The theory of Surface Enhanced Hyper Raman Scattering (A review)

Resumo

The Dipole Quadrupole theory of Surface Enhanced Hyper Raman Scattering (SEHRS), created by the authors is expounded in detail. Peculiarities of behavior of electromagnetic field on rough metal surfaces are considered. It is demonstrated that there is an enhancement of the dipole and quadrupole light-molecule interaction near the places of the surface with a large curvature. The expression for the SEHRS crosssection of symmetrical molecules is obtained. Selection rules for the scattering contributions are derived and a qualitative classification of the contributions after the enhancement degree is performed. Analysis of experimental spectra of pyrazine and phenazine, and also some another molecules is performed too. It is demonstrated a full coincidence of experimental regularities in these spectra with the theory suggested.