ULTRAFAST EXCITED SINGLET-STATE ABSORPTION GAIN SPECTROSCOPY OF PERYLENE IN SOLUTION

Time-resolved absorption and gain spectroscopy of perylene in the lowest excited singlet state S-1 in solution is performed in the spectral range 350-1000 nm using subpicosecond excitation at 425 nm. Strong S1Sn absorption at 700 nm (epsilon = 53000 M(-1) cm(-1)) as well as the full S1S0 stimulated emission cross section spectra are measured. A way to extract, from the sample absorbance variation, the S-1 population, and the absolute value of the transition cross sections, is given for the perylene case. Direct evidence of fast vibrational relaxation in about 1 ps is given for the 352 cm(-1) mode in the S-1 state. It is suggested that this molecule could be a good choice as a reference for the measurement of the excited state absorption cross sections.