利用石墨烯-金属复合结构实现太赫兹电磁诱导透明超表面主动调控

近年来，在超表面中实现对电磁诱导透明的主动式调控引起了越来越多的研究兴趣。采用石墨烯-金属复合结构，设计并研制了一种新颖的调制策略，通过同时施加光泵和偏置电压改变石墨烯的电导率，在太赫兹波段实现了一种主动式电磁诱导透明超表面，其在透射窗口频率处的振幅调制深度可达73%。模拟和理论分析表明，其内在物理机理在于石墨烯对金属谐振结构的短接作用，石墨烯的电导率越大，短接效果越明显，谐振强度也越弱。该石墨烯-金属复合超表面为设计紧凑的主动式太赫兹光开关器件提供了一种实现途径，在太赫兹通信中具有潜在的应用前景。

Active control of terahertz electromagnetically induced transparency metasurface using a graphene-metal hybrid structure

In recent years, achieving active control over the electromagnetically induced transparency (EIT) effect in metasurfaces has attracted grown interests. A novel modulation strategy was designed and fabricated based on a graphene-metal hybrid structure. An active EIT metasurface was realized in the terahertz (THz) regime by simultaneously applying optical pump and bias voltage, where the amplitude modulation depth at the transparency window frequency reached 73%. The simulation and theoretical analysis indicate that the inner physical mechanism lies in the shorting effect of the graphene to the metal resonant structure. The higher the conductivity of graphene is, the stronger the shorting effect is, and the weaker the resonance strength becomes. The proposed graphene-metal hybrid metasurface provides an alternative way towards designing compact active terahertz switching devices, and has potential in terahertz communication applications.