Resonator fiber-optic gyro with intensity error suppression using a bias-sampling compensation technique

Resonator fiber-optic gyros (RFOGs) are one of the most promising candidates for next-generation inertial rotation sensors. The frequency servo loop is used to lock the laser frequency to the resonance frequency of fiber ring resonator via adjusting the laser diode current, which increases accompanying intensity variation and induces RFOG drift. RFOG output compensation using a bias-sampling technique is proposed to suppress intensity error. The linear relationship between the RFOG output and bias is verified by theory and experimental results, and the bias-sampling compensation technique by monitoring the bias signal is analyzed in detail. With the compensation technique, intensity error is significantly suppressed, and the RFOG bias stability is effectively improved from 127.2 to 7.4 deg/h, which demonstrates tactical-grade performance.