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arXiv · 2101.02048

Three-dimensional acoustic lensing with a bubbly diamond metamaterial

Maxime Lanoy·Fabrice Lemoult·Geoffroy Lerosey·Arnaud Tourin·Valentin Leroy·John H. Page
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Abstract

A sound wave travelling in water is scattered by a periodic assembly of air bubbles. The local structure matters even in the low frequency regime. If the bubbles are arranged in a face-centered cubic (fcc) lattice, a total band gap opens near the Minnaert resonance frequency. If they are arranged in the diamond structure, which one obtains by simply adding a second bubble to the unit cell, one finds an additional branch with a negative slope (optical branch). For a single specific frequency, the medium behaves as if its refractive index (relative to water) is exactly $n=-1$. We show that a slab of this material can be used to design a three three-dimensional flat lens. We also report super-resolution focusing in the near field of the slab and illustrate its potential for imaging in three dimensions.

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Maxime Lanoy, Fabrice Lemoult, Geoffroy Lerosey, Arnaud Tourin, Valentin Leroy, John H. Page. 2021-01-06. Three-dimensional acoustic lensing with a bubbly diamond metamaterial. https://doi.org/10.1063/5.0046090

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