Huang Jin, Li Jining, Yang Yue, Li Jie, Li Jiahui, Zhang Yating, Yao Jianquan
Opt Express. 2020 Mar 2;28(5):7018-7027. doi: 10.1364/OE.387156.
In this paper, we present an active controllable terahertz absorber with dual broadband characteristics, comprised by two diagonal identical patterns of vanadium dioxide in the top layer of the classical three-layer structure of metamaterial perfect absorbers. Simulation results show that two bandwidths of 80% absorption are 0.88 THz and 0.77 THz from 0.56 to 1.44 THz and 2.88 to 3.65 THz, respectively. By using thermal control to change the conductivity of the vanadium dioxide, absorptance can be continuously adjusted from 20% to 90%. The impedance matching theory is introduced to analyze and elucidate the physical mechanism of the perfect absorption. Field analyses are further investigated to get more insight into the physical origin of the dual broadband absorption. In addition, incident polarization insensitivity and wide-angle absorption are also demonstrated. The proposed absorber promises diverse applications in terahertz regime, such as imaging, modulating, sensing and cloaking.
在本文中，我们展示了一种具有双宽带特性的有源可控太赫兹吸收器，它由超材料完美吸收器经典三层结构顶层中的两个对角相同的二氧化钒图案组成。仿真结果表明，吸收率为80%时的两个带宽分别为0.88太赫兹（从0.56至1.44太赫兹）和0.77太赫兹（从2.88至3.65太赫兹）。通过热控制来改变二氧化钒的电导率，吸收率可在20%至90%之间连续调节。引入阻抗匹配理论来分析和阐明完美吸收的物理机制。进一步研究场分析以更深入了解双宽带吸收的物理根源。此外，还展示了入射偏振不敏感性和广角吸收特性。所提出的吸收器在太赫兹领域有望实现多种应用，如成像、调制、传感和隐身。
