Tunable metasurface composed of graphene-coated silicon dioxide spherical particles

A theoretical analysis and numerical results of a tunable metasurface composed of graphene-coated silicon dioxide spherical particles is presented. For completeness, metasurfaces composed of hollow graphene spheres and silicon dioxide spheres without graphene coating are also considered. It is shown that a graphene-coated silicon dioxide sphere has a dipolar response to the wavelengths of interest under some specified conditions. It is studied that by varying the chemical potential of the graphene coating, one can tune the maximum and minimum reflections at the specific wavelength by keeping all other geometrical parameters fixed. Influences of the sizes of spheres and spacing among spheres in the metasurface plane upon the reflection characteristics have also been explored. It is studied that a metasurface composed of hollow graphene spherical particles may act as an almost perfect reflector at a single wavelength under some specified conditions. Likewise, metasurfaces composed of graphene-coated silicon dioxide and hollow graphene spherical particles may be configured as transparent sheets for the incoming waves. These types of almost perfect reflector metasurface without ground plane backing and transparent metasurface may find applications in the design of protecting surfaces against high power radiation and stealth technology, respectively.