Design of a highly magnified directional acoustic source based on the resonant cavity of two-dimensional phononic crystals

The authors report a design of a highly magnified directional acoustic source based on the planar resonant cavity of two-dimensional phononic crystals. The authors demonstrate that the order of the resonant mode and the reflective ratio of the double phononic crystal slab are the key factors to the magnified ratio of the directional acoustic amplifier. With properly designed mode and cavity width of the asymmetric phononic structure, the optimal magnified amplitude can be achieved by more than 86.5 times in comparison with the amplitude of the original line source freely radiating in water. (c) 2006 American Institute of Physics.