Peculiarities of increasing the third harmonic generation efficiency upon noncollinear excitation of a surface plasmon on a metal diffraction grating

The efficiency of third harmonic generation (THG) upon noncollinear excitation of a surface plasmon on a metal diffraction grating is studied based on theoretical simulations. The basic channels of the nonlinear interaction of surface plasmons determining the intensity of the THG nonlinear response of the grating are considered. The influence of the period and groove depth of the diffraction grating on the THG efficiency is analysed.