Improving Long-Term Stability of a Resonant Micro-Optic Gyro by Reducing Polarization Fluctuation

Resonant micro-optic gyros (RMOGs) with waveguide-type ring resonators are promising candidates for applications demanding small, light, and robust gyros. However, the nonzero bias at the gyro output fluctuates in terms of both the bias and the bias stability, owing to the temperature variations of the waveguide-type resonator. In particular, the temperature sensitivity of the bias stability varies greatly depending on the temperature. This paper intends to reveal that these observed fluctuations arise from the temperature-dependent polarization fluctuation. We will investigate how such polarization fluctuation affects the bias of the gyro-output through the state of polarization of the input beam, the polarization characteristics of the resonator coupler, and the temperature variation of the resonator. Both our numerical simulation and experimental verification are carried out, which, for the first time to our best knowledge, demonstrate that the long-term stability of the RMOG can be significantly improved by optimizing the temperature of the waveguide resonator.