Z-Axis Optomechanical Accelerometer

TL;DR

This paper introduces a silicon nitride z-axis accelerometer that uses waveguided light in an optical ring resonator to detect proof mass displacement caused by acceleration, achieving high sensitivity.

Contribution

It presents a novel optomechanical accelerometer design utilizing waveguided light in a ring resonator for precise z-axis acceleration sensing.

Findings

Achieved 22% per g optical modulation sensitivity.

Demonstrated high optical quality factor (Q_o) devices.

Validated the effectiveness of the cavity-enhanced optomechanical approach.

Abstract

We demonstrate a z-axis accelerometer which uses waveguided light to sense proof mass displacement. The accelerometer consists of two stacked rings (one fixed and one suspended above it) forming an optical ring resonator. As the upper ring moves due to z-axis acceleration, the effective refractive index changes, changing the optical path length and therefore the resonant frequency of the optical mode. The optical transmission changes with acceleration when the laser is biased on the side of the optical resonance. This silicon nitride "Cavity-enhanced OptoMechanical Accelerometer" (COMA) has a sensitivity of 22 percent-per-g optical modulation for our highest optical quality factor (Q_o) devices