Tian Ying, Han Lichang, Yan Li, Wang Jiayun, Zhang Binzhen, Jiao Zan
Sichuan Aerospace Liaoyuan Science and Technology Co., Ltd., Chengdu 610100, China.
Key Laboratory of Instrumentation Science & Dynamic Measurement, North University of China, Taiyuan 030051, China.
Micromachines (Basel). 2022 Aug 25;13(9):1387. doi: 10.3390/mi13091387.
In the terahertz band, how integrating multiple functions into a device with a tiny unit structure is a challenge. In this paper, an optically-controlled multifunctional linear polarization conversion metasurface working in the terahertz band is proposed. The reflection and transmission polarization conversion functions can be realized by irradiating the metasurface with pump light with different wavelengths. The metasurface is designed with a multilayer structure, and a photosensitive semiconductor alone is used to control multiple functions, which makes the manipulation of multifunctional devices easy. When the photosensitive semiconductor germanium (Ge) and silicon (Si) are in different states, the metasurface can realize broadband reflection and transmission polarization conversion functions, the corresponding relative bandwidth are 102.4% and 98.9%, respectively, and the work efficiency can be regulated by pump light with different intensity and wavelength. In addition, the working principle of the metasurface is analyzed by eigenmode theory and surface current distributions. The stability of the metasurface to structural parameters and incident angles are discussed.
在太赫兹频段，如何将多种功能集成到具有微小单元结构的器件中是一项挑战。本文提出了一种工作在太赫兹频段的光控多功能线性偏振转换超表面。通过用不同波长的泵浦光照射超表面，可以实现反射和透射偏振转换功能。该超表面采用多层结构设计，仅使用一种光敏半导体来控制多种功能，这使得多功能器件的操控变得容易。当光敏半导体锗（Ge）和硅（Si）处于不同状态时，超表面可实现宽带反射和透射偏振转换功能，相应的相对带宽分别为102.4%和98.9%，并且工作效率可通过不同强度和波长的泵浦光进行调节。此外，通过本征模理论和表面电流分布分析了超表面的工作原理。讨论了超表面对结构参数和入射角的稳定性。
