Frequency tracking and locking method used in resonator micro-optic gyro

Based on Sagnac effect and MEMS fabrication technique, resonator micro-optic gyro (RMOG) makes essential sense in promoting miniaturized and sensitive gyros. In this letter, a frequency tracking and locking method, referred to the mean value of the two resonant frequencies of the counter-propagating light beams in the resonator, is presented and applied to the established resonator micro-optic gyro system. Compared with the commonly used single light beam-based method, the proposed technique shows great advantage in improving its dynamic response, as well as its bias stability. Testing result shows that the frequency tracking time (dynamic response) under rotation rate variations improves from 0.27 ms/(°/s) to 0.09 ms/(°/s) by using the proposed frequency tracking and locking methods in the RMOG system.