Polarization effects in the total rate of biharmonic $ω+ 3ω$ ionization of atoms

Abstract

Total ionization rate of biharmonic (ω + 3ω) ionization are studied within the independent particle approximation and third order perturbation theory. Particular attention is payed to how the polarization affects the total rate. The ratio of the biharmonic ionization is analyzed for linearly and circularly polarized beams as well as for co-and counterrotating elliptically polarized beams are analyzed and their dependence on beam parameters, such as the photon frequency or the phase between the ω and 3ω light beams, is explained. We show that the interference of the biharmonic ionization amplitudes determines the dominance of a particular beam polarization over another and that it can be controlled by an appropriate choice of beam parameters. We demonstrate our findings for the ionization of neon L shell electrons.