Transmission cloaking by metasurfaces and index-near-zero materials

Metasurfaces have been successfully applied to realize cloaking in the reflection geometry recently[1, 2]. We propose a transmission cloaking scheme by using a cloaking shell consisting of a metasurface and a thin layer of zero-index medium. The metasurface is designed to impose a suitable amount of phase change on the incident waves and radiation waves, so as to avoid the total reflection on the surface of zero-index medium and to restore the propagating wave front. The energy flux is tunneled through the zero-index medium. Full-wave simulation results show good cloaking effects for cloaks of almost arbitrary shapes. We design and fabricate a rhombus cloaking shell for operation in the microwave region and the experimental results agree well with the numerical simulations.