Zhang Shihua, Yan Liping, Chen Benyong, Xu Zheyi, Xie Jiandong
Opt Express. 2017 Jan 9;25(1):472-485. doi: 10.1364/OE.25.000472.
As the phase delay between the carrier component of the detected interference signal and the carrier has adverse effect for phase generated carrier (PGC) demodulation, it is essential to compensate the phase delay to improve the accuracy of precision displacement measurement in sinusoidal phase-modulation interferometer (SPMI). In this paper, a real-time phase delay compensation method is proposed by regulating a compensating phase introduced to the carrier to maximize the output of the low pass filter so as to make the carrier synchronize with the interference signal. The influence of phase delay for PGC demodulation is analyzed and the method for real-time phase delay compensation is described in detail. The simulation of the method was performed to verify the validity of the phase delay compensation algorithm. A SPMI using an EOM was constructed and several comparative experiments were carried out to demonstrate the feasibility of the proposed method. The experimental results show that the phase delay can be compensated accurately in real time, and nanometer accuracy is achieved for precision displacement measurement.
由于检测到的干涉信号的载波分量与载波之间的相位延迟对相位生成载波（PGC）解调有不利影响，因此必须补偿相位延迟，以提高正弦相位调制干涉仪（SPMI）中精密位移测量的精度。本文提出了一种实时相位延迟补偿方法，通过调节引入到载波中的补偿相位，使低通滤波器的输出最大化，从而使载波与干涉信号同步。分析了相位延迟对PGC解调的影响，并详细描述了实时相位延迟补偿方法。对该方法进行了仿真，验证了相位延迟补偿算法的有效性。构建了一个使用电光调制器（EOM）的SPMI，并进行了几个对比实验，以证明所提方法的可行性。实验结果表明，相位延迟可以实时精确补偿，精密位移测量实现了纳米级精度。
