New effects in the multiphoton ionization of atoms

Abstract

The review is devoted to new effects discovered recently in the course of studying the process ofnonlinear ionization of atoms in the field of laser radiation—above-threshold ionization,manifestation of multielectron structure of complex atoms, formation of multiply charged ions,tunneling ionization, and emission of short-wavelength radiation. The main experimental data andtheir theoretical interpretation are presented. A discussion is given of the criteria for theapplicability of the lowest non-vanishing order of non-steady-state perturbation theory to thedescription of the interaction of an atom with the electromagnetic field.