基于石墨烯人工微结构的三频段太赫兹传感与慢光  

Tri-band terahertz sensing and slow light based on graphene artificial microstructure

作　　者：成昱轩 许辉 于鸿飞 黄林琴 谷志超 陈玉峰 贺龙辉 陈智全 侯海良 CHENG Yuxuan;XU Hui;YU Hongfei;HUANG Linqin;GU Zhichao;CHEN Yufeng;HE Longhui;CHEN Zhiquan;HOU Hailiang(School of Microelectronics and Physics,Hunan University of Technology and Business,Changsha 410205,China;Xiangjiang Laboratory,Changsha 410205,China)

机构地区：[1]湖南工商大学微电子与物理学院,长沙410205 [2]湘江实验室,长沙410205

出　　处：《物理学报》2025年第6期243-255,共13页Acta Physica Sinica

基　　金：湘江实验室重点项目(批准号:23XJ02001);湖南省自然科学基金(批准号:2023JJ40218,2022JJ30201);长沙市自然科学基金(批准号:kq2202298);湖南省教育厅资助科研项目(批准号:21B0574,21B0556)资助的课题.

摘　　要：提出了一种三频段太赫兹双重等离激元诱导透明的单层石墨烯器件,本器件结构简单且拥有优秀的慢光与传感性能.器件中的长石墨烯带能够直接被入射光激发,进而产生一个明模式;短石墨烯带则无法被入射光直接激发产生暗模式,但能够被明模式间接激发,明暗模式相互干涉从而形成表面等离子体诱导透明现象.本文通过耦合模理论推导此现象产生的机理,发现计算的结果与时域有限差分法基本一致.该结构不仅存在外部动态调节的优点,同时慢光与传感性能也十分优异.本文发现提高石墨烯器件的费米能级能够显著地提高慢光效应,群折射率在石墨烯费米能级为1.1 eV时达到最大值327.1.本结构还拥有优秀的传感性能,其灵敏度与品质因子最高分别达到1.442 THz/RIU与39.6921.本研究有望为慢光与传感等领域的应用提供思路与理论基础.A monolayer graphene-based tunable triple-band terahertz plasmon device with superior sensing and slow light performance is proposed in this work.A very obvious dual PIT phenomenon is observed by adjusting the device structure.Then,the transmission curves and electric field distributions of the long-and short-graphene band at the three transmission windows are analyzed,to further investigate the mechanism of the bright mode and the dark mode of this structure.Afterward,the comparison between the theoretical data from the coupledmode theory(CMT)and the simulation results of finite difference time domain(FDTD)shows that they are in excellent agreement with each other.In addition,the effective refractive indices of the real and imaginary parts at different Fermi energy levels are analyzed.The effective refractive indices are linearly related to the Fermi energy level.In this research,it is found that the phase of the electromagnetic wave fluctuates strongly at the transmission window.With the increase of the Fermi energy level,the peak frequency of the group refractive index peak value increases.When the Fermi energy level is at 1.1 eV,the peak value of the group refractive index reaches 327.1.In order to study the sensing effect of this device in more depth,various refractive indices of the medium are tested.Based on these results it can be seen that the device has excellent sensing performance.Its sensitivity and figure of merit(FOM)reach up to 1.442 THz/RIU and 39.6921,respectively.Compared with the traditional structure,this structure can regulate the Fermi energy levels very conveniently by applying a voltage,in order to modulate the resonant frequency of the dual PIT.The findings in this study are expected to lay a theoretical foundation and provide a design reference for potential applications in fields such as slow light technology and sensing.

关 键 词：微结构 等离激元 慢光 传感 

分 类 号：O441.4[理学—电磁学] TQ127.11[理学—物理]