Light-controlled perfect absorption of light

TL;DR

This paper investigates coherent perfect absorption (CPA) in nonlinear and linear Kerr composite media, revealing conditions for CPA, its power sensitivity in nonlinear systems, and linking CPA to waveguiding phenomena.

Contribution

It provides a unified framework for understanding CPA and waveguiding, including conditions for CPA in nonlinear media and the hysteretic behavior at specific intensities.

Findings

CPA requires equal incident intensities for both linear and nonlinear systems.

CPA in nonlinear systems occurs at discrete intensities with hysteresis.

CPA and waveguiding are identified as opposite scattering phenomena.

Abstract

We study coherent perfect absorption (CPA) of light in a Kerr nonlinear metal-dielectric composite medium, illuminated from the opposite ends. Elementary symmetry considerations reveal that equality of the incident light intensities is a prerequisite to ensure CPA in both linear and nonlinear systems for specific system parameters. We also derive the sufficient conditions for having CPA. We further show that while CPA in a linear system is insensitive to the incident power level, that in a nonlinear system can be achieved only for discrete intensities with interesting hysteretic response. Our unified formulation of CPA and waveguiding identifies them as opposite scattering phenomena. We further investigate light-induced CPA in on- and off- resonant systems.