Coupled electric and magnetic dipole formulation for planar arrays of dipolar particles: metasurfaces with various electric and/or magnetic meta-atoms per unit cell

TL;DR

This paper introduces a coupled electric and magnetic dipole analytical model for infinite planar arrays of dipolar particles, enabling accurate prediction of their optical reflection and transmission properties across various metasurface configurations.

Contribution

It develops a comprehensive coupled dipole formulation that accounts for multiple meta-atom types and orientations, simplifying the analysis of complex metasurfaces and metagratings.

Findings

The model accurately predicts reflection and transmission spectra.

It converges efficiently using a 1D lattice Green function.

Applicable across plasmonic, dielectric, and hybrid metasurfaces.

Abstract

The optical properties of infinite planar array of scattering particles, metasurfaces and metagratings, are attracting special attention lately for their rich phenomenology, including both plasmonic and high-refractive-index dielectric meta-atoms with a variety of electric and magnetic resonant responses. Herein we derive a coupled electric and magnetic dipole (CEMD) analytical formulation to describe the reflection and transmission of such periodic arrays, including specular and diffractive orders, valid in the spectral regimes where only dipolar multipoles are needed. Electric and/or magnetic dipoles with all three orientations arising in turn from a single or various meta-atoms per unit cell are considered. The 2D lattice Green function is rewritten in terms of a 1D (chain) version that fully converges and can be easily calculated. Modes emerging as poles of such lattice Green function can be extracted. This formulation can be applied to investigate a wealth of plasmonic, all-dielectric, and hybrid metasurfaces/metagratings of interest throughout the electromagnetic spectrum.