Non-singular arbitrary cloaks dressing three-dimensional anisotropic obstacles

TL;DR

This paper presents a novel method for designing three-dimensional electromagnetic cloaks that avoid singularities by cloaking complex-shaped regions, with analytical derivations and finite element validation showing reduced scattering.

Contribution

It introduces a non-singular, three-dimensional cloak design based on a transformation of complex-shaped regions, expanding the scope of electromagnetic cloaking techniques.

Findings

Finite element simulations confirm reduced scattering with the cloak.

Eigenvalues of the transformation remain finite inside the cloak.

Neither the object nor the cloak alone are fully invisible.

Abstract

We design three dimensional electromagnetic cloaks, starting from a small region of complex shape instead of a point. We derive the expression of a transformation matrix describing an objet with a surface of revolution and its associated non-singular cloak. We note that while none of the eigenvalues vanish inside the cloak, they suffer a discontinuity on its inner surface. Moreover, all three eigenvalues are independent upon the radius in the concealed object. The validity of our analytical results is confirmed by finite edge-elements computations showing scattering is much reduced when the object is dressed with the cloak. We note that neither the object nor the cloak are invisible on their own.