Subthreshold phonon generation in an optomechanical system with an exceptional point

TL;DR

This paper investigates phonon and photon generation in an optomechanical system near an exceptional point, showing that modulation can produce both particles below the instability threshold.

Contribution

It introduces the concept of subthreshold phonon and photon generation facilitated by an exceptional point in an optomechanical system.

Findings

Existence of an exceptional point at a specific external wave amplitude.

Periodic modulation enables simultaneous photon and phonon generation below instability threshold.

Eigenfrequency splitting occurs when external wave amplitude is below the exceptional point.

Abstract

A phonon laser based on an optomechanical system consisting of two optical modes interacting with each other via a phononic mode is considered. An external wave exciting one of the optical modes plays a role of the pumping. It is shown that at some amplitude of the external wave an exceptional point exists. When the external wave amplitude is less than one corresponding to the exceptional point, the splitting of the eigenfrequencies takes place. It is demonstrated that in this case, the periodic modulation of the external wave amplitude can result in simultaneous generation of photons and phonons even below the threshold of optomechanical instability.