LETTER TO THE EDITOR: The dispersion relation of surface plasmons on rough surfaces

The dispersion relation of surface plasmons ω(kperpendicular) on rough silver surfaces has been measured by the reflection method and the light scattering method. The resonances (minimum reflection intensity and maximum scattering intensity) are in general displaced to higher kperpendicular-values compared with smooth surfaces, and the halfwidth of the resonances increases with roughness.