AC STARK SPLITTING OF BOUND-CONTINUUM DECAYS

The effects of saturation of a bound-bound atomic resonance on bound-continuum decays in investigated using the dressed state concept. Two special cases are discussed: the modification of spontaneous radiative decay by coupling to a third bound atomic state, and the changes in single-photon photoionisation when the initial discrete state is coupled by an external field to another bound state. For strong external fields Rabi oscillations and dynamic Stark splittings profoundly alter the 'decay'; but for weak fields the alterations at line centre are no less dramatic.