Differential Transmission (DT) measurements were performed on the composite solution in a pump and probe configuration. Ti:Sapphire laser (Libra -Coherent) delivering 100-fs pulses at 800nm with 1kHz repetition rate is sent to a tunable parametric optic amplifier (TOPAS -Light Conversion) to get pulses at the chosen excitation wavelength (360nm). The measurement is performed with two different configurations to explore two different delay range: