Enhanced nonlinear interaction effects in a four-mode optomechanical ring

TL;DR

This paper investigates how a four-mode optomechanical ring enhances nonlinear interactions through resonant scattering, revealing significant effects even with weak single-photon coupling, using a perturbative Green's function approach.

Contribution

It introduces a four-mode optomechanical system that exhibits amplified nonlinear effects via resonant scattering, extending beyond traditional two-mode setups.

Findings

Resonant scattering between five types of polariton modes identified.

Largest nonlinear effects occur with decay involving two phonon-like polaritons.

Prominent nonlinear features observed even with weak single-photon coupling.

Abstract

With a perturbative treatment based on the Keldysh Green's function technique, we study the resonant enhancement of nonlinear interaction effects in a four-mode optomechanical ring. In such a system, we identify five distinct types of resonant scattering between unperturbed polariton modes, induced by the nonlinear optomechanical interaction. By computing the cavity density of states and optomechanical induced transparency signal, we find that the largest nonlinear effects are induced by a decay process involving the two phonon-like polaritons. In contrast to the conventional two-mode optomechanical system, our proposed system can exhibit prominent nonlinear features even in the regime when the single-photon coupling is much smaller than the cavity damping.