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.
Highlights
A two-dimensional2Dsonic crystalSCis just a periodic distribution of solid cylinders in air with their axis parallel aligned
A GRIN SC lens based on a different approach has been proposed and experimentally demonstrated;11 it is designed for a frequency within the first acoustic band with negative slope. The drawback of this type of GRIN lenses, whose wavelengths are of the order of the lattice parameter, is that they work for the single operational frequency at which they have been designed
Each lens is made of a rectangular cluster of aluminum cylinders distributed in a hexagonal lattice. Their focusing properties are here comprehensively studied either experimentally as well as theoretically. We demonstrate that their focusing behavior is a true GRIN effect that is fairly well reproduced by simulations based in the multiple scattering theoryMSTand it is supported by an analytical model based on ray theory
Summary
A two-dimensional2Dsonic crystalSCis just a periodic distribution of solid cylinders in air with their axis parallel aligned.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
