Effects of slant angle of metallic fish-scale structure on polarization conversion in the terahertz spectral range
Effects of slant angle of metallic fish-scale structure on polarization conversion in the terahertz spectral range
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DOI：
10.1007/s00339-018-2205-1
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
T. Sasaki;Kazutaka Saito;M. Sakamoto;Kohei Noda;Y. Tamayama;H. Okamoto;N. Kawatsuki;H. Ono
中科院分区：
文献类型：
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作者：
T. Sasaki;Kazutaka Saito;M. Sakamoto;Kohei Noda;Y. Tamayama;H. Okamoto;N. Kawatsuki;H. Ono
我们在本文中报告了我们对具有金属鱼鳞结构的平面太赫兹（THz）超材料的研究。基于时域有限差分法模拟设计了具有不同倾斜角度的鱼鳞状超材料，并利用激光束刻蚀系统在介质衬底上制备了鱼鳞状超材料。理论模拟表明，倾斜鱼鳞形超材料的本征偏振态是具有正交方位角的共转椭圆偏振（即，倾斜的鱼鳞状超材料在THz光谱范围内具有平面手性）。我们利用太赫兹时域光谱仪和线栅偏振器测量了所制备的超材料的透射光谱和偏振转换特性。结果与理论模拟一致。实验和计算结果表明，利用鱼鳞图案的倾斜角度可以控制太赫兹波在平面超材料中传播的方位角和椭圆角。这项研究表明，在太赫兹光谱范围内的偏振转换器的鱼鳞超材料的潜力。
We report herein our investigation of planar terahertz (THz) metamaterials with metallic fish-scale structure. The fish-scale metamaterials with different slant angles were designed based on finite-difference time-domain simulations and fabricated on a dielectric substrate by using a laser-beam drawing system. Theoretical simulations indicate that the eigenpolarization states of the slant fish-scale metamaterials are corotating elliptical polarizations with orthogonal azimuth angles (i.e., the slant fish-scale metamaterials possess planar chirality in the THz spectral range). We measured the transmission spectra and polarization-conversion property of the fabricated metamaterials by using THz time-domain spectroscopy with a wire-grid polarizer. The results were consistent with the theoretical simulations. The experimental and calculation data clarify that both the azimuth angle and elliptical angle of the polarized THz wave transmitted through the planar metamaterial can be controlled by the slant angle of the fish-scale pattern. This study demonstrates the potential of the fish-scale metamaterials for polarization converters in the THz spectral range.