提出了一种光纤干涉仪动态相移测量的新方法。该方法无需对光源进行调制, 直接利用干涉信号的直流量和一次谐波分量, 通过构造匹配函数的方法求解动态相移, 实现了无源零差检测, 而且具有信号解调简单、工作频带宽等特点。为了验证该方法的有效性, 搭建了一个全保偏Mach-Zehnder光纤干涉仪系统, 对压电陶瓷(PZT)产生的模拟动态相移进行求解。结果表明, 求解得到的动态相移幅度与加载在PZT上的电压具有很好的线性关系, 这与PZT的低频小信号特性一致。最后将该方法用于干涉型光纤水听器声压相位灵敏度频响的测量, 实验结果与采用相位载波调制解调方法获得的结果基本吻合。

A new measurement method for dynamic phase changes in fiber interferometers is demonstrated. The amplitude of the dynamic phase is obtained directly from the zero and fundamental frequency components of the fiber interferometer output by method of constructing match-functions without modulating the laser. It has the advantages of no active element in the interferometer, simple signal demodulation and large operating bandwidth. To test this new method, an all polarization-maintaining Mach-Zehnder fiber interferometer is constructed, and the simulation dynamic phase change induced by PZT is measured. Experimental results show that the calculated amplitude of the dynamic phase shift is a good linear function of the voltage applied to the PZT, which accords well with PZT’s properties of low-frequency and small amplitude. This method is applied to the measurement for the acoustic sensitivity of interferometric fiber-optic hydrophones, and the test results are in agreement with the results obtained by phase generated carrier method.