Classical electrodynamics of non-specular conducting surfaces

For dispersive conducting media the role of surface scattering of electrons is studied in a semiclassical approximation using a phenomenological specularity parameter p (0 ≤ p ≤ 1). The problem of unphysical charge accumulation at the surface, which often appears in treatments in terms of p, is explicitly discussed and avoided. The P-mode surface plasmon dispersion relation in the quasistatic limit (c → ∞) is obtained for arbitrary p and κ (propagation vector). This permits a study of the effect of surface scattering on surface plasmon damping and also of the different roles of the longitudinal and transverse dielectric functions. This is illustrated with an application in terms of simple interpolation formulae for the dielectric functions.