Transient absorption experimental set-up with femtosecond time resolution.Femto- and picosecond study of DCM molecule in cyclohexane and methanol solution

The experimental set-up for time dependent transient absorption/gain measur ements with femtosecond time resolution is presented, Using; pump-probe spe ctroscopy technique with femtosecond pulses from Ti:Sapphire laser system ( Spectra Physics), the optical density of transient absorption and transient gain in the spectral range of 330-700 nm, time resolution of 120 fs, can b e measured with the precision of up to 0.005, Knowing the real lime resolut ion and "zero time" dispersion of the system from two-photon absorption mea surements, we performed femto- and picosecond study of electronically excit ed DCM molecule in c-C6H12 and MeOH solution. The emission decay of the DCM molecule in the locally excited singlet state, S-1-LE, was measured with p icosecond time resolution using TCSPC set-up (Time Correlated Single Photon Counting). The steady-state and time resolved measurements permitted the d etermination of the properties of this locally excited singlet S-1-LE state and the pathways of its deactivation. (C) 2000 Elsevier Science B.V. All r ights reserved.