Ultra-wideband terahertz fingerprint enhancement sensing and inversion model supported by single-pixel reconfigurable graphene metasurface  

作　　者：Bingwei Liu Yan Peng YuFan Hao Yiming Zhu Shengjiang Chang Songlin Zhuang 

机构地区：[1]Terahertz Technology Innovation Research Institute,Terahertz Spectrum and Imaging Technology Cooperative Innovation Center,Shanghai Key Lab of Modern Optical System,University of Shanghai for Science and Technology,Shanghai 200093,China [2]Institute of Modern Optics,Nankai University,Tianjin 300350,China

出　　处：《PhotoniX》2024年第1期547-568,共22页智汇光学(英文)

基　　金：supported in part by National key research and development program of China(grant No.2022YFA1404004);National Natural Science Foundation of China(grant No.61988102,No.62335012).

摘　　要：The molecular fingerprint sensing technology based on metasurface has unique attraction in the biomedical field.However,in the terahertz(THz)band,existing metasurface designs based on multi-pixel or angle multiplexing usually require more analyte amount or possess a narrower tuning bandwidth.Here,we propose a novel single-pixel graphene metasurface.Based on the synchronous voltage tuning,this metasurface enables ultra-wideband(1.5 THz)fingerprint enhancement sensing of trace analytes,including chiral optical isomers,with a limit of detection(LoD)≤0.64μg/mm2.The enhancement of the fingerprint signal(17.4 dB)originates from the electromagnetically induced transparency(EIT)effect excited by the metasurface,and the ideal overlap between the light field constrained by single-layer graphene(SLG)and ultra-thin analyte.Meanwhile,due to the unique nonlinear enhancement mechanism in graphene tuning,the absorption envelope distortion is inevitable.To solve this problem,a universal fingerprint spectrum inversion model is developed for the first time,and the restoration of standard fingerprints reaches Rmax 2≥0.99.In addition,the asynchronous voltage tuning of the metasurface provides an opportunity for realizing the dynamic reconfiguration of EIT resonance and the slow light modulation in the broadband range.This work builds a bridge for ultra-wideband THz fingerprint sensing of trace analytes,and has potential applications in active spatial light modulators,slow light devices and dynamic imaging equipments.

关 键 词：Graphene metasurface Chiral molecules Terahertz fingerprint Electromagnetically induced transparency Spectrum inversion model 

分 类 号：O43[机械工程—光学工程]