基于双开口谐振环的太赫兹超宽带线偏振转换超表面  

Terahertz Ultrawide⁃Band Linear Polarization Conversion Metasurface Based on Double Split⁃Ring Resonator

作　　者：孙华燕 陈哲 许永平 黄泽宇 Sun Huayan;Chen Zhe;Xu Yongping;Huang Zeyu(School of Information Science and Engineering,Yunnan University,Kunming 650500,Yunnan,China)

机构地区：[1]云南大学信息学院,云南昆明650500

出　　处：《中国激光》2024年第23期176-183,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(62061051);云南省基础研究计划(202101AT070187,202301AT070249)。

摘　　要：提出了一个基于双开口谐振环的圆形结构超表面,实现了一个超宽带线交叉偏振的太赫兹偏振器。该超表面在频率点2.67、3.48、5.45、7.08、7.57 THz处出现显著的谐振现象。模拟数据显示,在这些谐振频率处,交叉偏振转换率(PCR)接近100%。该结构在2.55~7.61 THz频率范围内实现了线偏振转换,相对带宽达到99.4%,表明其宽带频率响应良好。在整个频率范围内,偏振转换率维持在90%以上。通过表面电流分布对交叉偏振转换功能的实现原理进行了分析和解释。所提出的太赫兹超表面超宽带线偏振转换器件在太赫兹系统、通信、光学等领域中具有较广阔的应用前景。Objective Terahertz waves are underdeveloped waves between microwaves and infrared waves that exhibit abundant spectral resources and have received wide attention in many fields,including medical detection,security imaging,and communication.Polarization is an important characteristic of electromagnetic waves,and a metasurface can flexibly control the propagation of light waves using its subwavelength structural unit,thus rendering it suitable for the design of lightweight and compact polarization converters.Research on terahertz polarization converters based on metasurfaces is expected to promote the development of terahertz wave bands. However, to realize practical applications of terahertz systems in the future, improving metasurface-based terahertzpolarization converters is necessary. First, a simple structure can be designed to enable polarization conversion, thereby enhancing itsadvantages in the design process and practical applications. Second, the operating bandwidth of the polarization-conversion device canbe expanded, and a wide bandwidth operating range can improve the spectrum utilization of terahertz systems. Furthermore, thepolarization-conversion effect must be enhanced to ensure stable optical performance. In this study, the proposed terahertz-linepolarization-conversion metasurface based on a double split-ring resonator features a simple design process, few structuralparameters, high optimization efficiency, and a wide operating bandwidth. Moreover, through the structural optimization and designof notches on a double-split-ring resonator, the structure can achieve efficient polarization conversion over the entire operatingfrequency band. The metasurface structure designed in this study may promote the application of terahertz technology in fields such aswireless communication, liquid-crystal displays, and medical detection.Methods The structure proposed in this study comprises a long, metal, rectangular bar connected to a double split-ring resonator,with two symmetrical notches on the double spli

关 键 词：太赫兹 超表面 偏振器 双开口谐振环 

分 类 号：O436[机械工程—光学工程]