Exploiting the surface dispersion of nanoparticles to design optical-resistive sheets and Salisbury absorbers

In this Letter, we propose a method to implement resistive sheets exhibiting a desired value of the intrinsic surface resistance at optical frequencies. Considering the sheet made by arrays of plasmonic nanoparticles, the idea is to tailor the surface dispersion occurring when the dimensions of the nanoparticles are smaller than the mean free path of electrons in the constituent material. An analytical model of the surface resistance is proposed and its effectiveness assessed through full-wave simulations. Finally, the applicability of the proposed resistive sheets to implement optical Salisbury screens is discussed and validated through full-wave simulations.