Study on current-tuning-induced intensity noise in resonator integrated optic gyro

Resonator integrated optic gyro (RIOG) employing laser diode (LD) is beneficial to miniaturization developing. However, when the frequency of the LD is tuned by current, accompany intensity noise is produced. Influence of current-tuning-induced intensity noise on the open-loop RIOG was theoretically analyzed; linear relationship between frequency locking position and output intensity of the LD was obtained. Subsequently, method of the intensity noise elimination was proposed based on the frequency locking position. Intensity fluctuation of the LD was monitored in real time by the frequency locking position. Compensation coefficients were calculated according to the monitor values, and they were used to compensate the gyro output. Finally, theoretical model that suppressing the current-tuning-induced intensity noise was set up, and the experiments were demonstrated, in which the bias stability of the RIOG was improved from 0.768(°)/s to 0.103(°)/s.