Bending and branching of acoustic waves in two-dimensional phononic crystals with linear defects

Using supercell plane wave method, we study acoustic waves propagating in the bend and branching linear defects in two-dimensional phononic crystals. Dispersion relations and pressure fields for acoustic waves in the structures with the linear defects are calculated, which show that there exists not only the guiding modes, but also the localized modes along or in the defects. With suitably designed linear defects, the phononic crystals may be act as the acoustical filter or the waveguides of special functions.