提出并设计了一种基于双层石墨烯结构的电控太赫兹波开关。该开关结构由棱镜-石墨烯-二氧化硅-石墨烯-锑化铟组成。太赫兹波从棱镜左侧以特定角度入射, 棱镜右侧固定有太赫兹波探测器, 通过外加电场改变石墨烯介电常数, 影响等离子体波矢匹配, 进而控制太赫兹波反射率, 实现太赫兹开关目的。实验运用COMSOL软件对双层石墨烯电控开关进行仿真模拟, 将1 THz的太赫兹波以35.42°从棱镜左上方入射, 在无外加电场时, 太赫兹波反射率为2.63%, 此时为太赫兹波开关的“关”状态。施加外加电场时, 石墨烯的介电常数发生变化, 太赫兹波反射率改变并达到93.01%, 棱镜结构接近全反射, 此时为太赫兹波开关的“开”状态。研究结果表明该结构具有良好的太赫兹波强度控制性能, 电控太赫兹波开关消光比为15.5 dB。

An electrically controlled terahertz wave switch was designed and proposed based on double layer graphene structure. The switch was made up of prism - graphene - SiO2 - graphene - InSb. The terahertz wave was incident from the left side of the prism at a specific angle, and the terahertz wave detector was fixed on the right side of the prism. By adjusting the external voltage bias, the refractive index of the graphene layers was changed in order to control the reflectance to achieve the purpose of terahertz switching. COMSOL software was used to simulate the double-layer graphene electronic switch.Terahertz wave with frequency of 1 THz was incident at 35.42° from the top of the prism in experiment. When there was no external electric field, the reflectivity of terahertz wave was 2.63%, which was defined as the "off" state of the terahertz wave switch. When the applied electric field was applied, the dielectric constant of graphene changed, and the reflectivity of terahertz wave changed to 93.01%. The structure of prism was close to total reflection, which was defined as the "open" state of terahertz wave switch. The simulation results show that the device has good performance in controlling the intensity of the terahertz wave. Extinction ratio of the switch was 15.5 dB.