A transient two-photon–one-photon double resonance on interband transitions in crystals: I. General relations

Abstract

A theory of the transient absorption of femtosecond light pulses at a two-photon–one-photon double resonance on adjacent interband transitions in the electronic system has been developed. Approximate expressions for the reactive component of the nonlinear polarization of the three-level system, P_s, which determines the absorbed power in the medium, have been obtained, and the dependences of P_s on the light intensity and detunings of resonances have been calculated.