Novel Measuring Methods of Femtosecond Dynamics of Nonlinear Optical Responses

In the present paper several measuring methods of femtosecond time-resolved nonlinear response newly developed mainly by the author's group are presented. It contains methods using time incoherent light and coherent short pulse. Both of them can be utilized for the Kerr dynamics of liquids, electronic dephasing, vibrational dephasing, and depopulation processes with femtosecond resolution. They can be used for the determination of femtosecond-resolved complex third-order nonlinear susceptibility with spectral resolution. Several examples of experiments which demonstrate the usefulness of those methods are also described.