Higher-order harmonic generation in xenon at 1064 nm: The role of phase matching

Abstract

We present a completely ab initio calculation of harmonic generation in xenon exposed to a strong laser field. The time-dependent Schr\"odinger equation for the atomic response and the propagation equation are numerically integrated yielding excellent agreement with experiment. The weaker variation with pump intensity of the induced dipole in the high-field regime leads to an enormous enhancement in phase matching compared to the perturbative limit and a defocusing of the generated harmonics.