The Faraday rotation effect of both the La: yttrium iron garnet (YIG) film and the YIG metasurface were experimentally and numerically investigated in the terahertz (THz) region. A THz magneto-optic polarization measurement system was used to observe the transmission, resonance, and magneto-optical effect of the La:YIG film and YIG metasurface. The THz artificial chirality and resonance localization of the helical metasurface generate the superchiral THz field, which enhances the THz magneto-optical effect of the YIG film. The results show that the Faraday effect of the YIG metasurface is about three times that of the pure YIG film, whose differential rotation angle increases from 8° to over 24°. This work achieves more sensitively active polarization control of THz waves, which is of great significance for THz polarization conversion, sensing, and non-reciprocal transmission.

中文翻译：

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螺旋超表面增强的磁光膜的太赫兹法拉第旋转

La: 钇铁石榴石 (YIG) 薄膜和 YIG 超表面的法拉第旋转效应在太赫兹 (THz) 区域进行了实验和数值研究。太赫兹磁光偏振测量系统用于观察 La:YIG 薄膜和 YIG 超表面的透射、共振和磁光效应。螺旋超表面的太赫兹人工手性和共振定位产生超手性太赫兹场，增强了 YIG 薄膜的太赫兹磁光效应。结果表明，YIG超表面的法拉第效应约为纯YIG薄膜的三倍，其微分旋转角从8°增加到24°以上。该工作实现了对太赫兹波更灵敏的主动偏振控制，对太赫兹偏振转换、传感、