Filtering of Rayleigh surface waves by means of periodic corrugations

Using a periodic corrugation at the surface of a semi-infinite elastic medium, the incident and reflected Rayleigh modes are strongly coupled when the Bragg condition is satisfied. The method of multiple scales is used to derive the coupled-mode equations describing such an interaction. The filter response is presented in terms of the reflection coefficient. An improved filter response may be obtained by imposing an amplitude taper on the corrugation, resulting in a close to ideal narrower midband response. By further introducing a chirped corrugation, an optimized wider midband response is realized.