Research on Intensity Noise Suppression for Closed Loop FOG

The main factor of random walk in a high precision fiber optic gyroscope is the intensity noise using erbium-doped fiber source, so decrease the intensity noise can reduce random walk. An intensity noise suppression method is proposed to reduce the random walk. An approach to reduce the random walk using subtraction combined with depolarizer was advanced after analyzing the relation of light intensity, phase and degree of polarization between two light beams. Analyze the gyroscope output data with Allan variance and we could determine from the result that the random walk coefficient was reduced by 32% than before.