消除光强扰动和调制深度影响的相位解调算法

Phase demodulation algorithm for eliminating the influence of light intensity disturbance and modulation depth

为了消除光强扰动和相位调制深度对相位生成载波(PGC)解调的影响,提出一种基于混频滤波、相除和差分的相位解调算法——PGC解调改进算法。该算法通过滤波和微分两两相除以及差分、积分运算,使得解调信号不含任何变量。对PGC解调改进算法进行了理论分析和推导,利用Labview平台构建仿真模型,验证了该算法相对于传统解调算法的优势,搭建了基于迈克尔逊干涉的解调系统并进行实验验证。实验结果表明:在不同的相位调制深度情况下,PGC解调改进算法解调出的待测信号不会产生谐波失真;在不同光强的情况下,解调出的信号幅度保持一致。

In order to eliminate the influence of light intensity disturbance and phase modulation depth on the phase generated carrier(PGC)demodulation,this paper proposes a phase demodulation algorithm based on mixing and filtering and phase division differential which is called PGC demodulation improved algorithm.The algorithm makes the demodulated signal without any variables by filtering and differential division and differential and integration operation.PGC demodulation improved algorithm is theoretically analyzed and deduced,and the simulation model is constructed by using Labview platform to verify the advantages of the proposed algorithm over traditional algorithm.A demodulation system based on Michelson interference is built for experimental verification.The experimental results show that the signal to be measured demodulated by the improved PGC demodulation algorithm will not produce harmonic distortion under different phase modulation depth.In the case of different light intensities,the demodulated signal amplitude remains the same.