Analysis On Influence Of External Disturbances And Acousto-optic Frequency Shifter Characteristics On Integrated Optic Gyros

As the third-generation optic gyro, the resonant integrated optic gyro has the advantage of high theoretical precision, anti-impact, integration and high reliability. It is an important developing direction of inertial sensors. Due to its high sensitivity to various noises, noise suppression is the emphasis and difficulty in the research of resonant integrated optic gyros.For the problem that polarization and thermal fluctuations influence performance of resonant integrated optic gyros, the effects of thermal and polarization fluctuations on the resonance curve of a waveguide ring resonator and the functions of relevant suppressing methods are measured. Experimental results show that the influence of the thermal and polarization fluctuations on the resonance curve of the ring resonator is remarkable. Thermostatic control can be very effective in reducing the temperature drift of the resonance curve. Although the polarization control method can decrease the effect of polarization fluctuation to a certain extent, its function is limited and cannot meet the demands of high precision gyros on the stability of the resonance curve.The spectral response and the power loss under different frequency-shifts of an acousto-optic frequency shifter are measured. The expression of demodulation curve including the AOFS response is derived. Calculations show that the slope of the demodulation curve is different under different frequency shifts due to the variation of the power loss, which should be compensated when the gyro is working.