Measuring bulk and surface acoustic modes in diamond by angle-resolved Brillouin spectroscopy

The acoustic modes of diamond are not only of profound significance for studying its thermal conductivity, mechanical properties, and optical properties, but also play a definite role in the performance of high-frequency and high-power acoustic wave devices. Here, we report on the bulk acoustic waves (BAWs) and surface acoustic waves (SAWs) of single-crystal diamond using angle-resolved Brillouin light scattering (BLS) spectroscopy. We identify two high-speed surface skimming bulk waves (SSBW) with acoustic velocities of 1.277x10(6) and 1.727x10(6) cm/s, respectively. Furthermore, we obtain the relationship between the velocity of arbitrary BAWs and that of BAWs propagating along the high-symmetric axis at different incident angles. In the community of diamond-based acoustic studies, our results may provide a valuable reference for fundamental research and device engineering.