2014 Three types of short-time measurements using temporally incoherent light instead of short pulses are described. Electronic dephasing in a polydiacetylene film, vibrational dephasing in dimethylsulfoxide liquid, and relaxation of optical Kerr effect in CS2 and nitrobenzene were observed with femtosecond time resolution. Revue Phys. Appl. 22 (1987) -1785 DÉCEMBRE 1987, PAGE 1773