Dual-Band High Efficiency Terahertz Meta-Devices Based on Reflective Geometric Metasurfaces
Dual-Band High Efficiency Terahertz Meta-Devices Based on Reflective Geometric Metasurfaces
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DOI：
10.1109/access.2019.2912017
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发表时间：
2019-04
期刊：
影响因子：
3.9
通讯作者：
Tailei Wang;Rensheng Xie;Shouzheng Zhu;Jianjun Gao;Mingbo Xin;S. An;B. Zheng;Hang Li;Yuankun Lin;Hualiang Zhang;Guohua Zhai;J. Ding
中科院分区：
文献类型：
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作者：
Tailei Wang;Rensheng Xie;Shouzheng Zhu;Jianjun Gao;Mingbo Xin;S. An;B. Zheng;Hang Li;Yuankun Lin;Hualiang Zhang;Guohua Zhai;J. Ding
超表面的波长依赖性是超表面应用中的一个严重缺点，这极大地限制了超表面的应用。在这项工作中，已经提出了一种新的反射构建块（单位单元）工作在两个任意的太赫兹频段，在每个频段独立的相位控制。几何相位积木可以反射入射的圆偏振波，并将其转换为具有相反螺旋度的波，并且在两个波段都具有高转换效率。作为概念演示的证明，研究了在0.45和0.7 THz下工作的双波段圆柱形超透镜和两个涡旋光束发生器，以验证所提出的构建块的性能。超透镜的模拟结果与理论计算结果吻合较好，符合设计目标。此外，所设计的涡旋超颖表面揭示了一种方便和低成本的方式来实现在两个波段携带不同/相同的轨道角动量模式的涡旋光束。
The wavelength-dependent behavior of the metasurface is one of the severe disadvantages in the metasurface-based applications, which greatly limits its applications. In this work, a novel reflective building block (unit cell) has been proposed to work at two arbitrary terahertz frequency bands with independent phase control at each band. The geometric phase building block can reflect the incident circularly polarized wave and convert it to the wave with opposite helicity and high conversion efficiencies at both bands. As proof of concept demonstrations, a dual-band cylindrical meta-lens and two vortex beam generators operating at 0.45 and 0.7 THz are investigated to verify the performance of the proposed building block. The simulated results of the metalens agree very well with the theoretical calculations, which are consistent with the design goals. Moreover, the designed vortex metasurfaces reveal a convenient and low-cost way to realize the vortex beam carrying different/same orbital angular momentum modes at two bands.