High sensitivity, high bandwidth photonic integrated optomechanical accelerometer: a numerical approach

We present a theoretical and numerical investigation of a novel photonic integrated optomechanical accelerometer, which utilizes the elasto-optic effect in a silicon nitride racetrack resonator for precise motion detection. The study combines finite-element analysis using COMSOL Multiphysics, coupling structural mechanics, wave optics at telecom wavelengths, and heat transfer in solids to estimate key performance metrics based on realistic material parameters. We estimate an optomechanical coupling constant of 0.8MHz per nanometer, along with high mechanical and optical quality factors. Our predictions indicate a shot noise-limited displacement resolution at the femtometer level, and acceleration noise floors below 300nano-g across a 15kHz bandwidth. These results represent a state-of-the-art performance, placing this proposed accelerometer among the best integrated optomechanical accelerometers with comparable bandwidth and footprint.