Reduction of Backscattering Induced Noise by Carrier Suppression in Waveguide-type Optical Passive Ring Resonator Gyroscope

摘要

For applications requiring smaller, lighter and robust gyros, waveguide-type optical passive ring resonator gyroscope (OPRG) is a promising candidate. The drift level of OPRG, which is seriously affected by the backscattering induced noise, is limited by the carrier suppression levelin phase modulation spectroscopy technique. In this paper, we examine the influence of the carrier suppression level on the gyro performance experimentally. In order to achieve high carrier suppression directly by controlling the peak-to-peak voltage of the sine wave applied to the phase modulator, high precision calibration of the phase modulator is necessary. Suppressed carrier level higher than 50dB has been obtained by controlling the voltage with the accuracy of 1 mV. Proportional integrator (PI) is adopted to eliminate the residual error for the lock-in frequency. A bias stability of 3.17s is firstly demonstrated in a silica waveguide ring resonator with the ring length of 7.9cm.