Theoretical study on generation of radially polarized beam from linearly polarized beam with all-silicon metasurface in the terahertz regime
Theoretical study on generation of radially polarized beam from linearly polarized beam with all-silicon metasurface in the terahertz regime
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DOI：
10.1016/j.optlastec.2020.106763
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发表时间：
2021-04
影响因子：
5
通讯作者：
Zewen Wang;Qi Li;Fei Yan
中科院分区：
文献类型：
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作者：
Zewen Wang;Qi Li;Fei Yan
设计了一种边长为12.4 mm的透射全硅介电方形超表面。在2.52太赫兹下，在距离超表面45 mm的距离处，正常入射的x偏振高斯光束可以形成具有贝塞尔-高斯振幅分布的径向偏振窄宽环形光束。在硅衬底上设置不同尺寸和旋转角度的各向异性矩形硅柱来操纵光束。为了抑制反射损耗，还提出了一种与偏振无关的方形硅柱阵列，该阵列在衬底的另一侧进行图像化。此外，还对误差分析进行了讨论。我们的研究有望将太赫兹波应用于高分辨率显微镜和三维粒子捕获。
A transmissive all-silicon dielectric square metasurface with a side length of 12.4 mm is designed in this paper. At 2.52 terahertz, the normally incidentx-polarized Gaussian beam can be shaped into the radially polarized narrow-width annular beam with Bessel-Gaussian amplitude distribution at a propagation distance of 45 mm away from the metasurface. Anisotropic rectangular silicon pillars with different dimensions and rotation angles are arranged on the silicon substrate to manipulate the beam. To suppress the reflection loss, a polarization-independent square silicon pillar array is also proposed, which is patterned at the other side of the substrate. In addition, the errors analysis is also discussed. It is expected that our study may have potential for applying terahertz wave in high-resolution microscopy and capturing particles in three dimensions.