Study of roughness-induced diffuse and specular reflectance at silver-air and silver-liquid interfaces. Final report, July 1, 1979-August 31, 1980

Results of an extended investigation of surface plasma-wave absorption and roughness-induced optical scattering from an interface of silver and air are described. In particular, the position of the surface plasma resonance minimum in reflectivity for a stochastically roughened metal silver surface has been studied as a function of a number of distinct roughness perturbations. In the case of a transparent liquid-silver boundary the frequency red shift of the resonance minimum has been determined and the location of the surface plasmon dip for various liquids is shown to agree well with a simple roughness theory. The additional interfacial properties due to the formation of a thin inhomogeneous oxide layer occurring either spontaneously or due to application of a small interfacial electrical potential are more complex. However, the optical constants of the interlayer have been determined from differential specular reflectance measurements at the boundary. Nodule size parameters determined from scattering and absorption measurements and features of both polarized and depolarized diffuse reflectance give further information on the state of the interface. Reflectance of ordered-corrugated surfaces are also described