Subwavelength diffractive acoustics and wavefront manipulation with a reflective acoustic metasurface
Subwavelength diffractive acoustics and wavefront manipulation with a reflective acoustic metasurface
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DOI：
10.1063/1.4967738
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发表时间：
2016-11
影响因子：
3.2
通讯作者：
Wenqi Wang;Yangbo Xie;B. Popa;S. Cummer
中科院分区：
文献类型：
--
作者：
Wenqi Wang;Yangbo Xie;B. Popa;S. Cummer
声学超表面在紧凑结构中提供有用的波前成形能力，诸如波束转向、声学聚焦和非对称传输。文献中描述的大多数声学超表面是透射装置，并且将其性能集中在基本衍射阶的转向声束上。此外，研究的入射角范围通常低于由广义Snell反射定律预测的临界入射角。在这项工作中，我们全面分析了波的相互作用与一个通用的周期性相位调制结构，以预测所有衍射订单的行为，特别是超过临界入射的情况下。在分析的指导下，基于扩展的超声波材料库设计了一种宽带反射超材料表面。实验证明了各种局部和非局部波前整形特性，并首次实验证明了高阶衍射波的增强吸收。所提出的方法为预测实际绕射波行为提供了一种精确的方法，为声学周期结构的研究开辟了一个新的视角。所设计的超颖表面扩展了声学超颖表面的功能，并为宽带声波操纵和非凡吸收的薄平面反射结构的设计铺平了道路。
Acoustic metasurfaces provide useful wavefront shaping capabilities, such as beam steering, acoustic focusing, and asymmetric transmission, in a compact structure. Most acoustic metasurfaces described in the literature are transmissive devices and focus their performance on steering sound beam of the fundamental diffractive order. In addition, the range of incident angles studied is usually below the critical incidence predicted by generalized Snell's law of reflection. In this work, we comprehensively analyze the wave interaction with a generic periodic phase-modulating structure in order to predict the behavior of all diffractive orders, especially for cases beyond critical incidence. Under the guidance of the presented analysis, a broadband reflective metasurface is designed based on an expanded library of labyrinthine acoustic metamaterials. Various local and nonlocal wavefront shaping properties are experimentally demonstrated, and enhanced absorption of higher order diffractive waves is experimentally shown for the first time. The proposed methodology provides an accurate approach for predicting practical diffracted wave behaviors and opens a new perspective for the study of acoustic periodic structures. The designed metasurface extends the functionalities of acoustic metasurfaces and paves the way for the design of thin planar reflective structures for broadband acoustic wave manipulation and extraordinary absorption.