Anomalous Beam Steering and Broadband Sound Absorption by Acoustic Metasurfaces with A Periodic Subwavelength Modulation

摘要

Both periodic subwavelength structures and phase gradient metasurfaces have opened up new degrees of freedom to manipulate the acoustic waves respectively. In this paper, manipulation of elastic waves by phase gradient metasurfaces with periodic subwavelength modulation is studied. Anomalous sound reflection beam steering is observed, as well as significant sound absorption is achieved with deep subwavelength thickness in a broadband frequency range as damping is considered. The results extends the functionalities of acoustic metasurfaces and paves the way for the design of thin planar structures for broadband acoustic wave manipulation and extraordinary absorption.