Ultrahigh Resolution Acceleration Sensing Based on Prism-Microcavity Dissipative Coupling Architecture

Optical microcavities with ultrahigh quality factors are still currently considered as one of the solutions to achieve miniaturized and ultrahigh precision accelerometers, but the measurement of sub-ng/Hz1/2 acceleration has yet to be proven. Here we propose a new architecture for optomechanical acceleration sensing using prism and microcavity coupling. The relative displacement between the coupled prism and the microcavity is read in real time using the carrier information on the resonance spectrum, which inverts the loaded acceleration signal. In the sensing framework of the dissipative coupling mechanism, the self-referencing detection approach immunizes the majority of the common mode noise. The resonance frequency shift induced by the mismatch of the optical modes within the evanescent field improves the acceleration resolution to 91 pg/Hz1/2 at 40 Hz, which to the best of our knowledge is the first reported measurement of sub-ng/Hz1/2 acceleration based on a microcavity sensing architecture. It is expected to find applications in industrial manufacturing, inertial navigation, and gravity measurements.