Material anisotropy unveiled by random scattering of surface acoustic waves

Vincent Laude (1) , Kimmo Kokkonen (2) , Sarah Benchabane (1) , Matti Kaivola (2)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
2 Optics and Molecular Materials Laboratory

We consider launching a monochromatic surface acoustic wave packet on a large set of random scatterers. The interference of the multiple scattered waves creates a random pattern of ripples on the crystal surface that is recorded by optical interferometry. The Fourier transform of the amplitude and phase data of the measured wave field unveils the complete slowness curve, i.e., the wave-vector as a function of the propagation angle. A simple acoustic speckle model is proposed to explain this observation.

Mots clés: acoustic wave scattering; Fourier transforms; light interferometry; surface acoustic waves; Acoustical properties of solids; Acoustical properties

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

Vincent Laude, Kimmo Kokkonen, Sarah Benchabane, Matti Kaivola. Material anisotropy unveiled by random scattering of surface acoustic waves. Applied Physics Letters, 2011, 98, pp.3506. ⟨10.1063/1.3554424⟩. ⟨hal-00639222⟩