Dispersion manipulation of multilayer dielectric plasmonic metasurfaces

Abstract

We theoretically investigate metasurfaces consisting of multilayered dielectric nanostructures periodically positioned on a metal substrate. The characteristics of the metasurface are determined by the dispersion of the multilayered surface-plasmon-dielectric-polariton systems. We manipulated the dispersion in two ways. First, the dispersion curve can be arbitrarily tailored by changing the dielectric thicknesses and refractive indices. Second, the plasmonic band structure of a periodically corrugated multilayer dielectric is introduced. Based on these two manipulations, we show that this system is tailored in momentum space. We also provide an example of broadband absorption. When the substrate metal is replaced by a graphene monolayer, the band structure of graphene plasmons can be tailored by multilayer dielectric at infrared frequencies. As a result, high optical absorption enhancement in graphene can be realized over a wide angular range in a narrow band. This method may be employed in optical absorption and solar cells.