Bias of an optical passive ring-resonator gyro caused by the misalignment of the polarization axis in the polarization-maintaining fiber resonator

An analysis is presented of the bias of an optical passive ring-resonator gyro caused by the misalignment of the polarization axis in the resonator formed by the polarization-maintaining fiber. A large bias takes place when the phase difference between the two polarization modes of the fiber is equal to the amount of 2π times an integer. It is clarified that the bias can be suppressed by setting the fiber polarizers at the lead portions of the resonator, which was a method proposed originally to reduce the bias in an ideal resonator without the misalignment