THE LADDER OF TRIPLETS IN THE RESONANCE FLUORESCENCE-SPECTRUM OF A 2-LEVEL ATOM

The fluorescence spectra of a two level atom interacting with amplitude modulated intense fields are presented. The spectra are multipeaked and can be in general described as a superposition of triplets. The incoherent spectra for the fully amplitude modulated field and those under conditions of parametric resonance are predicted to have a width that depends on the modulation intensity. This feature is different from the known intensity-independent widths of the peaks in the Mollow spectrum. The transient spectra for an atom placed in the dressed state of a partially amplitude modulated field are found to show variation in the peak height. In some cases, one of the peaks of each triplet is suppressed while in another situation, all the peaks lying to one side of the spectral centre are absent.