Multi-channel all-optical switching based on coherent perfect absorption in atom-cavity system

TL;DR

This paper introduces a broadband, multi-channel all-optical switch using coherent perfect absorption in a cavity QED system, enabling efficient light routing and quantum logic applications.

Contribution

It presents a novel scheme for ultrahigh-efficiency, broadband, multi-channel all-optical switching based on CPA in atom-cavity systems, with tunable polariton states and quantum interference control.

Findings

Achieves zero output in multiple channels under CPA conditions.

Demonstrates control of polariton states via system parameters.

Enables broadband multi-throw all-optical switching in nonlinear regimes.

Abstract

We propose an ultrahigh-efficiency, broadband and multi-channel all-optical switching scheme based on broadband coherent perfect absorption (CPA) in a linear and nonlinear regimes in a cavity quantum electrodynamics (CQED) system. Two separate atomic transitions are excited simultaneously by two signal fields coupled from two ends of an optical cavity under the collective strong coupling condition. Three polariton eigenstates are produced which can be tuned freely by varying system parameters. The output field intensities of multiple channels are zero when the CPA criterion is satisfied. However, destructive quantum interference can be induced by a free-space weak control laser tuned to the multi-polariton excitation. As a consequence, the CQED system acts as a coherent perfect light absorber/transmitter as the control field is turned on/off the polariton resonances. In particular, the proposed scheme may be used to realize broadband multi-throw all-optical switching in the nonlinear excitation regime. The proposed scheme is useful for constructing all-optical routing, all-optical communication networks and various quantum logic elements.