A major part of the giant Raman scattering by adsorbed molecules on a Ag-island film is shown to be due to the large increase in the electric field at the molecules and to the large electric dipole moment of the molecule-metal-island complex that result from the excitation of the transverse collective electron resonance of the film.

• Received 12 June 1980

DOI:https://doi.org/10.1103/PhysRevLett.45.1287