A picogram and nanometer scale photonic crystal opto-mechanical cavity

TL;DR

This paper presents the design, fabrication, and measurement of a silicon nitride zipper cavity that localizes optical and mechanical energy at the nanoscale, demonstrating a giant optical spring effect and novel damping regimes.

Contribution

It introduces a nanobeam zipper cavity with photonic crystal patterning that achieves strong opto-mechanical coupling at the picogram scale.

Findings

Demonstrated a giant optical spring effect.

Explored a new blue-detuned opto-mechanical damping regime.

Achieved localization of optical and mechanical energy in a cubic-micron volume.

Abstract

We describe the design, fabrication, and measurement of a cavity opto-mechanical system consisting of two nanobeams of silicon nitride in the near-field of each other, forming a so-called "zipper" cavity. A photonic crystal patterning is applied to the nanobeams to localize optical and mechanical energy to the same cubic-micron-scale volume. The picrogram-scale mass of the structure, along with the strong per-photon optical gradient force, results in a giant optical spring effect. In addition, a novel damping regime is explored in which the small heat capacity of the zipper cavity results in blue-detuned opto-mechanical damping.