Wigner function analysis of high harmonic generation in atoms

Abstract

The Wigner function provides the expression of phase space dynamics in quantum mechanics. In an application to non-linear optics, we describe its construction from time-dependent wavefunctions generated by numerical simulations, performed in both one and three dimensions, of the interaction of atoms with strong laser fields. From this analysis, the elements of the semi-classical three-step model of high-harmonic generation are extracted directly from the solution of the time-dependent Schrödinger equation. It is demonstrated that information contained in the Wigner function that is not relevant to this analysis may be removed by spatial filtering and state-projection operations.