Strong laser field effects in multiphoton Stark detachment

Abstract

A Green function approach is employed to obtain general expressions for electron flux distributions and partial widths in multiphoton detachment from a negative atomic ion placed into a uniform static electric field. The electric vector for the linearly polarized laser field has arbitrary direction with respect to the static field axis. The case of a weak static field is analysed in detail for arbitrary strength of the laser field. The separation of the uniform field and laser field effects allows simple and appealing expressions to be obtained for photodetachment partial widths via static-field-free amplitudes in the case of an arbitrary number of absorbed photons and quantum numbers of the initial state. Some implications of the present results for the interpretation of recent experiments on H- Stark photodetachment are discussed.