Analysis of leaky surface waves in crystals with strong acoustic anisotropy

The peculiarities of LSAW analysis in crystals with strong acoustic anisotropy are described, when there is a concavity of the slowness surface in the sagittal plane. The additional real roots of the characteristic equation appearing in the region of concavity, are involved in LSAW structure and can build a new leaky solution. The analysis of LSAWs has been performed in some orientations of quartz in terms of contributing partial bulk waves. The continuous transformation of the slowness surface following from the rotation of the sagittal plane, changes gradually the nature of LSAW from the surface-guided mode to the solution of the reflection problem for bulk waves. The concavity of the slowness surface is shown to cause the splitting of LSAW branch. The composite exceptional wave, earlier known to exist in symmetric orientations of some crystals, has been found in non-symmetric orientation.