We study the acoustic scattering properties of a phononic crystal designed to behave as a gradient index lens in water, both experimentally and theoretically. The gradient index lens is designed using a square lattice of stainless-steel cylinders based on a multiple scattering approach in the homogenization limit. We experimentally demonstrate that the lens follows the graded index equations derived for optics by mapping the pressure intensity generated from a spherical source at 20 kHz. We find good agreement between the experimental result and theoretical modeling based on multiple scattering theory.
@article{arxiv.1006.3582,
title = {Sonic Gradient Index Lens for Aqueous Applications},
author = {Theodore P. Martin and Michael Nicholas and Gregory J. Orris and Liang-Wu Cai and Daniel Torrent and Jose Sanchez-Dehesa},
journal= {arXiv preprint arXiv:1006.3582},
year = {2010}
}