1 南昌大学材料科学与工程学院, 江西 南昌 330031
2 南昌大学物理系, 江西 南昌 330031
3 南昌大学空间科学与技术研究院, 江西 南昌 330031
4 中国科学院上海微系统与信息技术研究所太赫兹固态技术重点实验室, 上海 200050
提出了每个超晶胞由8个不同V-形天线组成的双周期超晶胞错位超表面结构,并从理论和实验上研究了其特性。计算表明,当横电光垂直入射时,会得到共偏振透射和交叉偏振异常折射。通过调节两个超晶胞周期单元的横向错开距离,可改变异常折射的相位差,调控其振幅。实验结果表明,当4.3 THz的光垂直入射到两个超晶胞周期单元横向错开距离为0,2,4,6个V-形单元的样品上时,异常折射光强分别为入射光强的3.6%,1.7%,0.7%,1.9%,与计算结果一致。
集成光学 太赫兹 超表面 异常折射 振幅调控
Author Affiliations
Abstract
1 Key Laboratory of Terahertz Solid-State Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
We propose and experimentally demonstrate a wideband linear polarization converter in a reflection mode operating from 2.4 to 4.2 THz with conversion efficiency of more than 80%. Our device can expand the applications to a higher frequency band. A numerical simulation is performed for this metamaterial converter, which shows a good agreement with experimental results. Importantly, a concise and intuitive calculating model is proposed for the Fabry–Pérot cavity. The theoretical results indicate that the underlying reason for the enhanced polarization conversion is the additional phase difference induced by the resonance of the meta-structure and multiple reflections within the Fabry–Pérot cavity.
310.5448 Polarization, other optical properties 310.6628 Subwavelength structures,nanostructures 310.6805 Theory and design 240.5445 Polarization-selective devices Chinese Optics Letters
2019, 17(9): 093101
