# Perfect photon absorption in hybrid atom-optomechanical system

## TL;DR

This paper investigates perfect photon absorption in a hybrid atom-optomechanical system, demonstrating its persistence beyond low-excitation limits and its potential for optical switching applications.

## Contribution

It introduces a scheme for perfect photon absorption in a hybrid system, analyzing its behavior both below and beyond the low-excitation limit, including the relation to optical multistability.

## Key findings

- Perfect photon absorption persists in both linear and nonlinear regimes.
- Optical nonlinearity from optomechanical and atomic interactions can be combined.
- Switching from optical bistability to multistability is achievable by increasing input intensity.

## Abstract

Recently, the photon absorption attracts lots of interest and plays an important role in a variety of applications. Here, we propose a valuable scheme to investigate the perfect photon absorption in a hybrid atom-optomechanical system both under and beyond the low-excitation limit. The perfect photon absorption persists both in the linear atomic excitation regime and nonlinear atomic excitation regime, below the threshold of the optical bistability/multistability, respectively. We also show that the optical nonlinearity raised by the nonlinear optomechanical interaction and nonlinear atomic excitation can be overlap-added, there presents a perfect corresponding relation between perfect photon absorption and the optical multistability beyond the low-excitation limit, the optical bistability can be switched to the optical multistability by increasing the input intensity. The combination of the perfect photon absorption and optical bistability/mutistability is useful for the photon switch application. We believe that this study will provide a possible design of an optical switch.