Resonantly-Enhanced Harmonic Conversion at High Laser Intensity

Abstract

In much the same way that intermediate states shifted through resonance by a strong field influence the electron spectrum in above threshold ionization (ATI),1,2 so too can these states influence the nonlinear dipole responsible for high order harmonic generation.3 However, because of the additional propagation effects (phase matching), such field induced resonances can have an even more important effect on the harmonic spectrum.