SUBPICOSECOND TRANSIENT GRATING MEASUREMENTS OF THE RESONANT ENERGY-TRANSFER IN CRESYL VIOLET SOLUTIONS - EVIDENCE FOR NONDIFFUSIVE ENERGY-TRANSPORT

Three exponentials are needed to fit the decrease in scattered light intensity with increasing delay time between pump and probe pulses. The decay time of the fastest component varies between 270 and 120 fs if the grating fringe spacing is reduced from 15.5 to 7.8 mu m at constant dye concentration (4 X 10(-3) M) or if the dye concentration is increased from 2 X 10(-3) to 5 X 10(-3) M at constant fringe spacing (10 mu m). The results are discussed as evidence for non-diffusive energy transport.