Off-Resonant Fifth and Seventh Order Time-Domain Nonlinear Spectroscopy on Vibrational Dephasing in Liquids

Recent developments of off-resonant higher-order, fifth and seventh order, nonlinear spectroscopy in liquids are reviewed. Vibrational spectra in both low- and high-frequency regions are studied by these techniques to obtain microscopic information of liquids. Vibrational dephasing is theoretically described with emphasizing its relation to liquid dynamics. A brief introduction of nonlinear spectroscopy is given. A couple of different higher-order nonlinear techniques, Raman echo, temporally two-dimensional impulsive stimulated Raman scattering, and one- and two-dimensional overtone dephasing, are discussed together with conventional third order nonlinear techniques such as coherent anti-Stokes Raman scattering and femtosecond optical Kerr effect.