The scattering of a cylindrical invisibility cloak: reduced parameters and optimization

TL;DR

This paper analyzes how simplified 2D cylindrical invisibility cloaks scatter electromagnetic waves, identifying key factors influencing scattering and proposing design restrictions to minimize it using composite materials like photonic crystals.

Contribution

It introduces a theoretical framework to understand scattering in simplified cloaks and suggests design restrictions to reduce scattering using composite materials.

Findings

Scattering arises from boundary conditions and permittivity/permeability variation.

Proposes restrictions to minimize scattering in simplified cloaks.

Designs using photonic crystals can effectively mimic refractive index landscapes.

Abstract

We investigate the scattering of 2D cylindrical invisibility cloaks with simplified constitutive parameters with the assistance of scattering coefficients. We show that the scattering of the cloaks originates not only from the boundary conditions but also from the spatial variation of the component of permittivity/permeability. According to our formulation, we propose some restrictions to the invisibility cloak in order to minimize its scattering after the simplification has taken place. With our theoretical analysis, it is possible to design a simplified cloak by using some peculiar composites like photonic crystals (PCs) which mimic an effective refractive index landscape rather than offering effective constitutives, meanwhile canceling the scattering from the inner and outer boundaries.