Experimental verification of the calculated diffraction field generated by inhomogeneous waves obliquely incident on a periodically rough liquid–solid boundary

Abstract

In this paper, the diffraction of an inhomogeneous plane bulk wave at a corrugated liquid–solid boundary is considered. The classical diffraction law of Bragg for homogeneous plane waves is generalized for incident inhomogeneous bulk waves, and the obtained results are verified experimentally. The solution of the generalized diffraction law is not unique. Depending on the chosen solution, the reflection (and transmission) coefficients of the diffracted inhomogeneous waves have a different modulus and phase. An illustration is given for the zeroth-order reflection and compared with experimental results. A reflection coefficient greater than unity is observed. This effect agrees with the inhomogeneous wave theory.