Qu Mei-Jun, Li Wen-Yu, Zeng Ting, Su Jian-Xun, Song Wei-Li
Opt Lett. 2021 Nov 1;46(21):5441-5444. doi: 10.1364/OL.440977.
In this Letter, a metasurface combined with emerging 3D printing technology is proposed. The proposed metasurface regards the simple cube as the unit cell, and the height of the cube is the only variable. A nearly linear transmission phase range covering 360° operating at 20 GHz is obtained when the height is regulated in [2.26 mm, 11.20 mm]. Therefore, the proposed unit cell can be adopted to any metasurface with various functions. Taking the generation of a non-diffractive Bessel beam as an example, two metasurfaces composed of 30×30 units with different focusing directions are designed based on non-diffractive theory and the generalized law of refraction. Two prototypes are 3D printed and measured by a near-field scanning system. The measured results validate our design with satisfactory focusing and beam deflection performance. Additionally, the 3D printed metasurface has lower cost and a shorter processing cycle, and avoids metal loss. Therefore, a 3D printed metasurface is an excellent candidate that can be applied in millimeter wave or even higher frequency bands.
在本信函中，提出了一种结合新兴3D打印技术的超表面。所提出的超表面将简单立方体作为单元结构，立方体的高度是唯一变量。当高度在[2.26毫米，11.20毫米]范围内调节时，可获得在20吉赫兹工作的覆盖360°的近线性传输相位范围。因此，所提出的单元结构可应用于具有各种功能的任何超表面。以产生无衍射贝塞尔光束为例，基于无衍射理论和广义折射定律，设计了由30×30个具有不同聚焦方向的单元组成的两个超表面。通过近场扫描系统对两个原型进行了3D打印和测量。测量结果验证了我们的设计，具有令人满意的聚焦和光束偏转性能。此外，3D打印的超表面成本更低、加工周期更短，并且避免了金属损耗。因此，3D打印的超表面是一种可应用于毫米波甚至更高频段的优秀候选方案。
