石墨烯双曲超材料中的太赫兹渡越辐射  

Terahertz Transition Radiation in Graphene Hyperbolic Meta-Materials

作　　者：龚森[1,2] 王维 赵陶[1,2] 吴振华 张开春[1,2] 钟任斌 刘頔威[1,2] 胡旻 GONG Sen;WANG Wei;ZHAO Tao;WU Zhen-hua;ZHANG Kai-chun;ZHONG Ren-bin;LIU Di-wei;HU Min(Terahertz Research Center,School of Physical Electronics,University of Electronic Science and Technology of China,Chengdu 610054,China;Key Laboratory of Terahertz Technology,Ministry of Education,Chengdu 610054,China)

机构地区：[1]电子科技大学电子科学与工程学院太赫兹研究中心,四川成都610054 [2]太赫兹技术重点实验室,四川成都610054

出　　处：《真空电子技术》2020年第5期61-65,70,共6页Vacuum Electronics

基　　金：国家重点研发计划项目(2017YFA0701000,2018YFF01013001);国家自然科学基金项目(61701084,61505022,61901093)。

摘　　要：本文理论预期了一种中心频率可调、高功率密度的宽频太赫兹辐射。研究表明,该辐射来源于自由电子垂直穿过多层石墨烯-介质复合结构时激发的表面等离子体激元的相互耦合。数值计算结果表明,该辐射所需自由电子能量极低;辐射频率几乎覆盖了整个太赫兹频段,其中心频率可通过调节石墨烯化学势进行调谐;且由于表面激元的场增强作用,该辐射场强较普通渡越辐射大两个数量级以上。因此,本文所提出的机理有利于开发小型化的宽频可调片上太赫兹辐射源。A high-power density broadband terahertz radiation with adjustable center frequency is theoretically predicted.The research reveals that the radiation comes from the coupling of surface plasmonpolaritons excited by free electrons passing vertically through the multilayer composite structure of graphene and dielectric.The numerical simulation results show that the free electron energy required for the radiation is very low;the radiation frequency covers almost the entire terahertz band,and its central frequency can be tuned by adjusting the chemical potential of graphene;and due to the field enhancement effect of surface plasmonpolaritons,the radiation field intensity is more than two orders of magnitude higher than that of ordinary transition radiation.Therefore,the mechanism proposed is conducive to the development of miniaturized broadband on-chip terahertz radiation sources with tunable frequency.

关 键 词：石墨烯 双曲超材料 自由电子 太赫兹辐射 

分 类 号：O441.4[理学—电磁学]