title: Efficient method for the calculation of time- and frequency-resolved four-wave mixing signals and its application to photon-echo spectroscopy.
abstract: An efficient method has been developed for the calculation of third-order time- and frequency-resolved optical signals. To obtain the general four-wave mixing signal, seven auxiliary density matrices have to be propagated in time. For the special cases of two-pulse photon-echo and transient-grating signals, two or three density matrices, respectively, are required. The method is limited to weak laser fields (it is thus valid within the third-order perturbation theory) but allows for any pulse durations and automatically accounts for pulse-overlap effects. To illustrate the method, we present the explicit derivation of the three-pulse photon-echo signal. Any other third-order optical signal can be calculated in the same manner. As an example, two- and three-pulse photon-echo and transient-grating signals for a weakly damped displaced harmonic oscillator have been calculated.
authors.affiliation: Department of Chemistry, Technical University of Munich, D-85747 Garching, Germany.
authors.forename: Maxim F
authors.initials: MF
authors.lastname: Gelin
authors.forename: Dassia
authors.initials: D
authors.lastname: Egorova
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Domcke