Abstract

It is well established in the literature that three factors contribute to coherent anti-Stokes Raman scattering with ultrashort laser pulses: resonant scattering via the (i) isotropic and (ii) anisotropic parts of the Raman scattering tensor and (iii) non-resonant scattering via the third order nonlinear susceptibility ${\text{χ}}_{\text{nr}}^{(3)}$. The temporal information associated with the three contributions is different. The time evolution of the isotropic scattering represents vibrational dephasing while the anisotopic scattering is also affected by the reorientational motion of the molecules. The non-resonant scattering, on the other hand, follows almost instantaneously the time evolution of the input laser pulses.

© 1992 IQEC