Subwavelength imaging through spoof surface acoustic waves on a two-dimensional structured rigid surface

We demonstrate that acoustic subwavelength imaging can be realized through the spoof surface acoustic waves on the surface phononic crystal which is composed of borehole arrays with square lattice in a rigid plate. The dispersion property of the spoof surface acoustic waves on the two-dimensional textured rigid plate is analyzed theoretically. By utilizing the broad flat equifrequency contour of the spoof surface acoustic waves, a subwavelength image with full width at half maximum of 0.14 lambda has been obtained both numerically and experimentally. We believe that such work can bring potential applications in the design of acoustic imaging and focusing devices. (C) 2013 AIP Publishing LLC.