Improving the error compensation capability in self-mixing interferometry

A scheme to improve the error compensation capability in self-mixing interferometry is proposed. Two beams of different frequencies are used as the measurement and reference light to compensate for the error. The short-term drift of the system is 12 nm and the long-term drift is 59 nm, and the experimental results show the effectiveness of the compensation. The performance is also evaluated, and the linearity of the frequency measurement can reach the order of 10-5, and the maximal standard deviation of the amplitude precision is 4.31 nm. The optical structure of this scheme is simple, the optical paths of measurement and reference light are easy to adjust, and the system has high robustness, which can be used as a sensor for real-time monitoring in practical engineering.