Radiative Decay of Electron‐Induced Surface Plasmons in Rough Surfaces

Abstract

Abstract Coupling between fast electron‐induced surface plasma waves in metals and an electromagnetic field was calculated for surfaces with statistical roughness. Measurements of electron‐induced surface plasmon radiation from evaporated silver targets (3.54 eV ≙ ≙ 350 nm peak wavelength) showed that a non Gaussian surface autocorrelation function must be assumed, which prefers medium spatial frequencies, and that the assumption of a plane surface for the surface plasmon excitation process is allowed if the surface is not too rough. With increasing roughness additionally lower frequency excitations take place. Agreement with the measured spectral distributions only could be obtained, if the optical constants of Philipp and Taft were used; from the optical constants of evaporated silver targets follows the peak intensity at 3.62 eV (λ = 342 nm), retardation taken into account.