Refraction, beam splitting and dispersion of GHz surface acoustic waves by a phononic crystal

Imaging phonon eigenstates and elucidating the energy storage characteristics of a honeycomb-lattice phononic crystal cavity

“…4 (b) indicates that either a low-group velocity zone-centre eigenmode or ones at the 2nd BZ edge may be responsible. The effect of Bloch harmonics produces an array of dots in -space at the centre of each translated BZ, as previously observed for other PC lattices [43] , [54] . We have superimposed the full BZ pattern on the image in Fig.…”

Special issue introduction: Ultrafast photoacoustics

“…Two articles [22] , [23] describe new achievements in the application of ultrafast photoacoustics to the 2D imaging of the propagation of surface acoustic waves. Article [22] reports on a detailed study of the propagation of point-excited GHz surface acoustic waves on a microscopic 2D phononic crystal. Constant-frequency images are extracted in the region around the phononic band gap.…”

“…A novel numerical approach to extract the cavity Q factor by means of toneburst acoustic excitation and analysis of the acoustic Poynting vector distribution allowed a quantitative measure of the spatial acoustic energy storage characteristics of the cavity. The experimental and analytical techniques developed in the articles [22] , [23] open the way for a more detailed understanding of the acoustic properties of phononic crystals, phononic metamaterials, and their derived surface wave devices.…”