Electromagnetic Energy Sink

TL;DR

This paper introduces the concept of the ideal conjugate matched layer (CML), a new electromagnetic absorber capable of fully absorbing both propagating and evanescent fields, surpassing traditional black bodies and PMLs.

Contribution

The paper proposes the CML concept, derives conditions for its material parameters, and demonstrates its potential through numerical simulations and possible material realizations.

Findings

CML fully absorbs propagating and evanescent fields.

Numerical simulations show effective absorption in planar and cylindrical geometries.

Potential for practical realization using metal-dielectric composites.

Abstract

The ideal black body fully absorbs all incident rays, that is, all propagating waves created by arbitrary sources. The known idealized realization of a black body is the perfectly matched layer (PML), widely used in numerical electromagnetics. However, ideal black bodies and PMLs do not interact with evanescent fields existing near any finite-size source, and the energy stored in these fields cannot be harvested. Here we introduce the concept of the ideal conjugate matched layer (CML), which fully absorbs energy of both propagating and evanescent fields of sources acting as an ideal sink for electromagnetic energy. Conjugate matched absorbers have exciting application potentials, as resonant attractors of electromagnetic energy into the absorber volume. We derive the conditions on the constitutive parameters of media which can serve as CML materials, numerically study the performance of planar and cylindrical CML and discuss possible realizations of such materials as metal-dielectric composites.