Direct S-matrix calculation for diffractive structures and metasurfaces

TL;DR

This paper derives analytical S-matrix formulas for planar diffractive structures and metasurfaces, enabling improved numerical simulations and applications to graphene plasmon resonances and layered materials.

Contribution

It provides general Fourier domain formulas for S-matrices applicable to arbitrary structures, including complex 2D material layers, enhancing simulation capabilities.

Findings

Validated formulas through simulation of graphene plasmon resonances.

Demonstrated impact of silica interlayer on reflection spectra.

Enhanced numerical methods for diffractive structure analysis.

Abstract

The paper presents a derivation of analytical components of S-matrices for arbitrary planar diffractive structures and metasurfaces in the Fourier domain. Attained general formulas for S-matrix components can be applied within both formulations in the Cartesian and curvilinear metric. A numerical method based on these results can benefit from all previous improvements of the Fourier domain methods. In addition, we provide expressions for S-matrix calculation in case of periodically corrugated layers of 2D materials, which are valid for arbitrary corrugation depth-to-period ratios. As an example the derived equations are used to simulate resonant grating excitation of graphene plasmons and an impact of silica interlayer on corresponding reflection curves.