Resonance Raman scattering of multimode systems: Fourier amplitude approach

Abstract

The time-dependent description of resonance Raman scattering of multimode systems is presented and discussed. The basic quantities of the theory are the Fourier transforms of the Raman amplitudes. For a number of vibronic models they are related to the optical absorption. These relationships enable one to transform the absorption spectrum to the Raman excitation profiles. In the transform method, model parameters are needed only for the Raman mode; the multimode information is automatically included via the measured optical absorption. The method holds for an arbitrary temperature. Transform relationships are derived for the basic model of linear vibronic coupling and for more complicated models including linear non-Condon interaction, frequency shifts and mode mixing with electronic excitation, the Jahn-Teller effect and inhomogeneous broadening.

Thermal Effects in Resonance Raman Scattering: Analysis of the Raman Intensities of Rhodopsin and of the Time-Resolved Raman Scattering of Bacteriorhodopsin

“…In more general cases, where the first-order approximation becomes inaccurate, the Raman cross section can no longer be evaluated as the modulus squared of a single-time Fourier transform. One approach is to retain the spirit of the transform theory method, but with the Raman cross section now expressed as a series of terms, each of which is calculated using a transform equation with an appropriate frequency argument of 0 24,26,30 An alternative method, used here, is simply to evaluate directly the series expansions of eq 22-24 followed by the twodimensional Fourier transform of eq 25. In this evaluation a simple transformation of time variables…”

A possibility of distinguishing the inhomogeneous broadening via coherent Raman spectra

“…To calculate coherent Raman excitation profiles, it is convenient to use the transform theory [5][6][7], which relates the scattering amplitudes to the absorption spectrum. In the case of A-type scattering with linear vibronic coupling,…”

Transform method in resonance Raman scattering: effect of mode mixing

“…In spite of numerous papers dedicated to the relations between the optical absorption and the resonance Raman profiles, 15,16 starting from the so-called basic vibronic model and extended beyond the standard assumptions (including mode mixing 6 -11 ), it seems that the opportunities of the transform technique have been used only partly. As a rule, one restricts oneself to the basic transform law which takes into account only the linear vibronic coupling.…”