Effects of nonresonant ionization on multiphoton ionization line shapes

Publisher Website
Google Scholar
Abstract
A kinetics model of multiphoton ionization (MPI) is developed to account for nonresonant ionization and collisional rethermalization effects on MPI. Simple quantitative criteria to describe MPI line shapes are derived. In cases where resonantly enhanced MPI (REMPI) is not an effective spectroscopic tool, it is demonstrated that absorption can deplete ground state levels which would otherwise have contributed to nonresonant ionization. The resulting structured valleys in the ionization current contain spectroscopic and dynamical information which may otherwise be unattainable. The feasibility of depletion of nonresonant ionization (DNRI) as a general technique is investigated and the first experimental observations of DNRI are reported and analyzed.