基于石墨烯和二氧化钒的双重可调谐宽带超材料吸收器  

Research on Dual Tunable Broadband Metamaterial Absorber Based on Graphene and Vanadium Dioxide

作　　者：吕乙松 田晋平[1] 杨荣草[1] Lü Yi-song;TIAN Jin-ping;YANG Rong-cao(College of Physics and Electronic Engineering,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学物理电子工程学院,山西太原030006

出　　处：《量子光学学报》2022年第2期170-179,共10页Journal of Quantum Optics

基　　金：国家自然科学基金(61775126);集成光电子学国家重点实验室开放课题(IOSKL2019KF16)。

摘　　要：设计了一款基于石墨烯和二氧化钒图案的双重可调谐宽频带超材料吸收器,当二氧化钒的电导率和石墨烯的化学势分别为200 000 S/m和0.5 eV时,吸收率超过90%的带宽达到4.2 THz。研究结果表明,保持二氧化钒电导率不变,吸收频带的位置和平坦性可以通过改变石墨烯的化学势在一定范围内进行调节;如果固定石墨烯的化学势,则宽吸收频带的吸收率的强弱可以通过改变二氧化钒的电导率进行大幅度调节,最大调制深度约为75%。同时,所设计的超材料吸收器还具有极化不敏感以及宽入射角的特性。基于二氧化钒电导率和石墨烯化学势的双重可调控特性,使得所设计的超材料吸收器在宽带THz吸收、开关和调制等领域具有潜在的应用价值。A type of dual tunable broadband metamaterial absorber based on graphene and vanadium dioxide pattern is designed, of which the dynamically tunable characteristics can be achieved based on the properties of vanadium dioxide(VO;) and graphene. It is well known that VO;has the characteristic of phase transition at a temperature of 68℃, while the conductivity of graphene can be changed by adjusting its chemical potential. When the conductivity of VO;and the chemical potential of graphene are 200 000 S/m and 0.5 eV, respectively, the bandwidth of the proposed absorber with an absorption rate exceeding 90% can reach 4.2 THz. Study results will show that by keeping the conductivity of VO;unchanged, the location and the smoothness of the broad absorption band can be adjusted by the chemical potential of graphene to a certain degree. If the chemical potential of the graphene is fixed at 0.5eV, the maximum absorption rate of the broad absorption band can be significantly adjusted by the conductivity of VO;, and the maximum modulation depth can be as high as 75%. Therefore, the proposed metamaterial absorber not only has the characteristic of dynamically tunable absorption bandwidth but also has the function of modulating or switching in the electromagnetic waves.The absorption mechanism is analyzed according to the distribution of the electric fields along the VO;and graphene. Next, the effect of different geometric parameters of the absorber on the absorption properties has also been studied, from which optimal geometrical parameter ranges can be selected for further laboratory fabricating and testing. Meanwhile, through the research of the absorption properties under different polarization angles and incident angles, it is found that the proposed metamaterial absorber possesses the characteristics of polarization-insensitive and wide incident angles. In terms of the dual tunable properties originating from the conductivity of VO;and the chemical potential of graphene, it makes the proposed metamaterial absorber have p

关 键 词：石墨烯 二氧化钒 超材料吸收器 调制器 

分 类 号：TN822.8[电子电信—信息与通信工程]