Optomechanical Cavity with a Buckled Mirror

TL;DR

This paper investigates an optomechanical cavity with a buckled mirror, revealing unique self-excitation phenomena driven by thermal forces under red detuned light, and reports complex oscillation behaviors.

Contribution

It introduces a novel optomechanical system with a buckled mirror exhibiting self-excited oscillations under red detuning, differing from typical blue detuning cases.

Findings

Self-excited oscillations occur with red detuned light.

Thermal (bolometric) force causes inward motion of the buckled mirror.

High laser power induces period doubling and intermode coupling.

Abstract

We study an optomechanical cavity, in which a buckled suspended beam serves as a mirror. The mechanical resonance frequency of the beam obtains a minimum value near the buckling temperature. Contrary to the common case, in which self-excited oscillations of the suspended mirror are optically induced by injecting blue detuned laser light, in our case self-excited oscillations are observed with red detuned light. These observations are attributed to a retarded thermal (i.e. bolometric) force acting on the buckled mirror in the inwards direction (i.e. towards to other mirror). With relatively high laser power other interesting effects are observed including period doubling of self-excited oscillations and intermode coupling.