Optically tunable nonlinear mechanical damping in an optomechanical resonator

TL;DR

This paper demonstrates a method to optically control nonlinear mechanical damping in an optomechanical resonator, enabling tunable damping effects and cross-mode interactions for advanced system control.

Contribution

It introduces a novel approach to achieve and tune nonlinear damping in optomechanical systems through optical means, supported by both theoretical and experimental evidence.

Findings

Optically tunable nonlinear damping observed in experiments.

Demonstration of cross-nonlinear damping between mechanical modes.

Theoretical model matches experimental results for damping control.

Abstract

We theoretically propose and experimentally demonstrate optically tunable nonlinear mechanical damping in a cavity optomechanical system utilizing a partly resolved sideband regime. Optomechanical coupling provides a delayed nonlinear backaction to the mechanical modes, resulting in nonlinear mechanical damping. This optically induced nonlinear damping is observed in the frequency and time domains, and we show using both theory and experiment that it can be tuned via laser detuning. We also observe optically mediated cross-nonlinear damping between two mechanical modes: the amplitude of one mode modulates the damping of the other. The presented results show a fully tunable scheme of nonlinear mechanical damping that will be applicable to various non-trivial systems, governed by nonlinear, nonequilibrium, and non-Hermitian phenomena.