Design and experimental realization of triple-band filtering metamaterial in sub-terahertz band enabled by conductivity coupling response of two identical split rings

• Published in: Optics and laser technology 2025-05, Vol.183, p.112345, Article 112345
• Main Authors: Fang, Sijun, Yang, Zhuchuang, Tao, Yi, Lv, Wangze, Jiang, Jieying, Zhang, Dong-Qin, Wang, Ben-Xin, Yang, Guofeng, Shu, Fang-Zhou
• Format: Article
• Language: English
• Subjects: Conductivity coupling; Sensing; Sub-terahertz region; Terahertz metamaterials; Triple-band filtering
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2024.112345

[Display omitted] •A new scheme is proposed to achieve triple-band filtering sub-terahertz meta-device•Its surface structure comprises of two identical aluminium split rings connected by a horizontal aluminium strip .•Three filtering dips located at 0.238 THz, 0.504 THz and 0.636 THz are experimentally obtained.•Near-field enhancement and surface current of these filtering dips are extracted to explore their mechanisms.•The experiment further proves the glucose concentration sensing for the given sub-terahertz meta-device. Herein, a new scheme is proposed to achieve triple-band filtering sub-terahertz meta-device by employing the strategy of conductive coupling to excite strong interaction between two identical sub-resonators. Its surface structure comprises of two identical aluminium split rings connected by a horizontal aluminium strip to form a composite meta-surface having the feature of conductive connection, which is placed on a flexible and ultra-thin polyimide film. Three filtering dips located at 0.238 THz, 0.504 THz and 0.636 THz are experimentally obtained, which are consistent with theoretical results. Near-field enhancement and surface current of these filtering dips are extracted to explore their mechanisms. Moreover, the horizontal aluminium strip responsible for conducting connection plays an important role in manipulating the triple-band filtering response. The experiment further proves the glucose concentration sensing for the given sub-terahertz meta-device. In sharp contrast to traditional multiple-band filtering meta-devices that frequently use complex or stacked metasurfaces, we directly enable triple-band filtering response in a simple pattern while also possessing the features of ultra-thin, flexibility, low cost, easy fabrication, and tunable.