Numerical Investigation of Light Scattering off Split-Ring Resonators

TL;DR

This paper numerically investigates light scattering off split-ring resonators in the near-infrared and optical regimes using finite-element methods, providing detailed spectra and resonance analysis aligned with experimental data.

Contribution

It introduces a finite-element simulation approach for modeling light interaction with SRRs, including advanced boundary conditions and arbitrary incident wave parameters.

Findings

Numerical spectra match experimental results.

Resonance behaviors are characterized across different angles and polarizations.

The method enables detailed analysis of light-SRR interactions.

Abstract

Recently, split ring-resonators (SRR's) have been realized experimentally in the near infrared (NIR) and optical regime. In this contribution we numerically investigate light propagation through an array of metallic SRR's in the NIR and optical regime and compare our results to experimental results. We find numerical solutions to the time-harmonic Maxwell's equations by using advanced finite-element-methods (FEM). The geometry of the problem is discretized with unstructured tetrahedral meshes. Higher order, vectorial elements (edge elements) are used as ansatz functions. Transparent boundary conditions and periodic boundary conditions are implemented, which allow to treat light scattering problems off periodic structures. This simulation tool enables us to obtain transmission and reflection spectra of plane waves which are incident onto the SRR array under arbitrary angles of incidence, with arbitrary polarization, and with arbitrary wavelength-dependencies of the permittivity tensor. We compare the computed spectra to experimental results and investigate resonances of the system.