Mechanical bound state in the continuum for optomechanical microresonators

TL;DR

This paper demonstrates that using the mechanical bound state in the continuum can significantly reduce clamping loss in optomechanical microresonators, enabling ultra-high quality factors by orthogonal coupling channels.

Contribution

It introduces a universal mechanism leveraging mechanical bound states in the continuum to suppress clamping loss in various optomechanical resonator geometries.

Findings

Achieved mechanical Q factor up to 10^8 in microspheres.

Identified specific stem radius for optimal quality factor.

Universal applicability across different geometries and materials.

Abstract

Clamping loss limits the quality factor of mechanical mode in the optomechanical resonators supported with the supporting stem. Using the mechanical bound state in the continuum, we have found that the mechanical clamping loss can be avoided. The mechanical quality factor of microsphere could be achieved up to 10^8 for a specific radius of the stem, where the different coupling channels between the resonator and supporting stem are orthogonal to each other. Such mechanism is proved to be universal for different geometries and materials, thus can also be generalized to design the high quality mechanical resonators.