Tunable nonlinear coherent perfect absorption and reflection in cavity QED

TL;DR

This paper presents a method to achieve tunable coherent perfect absorption and reflection in a three-level atom-cavity system using EIT-like interference, enabling control over absorption regimes for optical computing.

Contribution

It introduces a novel scheme for tunable CPA and CPR in a three-level atom-cavity system utilizing EIT-type interference and incoherent pumping, with controllable bistability and absorption.

Findings

Achieves near CPR at two-photon resonance.

Demonstrates transition from linear to nonlinear bistable CPA.

Shows controllable absorption from 0% to 100%.

Abstract

We propose and analyze a scheme for realizing tunable coherent perfect absorption (CPA) and reflection (CPR) in a three-level $\Lambda$-type atom-cavity system. With EIT-type interference induced by a coherent coupling laser, the scheme provides a new method of attaining tunable near CPR at two-photon resonance. By different coupling strength, the system can be excited from linear CPA regime into nonlinear even bistable CPA regime without changing the frequency of the probe field, where the hysteresis cycle of the bistability is controllable. In addition, the CPA regime can be transferred into the near CPR regime with controllable atomic coherence and linear absorption induced by an incoherent pump field. Our work suggests a mechanism for manipulation on extreme absorption (0% and 100%), which can potentially be applied in logical gates and optical switches for coherent optical computing and communication.