Abstract

The ionization of atoms in intense laser fields displays some typical phenomena. One of these is above-threshold ionization (ATI), i. e. the absorption of more photons than necessary for ionization, leading to a series of peaks in the electron energy spectra. It is remarkable that the main features are qualitatively similar for different atomic systems, in particular for the rare gases. A lot of insight was gained from a classical model that treats the atom as a source providing electrons via tunneling. Subsequently, the atomic binding potential is ignored and the electrons are described by classical trajectories merely in the laser field.

© 1998 IEEE