  We study Raman scattering in active media placed in proximity of different
types of metal nanostructures, at wavelengths that display either Fabry-Perot
or plasmonic resonances, or a combination of both. We use a semi-classical
approach to derive equations of motion for Stokes and anti-Stokes fields that
arise from quantum fluctuations. Our calculations suggest that local field
enhancement yields Stokes and anti-Stokes conversion efficiencies between five
and seven orders of magnitudes larger compared to cases without the metal
nanostructure. We also show that to first order in the linear susceptibility
the local field correction induces a dynamic, intensity-dependent frequency
detuning that at high intensities tends to quench Raman gain.
