Achieving Invisibility of Homogeneous Radially Anisotropic Cylinders by Effective Medium Theory

TL;DR

This paper develops a full-wave electromagnetic scattering theory and an effective medium approximation to achieve invisibility of radially anisotropic cylinders by tuning dielectric and magnetic properties.

Contribution

It introduces a comprehensive scattering model and effective medium theory for anisotropic cylinders, enabling invisibility through property adjustments.

Findings

Effective scattering width can be minimized by adjusting dielectric anisotropy.

Invisibility achieved when both dielectric and magnetic anisotropies are tuned.

Effective medium theory accurately predicts invisibility conditions for small cylinders.

Abstract

In this paper, we establish the full-wave electromagnetic scattering theory to study the electromagnetic scattering from infinitely long cylinders with radially anisotropic coatings. We show that the total effective scattering width can be dramatically reduced by the suitable adjustment of the dielectric anisotropy of the shell, while it is not the case for tuning the dielectric anisotropy of the core. Furthermore, we could make the cylindrical objects invisible when both dielectric and magnetic anisotropies are adjusted. In the long wavelength limit, we develop effective medium theory to derive the effective isotropic permittivity and permeability for the anisotropic coated cylinders, and the invisibility radius ratio derived from the full-wave theory for small coated cylinders can be well described within the effective medium theory.