Plasmonic metasurfaces for nonlinear structured light

Abstract

Nonlinear optical processes can be enhanced at the nanoscale by exploiting plasmonic field enhancement [1]. Recently, hybrid metallic/dielectric nanostructures have been proposed to boost the nonlinear emission [2], but separating the nonlinear contributions from metal and dielectric is not easy in experiments. This led us to study the third harmonic generation (THG) from a gold dipole nanoantenna containing a nonlinear dielectric nanoparticle in its gap [3], such to delineate the design conditions to have the nonlinear emission dominating in the gap material or in the metal.