Universal non-near-field focus of acoustic waves through high-symmetry quasicrystals

The focus behaviors of acoustic waves through high-symmetry quasicrystals (QC) have been investigated by using exact multi-scattering numerical simulation. We have found that eightfold, tenfold, and twelvefold two-dimensional (2D) QC slabs possess some universal features for non-near-field focus of the acoustic wave. The non-near-field focus of the acoustic wave can be realized by these QC slabs from very low packing density (filling fraction β=10%) to close packing (filling fraction β=40%) at large ranges of the frequency. The physical origin for such a superior feature has also been analyzed. Thus, it is anticipated that such a phenomenon can be potentially applied to phononic devices.