An annulus acoustic metasurface (AAM) with multi‐layered rings is proposed to achieve the enhanced fractional acoustic vortices (FAVs). It is found that the enhancement of the transmitted FAV through the AAM is sensitive to the radial interval between adjacent ring‐structures. A greatly enhanced FAV is theoretically obtained by the optimized AAM. Then finite element models based on composite labyrinthine structures are established and the generation of the enhanced FAV is confirmed by simulations. Furthermore, the optimized AAM samples are fabricated and experimentally generate the enhanced FAV with topological charge of 1.5. The FAV generated by the optimized AAM with three‐rings is ≈5.4 times stronger than that generated by the classical AAM with one‐ring. Finally, experimental results show that the greatly enhanced FAV can capture micro‐particles and rotate a sound absorbing disk easily. The greatly enhanced FAV by the AAM may be more efficient for the micro‐particle manipulation, edge‐detection image, and acoustic communication.

中文翻译：

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具有多层环的环形声学超表面增强的分数声涡旋

为了实现增强的分数声涡（FAV），提出了具有多层环的环形声超表面（AAM）。发现通过AAM传输的FAV的增强对相邻环结构之间的径向间隔很敏感。理论上，通过优化的AAM可大大提高FAV。然后建立了基于复合迷宫结构的有限元模型，并通过仿真确定了增强型FAV的产生。此外，制造了优化的AAM样品，并实验生成了拓扑电荷为1.5的增强型FAV。经过优化的带有三环的AAM生成的FAV比传统带有一环的AAM生成的FAV约强5.4倍。最后，实验结果表明，大大增强的FAV可以捕获微粒并轻松旋转吸声盘。AAM大大增强了FAV，对于微粒操纵，边缘检测图像和声音通信而言，可能更有效。