Spoof polariton enhanced modal density of states in planar nanostructured metallic cavities

TL;DR

This paper investigates how nanostructured metallic cavities with spoof surface modes can enhance the modal density of states, with potential applications in electromagnetic absorption and heat transfer.

Contribution

It introduces a scattering matrix approach to analyze spoof polariton dispersion in nanostructured metallic cavities, providing new insights into mode classification and density of states.

Findings

Spoof polariton dispersion depends on geometric patterning.

Differential modal density of states reveals mode enhancement.

Applications include perfect absorbers and radiative heat transfer.

Abstract

Spoof surface modes on nanostructured metallic surfaces are known to have tailorable dispersion dependent on the geometric characteristics of the periodic pattern. Here we examine the spoof plasmon dispersion on an isolated grating and a grating-planar mirror cavity configuration. The spoof polariton dispersion in the cavity is obtained using the scattering matrix approach, and the related differential modal density of states is introduced to obtain the mode dispersion and classify the cavity polariton modes. The grating-mirror cavity geometry is an example of periodically nanostructured metals above a planar ground plane. The properties discussed here are relevant for applications ranging from thin electromagnetic perfect absorbers to near-field radiative heat transfer.