Electron-Energy Resolved Experiments on Multiphoton Detachment from Negative Ions

Abstract

In many experiments on atoms in strong laser fields, it is the nature of the interaction of the atom with the radiation field which is the subject of investigation, more than the specific structure of the atom which is used. An example of the phenomena that have been discovered in this kind of experiments is the effect of excess-photon ionization (EPI), also called above-threshold ionization (ATI). It is found that electrons can absorb more photons than required to overcome the threshold for ionization and this manifests itself for example in electron-energy spectra consisting of several peaks separated by the photon energy. Since the first observation by Agostini et al1 in 1979, the effect of EPI has been thoroughly investigated2. It was probably initially assumed that in experiments performed at high light intensities the structure of the particular atom was of no importance, however, in later experiments it was found that the structure of the atom leaves its mark on the measurement by means of resonance enhancement of the EPI3.KeywordsPhoton EnergyCircular PolarizationRing ElectrodePole PieceStokes LineThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.