Dynamical scattering models in optomechanics: Going beyond the 'coupled cavities' model

TL;DR

This paper compares the scattering model and the coupled cavities model in optomechanics, showing that the simpler coupled cavities approach becomes inaccurate for semi-transparent mirrors with reflectivity below 50%.

Contribution

It introduces a detailed scattering model for optomechanical systems and highlights its differences from the traditional coupled cavities approximation.

Findings

Scattering model provides more accurate forces for semi-transparent mirrors.

Coupled cavities model diverges from scattering results below 50% reflectivity.

The study clarifies the limitations of the coupled cavities approximation.

Abstract

Recently [A. Xuereb, et al., Phys. Rev. Lett. 105, 013602 (2010)], we calculated the radiation field and the optical forces acting on a moving object inside a general one-dimensional configuration of immobile optical elements. In this article we analyse the forces acting on a semi-transparent mirror in the 'membrane-in-the-middle' configuration and compare the results obtained from solving scattering model to those from the coupled cavities model that is often used in cavity optomechanical system. We highlight the departure of this model from the more exact scattering theory when the reflectivity of the moving element drops below about 50%.