Abstract A dual-band and polarization insensitive tunable graphene absorber for THz frequency has been proposed and investigated. The absorber consists of a square graphene ring with a slit at the middle of each side separated from a metallic mirror by a dielectric spacer. Two distinct absorption peaks of 99.87% and 97.82% are observed at 3.92 THz and 6.96 THz, respectively. In addition, the distributions of electric field intensity are also presented for well-recognized the physical origin of such perfect absorption phenomenon. Furthermore, the influence of geometric parameters on the dual-band absorption properties is studied in detail to provide a useful guidance for practical fabrication. The perfect dual-band absorption properties can also be dynamically tuned through the change of the Fermi energy along with large angle insensitivity, both are interesting for real application. The proposed tunable graphene absorber should found potential applications in areas including sensors, modulators, and detectors.

中文翻译：

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太赫兹频率下极化不敏感的双波段可调石墨烯吸收器

摘要 提出并研究了一种用于太赫兹频率的双波段和偏振不敏感可调谐石墨烯吸收器。吸收体由一个方形石墨烯环组成，每侧中间有一个狭缝，通过介电垫片与金属镜隔开。分别在 3.92 THz 和 6.96 THz 处观察到两个不同的吸收峰，分别为 99.87% 和 97.82%。此外，为了更好地认识这种完美吸收现象的物理起源，还给出了电场强度的分布。此外，详细研究了几何参数对双波段吸收特性的影响，为实际制造提供了有用的指导。完美的双波段吸收特性也可以通过费米能量的变化以及大角度不敏感度进行动态调整，两者对于实际应用都很有趣。所提出的可调石墨烯吸收器应该在传感器、调制器和检测器等领域找到潜在的应用。