Chirped pulse excitation in condensed phases involving intramolecular modes. II. Absorption spectrum

Abstract

We have calculated the absorption spectrum of an intense chirped pulse exciting a solute molecule in a solvent. The excitation of quantum intramolecular modes has been also taken into account. In general absorption depends on both the real and imaginary part of the susceptibility (a phase-dependent absorption in the nonstationary media). We have shown that for strongly chirped pulses, the absorption spectrum can be expressed by the difference of the convolutions of the “intramolecular” absorption and luminescence spectra with the instantaneous population wave packets in the ground and excited electronic states, respectively. Incorporating of optically active high-frequency intramolecular vibrational modes eliminates the qualitative discrepancies between experimental and calculated absorption spectra which occurred in the model of one vibronic transition.