基于光纤法珀干涉仪偏置点控制的高频振动位移测量方法

High-Frequency Vibration Displacement Measurement Method Based on Phase Bias Point Controlling of Fiber-Optic Fabry-Perot Interferometer

为了实现超声换能器辐射面的振动测量,本文研究了一种基于光纤法珀干涉仪偏置点控制的高频振动位移测量方法,具有抗环境干扰、精度高等优点.针对正交相位偏置点解调方法中偏置点不稳定的问题,提出并分析了一种采用压电陶瓷叠堆执行器调整腔长稳定偏置点的工作原理,并对高频振动位移测量系统的性能进行了实验测试.实验结果表明:通过反馈控制腔长可以实现法珀干涉仪相位偏置点的稳定;位移测量系统的位移分辨率高于0.229nm;测得位移和换能器的输入电压的非线性度小于3.41%.

In order to measure the vibration of the radiating surface of the ultrasonic transducer,the high-frequency vibration displacement measurement method based on phase bias point control of the fiber-optic fabry-perot interferometer is described,and the sensing system has the advantages of anti-interference and high accuracy.To solve the problem of instability of the phase bias point of the fabry-perot interferometer,the principle of a fiber-optic fabry-perot interferometer employing apiezoelectric ceramic stack actuator to adjust the cavity length is proposed and implemented.At last,the performances of the fiber optic fabry-perot vibration displacement measurement system are experimentally tested.The experimental results show that：The feedback controlling of the cavity length can stabilize the phase bias point of the fiber-optic fabry-perot interferometer;The displacement resolution of the measurement system is higher than 0.229nm;The non-linearity of the measured vibration displacement and applied voltage of ultrasonic transducer is about 3.41%.