Multi-dimensional vibrational spectroscopy measured from different phase-matching conditions

We developed a theoretical method that can systematically treat the phase-m atching condition of nonlinear infrared or Raman measurements. This method might be a rational tool for the analysis of observed signals from various directions based on the response Function especially under non-impulsive ex citation. Model calculations of the third-order nonlinear IR spectroscopy f or a Brownian harmonic oscillator system are performed. We discuss the vari ation of signals that depend on the observation direction and the temporal width of excitation pulse in comparison with the behavior within the impuls ive limit approximation. (C) 2001 Elsevier Science B.V. All rights reserved .