Metamaterial slab as a lens, a cloak or something in between

TL;DR

This paper demonstrates that metamaterial slabs can function as lenses, cloaks, or intermediate devices by manipulating electromagnetic reflections and excitations, enabling cloaking of small objects at specific frequencies.

Contribution

It introduces a novel understanding of how arbitrary epsilon and mu values in metamaterial slabs can achieve cloaking effects at finite frequencies.

Findings

Metamaterial slabs can suppress optical excitations of nearby objects.

Evanescent components enable complete cloaking.

Veselago slabs with epsilon = mu = -1 + i delta can fully cloak small objects as delta approaches zero.

Abstract

We show that a metamaterial slab with arbitrary values of epsilon and mu behaves as a cloak at a finite frequency for a small object located sufficiently close to it due to the suppression of the object's optical excitations by enhanced reflections. Reflections due to propagating components can partially suppress the excitation while evanescent components can cloak the object completely. In particular, a Veselago slab with epsilon = mu = -1 + i delta, as well as a class of anisotropic negative refractive index slabs, can completely cloak the small object placed within a finite distance from the slab when delta -> 0.