Eliminating Structural Loss in Optomechanical Resonators Using Elastic Wave Interference

TL;DR

This paper demonstrates a method to nearly eliminate structural loss in optomechanical resonators by using elastic wave interference in dual-disk structures, significantly enhancing their mechanical quality factors.

Contribution

The study introduces a novel approach employing elastic wave interference to reduce structural loss in optomechanical resonators, supported by analytical, numerical, and experimental validation.

Findings

Mechanical Q-factors up to 10^4 at 102 MHz

Elastic wave interference effectively suppresses structural loss

Room temperature operation with high performance

Abstract

Optomechanical resonators suffer from the dissipation of mechanical energy through the necessary anchors enabling the suspension of the structure. Here we show that such structural loss in an optomechnaical oscillator can be almost completely eliminated through the destructive interference of elastic waves using dual-disk resonators. We also present both analytical and numerical model that predicts the observed interference of elastic waves. Our experimental data reveal unstressed SiN devices with mechanical Q-factors up to $10^4$ at mechanical frequencies of $f=102$ MHz ($fQ = 10^{12}$) at room temperature.