基于石墨烯超材料的宽频带可调太赫兹吸波体

Tunable broadband terahertz absorber based on graphene metamaterial

摘要:

基于二维材料石墨烯，设计了一款宽频带可调谐超材料太赫兹吸波体。该吸波体由三层结构组成，顶层为石墨烯超材料，中间层为二氧化硅，底层为金属薄膜。仿真结果表明，当石墨烯的费米能级为0.7 eV时，该吸波体在1.11~2.61 THz频率范围内吸收率超过90%，相对吸收带宽为80.6%。当石墨烯的费米能级从0 eV增大到0.7 eV时，该吸波体器件的峰值吸收率可以从20.32%增大到98.56%。此外，该吸波体器件还具有极化不敏感和广角吸收的特性。因此，它在太赫兹波段的热成像、热探测、隐身技术等领域具有潜在的应用价值。

Abstract:

A tunable broadband terahertz absorber based on graphene metamaterial is proposed and numerically demonstrated. The absorber consists of three layers: the upper is the graphene metamaterial layer, the middle is the SiO2 layer, and the bottom is the metallic layer. Simulation results demonstrate that the proposed absorber achieves over 90% absorption in 1.11- 2.61 THz with a relative bandwidth of 80.6% when Fermi level ?c=0.7 eV. The peak absorption rate of the proposed absorber can be tuned from 20.32% to 98.56% by changing the Fermi energy of graphene from 0 eV to 0.7 eV. Additionally, the proposed absorber is insensitive to polarization and has high absorbance to wide incidence angles. Such design may have some potential applications in thermal imaging, thermal detecting, and stealth technique.