Surface Acoustic Waves and Film Excitations in CaF sub 2 /Si Heterostructures.
01 January 1988
The principal and up to six higher order localized acoustic surface modes from CaF sub 2 films grown epitaxially on Si (111) have been observed using Brillouin scattering. The effective elastic constants of the film and substrate in the vicinity of the interface are evaluated from a fit of the measured mode dispersions. The striking modifications to the Brillouin peak intensities with layer thickness are accounted for by strong interference between various photon coupling mechanisms.