Abstract:

Ultrafast vibrational relaxation dynamics of LDS698 dye molecule in solution are theoretically studied on the basis of the perturbative density operator method and the transient linear susceptibility theory. Femtosecond time-resolved profile on stimulated emission pumping fluoresence depletion is simulated for the system with the single vibrational mode. The vibrational transition rate constant γ1→0 is 4.5 ps-1 ,the two constants C1 and k relating to the solvation are1.0 and 0.08ps-1 respectively. It is 2.4 for the Huang-Rhy factor S between the first excited S1state and the ground S0 state. The SEP signal reveals that the fast and the slow decay components reflect the vibrational relaxation and the excited state solvation of the molecule respectively .

Key words: LDS698 dye molecule, Ultrafast vibrational relaxation, Stimulated emission