Imaging with air bubbles arranged within a diamond lattice
Résumé
In this presentation, we numerically investigate the properties of an assembly of air bubbles arranged within a diamond lattice. Near the Minnaert resonance frequency, we find that this specific structure exhibits an effective refractive index of n=-1 for all directions. This result provides unambiguous evidence that the microstructure plays a crucial role, even in the low frequency regime, in the behavior of locally resonant metamaterials. We show that a slab of this material can be used to design a 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.