Plus-minus construction leads to perfect invisibility

TL;DR

This paper introduces a novel cloaking design using plus-minus refractive index construction that achieves perfect invisibility by eliminating reflections and time delays, surpassing traditional impedance matching methods.

Contribution

The paper presents a new cloaking approach with plus-minus refractive indices enabling perfect invisibility and reflection elimination in isotropic media, a significant advance over existing methods.

Findings

Achieves perfect invisibility with no reflection or delay

Uses plus-minus refractive index combination for cloaking

Potential applications beyond cloaking in reflection management

Abstract

Recent theoretical advances applied to metamaterials have opened new avenues to design a coating that hides objects from electromagnetic radiation and even the sight. Here, we propose a new design of cloaking devices that creates perfect invisibility in isotropic media. A combination of positive and negative refractive indices, called plus-minus construction, is essential to achieve perfect invisibility (i.e., no time delay and total absence of reflection). Contrary to the common understanding that between two isotropic materials having different refractive indices the electromagnetic reflection is unavoidable, our method shows that surprisingly the reflection phenomena can be completely eliminated. The invented method, different from the classical impedance matching, may also find electromagnetic applications outside of cloaking devices, wherever distortions are present arising from reflections.