Coherent Perfect Absorption of Arbitrary Wavefronts at an Exceptional Point

TL;DR

This paper introduces a novel cavity design that combines exceptional-point physics and degenerate cavities to achieve broadband, wavefront-agnostic coherent perfect absorption, overcoming previous spectral and spatial limitations.

Contribution

It proposes a new cavity architecture that enables broadband, arbitrary wavefront absorption by integrating exceptional-point physics with degeneracy, validated through analytical and numerical methods.

Findings

Achieves broadband absorption of arbitrary wavefronts.

Combines exceptional-point physics with degenerate cavity design.

Validated results with analytical and numerical simulations.

Abstract

A Coherent Perfect Absorber (CPA) exploits the interferometric nature of light to deposit all of a light field's incident energy into an otherwise weakly absorbing sample. The downside of this concept is that the necessary destructive interference in CPAs gets easily destroyed both by spectrally or spatially detuning the incoming light field. Each of these two limitations has recently been overcome by insights from exceptional-point physics and by using a degenerate cavity, respectively. Here, we show how these two concepts can be combined into a new type of cavity design, which allows broadband exceptional-point absorption of arbitrary wavefronts. We present two possible implementations of such a Massively Degenerate Exceptional-Point absorber and compare analytical results with numerical simulations.