Triple plasmon induced transparency based on multilayer graphene metamaterials

• Published in: Optics communications 2025-01, Vol.574, p.131083, Article 131083
• Main Authors: Zhang, Ruiling, Cui, Zherui, Wen, Kunhua, Lv, Haopeng, Liu, Wenjie, Li, Canqin, Yu, Yuesi, Liu, Runming
• Format: Article
• Language: English
• Subjects: Modulation depth; Optical switch; Plasmon-induced transparency; Triple-PIT
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2024.131083

In this study, a novel multilayer terahertz metamaterial with four graphene sub-structures is designed to achieve dynamically tunable triple plasmon-induced transparency (PIT) due to interference among bright-bright modes. Coupled mode theory (CMT) and finite-difference time-domain (FDTD) simulations show a high degree of consistency in their results. Interestingly, enhanced transmission dips are observed when various graphene structures couple with the two longitudinal graphene strips at the bottom layer. Based on the dynamic modulation characteristics of graphene, the metamaterial demonstrates seven-band optical switching capabilities, achieving modulation depths (MD) of 94.6%, 88.1%, 90.8%, 90.8%, 90.4%, 86.6%, and 87.5%. Additionally, the proposed graphene metamaterial also shows excellent slow-light effects, with a group index reaching up to 1034. This proposed terahertz metamaterial holds significant theoretical implications for the development of dynamically integrated terahertz optoelectronic devices. •A multilayer terahertz graphene metamaterial structure has been proposed for achieving dynamically tunable triple PIT.•The optical switching effect can be achieved by adjusting the Fermi energy level.•Enhanced transmission dips are observed when different graphene structures are coupled with two graphene strips.