Broadband unidirectional cloak designed by eikonal theory

Abstract

A method for designing optical device is derived based on the eikonal theory, which could obtain the eikonal distribution on a curved surface according to the propagation characteristics of the subsequent light wave. Then combining with the phase matching condition, we designed a broadband unidirectional cloak. Different from the reported unidirectional cloaks, the proposed one could be used for coherent wave and has continuous broadband performance. Moreover, it has three cloaked regions. Full-wave simulation results verify the properties of the cloak.

A multidirectional cloak for visible light

“…Likewise, conformal transformation also shows great advantages in easing the material properties since the materials it results in are isotropic [1,13,14]. Subsequently, plasmonic resonances [15], metasurfaces [16,17], analogies to eikonal equations [18][19][20], and topology optimization [21], etc, were also proposed to enrich the cloaking strategies. Furthermore, conventional optical lens fabrication was incorporated into a transformation principle by applying calcite [22,23], a kind of natural anisotropic optical material, to eliminate the process of complicated nano-or microfabrication that the previous cloaks required [10][11][12]16], through which macroscopic cloaks were demonstrated at polarized light.…”

Optic-null space medium for cover-up cloaking without any negative refraction index materials

“…transformation optics (TO) 1 2 3 ) and new technologies (e.g. meta-materials 4 5 ), many different schemes have been proposed to design invisibility cloaking, some of which have also been experimentally demonstrated for some specific frequencies 6 7 8 9 10 11 12 13 14 15 . These methods are based on different principles, which can mainly be classified into two kinds: one is optical-isolated cloaking (e.g.…”

“…These methods are based on different principles, which can mainly be classified into two kinds: one is optical-isolated cloaking (e.g. point-extended cloaking by TO 6 7 , or cloaking based on the geometrical optic 8 9 ); the other is scattering cancellation cloaking (e.g. the complementary medium method 10 11 , cloaking based on optimization algorithms 12 13 , and active cloaking 14 15 ).…”