Focusing and directional beaming effects of airborne sound through a planar lens with zigzag slits

TL;DR

This paper presents a planar acoustic lens with zigzag slits that efficiently focuses and directs airborne sound, enabling improved sound manipulation for applications like medical imaging and detection.

Contribution

A novel planar lens design using zigzag slits based on Huygens-Fresnel principle for efficient sound beam focusing and steering in air.

Findings

Experimental results agree with theoretical predictions.

The lens achieves effective sound focusing and beaming.

Potential applications in medical and detection fields.

Abstract

Based on the Huygens-Fresnel principle we design a planar lens to efficiently realize the interconversion of the point-like source and Gaussian beam in the air ambience. The lens is constructed by a planar plate drilled elaborately with a nonuniform array of zigzag slits, where the slit exits act as subwavelength-sized secondary sources carrying desired sound responses. The experiments operated at audible regime agree well with the theoretical predictions. This compact device could be useful in daily life applications, such as for medical and detection purposes.