The frequency mixing impact analysis of the light intensity noise with modulation signals in phase generated carrier (PGC) demodulation method

摘要

In order to improve the resolution of laser Doppler interferometer, the noise of the system need to be suppressed. Through the analysis of the influence of laser relaxation oscillation mixing with signals in phase generated carrier (PGC) demodulation, we can get a conclusion that the low-frequency part of the laser intensity noise have a greater impact on the signal to noise ratio of PGC demodulation. By using Optoelectronic negative feedback method, we can achieve effective suppression of the low-frequency laser intensity noise and laser relaxation oscillation peak, which reduce the influence of the mixing of the light source intensity noise, and the system signal to noise ratio (SNR) is improved.