▎ 摘　　要

The metasurface of graphene nanodisks with atomic thicknesses is considered as a cloaking shell around a cylindrical dielectric object. The synthesis of this cloaking layer is done analytically by using the equivalent conductivity method. We derive the polarizability of graphene nanodisks and calculate the equivalent conductivity of the cloaking layer. The cloaking frequency can be found by comparing the calculated equivalent reactance and ideal reactance of the cloaking shell. Also, to provide multi-spectral and wideband invisibility, we use symmetrical inhomogeneous metasurfaces consisting of different types of graphene nanodisks. Using graphene nanodisks with various radii on a monolayer metasurface causes additional resonances. This approach not only establishes the multi-spectral and wideband cloaking but also keeps the simplicity, unlike multilayer structures. (C) 2016 Optical Society of America