基于压电陶瓷相位调制器的外调制相位生成载波法研究

摘要

对基于压电换能器PZT(Piezoelectric Transducer)的外调制相位生成载波PGC(Phase-Generated Carrier)法进行了深入的理论分析和实验研究.PZT光纤相位调制器利用电致伸缩效应来改变缠绕在其上面的光纤的长度,进而实现对光纤中光相位的周期性调制.在马赫曾德尔光纤干涉仪MZI(Mach-Zehnder Interferometer)的参考臂中加入该光纤相位调制器便可以将载波信号调制到光纤干涉仪的输出信号当中.计算机仿真分析了调制参数对PGC解调结果的影响.并通过实验验证了这种调制解调方案的可行性.利用美国国家仪器公司的数据采集系统及Labview编写的解调算法,在臂长为200 m的MZI中成功实现了相位解调,恢复出MZI传感臂中的原始相位信息,解调信号与原始信号的相关系数在0.99以上.%The external modulation phase-generated carrier(PGC)method based on piezoelectric transducer(PZT)is theoretically and experimentally investigated.The PZT phase modulator changes the length of winding fibers by electrostrictive effect to realize periodic phase modulation.The carrier is contained in the output interference signals when the phase modulator is inserted into the reference arm of a Mach-Zehnder Interferometer(MZI).Numerical simulations are carried out to study the influence of modulation parameters on PGC demodulation results.And feasibility of the scheme is verified by experiments.Phase demodulation is successfully achieved in a 200 m long MZI,and the original phase information on sensing arm is recovered by using NI Data Acquisition System and demodulation algorithm written by Labview,the correlation coefficient between demodulation results and original signals is above 0.99.