Skip to Main content Skip to Navigation
Journal articles

Acoustic flat lensing using an indefinite medium

Abstract : Acoustic flat lensing is achieved here by tuning a phononic array to have indefinite medium behaviour in a narrow frequency spectral region along the acoustic branch in the irreducible Brillouin zone (IBZ). This is confirmed by the occurrence of a flat band along an unusual path in the IBZ and by interpreting the intersection point of isofrequency contours on the corresponding isofrequency surface; coherent directive beams are formed whose reflection from the array surfaces create lensing. Theoretical predictions using a mass-spring lattice approximation of the phononic crystal (PC) are corroborated by time-domain experiments, airborne acoustic waves generated by a source with a frequency centered about 10.6 kHz, placed at three different distances from one side of a finite PC slab, constructed from polymeric spheres, yield distinctive focal spots on the other side. These experiments evaluate the pressure field using optical feedback interferometry and demonstrate precise control of the three-dimensional wave trajectory through a sonic crystal.
Complete list of metadata

Cited literature [35 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-01917261
Contributor : Sébastien Guenneau <>
Submitted on : Friday, November 9, 2018 - 11:48:05 AM
Last modification on : Thursday, April 1, 2021 - 4:12:49 PM
Long-term archiving on: : Sunday, February 10, 2019 - 1:03:16 PM

File

prl-submitted-131018.pdf
Files produced by the author(s)

Identifiers

Citation

M. Dubois, Julien Perchoux, A Vanel, Clément Tronche, Y Achaoui, et al.. Acoustic flat lensing using an indefinite medium. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2019, 99, pp.100301(R). ⟨10.1103/PhysRevB.99.100301⟩. ⟨hal-01917261⟩

Share

Metrics

Record views

248

Files downloads

367