We present an implementation of Maxwell's equations on adaptive meshes in order to study interaction of light with metal surfaces. For the first time it is possible to handle surfaces consisting of complex particles close enough to interact strongly. A fully retarded implementation allows treatment of large particles as well as small. By way of example we model a rough silver surface as an array of half-cylinders embedded in a silver surface. Very localized plasmon modes, created by strong electromagnetic coupling between touching metallic objects, dominate the surface enhanced Raman scattering response.

• Received 7 February 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.1163