为提高单层石墨烯薄膜电控太赫兹调制器的调制深度, 提出一种臂型金属网格微结构与石墨烯结合的太赫兹波透射调制器件.通过臂型金属网格结构激发的共振耦合场增强石墨烯与太赫兹波的相互作用, 使石墨烯在外加电压调制下对太赫兹波透射幅度的调制深度获得大幅提升.通过有限元仿真分析了金属结构参数对石墨烯与太赫兹波相互作用增强规律的影响, 理论结果表明, 臂型网格结构使石墨烯对太赫兹波透射幅度调制深度从7.7%提升到了28.2%.在理论结果的基础上, 基于光刻工艺完成了器件的结构制作, 实验测试中获得了24%的太赫兹幅度调制深度, 且调制深度曲线与理论仿真规律基本一致.

In order to improve the modulation depth of the single layered graphene electronic controlled terahertz modulator, a terahertz transmission modulator with an arm type metal mesh structure combined with graphene is proposed. The resonant coupling field excited by the arm type metal mesh structure enhances the interaction between graphene and terahertz wave, which greatly improves the modulation depth of the terahertz modulator when the modulation voltage is applied. The influences on the interaction enhancement of graphene and terahertz wave at different metal structure parameters are analyzed by finite element method simulation. The theoretical results indicate that the arm type metal grid structure increases the modulation depth from 7.7% to 28.2%. On the basis of the theoretical results, the device is fabricated with the photolithography process. The 24% modulation depth is obtained in the experimental measurements, and the experimental modulation depth curve is basically in agreement with the theoretical simulation.