Sound focusing by gradient index sonic lenses

TL;DR

This paper presents the design, fabrication, and characterization of gradient index sonic lenses using 2D sonic crystals, demonstrating effective sound focusing through both analytical and numerical methods.

Contribution

It introduces a novel flat lens design with a gradient index achieved by varying the sonic crystal filling fraction, validated by experiments and simulations.

Findings

Effective sound focusing demonstrated

Analytical and numerical models agree with experimental results

Gradient index lenses outperform uniform ones in focusing ability

Abstract

Gradient index sonic lenses based on two-dimensional sonic crystals are here designed, fabricated and characterized. The index-gradient is achieved in these type of flat lenses by a gradual modification of the sonic crystal filling fraction along the direction perpendicular to the lens axis. The focusing performance is well described by an analytical model based on ray theory as well as by numerical simulations based on the multiple-scattering theory.