Suppression of Nonlinear Effects in a Whispering Gallery Mode Resonator for the Realization of Resonant Optical Gyroscope

The whispering gallery mode resonator (WGMR) possesses the characteristics of a small volume and a high quality (Q) factor, making the resonant optical gyroscope (ROG) based on it highly promising for development in terms of high accuracy, miniaturization, and integration. However, as the Q factor increases, the threshold for nonlinear effects decreases, posing challenges in obtaining resonance curves with high-Q. This phenomenon is a crucial factor influencing measurement accuracy. In this study, we conduct a thorough investigation of the underlying mechanisms that contribute to nonlinear effects. By meticulously adjusting the sweep speed and polarization state of the incident light, we successfully mitigate both thermally induced nonlinear effects (TINEs) and those stemming from mode-coupling, thereby enhancing the performance of our system. After meticulous high-frequency modulation, demodulation, and swift frequency locking procedures, we triumphantly realized the ROG featuring a bias instability (BI) of 9.03°/h, utilizing a compact 6-cm-diameter WGMR. This work presents significant backing for the progression of small, high-precision ROG technology.