Polarization dependence of surface-enhanced Raman scattering in gold nanoparticle-nanowire systems.

We study the polarization dependence of surface-enhanced Raman scattering (SERS) in coupled gold nanoparticle-nanowire systems. The coupling between the continuous nanowire plasmons and the localized nanoparticle plasmons results in significant field enhancements and SERS enhancements comparable to those found in nanoparticle dimer junctions. The SERS intensity is maximal when the incident light is polarized across the particle and the wire, and the enhancement is remarkably insensitive to the detailed geometrical structures of the nanoparticles.