Harmonic generation at the nanoscale in strategic materials for nanophotonics

The use of semiconductors and metals in the process of nano-devices fabrication exploits the properties of light localization at the nanometer scale in new and surprising ways. At the nanoscale and under pulsed illumination, phase matching condition plays no role, light can propagate and resonate even in opaque spectral ranges and surface nonlinear effects may be as efficient as the bulk components. Effective 2) and (3) are different from their bulk counterparts and may depend on pump depletion, pulse duration and type of nonlinearities that are triggered. We report experimental results of harmonic generation at nanoscale in metals (Au and Ag) and semiconductors (Si). The comparison of these experimental results with numerical predictions of our theoretical model identifies, distinguishes and explains the different nonlinear contributions to the harmonics generated by these materials at the nanoscale.