Polarization Kinetics of the Fluorescence of Solutions of Complex Molecules Undergoing Impulse Optical Quenching

The influence of optical quenching on the polarization of the integral (in time) fluorescence of solutions of complex molecules using picosecond pulses has been investigated theoretically. The resulting dependences of the degree of polarization on the time shift of pulses for the case of a thin layer of a medium (with no regard for the change in the intensity of the pulses) are in qualitative agreement with the results obtained for quasistationary excitation. A calculation has been made for the case of an extended medium with regard for the amplification of the quenching pulse. It is shown that scanning of the degree of polarization along the length of the cuvette makes it possible to obtain additional information on the mechanism of optical quenching in solutions and on the routes of deactivation of the energy of the molecule's excited state.