Applicability of point dipoles approximation to all-dielectric metamaterials

TL;DR

This paper evaluates the effectiveness of the point dipoles approximation in predicting the properties of all-dielectric metamaterials, specifically dielectric ring structures, and finds it accurate up to a certain size.

Contribution

It demonstrates that the dipole approximation remains valid for high-dielectric meta-atoms with sizes up to 0.8 of the lattice constant, aiding design of dielectric metamaterials.

Findings

Dipole approximation accurately predicts metamaterial properties for rings up to ~0.8 of lattice size.

High-dielectric meta-atoms can be effectively modeled despite their large electrical size.

Provides guidelines for designing all-dielectric metamaterials using dipole models.

Abstract

All-dielectric metamaterials consisting of high-dielectric inclusions in a low-dielectric matrix are considered as a low-loss alternative to resonant metal-based metamaterials. In this contribution we investigate the applicability of the point electric and magnetic dipoles approximation to dielectric meta-atoms on the example of a dielectric ring metamaterial. Despite the large electrical size of high-dielectric meta-atoms, the dipole approximation allows for accurate prediction of the metamaterials properties for the rings with diameters up to ~0.8 of the lattice constant. The results provide important guidelines for design and optimization of all-dielectric metamaterials.