Sub-wavelength localization of hot-spots in SERS

Localization of plasmon resonances within fractions of the wavelength of the exciting laser is shown by means of surface enhanced Raman scattering (SERS). Our results confirm speculations on sub-wavelength resolution capabilities of SERS as well as provide a tool to understand highly localized plasmon excitations in disordered metallic nanostructures. It also provides some insight into the nature of hot-spots, believed to be responsible for the huge amplifications seen in single molecule SERS.