LAUSR

Abstract Multiple self-mixing (MSM) interferometry, a high-precision and effective method for measuring micro-displacement, is proposed in this paper. First, a triangular wave is used to drive an electro-optic modulator for the phase modulation of MSM interference signals. Then, the five-step phase-shifting algorithm is used to demodulate the modulated MSM interference signals. Finally, the displacement curves of the vibrating target are reconstructed. MSM interferometry is used to measure the displacement of sinusoidal motion with a peak-to-peak value of 2000 nm and a frequency of 10 Hz. Simulation results show that the maximum reconstruction error of MSM interferometry is 0.074 nm. Experimental results show that the maximum reconstruction errors of MSM interferometry are less than 4 nm. Therefore, MSM interferometry satisfies the high precision required by displacement measurement systems.