Three-dimensional Negative-Refractive-Index Metamaterials Based on All-Dielectric Coated Spheres

TL;DR

This paper proposes a theoretical design for 3D optical negative-refractive-index metamaterials using all dielectric nanospheres with concentric shells, achieving negative index through Mie resonances.

Contribution

It introduces a novel all-dielectric 3D metamaterial structure with negative index based on paired nanospheres and Mie theory analysis.

Findings

Negative index achieved within specific resonant frequency range

Dielectric core provides negative permeability

Dielectric shell provides negative permittivity

Abstract

A type of 3-dimensional optical negative-refractive-index metamaterials composed of all dielectric nanospheres is proposed and demonstrated theoretically. The metamaterials are constructeded by pairing together two kinds of dielectric nanospheres as concentric shells embedded in a host medium. Mie-based extended effective theory shows that the dielectric core and the dielectric shell provide the negative permeability and the negative permittivity, respectively, both due to the strong Mie resonances. Within the coupled resonant frequency region, the negative index of refraction can be achieved.