Analysis and simulation of optical polarization fluctuation of interferometric fiber optic gyroscope

One of the most important errors in the IFOG system is polarization noise which is derived from the cross-talking between two individual modes in the fiber. How to decrease polarization noise is one of the key technologies to increase the accuracy of IFOG, especially of high precision IFOG. In this paper, a whole mathematical model of the light path transferring system of polarization maintaining interferometric fiber optic gyroscope (PM-I-FOG) is first established by making use of Jones matrix. Based on the model mentioned above, theoretic analysis on the optic path polarization is made, the influences of each apparatus on polarization noise are discussed, including super-fluorescent fiber source, polarization maintaining coupler, Y-junction waveguide modulator and polarization maintaining fiber ring, which are the most important optical devices in the IFOG. This paper also simulates the polarization noises of the PM-I-FOG. We first break down the optic fiber system and simulate polarization noise of every part mentioned above, then simulate the characters of the whole fiber optic gyroscope system, which is consistent well with the theoretic analysis results. At last we suggest a new technology to restrain the polarization noise, which has reference value in designing high precision PM-I-FOG.