Quantum Theory of Continuum Optomechanics

TL;DR

This paper extends cavity optomechanics to continuum systems, analyzing photon-phonon interactions in waveguides, discussing quantum noise, dissipation, boundary conditions, and identifying a potentially accessible strong coupling regime.

Contribution

It introduces a real-space framework for continuum optomechanics, connecting it to Brillouin scattering and optomechanical arrays, and highlights the strong coupling regime potential.

Findings

Real-space picture of continuum optomechanics

Analysis of quantum noise and boundary conditions

Identification of the strong coupling regime

Abstract

We present the basic ingredients of continuum optomechanics, i.e. the suitable extension of cavity-optomechanical concepts to the interaction of photons and phonons in an extended waveguide. We introduce a real-space picture and argue which coupling terms may arise in leading order in the spatial derivatives. This picture allows us to discuss quantum noise, dissipation, and the correct boundary conditions at the waveguide entrance. The connections both to optomechanical arrays as well as to the theory of Brillouin scattering in waveguides are highlighted. We identify the 'strong coupling regime' of continuum optomechanics that may be accessible in future experiments.