Abstract

Optical nanoantennas are excellent tools for accessing the nonlinear response of noble metals owing to the strong enhancement of light-matter interaction occurring in the near-field. For example, excitation of gold nanostructures with intense radiation triggers both coherent and incoherent phenomena such as third-harmonic generation (THG) [1] and multi-photon photoluminescence (MPPL), respectively [2,3]. In this work, we study the interplay between these frequency conversion mechanisms in order to unveil the effective χ⁽³⁾ nonlinear response of metals.

© 2017 IEEE