Dispersion curves of surface acoustic waves in a two-dimensional phononic crystal

Reliable numerical simulations of band structure for surface acoustic waves propagating in a two-dimensional phononic crystal are reported. Through an efficient finite element method and specific boundary conditions, a theoretical approach allowing a direct computation of surface acoustic wave's band structure for phononic crystal is proposed. Three types of phononic structures are investigated; fluid/solid, solid/solid, and air connected stubbed substrate. Using sound cone limitation, calculated results show the propagation of surface acoustic waves in the nonradiative region of the substrate. In addition, the modal displacements of the original guided surface modes supported by the studied structures are computed showing their original characteristics. (C) 2011 American Institute of Physics. [doi:10.1063/1.3626853]