5TH-ORDER COHERENT-LIGHT SCATTERING - EXTENSION OF THE KRAMERS-HEISENBERG EXPRESSION FOR LIGHT-SCATTERING AND 2-DIMENSIONAL MEASUREMENT OF VIBRATIONAL DYNAMICS

A theoretical description of the fifth-order coherent light scattering is presented. By calculating the corresponding radiative transition r ate, it is found that the intensity of the fifth-order scattering ligh t is proportional to the squares of the number density as well as to t he thickness of the optical sample. The fifth-order coherent light sca ttering expression is a two-dimensional extension of the Kramers-Heise nberg expression for light scattering. The intensity of each peak in t he two-dimensional spectrum is determined by the product of three Rama n transition matrix elements. A detailed discussion on the relative in tensities of the diagonal and off-diagonal peaks is presented. (C) 199 8 American Institute of Physics. [S0021-9606(98)01939-4].