Polarization-selective femtosecond Raman spectroscopy of isotropic and anisotropic vibrational dynamics in liquids

Femtosecond nonresonant pump-probe experiments using variable polarization configurations are used to directly measure the isotropic and anisotropic polarizability dynamics of the intramolecular vibrational modes of liquid CCl4. These two measurements form a fundamental 'basis set' that describes the nuclear nonresonant Raman dynamics of an isotropic sample. The isotropic spectrum observes only those dynamics that are totally symmetric, such as the A(1) C-Cl stretch, whereas the anisotropic response only observes the dynamics of the depolarized modes of E and T-2 symmetry. (C) 2000 Elsevier Science B.V. All rights reserved.