Two dimensional phononic band-gap materials for surface acoustic wave devices

The success of photonic crystals in the development of new microelectronic devices involves the increasing interest in developing new similar materials with acoustic properties called Phonon Crystals. The possibility of direct excitation of the surface waves on a piezoelectric material make them an interesting basis for phononic crystals used in devices for acousto-optical signal processing. This study is aimed at developing a numerical two-dimensional phononic band-gap structures consisting of different piezoelectric materials. We report the existence of the frequency band gap for surface waves in a phononic structure consisting in a square array of circular vacuum holes in a Silicon and Lithium niobate slab, after a theoretically and analytically procedure using the Plane-wave-expansion Method.