Analysis and countermeasure for polarization fluctuation induced noise in resonator fiber optic gyro considering polarization depended loss

摘要

Polarization fluctuation induced noise is a problem in Resonator Fiber Optic Gyro. The noise is enhanced when polarization depended loss exists in the resonator. As a countermeasure, a PM fiber resonator with 90° twisted splice at two points and with two couplers is analyzed. By adjusting the length difference between two fiber poritions, shape of the eigenstate of polarization (ESOP) becomes linear and coincides with polarization axis of the PM fiber. The resonant dips of the ESOPs locate with equal space with each other. Then, only one ESOP can be selectively excited. Consequently, the polarization fluctuation induced noise can be reduced even in the resonator with polarization dependent loss. By adapting appropriate parameters of the PM fiber and coil housing way, this resonator may realize a stable characteristic.