Quasi-flat high-index acoustic lens for 3D underwater ultrasound focusing

Olivier Lombard (1) , Raj Kumar (2) , Olivier Mondain-Monval (2) , Thomas Brunet (1) , Olivier Poncelet (1)

1 I2M - Institut de Mécanique et d'Ingénierie
2 CRPP - Centre de Recherche Paul Pascal

We report a quasi-flat and sub-wavelength acoustic lens built using a soft matter process for broadband ultrasonic 3D focusing in water. By using a simple emulsion templating method, a soft porous material with a high acoustic index relative to water (∼5) has been molded and shaped into a convergent lens with a very low curvature and a thickness smaller than the working wavelength in water. This kind of acoustic metasurface generates a narrow focused beam, and its focal length can be adjusted. These acoustic lenses may be of great interest for underwater applications, where acoustic focusing and imaging are highly demanded.

Domaines: Matériaux

Olivier Lombard, Raj Kumar, Olivier Mondain-Monval, Thomas Brunet, Olivier Poncelet. Quasi-flat high-index acoustic lens for 3D underwater ultrasound focusing. Applied Physics Letters, 2022, 120, pp.221701. ⟨10.1063/5.0088503⟩. ⟨hal-03875346⟩