Surface plasma oscillations at silver surfaces with thin transparent and absorbing coatings

Developing a second order theoretical approximation of the dispersion relation of surface plasma oscillations (SPO's) at coated silver surfaces, that the influence of thin coatings on the SPO properties is explained by the change of the field distribution of the SPO due to the surface contamination. The theoretical results are verified by attenuated total reflection experiments at LiF- and carbon-coated silver films. The experimental reflection curves were used to determine the optical constants and the thickness of the LiF and carbon coatings. It was found that vacuum evaporated LiF films must be described by a system of at least two layers of different refractive index due to the hygroscopic nature of this material. (Auth.)