Enhanced Raman scattering from self-affine thin films

Surface-enhanced Raman scattering (SERS) from a self-affine surface is shown to be very large. A theory is developed expressing this SERS in terms of the eigenmodes of a self-affine surface; the theory successfully explains the observed SERS from cold-deposited thin films that are known to have a self-affine structure. Spatial distributions of local fields at the fundamental and Stokes frequencies are strongly inhomogeneous and contain hot zones (high-field areas) localized in nanometer-sized regions that can be spatially separated for the two waves.