Analysis of wave propagation in phononic crystals with channel using the plane-wave expansion and supercell techniques

Abstract

In this paper, based on the plane-wave expansion method and the supercell technique, we analyze the defect modes and extended modes of two-dimensional phononic crystals. In addition, with the supercell technique, the propagating modes of phononic band structures with acoustic channel are studied. The glycerin/mercury and vacuum/silicon band structures are the examples employed in this paper. Couplings of propagating modes and point defect modes are also investigated in phononic crystals with channel. From the calculated results, we can find that the defect modes and extended modes are obvious not only for the bulk acoustic waves but also for the surface acoustic waves in phononic crystals. On the other hand, the mode shapes for different defect modes and propagating modes can also be expressed using the plane-wave expansion and supercell techniques. Through a suitable design, the acoustic filters and waveguides are the possible applications in the two-dimensional phononic crystals.