设计并制备了基于人工超表面/离子凝胶/石墨烯复合结构的太赫兹调幅器件,并对其调制效果进行了模拟仿真和实验验证。该器件以嵌在石墨烯和超表面之间的离子凝胶为电解质,以石墨烯为主动材料,用超表面实现太赫兹波与石墨烯相互作用的增强。通过外加偏压调节石墨烯的电导率,进而达到对太赫兹波的主动控制。结果表明:该器件在较小的外加偏压下就可以在谐振频率处实现73%的调制深度,并且在调制过程中谐振频率几乎保持不变。该器件为小电压下的大幅度太赫兹调制提供了一种新手段。

In this study, a terahertz amplitude modulator based on metasurface/ion-gel/graphene hybrid structure was designed and fabricated. The modulation performance of the device was simulated and experimentally demonstrated. This device uses the ion-gel medium embedded between graphene and metasurface as the electrolyte, and the graphene as the active material. The enhancement of the interaction between terahertz wave and graphene is realized on the metasurface. Further, an external bias voltage was used to tune the electrical conductivity of graphene for actively controlling the terahertz waves. The results indicate that the device can achieve a modulation depth of up to 73% at the resonant frequency with a relatively small bias voltage. Moreover, the resonant frequency remains almost constant in the modulation process. Thus, the proposed device provides one novel tool in the large terahertz amplitude modulation under low voltages.