光功率的方法,可使±5%偏置点漂移下的灵敏度从0.02 dB提高到0.3 dB。利用设计完成的硬件反馈控制系统进行了多次实验,讨论了影响系统工作的各种因素及相应的解决办法,结果表明该方法工作有效。

A method called coherent hybrid is proposed to monitor the bias offset drift of Mach-Zehnder modulator （MZM） by mixing the unmodulated local oscillation lightwave with the modulated signal from the same light source and measuring the hybrid power ratio of the maximum to the minimum. The sensitivity at ± 5% bias offset is improved from 0.02 dB to 0.3 dB compared with the traditional method by measuring the signal average power. Experiments are carried out with the developed feedback and control system based on this scheme to find the impairment factors and explore the proper solutions. The results reveal the feasibility and effectiveness of the method.