Transient absorption experimental set-up with femtosecond time resolution

Experimental set-up for time dependent transient absorption/gain measuremen ts with femtosecond time resolution is presented.. The pump-probe spectrosc opy technique with femtosecond pulses from Ti: Sapphire laser system (Spect ra Physics) allowed measurements of the optical density of transient absorp tion and transient gain in the spectral range of 330-700 nm, time resolutio n of 120 fs, and the accuracy of up to 0.005. The real time resolution and "zero time" dispersion of the system were found in two-photon absorption ex periment.