Single Electron Atoms in Strong Laser Fields

Abstract

The interaction of light fields with atoms has a long history. A classic reference is the book “Photon–Atom Interactions” by Weissbluth [1]. The focus in that book is on the interaction of atoms with weak fields, leading to absorption or emission of only few quanta of radiation. In this chapter, some modern applications of laser–matter interaction in the field of atomic physics shall be studied, however. Due to the availability of short and strong laser pulses a range of new and partly counterintuitive phenomena can be observed. Some of these are: Above threshold ionization (ATI)Multiphoton ionization (MPI)Localization of Rydberg atoms by half cycle pulses (HCP)High harmonic generation (HHG) These phenomena can in general not be understood in the framework of perturbation theory. It turns out that the time-dependent wavepacket approach of Chap. 2 is the method of choice to describe and understand a lot of new atomic physics in strong laser fields. In this chapter, we will almost exclusively deal with the dynamics of a single electron initially bound in a Coulomb potential. The discussion will therefore begin with a short review of the unperturbed hydrogen atom.