In this paper, a polarization and angle-insensitive multi-band adjustable terahertz absorber is proposed and numerically investigated, which is composed of a kind of periodic array square graphene ring with a Jerusalem cross graphene sheet. The numerical results indicate that the peaks absorptivity reach 99.9%, 99.9%, and 98.5% at 2.02THz, 3.44 THz, and 7.58 THz, respectively. The three resonance frequencies can be dynamically tuned by varying the chemical potential. Its physical mechanism can be analyzed by using Coupled Mode Theory (CMT) and electric field distribution. Moreover, the designed absorber is insensitive to polarization state and has the capability of wide-angle absorptivity. As a sensing application, the sensing characteristics of this monolayer graphene metasurface structure were investigated. In addition, we can achieve multi-spectral absorption peaks by applying bilayer graphene composite structure arrays. The proposed terahertz absorber may benefit branches of science such as refractive sensors, solar absorption, stealth, and other optoelectronic devices.

本文提出了一种偏振和角度不敏感的多波段可调太赫兹吸收器，并进行了数值研究，该吸收器由一种周期性排列的正方形石墨烯环和一个耶路撒冷十字形石墨烯片组成。数值结果表明，在2.02THz，3.44THz和7.58THz处，峰吸收率分别达到99.9％，99.9％和98.5％。可以通过改变化学势来动态调节三个共振频率。可以使用耦合模式理论（CMT）和电场分布来分析其物理机制。而且，设计的吸收体对极化状态不敏感，具有广角吸收能力。作为传感应用，研究了这种单层石墨烯超表面结构的传感特性。此外，我们可以通过应用双层石墨烯复合结构阵列获得多光谱吸收峰。提议的太赫兹吸收器可能会有益于科学分支，例如折射传感器，太阳吸收，隐身和其他光电设备。