The coupling of discrete states with ionization continuum state induced by monochromatic lasers and configuration interaction was studied by means of both quasi-antoionization state appromation as well as the Fano's autoionizatum theory.
We present a theoretical study of laser-induced autoionization and laser-induced continuum structures, performed with the aim of deriving predictions on the effect of continuum-continuum transitions on the resonance line shape. The model, developed as an extension of models introduced for the description of laser-induced autoionization and laser-induced continuum structures, on one hand, and for above-threshold ionization, on the other hand, provides quantitative predictions. For specific atomic systems, the line shapes of the structures are shown not to be affected by continuum-continuum transitions, in contrast with previously reported results.
An analytical, time-dependent, fully nonperturbative solution of a general model of a light-induced continuum structure, in which a dense Rydberg-like quasi-continuum is laser-embedded into a previously structureless atomic continuum, is reported. On the basis of this solution we point to the limitations of Fano theory, which was originally formulated for an analogous problem of a number of discrete states and one continuum with configuration interaction, when this theory is adapted to the problem of multilevel light-induced continuum structures.