Acoustic wave transmission through a bull’s eye structure

Abstract

We study experimentally and theoretically acoustic transmission through a bull’s eye structure, consisting of a central hole with concentric grooves imprinted on both sides of a thin brass plate. At wavelength slightly larger than the groove periodicity, a transmission peak was observed for normally incident acoustic wave, with excellent collimation (only ±2° divergence) at far field. This phenomenon is a manifestation of the two-dimensional circular version of structure-factor induced resonant transmission. Theoretical predictions based on this mechanism are in good agreement with the experiments.