  We study light scattering by spherical nanoshells consistent of
metal/dielectric composites. We consider two geometries of metallic nanoshell
with dielectric core, and dielectric coated metallic nanoparticle. We
demonstrate that for both geometries the local field enhancement takes place
out of resonance regions ("dark states"), which, nevertheless, can be
understood in terms of the Fano resonance. At optimal conditions the light is
stronger enhanced inside the dielectric material. By using nonlinear dielectric
materials it will lead to a variety nonlinear phenomena applicable for
photonics applications.
