Automated Suppression of Polarization Fluctuation in Resonator Fiber Optic Gyro With Twin 90 $^{\circ}$ Polarization-Axis Rotated Splices

A method for automatically suppressing the polarization fluctuation in a resonator fiber optic gyro by adopting a resonator with twin 90° polarization-axis rotated splices is proposed and demonstrated experimentally. The scheme ensures that the input electric field excites only the desired eigenstate of polarization in the resonator by automatically setting the length difference of the fiber segments between the two 90° polarization-axis rotated splicing points at one half of the beat length of the polarization maintaining fiber. The feasibility of the proposed scheme is shown by simulation using a mathematical model based on the Jones transfer matrix. It is also demonstrated experimentally that the bias stability is enhanced when the feedback scheme is adopted.