Surface Brillouin Scattering in Ion-implanted Chemical Vapor Deposited Diamond

Acoustic waves occurring within an ion-damaged region of CVD diamond were studied using surface Brillouin scattering (SBS). By indirect scattering, the surface acoustic wave (SAW)-like mode of pure diamond, as well as those of carbon ion implanted diamonds to fluences of 1.0x1016 ions/cm2 and 1.5x1016 ions/cm2 were measured. Pristine diamond had a shear horizontal wave velocity of ≈12500 m/s and the irradiated diamonds showed a shear velocity of ≈12300 m/s. A necessary condition for observing Brillouin spectra via indirect scattering in a transparent medium is shown to be an optically smooth back surface.