Reduction of high-frequency laser noise in resonant fiber optic gyroscope with a phase-modulated feedback loop

The resonant fiber-optic gyroscope (RFOG) based on the Sagnac effect is a high-accuracy rotation sensor. The intermodulation error due to the laser noise at even harmonics of the modulation frequency deteriorates the performance of the RFOG. Aiming at the suppression of high-frequency laser noise, a phase-modulated feedback loop is developed and analyzed. The parameters of the servo loop is optimized to enhance the performance of the gyroscope.