基于石墨烯结合亚波长金属结构的太赫兹宽带动态吸收器

摘要

具有动态可调特性的太赫兹吸收器在太赫兹开关、传感器以及太赫兹探测等方面具有巨大的应用前景。然而，基于传统超材料的太赫兹吸收器通常不具备理想的动态可调特性。本文中，我们提出利用单层石墨烯结合十字形亚波长金属结构设计太赫兹动态可调吸收器的方法，实现太赫兹波段宽带动态可调吸收。通过控制加载在石墨烯上的偏置电压改变石墨烯的化学势，可以轻松实现吸收频率动态调节。仿真结果显示，吸收器平均吸收带宽达1.3 THz，90%吸收频率范围可从2.04 THz~3.53 THz到3.15 THz~4.24 THz连续动态调节。%Terahertz (THz) absorber with dynamically tunable bandwidth possesses huge application value in the field of switches, sensors and THz detection. However, the perfect absorbers based on traditional metamaterials are not intelligent enough to capture the electromagnetic wave in a tunable way. We utilized monolayer graphene and cross-shaped metallic sub-wavelength structure to design broadband absorber with tunable absorption frequency in terahertz regime. The absorption frequency can be turned by changing the chemical potential of graphene which can be easily controlled by the bias voltage supplied to graphene. Simulation results show that 1.3 THz average bandwidth was achieved. And the almost perfect absorption shifted from 2.04 THz~3.53 THz to 3.15 THz~4.24 THz continuously.