In this paper, a novel phase demodulation method for multiple self-mixing interferometry (MSMI) is proposed, which can improve the resolution and accuracy of vibration measurement in laser self-mixing interferometry (SMI). The sinusoidal phase modulation of the beam is obtained by an electro-optic modulator (EOM), and phase demodulation is performed by a lock-in amplifier analysis method. The phase equation of MSMI was derived and the theory of the lock-in amplification technique was analyzed in detail. The validity of the proposed method is confirmed by means of simulated signals and then demonstrated by several experimental measurements. The experimental results indicated a good correspondence between theory and experiment.

中文翻译：

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基于锁相放大器分析的多次自混干涉测量振动

本文提出了一种新的用于多自混合干涉（MSMI）的相位解调方法，该方法可以提高激光自混合干涉（SMI）中振动测量的分辨率和精度。通过电光调制器（EOM）获得光束的正弦相位调制，并通过锁定放大器分析方法执行相位解调。推导了MSMI的相位方程，并详细分析了锁相放大技术的原理。所提方法的有效性通过仿真信号得到证实，然后通过多次实验测量证明。实验结果表明理论与实验之间有很好的对应关系。