Demonstration of Ultra Low Dissipation Optomechanical Resonators on a Chip

TL;DR

This paper demonstrates an on-chip optomechanical resonator with independently optimized optical and mechanical properties, achieving ultra-high Q-factors and low dissipation, advancing the potential for quantum optomechanics.

Contribution

It introduces a novel on-chip resonator design allowing independent control of optical and mechanical modes, with optimized dissipation properties.

Findings

First direct observation of mechanical normal mode coupling in a micromechanical system.

Achieved mechanical Q-factors limited by intrinsic material loss.

Maintained ultra-high optical finesse alongside high mechanical quality.

Abstract

Cavity-enhanced radiation-pressure coupling of optical and mechanical degrees of freedom gives rise to a range of optomechanical phenomena, in particular providing a route to the quantum regime of mesoscopic mechanical oscillators. A prime challenge in cavity optomechanics has however been to realize systems which simultaneously maximize optical finesse and mechanical quality. Here we demonstrate for the first time independent control over both mechanical and optical degree of freedom within one and the same on-chip resonator. The first direct observation of mechanical normal mode coupling in a micromechanical system allows for a quantitative understanding of mechanical dissipation. Subsequent optimization of the resonator geometry enables intrinsic material loss limited mechanical Q-factors, rivalling the best values reported in the high MHz frequency range, while simultaneously preserving the resonators' ultra-high optical finesse. Besides manifesting a complete understanding of mechanical dissipation in microresonator based optomechanical systems, our results provide an ideal setting for cavity optomechanics.