Dressed-atom description of resonance fluorescence and absorption spectra of a multi-level atom in an intense laser beam

TLDR

The paper presents a dressed‑atom approach to resonance fluorescence in intense laser fields. The authors solve the master equation for spontaneous emission from the dressed atom in the high‑intensity limit, using this dressed‑atom framework to model resonance fluorescence. They derive simple, general expressions for the positions and widths of fluorescence and absorption spectral components, showing these correspond to the Bohr frequencies of the dressed atom and extending known two‑level predictions to multi‑level systems.

Abstract

A dressed-atom approach to resonance fluorescence in intense laser fields is presented. Simple and general results are derived which include the now well known predictions concerning two-level atoms but are not restricted to such simple cases. The positions of the various components of the fluorescence and absorption spectra are given by the allowed Bohr frequencies of the total system: atom+laser mode (dressed atom). The master equation, describing spontaneous emission from the dressed atom is solved in the limit of high intensities. Simple expressions, taking into account the effect of cascades, are derived for the widths of the components.