Mollow-like Triplets in Ultrafast Resonant Absorption

Abstract

We show that resonant absorption of smooth laser fields can yield Mollow-like triplet patterns. General conditions for such triplets are derived and illustrated with a super-Gaussian pulse sequence. Gaussian pulses cannot exhibit triplets, super-Gaussian pulses can form triplets depending on the pulse area, and flattop pulses can produce absorption triplets after one Rabi cycle. Our results are compared side by side with resonance fluorescence to emphasize similarities and differences between these unlike observables. In the high-intensity limit, we show that the central absorption peak is asymmetric, which we attribute to nonlinear photoionization, beyond two-level atomic physics.