School of Computer and Information, Hefei University of Technology, Hefei 230009, China.
Department of Physics, Harbin Institute of Technology, Harbin 150001, China.
Phys Rev E. 2019 Nov;100(5-1):053315. doi: 10.1103/PhysRevE.100.053315.
In this paper, we generalize the principle of a generated first-order acoustic vortex (AV) with the acoustic resonances (AR) of a metasurface, from which we have also proposed a method for generating the higher-order AVs by arranging the sequences of the AR metasurface properly. The usable frequency range of the designed AR metasurface has been investigated and is discussed in detail, which is about 4470-4600Hz and covers the range 0.977-1.006f (f=4573.31Hz is the preset working frequency) approximately. Meanwhile, the designed AR metasurface can produce a frequency-adjustable AV field efficiently by adjusting the structure size and parameters of the planar AR layer. By discretizing the continuous phase distribution, the multiplexed AV beam with multiple orbital angular momentum states can also be generated effectively by arranging AR metasurface properly. The generated single and multiplexed AV beams can also be detected with the aid of the acoustic reverse phase plates accordingly.
在本文中，我们将元表面的声学共振（AR）产生一阶声涡旋（AV）的原理进行了推广，由此我们还提出了一种通过合理排列 AR 元表面的序列来产生更高阶 AV 的方法。设计的 AR 元表面的可用频率范围已经过研究并进行了详细讨论，大约为 4470-4600Hz，大约覆盖 0.977-1.006f（f=4573.31Hz 是预设的工作频率）的范围。同时，通过调整平面 AR 层的结构尺寸和参数，设计的 AR 元表面可以有效地产生频率可调的 AV 场。通过对连续相位分布进行离散化，通过合理布置 AR 元表面，也可以有效地产生具有多个轨道角动量状态的复用 AV 光束。相应地，还可以借助声反向位相板来检测生成的单模和复用 AV 光束。
