Theoretical analysis of femtosecond fluorescence depletion spectra and vibrational relaxations of dye oxazine 750 and rhodamine 700 molecules in acetone solution

摘要

The fluorescence depletion spectra of oxazine 750 (OX750) and rhodamine 700 (LD700) molecules in acetone solution are calculated using the perturbative density operator method and the transient linear susceptibility theory. The calculated fluorescence depletion spectra of the dye OX750 and LD700 molecules agree well with the experimental results reported by Liu et al. The calculated decay time of the fluorescence depletion spectra due to the vibrational relaxation ranges from 300 to 450 fs, and the decay time resulting from the solvation effect is a few tens of picoseconds. The calculated vibrational relaxation rates are 4.3 and 4.9 ps(-1) for the OX750 and LD700 molecules, respectively. The effects of temperature and probe pulse parameters on the fluorescence depletion spectra are also discussed. (c) 2006 Wiley Periodicals, Inc.