Equivalent conductivity method: straightforward analytical solution for metasurface-based structures

We present an equivalent conductivity method for analyzing metasurface-based structures, which relies on the derivation of equivalent conductivity containing the properties such as the geometry, periodicity, and the surrounding materials. Using this approach, one can calculate the equivalent conductivity for a single metasurface layer and then consider it in further analysis of multilayer structures. Description of this method is made by considering an array of graphene nanodisks as a metasurface. The equivalent conductivity is achieved with the aid of the polarizability of a graphene nanodisk. This method is further applied to design graphene-based mid-infrared absorbers, and the results obtained by the equivalent conductivity method are confirmed by full-wave simulations

All-dielectric Bianisotropic and Multimode Unidirectional Microwave Metasurfaces

All-dielectric particles with small and large aspect ratio supporting Mie modes and hybrid Mie-Fabry-Pérot modes are experimentally studied in microwave frequency range. The all-dielectric bianisotropic and multimode unidirectional metasurfaces based on such particles are designed and experimentally investigated. We demonstrate the all-dielectric bianisotropic metasurface composed of the particles with broken symmetry exhibits different phase of the reflection coefficient being excited from the opposite directions. The all-dielectric metasurfaces based on the particles with large aspect ratio responsible for the existence of multiple magnetic dipole resonances reveal the multimode unidirectionality when the Kerker conditions are satisfied.The work was supported by Russian Science Foundation (project 17-19-01731). PK acknowledges the scholarship of the President of Russian Federation. AM and Yu.K acknowledge the support of Australian Research Council