Harry Potter's Cloak

TL;DR

This paper introduces a novel transformation optics-based cloaking method that enables perfect invisibility of objects with arbitrary properties using positive-index materials, while allowing undistorted communication and virtual imaging.

Contribution

It proposes a new cloaking recipe that functions like a lens, achieving broad-band invisibility for objects of any shape or material using practical positive-index materials.

Findings

Objects of arbitrary size, shape, or material can be invisibilized.

The cloaking shell acts like a lens, creating virtual images.

The cloaked object can communicate without distortion.

Abstract

The magic "Harry Potter's cloak" has been the dream of human beings for really long time. Recently, transformation optics inspired from the advent of metamaterials offers great versatility for manipulating wave propagation at will to create amazing illusion effects. In the present work, we proposed a novel transformation recipe, in which the cloaking shell somehow behaves like a "cloaking lens", to provide almost all desired features one can expect for a real magic cloak. The most exciting feature of the current recipe is that an object with arbitrary characteristics (e.g., size, shape or material properties) can be invisibilized perfectly with positive-index materials, which significantly benefits the practical realization of a broad-band cloaking device fabricated with existing materials. Moreover, the one concealed in the hidden region is able to undistortedly communicate with the surrounding world, while the lens-like cloaking shell will protect the cloaked source/sensor from being traced back by outside detectors by creating a virtual image.