Dressed-atom approach for probe spectroscopy in Doppler-broadened three-level systems with standing-wave saturator

The three-level probe spectroscopy of Doppler-broadened transitions in the presence of a standing wave pump laser is investigated through a diagrammatic method. A probe-response diagram is defined where the resonance positions versus the probe laser frequency and absorber velocity are plotted. The dressed atom description provides a convenient method for deriving the probe response diagram and calculating the position of the Doppler-free structures on the absorption spectrum, including the ac Stark shifts. We have interpreted probe spectra on the basis of the probe response diagram, presenting new features and giving a detailed physical interpretation of all the coherent effects appearing in the spectra. Population effects are not included in the dressed system analysis and are calculated on the basis of a semiclassical treatment, but the probe response diagram provides a complete interpretation of the involved phenomena. © 1983 Springer-Verlag.