Xiaodong Zeng, Qingwei Zhao, Ke Chen, Yang Yang, Shunyu Yao, Yiping Xu, Xin Huang, Wenxing Yang
{"title":"Numerical and theoretical research on quintuple plasmon-induced transparency based on graphene metamaterial and its multi-function application","authors":"Xiaodong Zeng, Qingwei Zhao, Ke Chen, Yang Yang, Shunyu Yao, Yiping Xu, Xin Huang, Wenxing Yang","doi":"10.1016/j.micrna.2025.208334","DOIUrl":null,"url":null,"abstract":"<div><div>A periodic terahertz metamaterial structure consisting of four concentric graphene square rings and the silicon substrate is proposed. Upon the irradiation of the incident light within the range of the THz band, a quintuple plasma-induced transparency (PIT) effect in the transmission spectrum of the proposed structure is produced. Then, the interaction between bright mode and dark mode acted by different graphene structures and the electric field distributions of the whole structure in the six transmission dip frequencies can well explain the forming physical mechanism of the quintuple-PIT effect. The results obtained by the FDTD numerical simulation agree well with those achieved by the coupling mode theory (CMT) theoretical calculations under different Fermi levels of the monolayer graphene. A set of eight-channel asynchronous switches, a set of nine-channel asynchronous switches, two sets of five-channel synchronous switches and a set of four-channel synchronous switches are obtained by adjusting the Fermi levels of graphene. The maximum modulation depth of these multi-channel optical switches is up to 0.9985, the corresponding insertion loss and extinction ratio reach 0.382 dB and 28.2179 dB, respectively. Moreover, the refractive index sensing characteristics of the whole structure are studied. The obtained maximum values of sensitivity and figure of merit (FOM) are up to 1.151 THz/RIU and 53.5059, separately. Finally, the slow light effect of the whole structure is also studied. The maximum group time delay and the corresponding group refractive index separately reach 2.2211ps and 3331.65. The high-performance and multi-function graphene terahertz metamaterial provides a significant guide for the design of the multi-channel optical switching, optical storage, refractive index sensing devices.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"208 ","pages":"Article 208334"},"PeriodicalIF":3.0000,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Micro and Nanostructures","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2773012325002638","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
A periodic terahertz metamaterial structure consisting of four concentric graphene square rings and the silicon substrate is proposed. Upon the irradiation of the incident light within the range of the THz band, a quintuple plasma-induced transparency (PIT) effect in the transmission spectrum of the proposed structure is produced. Then, the interaction between bright mode and dark mode acted by different graphene structures and the electric field distributions of the whole structure in the six transmission dip frequencies can well explain the forming physical mechanism of the quintuple-PIT effect. The results obtained by the FDTD numerical simulation agree well with those achieved by the coupling mode theory (CMT) theoretical calculations under different Fermi levels of the monolayer graphene. A set of eight-channel asynchronous switches, a set of nine-channel asynchronous switches, two sets of five-channel synchronous switches and a set of four-channel synchronous switches are obtained by adjusting the Fermi levels of graphene. The maximum modulation depth of these multi-channel optical switches is up to 0.9985, the corresponding insertion loss and extinction ratio reach 0.382 dB and 28.2179 dB, respectively. Moreover, the refractive index sensing characteristics of the whole structure are studied. The obtained maximum values of sensitivity and figure of merit (FOM) are up to 1.151 THz/RIU and 53.5059, separately. Finally, the slow light effect of the whole structure is also studied. The maximum group time delay and the corresponding group refractive index separately reach 2.2211ps and 3331.65. The high-performance and multi-function graphene terahertz metamaterial provides a significant guide for the design of the multi-channel optical switching, optical storage, refractive index sensing devices.