Resonant Stark effect for a sequence of fluorescent decays

A fully quantum-mechanical treatment is presented of the interaction of a two-level atom with an intense applied field. The resonant Stark effect spectrum is calculated for a single decay process in the case of an arbitrarily detuned applied field, and for a sequence of many fluorescent decays in the case of a resonant applied field. The results of these calculations agree with recent experimental observations, and with previous theoretical calculations using different methods. In addition, a misinterpretation contained in a previous letter by the present authors (see ibid., vol.7, L.432 (1974)) is pointed out.