Negative refraction of elastic waves in 2D phononic crystals: Contribution of resonant transmissions to the construction of the image of a point source
Anne-Christine Hladky-Hennion,
Charles Croënne,
Bertrand Dubus,
Jérôme Vasseur,
Lionel Haumesser,
Dimitri Manga,
Bruno Morvan
Affiliations
Anne-Christine Hladky-Hennion
Institut d’Électronique, de Microélectronique et de Nanotechnologie, UMR CNRS 8520, 41 Boulevard Vauban, 59046 Lille, France
Charles Croënne
Institut d’Électronique, de Microélectronique et de Nanotechnologie, UMR CNRS 8520, 41 Boulevard Vauban, 59046 Lille, France
Bertrand Dubus
Institut d’Électronique, de Microélectronique et de Nanotechnologie, UMR CNRS 8520, 41 Boulevard Vauban, 59046 Lille, France
Jérôme Vasseur
Institut d’Électronique, de Microélectronique et de Nanotechnologie, UMR CNRS 8520, 41 Boulevard Vauban, 59046 Lille, France
Lionel Haumesser
Laboratoire Imagerie et Cerveau, Université François Rabelais de Tours, ENIVL, 41034 Blois, France
Dimitri Manga
Laboratoire Imagerie et Cerveau, Université François Rabelais de Tours, ENIVL, 41034 Blois, France
Bruno Morvan
Laboratoire Ondes et Milieux Complexes, FRE-3102 CNRS, Place Robert Schuman, 76610 Le Havre, France
Negative refraction properties of a two-dimensional phononic crystal (PC), made of a triangular lattice of steel rods embedded in epoxy are investigated both experimentally and numerically. First, experiments have been carried out on a prism shaped PC immersed in water. Then, for focusing purposes, a flat lens is considered and the construction of the image of a point source is analyzed in details, when indices are matched between the PC and the surrounding fluid medium, whereas acoustic impedances are mismatched. Optimal conditions for focusing longitudinal elastic waves by such PC flat lens are then discussed.
