Grazing-angle scattering of surface acoustic waves in periodic groove arrays

A new powerful method for analysis of extremely asymmetrical scattering (EAS) in periodic arrays is extended to the case of scattering that is intermediate between EAS and the conventional Bragg scattering. It was called grazing-angle scattering (GAS), because it takes place when the scattered wave propagates at a small (grazing) angle with respect to boundaries of a strip-like periodic array. It is demonstrated that the diffractional divergence of the scattered wave plays a crucial role in the steady-state GAS. Strong resonant character of GAS and its unique features, which make it radically different from the conventional Bragg scattering and EAS, are analyzed theoretically for surface Rayleigh waves in periodic groove arrays. In particular, it is shown that the resonant increase of the scattered wave amplitude during GAS can be even stronger than for EAS.