  Surface enhanced Raman scattering mediated by surface plasmons polaritons
with wave vector much larger than those of light is considered. The excitation
of these polaritons and their efficient Raman scattering due to low group
velocity and electric field localization at the surface is discussed for the
case of two nearby surfaces. The Raman scattering depends not only on the
intensity of the electric fields seen by the molecules but also on the surface
plasmon density of states.
