Optomechanical microgear cavity

TL;DR

This paper presents a novel optomechanical microgear cavity design that achieves high-quality optical and mechanical confinement in amorphous silicon nitride, enabling advanced control of light and sound at GHz frequencies.

Contribution

The paper introduces a new microgear cavity design combining phononic and photonic crystal structures for enhanced optomechanical confinement in isotropic materials.

Findings

Mechanical resonance at 4.8 GHz with high Q-factors

Whispering gallery modes with Q above 10^7

Optomechanical overlap reaches 75% of ideal

Abstract

We introduce a novel optomechanical microgear cavity for both optical and mechanical isotropic materials, featuring a single etch configuration. The design leverages a conjunction of phononic and photonic crystal-like structures to achieve remarkable confinement of both optical and mechanical fields. The microgear cavity we designed in amorphous silicon nitride exhibits a mechanical resonance at 4.8 GHz, and whispering gallery modes in the near-infrared, with scattering-limited quality factors above the reported material limit of up $10^7$. Notably, the optomechanical photoelastic overlap contribution reaches 75% of the ideal configuration seen in a floating ring structure.