中国激光, 2018, 45 (3): 0314001, 网络出版: 2018-03-20
基于各向异性超表面的太赫兹宽带偏振转换器 下载: 1024次
Terahertz Broadband Polarization Converter Based on Anisotropic Metasurface
光学器件 太赫兹 宽带 偏振转换 超表面 偏振转换率 optical devices terahertz broadband polarization conversion metasurfaces polarization conversion rate
摘要
提出了一种基于各向异性超表面的太赫兹宽带偏振转换器,该器件由金属-电介质-金属三层构成,位于顶层的是沿对角线相交的正方形谐振腔,底层为金属板,中间被介质层隔开。通过仿真计算该结构在所研究频率范围内的反射比和偏振转换率,结果表明该偏振转换器可以在0.4~1.04 THz频率范围内将线偏振的太赫兹波偏振方向旋转90°,转换率达90%以上。同时, 在偏振转换率高的频率下对该结构表面电流分布进行仿真,分析了高偏振转换率的机理。该偏振转换器与以前的设计相比不但结构简单,而且工作带宽较宽,在太赫兹波的偏振调制方面具有潜在的应用价值。
Abstract
A terahertz broadband polarization converter based on anisotropic metasurface is proposed, which is composed of metal-dielectric-metal three layers. The top layer is a square-shaped resonator intersecting along a diagonal line. The bottom layer is the metal plate. The top and bottom layers are separated by a dielectric layer. The reflection ratio and polarization conversion rate of the structure in the studied frequency range are calculated by simulation. The results show that the polarization converter can rotate the polarization direction of the linearly polarized terahertz wave 90° in the frequency range of 0.4-1.04 THz, and the conversion rate is more than 90%. Meanwhile, the distribution of the surface current of the structure is simulated at the frequency with high polarization conversion rate, and the mechanism of high polarization conversion rate is analyzed. Compared with the previous design, the polarization converter has a simple structure and a broad operation bandwidth, and has a potential application value in the field of terahertz polarization modulation.
李永花, 周璐, 赵国忠. 基于各向异性超表面的太赫兹宽带偏振转换器[J]. 中国激光, 2018, 45(3): 0314001. Li Yonghua, Zhou Lu, Zhao Guozhong. Terahertz Broadband Polarization Converter Based on Anisotropic Metasurface[J]. Chinese Journal of Lasers, 2018, 45(3): 0314001.