Observation of light-induced inhomogeneous broadening in polyaniline solutions

Summary form only given. Electronic dephasing time T/sub 2/ can be studied in "real time" by using fs-pulse lasers or by using broadband noisy light with ps or ns pulse duration. In this case, the short coherence time (t/sub c/) of the noisy light, not the duration of the pulses, is the quantity that determines the time resolution in self-diffraction (SD) experiments. In this kind of experiments, when the transition under study is homogeneously broadened and T/sub 2/>t/sub c/, T/sub 2/ is determined from the asymmetric experimental curves, which relates the intensity of the signal and the time delay between the incident pulses. The broadband light sources were two dye lasers pumped by the second harmonic of a Q-switched Nd:YAG laser.