High order harmonic generation in noble gases using plasmonic field enhancement

Theoretical studies of high‐order harmonic generation (HHG) in rare gases driven by plasmonic field enhancement are presented. This kind of fields appears when plasmonic nanostructures are illuminated by an intense few‐cycle laser and have a particular spatial dependency, depending on the geometrical shape of the nanostructure. It is demonstrated that the strong nonhomogeneous character of the laser enhanced field plays an important role in the HHG process and significantly extends the harmonic cutoff. The models are based on numerical solution of the time dependent Schrödinger equation (TDSE) and supported by classical and semiclassical calculations.