Angular-rate sensing by mode splitting in a Whispering-gallery-mode optical microresonator

Angular- rate sensing can be achieved by monitoring the shift in or splitting of a resonant frequency. The mode-shift mechanism, described by the Sagnac effect, treats backscattering as a noise source in a traditional resonant optic gyroscope. While in an ultrahigh-Q resonator, backscattering can create mode splitting. Mode splitting as a self-reference sensing scheme can solve problems such as temperature vibration, which leads to a higher resolution. We propose the mode-splitting mechanism for angular-rate sensing. It is found that the angular rate can be derived from the amount of splitting instead of the frequency difference between the clockwise and counterclockwise waves. The theoretical highest resolution can reach 0.0614°/s. To realize enhanced performance, the issues that may affect the measurement are discussed.