A first part reports on the time-resolved dynamic Stokes shift of fluorescence for a solvatochromic dye in a dielectric solvent. This serves to introduce techniques, observables, and analysis in pump-probe spectroscopy with a fs white-light probe. A second part deals with the photodissociation of an aromatic disulfide into two polar radical fragments. The solvatochromism of the fragments is examined both statically as well as by fs spectroscopy. The solvation process is simulated by molecular dynamics calculations.