Eliminating the influence of modulation depth by a laser interference double detection system

Abstract

We propose a method of combining a double optical path detection system with a phase generation carrier arctangent algorithm. The feasibility of eliminating the influence of modulation depth by the double optical path detection vibration measurement system is verified by simulation and experiment. Results show that the average total harmonic distortion of the single frequency signal is 1%, and the signal-to-noise ratio of the speech signal is improved by an average of 5.6 dB. Therefore, the double optical path detection system can eliminate the influence of modulation depth, avoid nonlinear distortion, and improve the detection performance of the system.