Acoustic collimation based on an ultra-thin metasurface

Abstract

Abstract How to modulate the acoustic waves at small scales has been an area of intense investigation. In this paper, an artificial ultrathin structure with a series of zigzag-shaped grooves located in the center and bilateral symmetry is designed to realize ultra-strong directional collimated acoustic beams. The simulations agree well with the theoretical analysis and show that the acoustic collimated structure has high directivity at the resonant frequency with the beam length exceeding 40 wavelengths. The structure has deep subwavelength scales and simple design, which are expected to have applications in fields like directional acoustic radiation, medical ultrasound detection, et