Local spectra and field distributions on the surfaces of rough nanometer-structured metal films

Summary form only given.Recent advances in photon scanning tunneling microscopy made it possible to image with subwavelength resolution near-field intensity distributions of EM fields near rough surfaces irradiated by external light. This technique allows one to study localization and amplification of local fields near such surfaces, which is important for understanding of rough surface enhancement of nonlinear optical processes. We will discuss numerical and experimental studies of the spectral dependence and spatial distribution of local EM fields near the surface of self-affine silver films with nanometer structured roughness. We use the discrete-dipole approximation for numerical simulations and treat a rough surface as a collection of pointlike polarizable dipoles distributed in space according to two different algorithms.