Signatures of nonlinear cavity optomechanics in the weak coupling regime

TL;DR

This paper reveals observable signatures of nonlinear light-mechanical interactions in cavity optomechanics, even in weak coupling regimes, through novel transparency effects induced by specific laser detunings.

Contribution

It demonstrates how nonlinear optomechanical effects can be detected in the weak coupling regime using specific laser detunings, expanding the understanding of cavity optomechanics.

Findings

Observation of nonlinear optomechanically induced transparency at specific detunings

Detection of two-phonon and two-photon resonant processes

Effects observable with existing experimental coupling strengths

Abstract

We identify signatures of the intrinsic nonlinear interaction between light and mechanical motion in cavity optomechanical systems. These signatures are observable even when the cavity linewidth exceeds the optomechanical coupling rate. A strong laser drive red-detuned by twice the mechanical frequency from the cavity resonance frequency makes two-phonon processes resonant, which leads to a nonlinear version of optomechanically induced transparency. This effect provides a new method of measuring the average phonon number of the mechanical oscillator. Furthermore, we show that if the strong laser drive is detuned by half the mechanical frequency, optomechanically induced transparency also occurs due to resonant two-photon processes. The cavity response to a second probe drive is in this case nonlinear in the probe power. These effects should be observable with optomechanical coupling strengths that have already been realized in experiments.