Eliminating anchor loss in optomechanical resonators using elastic wave interference

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 optomechanical oscillator can be almost completely eliminated through the destructive interference of elastic waves using dual-disk structures. We also present both analytical and numerical models that predict the observed interference of elastic waves. Our experimental data reveal unstressed silicon nitride (Si3N4) devices with mechanical Q-factors up to 104 at mechanical frequencies of f = 102 MHz (fQ = 1012) at room temperature.