Wu Jiali, Yuan Xueguang, Zhang Yangan, Yan Xin, Zhang Xia
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China.
Micromachines (Basel). 2020 Dec 11;11(12):1096. doi: 10.3390/mi11121096.
A dual-controlled tunable broadband terahertz absorber based on a hybrid graphene-Dirac semimetal structure is designed and studied. Owing to the flexible tunability of the surface conductivity of graphene and relative permittivity of Dirac semimetal, the absorption bandwidth can be tuned independently or jointly by shifting the Fermi energy through chemical doping or applying gate voltage. Under normal incidence, the device exhibits a high absorption larger than 90% over a broad range of 4.06-10.7 THz for both TE and TM polarizations. Moreover, the absorber is insensitive to incident angles, yielding a high absorption over 90% at a large incident angle of 60° and 70° for TE and TM modes, respectively. The structure shows great potential in miniaturized ultra-broadband terahertz absorbers and related applications.
设计并研究了一种基于石墨烯-狄拉克半金属混合结构的双控可调谐宽带太赫兹吸收器。由于石墨烯表面电导率和狄拉克半金属相对介电常数的灵活可调性，通过化学掺杂或施加栅极电压来移动费米能级，可以独立或联合调节吸收带宽。在垂直入射时，该器件在4.06-10.7 THz的宽范围内对TE和TM极化均表现出大于90%的高吸收率。此外，该吸收器对入射角不敏感，在60°和70°的大入射角下，TE和TM模式的吸收率分别超过90%。该结构在小型化超宽带太赫兹吸收器及相关应用中显示出巨大潜力。
