Femtosecond time-resolved ERE-CARS of CV670 dye in solutions

We utilize femtosecond time-resolved electronic resonance-enhanced coherent anti-Stokes Raman scattering (ERE-CARS) to study the vibrational dynamics of cresyl violet 670 (CV670) dye molecules. For this purpose, the vibrational properties of CV670 are registered in diluted solutions of ethanol and methanol. By changing the timing (Δt > 0) of the laser pulses of this nondegenerate four wave mixing technique, the wavepacket dynamics on the electronically ground state can be detected as oscillations in the ERE-CARS signal. Two strong Raman vibrational modes with an average period of 0.401 and 0.423 ps in CV670-ethanol solutions are obtained simultaneously, and we observe a qualitative vibrational dephasing time difference of the Raman vibrational modes of CV670 in ethanol and methanol solvents (5 × 10 ^-5 mol/L), which may be due to the influence of the formation of the supramolecular structures in CV670-ethanol and CV670-methanol mixtures on the Raman modes of CV670.