@inproceedings{8425704b89fd4bc8972c2d7a14ab4bba,
title = "Diffraction in phase gradient acoustic metagratings: Multiple reflections and integer parity design",
abstract = "Diffraction occurs when acoustic waves are incident on periodic structures such as graded metasurfaces. While numerous interesting diffraction phenomena have been observed and demonstrated, the underlying mechanism of diffraction in these structures is often overlooked. Here we provide a generic explanation of diffraction in phase gradient acoustic metagratings and relate high-order diffractions to multiple reflections in the unit cells. As such, we reveal that the number of unit cells within the metagrating plays a dominant role in determining the diffraction patterns. It is also found that the integer parity of the metagrating leads to anomalous reflection and refraction with high efficiency. The theory is verified by numerical simulations and experiments on planar metagratings and provides a powerful mechanism to manipulate acoustic waves. We further extend the theory to cylindrical waveguides for the control of sound vortices via topological charge in the azimuthal metagratings. The relevance of the theory in achieving asymmetric wave control and high absorption is also discussed and verified both numerically and experimentally.",
author = "Mohammad Uzair and Xiao Li and Yangyang Fu and Chen Shen",
note = "Publisher Copyright: {\textcopyright} INTER-NOISE 2021 .All right reserved.; 50th International Congress and Exposition of Noise Control Engineering, INTER-NOISE 2021 ; Conference date: 01-08-2021 Through 05-08-2021",
year = "2021",
doi = "10.3397/IN2021-2320",
language = "English (US)",
series = "Proceedings of INTER-NOISE 2021 - 2021 International Congress and Exposition of Noise Control Engineering",
publisher = "The Institute of Noise Control Engineering of the USA, Inc.",
editor = "Tyler Dare and Stuart Bolton and Patricia Davies and Yutong Xue and Gordon Ebbitt",
booktitle = "Proceedings of INTER-NOISE 2021 - 2021 International Congress and Exposition of Noise Control Engineering",
}