Plasmonic metasurfaces for nonlinear beam shaping

Abstract

Controlling the nonlinear emission from each meta-atom in a metasurface is explored for the shaping of far-field nonlinear radiation. By arranging gold gap-nanostructures on a surface and by exploiting the nonlinear emission from the metal or from the gap material, we numerically demonstrate the creation of highly pure vortex beams at frequencies not accessible by linear plasmonics.