Lawrence A J, Goldsberry Benjamin M, Wallen Samuel P, Haberman Michael R
Applied Research Laboratories, 10000 Burnet Road, Austin, Texas 78758,
J Acoust Soc Am. 2020 Oct;148(4):EL365. doi: 10.1121/10.0002137.
Materials with sub-wavelength asymmetry and long-range order have recently been shown to demonstrate acoustical properties analogous to electromagnetic bianisotropy. One characteristic of bianisotropic acoustic media is the existence of direction-dependent acoustic impedance. Therefore, the magnitude and phase of the acoustic fields transmitted through bianisotropic acoustic media are dependent on the direction of bianisotropic polarization. These materials can therefore be used as acoustic metasurfaces to control acoustic fields. To demonstrate this behavior, a numerical model of bianisotropic acoustic waveguides is utilized to design a lens that focuses an incident plane wave by only manipulating the orientation of the bianisotropic coupling vector.
最近研究表明，具有亚波长不对称性和长程有序性的材料展现出与电磁双各向异性类似的声学特性。双各向异性声学介质的一个特点是存在与方向有关的声阻抗。因此，透过双各向异性声学介质传播的声场的幅度和相位取决于双各向异性极化的方向。所以，这些材料可用作声学超表面来控制声场。为证明这种特性，利用双各向异性声波导的数值模型设计了一种透镜，该透镜仅通过操纵双各向异性耦合矢量的方向就能使入射平面波聚焦。
