Comparison of f-Q scaling in wineglass and radial modes in ring resonators

TL;DR

This study compares the frequency scaling of quality factors in wineglass and radial modes of ring resonators, revealing that wineglass modes exhibit increasing f-Q with higher harmonics, approaching the highest values in silicon resonators.

Contribution

It provides a direct comparison of f-Q scaling in wineglass and radial modes using opto-mechanical measurements, highlighting the superior scaling of wineglass modes near the TED limit.

Findings

Higher harmonics of wineglass modes show increasing f-Q product.

Measured f-Q of 5.11e13Hz at 9.82GHz in air.

Wineglass modes approach the highest f-Q values in silicon resonators.

Abstract

Low phase noise MEMS oscillators necessitate resonators with high f-Q. Resonators achieving high f-Q (mechanical frequency-quality factor product) close to the thermo-elastic damping (TED) limit have been demonstrated at expense of feed-through. Here we present a study comparing frequency scaling of quality factors of wineglass and radial modes in a ring resonator using an opto-mechanical two port transmission measurement. Higher harmonics of the wineglass mode show an increasing trend in the f-Q product, as compared to a saturation of f-Q for radial modes. The measured f-Q of 5.11e13Hz at 9.82GHz in air at room temperature for a wineglass mode is close to the highest measured values in silicon resonators.