Specific features of the time dependence of intensity of differently polarized fluorescence components of bichromophore molecules caused by radiative dissipative interaction between their chromophores

Specific features of the time dependence of the intensity of differently polarized fluorescence components of a single bichromophore molecule and a monomolecular layer of such molecules are found. These features are related to the radiative dissipative interaction between chromophores of the molecule. The most prominent feature is the fall to zero of the intensity of fluorescence polarized perpendicular to polarization of the exciting light pulse at certain orientations of molecules with respect to the propagation direction of the light pulse. The complete quenching of this fluorescence component occurs when the excited-state population of an initially unexcited chromophore in molecules where only one of the two chromophores was excited reaches a maximum. As a result, the time dependence of the anisotropy of fluorescence of such molecular layers is described by hyperbolic secant with a maximum equal to unity at the quenching moment.