Resonant excitation of intense acoustic waves in crystals

Resonance excitation of intense acoustic beams in crystals of different syngonies

“…where [ ] denotes the mixed product of vectors and REFLECTION FROM THE SURFACE PARALLEL TO A PLANE OF SYMMETRY Choosing a surface parallel to the plane of symme try of a crystal simplifies the expressions in (5). Indeed, in this case vectors and must be sym metrical with respect to the plane of symmetry.…”

“…According to [5], the two main characteristics of resonance, K 2 and η, reach their maxima in different geometries of reflection when there is unrestricted anisotropy. This is why we limited our analysis in [5,6] to the effect for rather symmetric crystals by choosing the reflection geometries corresponding to surfaces and sagittal planes close to planes of symmetry.…”

“…This is why we limited our analysis in [5,6] to the effect for rather symmetric crystals by choosing the reflection geometries corresponding to surfaces and sagittal planes close to planes of symmetry. In these cases, extreme conditions for K 2 and η are attained simultaneously using the same reflection geometries.…”

“…There is a theorem of existence [7] that guaran n 0 m ties such eigensolutions occupying whole lines on the unit sphere of the directions of propagation for any anisotropic medium. Apart from the exceptional bulk wave, a three partial special reflection must also exist [5] in the sagittal plane { } for the identical tracing velocity υ of a stationary wave field's motion along the surface. This includes the incident and reflected waves from the outer sheet of the slowness surface and the localized partial component from the innermost sheet.…”

“…In this work, we consider another principle of energy concentration that is also due to crystal anisotropy. Described in [5,6], this effect is based on the reso nance concentration of energy in narrow acoustic beams arising at nonspecular reflection in geometry that allows proximity to the total internal reflection (Fig. 1).…”