Electromagnetic cloaking by layered structure of homogeneous isotropic materials

TL;DR

This paper presents a practical method to achieve electromagnetic cloaking using layered isotropic materials, avoiding complex anisotropic metamaterials, and demonstrates low-reflection, power-bending effects through rigorous analysis.

Contribution

It introduces a layered structure approach to realize cloaking without anisotropic or inhomogeneous materials, simplifying fabrication and potential experimental implementation.

Findings

Low-reflection cloaking demonstrated through analysis

Power-flow bending achieved with layered structure

Method applicable in optical frequency range

Abstract

Electromagnetic invisibility cloak requires material with anisotropic distribution of the constitutive parameters deduced from a geometrical transformation as first proposed by Pendry et al. [Science 312, 1780 (2006)]. In this paper, we proposed a useful method to realize the required radius-dependent, anisotropic material parameters and to construct an electromagnetic cloak through concentric layered structure of thin, alternating layers of homogeneous isotropic materials. With proper design of the permittivity or the thickness ratio of the alternating layers, we demonstrated the low-reflection and power-flow bending properties of the proposed cloaking structure through rigorous analysis of the scattered electromagnetic fields. The proposed cloaking structure does not require anisotropy or inhomogeneity of the material constitutive parameters usually realized by metamaterials with subwavelength structured inclusions, therefore may lead to a practical path to an experimental demonstration of electromagnetic cloaking, especially in the optical range.