Two-Photon Absorption under Propagation of Weak Pulses of Light in Dispersive Media

The propagation of short pulses of light in a three-level resonant medium under conditions of two-photon resonance and in the absence of one-photon resonance is considered. The probability of two-photon absorption is calculated for the case of a gaussian pulse accounting for group velocity dispersion. The dependence of the probability on the distance of propagation and on the frequency detuning between the pulse and one-photon transition is analyzed.