Optomechanical sensing of wine-glass modes of a BAW resonator

A critical element for inertial navigation is precise knowledge of the angular kinematics which are measured using gyroscopes. Optomechanics has been shown to be the most sensitive scheme for measuring mechanical motion [1, 2]. In this paper, we demonstrate electrostatic actuation and optical sensing of orthogonal wineglass modes on a silicon-on-insulator (SOI) platform as a fundamental building block for a Coriolis force measuring z-axis bulk acoustic wave (BAW) gyroscope [3]. To measure the wineglass modes, we monitor the laser light modulation from changes in the waveguide to ring resonator coupling due to the mechanical motion.