Wintzenrieth Frédéric, Cohen-Addad Sylvie, Le Merrer Marie, Höhler Reinhard
Université Paris 6, UMR 7588 CNRS-UPMC, INSP, 4 Place Jussieu, 75252 Paris Cedex 05, France.
Université Paris 6, UMR 7588 CNRS-UPMC, INSP, 4 Place Jussieu, 75252 Paris Cedex 05, France and Université Paris-Est, LPMDI, 5 Boulevard Descartes, 77454 Marne-la-Vallée, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jan;89(1):012308. doi: 10.1103/PhysRevE.89.012308. Epub 2014 Jan 23.
We image the evolution in space and time of an acoustic wave propagating along the surface of turbid soft matter by shining coherent light on the sample. The wave locally modulates the speckle interference pattern of the backscattered light, which is recorded using a camera. We show both experimentally and theoretically how the temporal and spatial correlations in this pattern can be analyzed to obtain the acoustic wavelength and attenuation length. The technique is validated using shear waves propagating in aqueous foam. It may be applied to other kinds of acoustic waves in different forms of turbid soft matter such as biological tissues, pastes, or concentrated emulsions.
