All-dielectric terahertz metasurface governed by bound states in the continuum with high-Q factor  

作　　者：Li Kun Zhao Xu Wang Meng Jia Xingning Zhao Ruiqi Lu Guizhen 

机构地区：[1]School of Integrated Circuit Science and Engineering,Tianjin University of Technology,Tianjin 300384,China [2]School of Electronic and Electrical Engineering,Ningxia University,Yinchuan 750021,China [3]QILU Aerospace Information Research Institute,Chinese Academy of Sciences(CAS),Jinan 250101,China [4]State Key Laboratory of Media Convergence and Communication,Communication University of China,Beijing 100024,China

出　　处：《The Journal of China Universities of Posts and Telecommunications》2024年第2期44-54,共11页中国邮电高校学报（英文版）

基　　金：the Key Research and Development Program of Ningxia Province,China(2021BEB04068)。

摘　　要：The method of terahertz(THz)resonance with a high-quality(high-Q)factor offers a vital physical mechanism for metasurface sensors and other high-Q factor applications.However,it is challenging to excite the resonance with a high-Q factor in metasurfaces with proper sensitivity as well as figure of merit(FOM)values.Here,an all-dielectric metasurface composed of two asymmetrical rectangular blocks is suggested.Quartz and silicon are the materials applied for the substrate and cuboids respectively.The distinct resonance governed by bound states in the continuum(BIC)is excited by forming an asymmetric cluster by a novel hybrid method of cutting and moving the cuboids.The investigation focuses on analyzing the transmission spectra of the metasurface under different variations in structural parameters and the loss of silicon refractive index.When the proposed defective metasurface serves as a transmittance sensor,it shows a Q factor of 1.08×10^(4)and achieves an FOM up to 4.8×10^(6),which is obtained under the asymmetric parameter equalling 1μm.Simultaneously,the proposed defective metasurface is sensitive to small changes in refractive index.When the thickness of the analyte is 180μm,the sensitivity reaches a maximum value of 578 GHz/RIU.Hence,the proposed defective metasurface exhibits an extensive number of possible applications in the filters,biomedical diagnosis,security screening,and so on.

关 键 词：terahertz(THz)metasurface high-quality(high-Q)factor bound states in the continuum figure of merit(FOM) 

分 类 号：O441.4[理学—电磁学]