Broadband sound focusing with tunable focus based on reconfigurable acoustic coding metagrating

Abstract

In this paper, we propose a reconfigurable acoustic coding metagrating composed of rotatable open-ended round tubes for realizing broadband sound focusing with tunable focus. Integrating reconfigurable idea into coding metagrating, we can implement the conversion of the logical units 0 and 1 simply by mechanically adjusting the rotational angle of the open-ended round tubes. The theoretical analysis, the numerical simulations, and experimental results demonstrate that the proposed coding metagrating can precisely manipulate the focus by alternating the coding arrangements. The proposed metagrating has the advantages of broadband property, precise focusing, and tunable focus. Our work provides promising applications in acoustic imaging, medical ultrasound treatment, and nondestructive testing.