Nonadiabatic three-dimensional model of high-order harmonic generation in the few-optical-cycle regime - art. no. 063801

A numerical model to calculate the high-order harmonics spectrum of a macro scopic gas target irradiated by a few-optical-cycle laser pulse is presente d. The single-atom response, calculated within the nonadiabatic strong-fiel d approximation, is the source term of a three-dimensional propagation code . The simulation results show remarkably good agreement with experiments pe rformed in neon using laser pulses with durations of 30 and 7 fs. Both simu lations and experiments show discrete and well-resolved harmonics even for the shortest driving pulses.