Exceptional-surface-enhanced rotation sensing with robustness in a whispering-gallery-mode microresonator

Traditional optical gyroscopes rely on the Sagnac effect that the resonant frequency shift is linear with the rotation rate. Recently, optical gyroscopes operating near an exceptional point (EP) have been extensively investigated to improve the response to rotation. However, the high-performance implementation of this kind of gyroscope requires strict conditions, which restrict the practical application of these devices. In this paper, a non-Hermitian photonic configuration based on a single resonator is proposed to establish an exceptional surface (EP surface) constructed of numerous EPs. It is demonstrated theoretically that rotation-induced frequency splitting in our configuration is four orders of magnitude higher than that in the traditional gyroscope. We also investigate the shot-noise-limited minimum detectable rotation rate compared to the conventional gyroscope with the same radius and intrinsic loss, when the system is tuned around the EP. This proposed approach attempts to combine robustness with high sensitivity detection of the rotation.