Surface Brillouin spectra of supported gold films (500 and 930 Å) and of bulk gold have been measured with a tandem multipass Fabry-Perot interferometer. By fitting the calculated cross section to the experimental data the elastic and the photoelastic constants of gold have been derived. The surface spectrum of bulk gold shows, in addition to the Rayleigh wave peak, a broad resonance which is interpreted in terms of a leaky surface pseudomode of longitudinal character.

• Received 3 February 1986

DOI:https://doi.org/10.1103/PhysRevB.34.1296