Laser frequency combination tuning and locking technology in resonant optical gyro

Abstract

Generally, resonant optical gyroscopes (ROG) based on the Sagnac effect are very sensitive to the changes of temperature and optical power, which directly affects the output of the gyroscope. To improve the frequency lock-in accuracy and thermal stability of ROG system, the technology of laser frequency combination tuning and locking is proposed and experimentally demonstrated. Using the characteristics of voltage and temperature tuning wavelength of semiconductor laser, the output frequency range of laser is increased, the temperature control system of the resonant cavity can be removed and the gyro can never be unlocked in theory. In addition, the frequency lock-in accuracy under light power fluctuation is improved. Using this technique, a long-term (1-h) bias stability of 24.7 °/h is observed. Moreover, the weight and volume of the ROG are greatly reduced.