On the Surface-to-Bulk Mode Conversion of Rayleigh Waves (Short Papers)

The surface-to-bulk wave conversion phenomena occurring at a discontinuity characterized by a surface contour deformation may be used as a means for tapping Rayleigh waves in a nonpiezoelectric solid. For this purpose, the mode conversion problem is treated in this short paper with the use of a boundary perturbation technique. A systematic procedure is obtained to calculate not only the first-order scattered waves which include the reflected surface wave and the converted bulk wave, but also the higher order terms. With careful design of the surface contour, the converted bulk-wave power and the direction of propagation into the substrate may be controlled.