Double Resonance with Pulsed Fields

An analytical semiclassical expression is derived for the two-photon transition in a three-level system under the influence of two pulsed fields. We study the Autler-Townes doublet as a function of the time dependence of the field amplitudes and the relaxation widths of the levels. The time variations of the field amplitudes cause shifts in the doublet and modify the radiative decay widths of the levels. The validity of the treatment extends into the intermediate-intensity regime.