Hidden symmetries in plasmonic gratings

TL;DR

This paper reveals how different types of plasmonic gratings derive their spectral properties from an underlying symmetric slab, using an analytical approach to better understand their mode spectra and physical behavior.

Contribution

It introduces an analytical formalism that accurately derives the mode spectrum of plasmonic gratings, linking their properties to underlying translational symmetry.

Findings

Spectral properties inherited from symmetric slab

Analytical method for mode spectrum derivation

Enhanced physical understanding of plasmonic gratings

Abstract

Plasmonic gratings constitute a paradigmatic instance of the wide range of applications enabled by plasmonics. While subwavelength metal gratings find applications in optical biosensing and photovoltaics, atomically thin gratings achieved by periodically doping a graphene monolayer perform as metasurfaces for the control of terahertz radiation. In this paper we show how these two instances of plasmonic gratings inherit their spectral properties from an underlying slab with translational symmetry.We develop an analytical formalism to accurately derive the mode spectrum of the gratings that provides a great physical insight.