匹配型迈克尔逊干涉结构中PZT相位调制对PGC解调算法的影响

通过对相位生成载波(PGC)解调算法的仿真以及参考大量相关文献,可以发现调制度C对PGC解调结果有着极其重要的影响。而调制度C的大小由压电陶瓷PZT(Piezoelectric Transducter)对光路实际产生的相位调制决定,因此,对PZT光相位调制器相位调制常数的校准以及实际产生的相位调制计算很重要。其中对于光相位调制器相位调制常数的校准,可以根据PZT的特性,对PZT施加固定频率的三角波电压,观察干涉信号的变化。通过分析匹配型迈克尔逊干涉仪的PZT调制方式,给出计算调制度C的公式,并分析了调制方式对载波调制度大小和相位的影响,得出PZT对光路信号调制两次,与PZT的调制度两次叠加基本相等,但是会对载波基频增加一个固定的相位延迟,对调制解调算算法有影响,需计算其具体大小,在运算时消掉其影响。

Influence of PZT Phase Modulation on PGC Demodulation Algorithm in Matched Michelson Interference Structure

Through the simulation of the Phase Generated Carrier(PGC)demodulation algorithm and referring to a large number of related literature,it can be found that the modulation degree C has an extremely important influence on PGC demodulation result.The degree of modulation C is determined by the phase modulation actually generated by piezoelectric ceramic PZT(Piezoelectric Transducter)on the optical path.Therefore,it is important to calibrate the phase modulation constant of the PZT optical phase modulator and the phase modulation calculation actually generated.For the calibration of the phase modulation constant of the optical phase modulator,a triangular wave voltage of a fixed frequency can be applied to PZT according to the characteristics of PZT,and the change of the interference signal can be observed.By analyzing PZT modulation mode of the matched Michelson interferometer,the formula for calculating the modulation degree C is given,and the influence of the modulation mode on the magnitude and phase of the carrier modulation is analyzed.It is found that the PZT modulates the optical path signal twice,and the modulation degrees of PZT are basically equal to these two super-positions,but it adds a fixed phase delay to the carrier fundamental frequency,which has an effect on the modulation and demodulation algorithm.It is necessary to calculate its specific size and eliminate its influence during the operation.