Zhang Yonggang, Qiu Fu, Liang Lanju, Yao Haiyun, Yan Xin, Liu Wenjia, Huang Chengcheng, Yao Jianquan
Opt Express. 2022 Jul 4;30(14):24703-24715. doi: 10.1364/OE.465631.
This letter presents a fabricated Dirac point modulator of a graphene-based terahertz electromagnetically induced transparency (EIT)-like metasurface (GrE & MS). Dynamic modulation is realized by applying three stimulus modes of optical pump, bias voltage, and optical pump-bias voltage combination. With increasing luminous flux or bias voltage, the transmission amplitude undergoes two stages: increasing and decreasing, because the graphene Fermi level shifts between the valence band, Dirac point, and conduction band. Thus, an approximate position of the Dirac point can be evaluated by the transmission spectrum fluctuation. The maximum modulation depth is measured to be 182% under 1 V. These findings provide a method for designing ultrasensitive terahertz modulation devices.
本文介绍了一种基于石墨烯的太赫兹电磁诱导透明（EIT）类超表面（GrE & MS）的虚构狄拉克点调制器。通过施加光泵浦、偏置电压以及光泵浦 - 偏置电压组合这三种激励模式来实现动态调制。随着光通量或偏置电压的增加，传输幅度经历增加和减小两个阶段，这是因为石墨烯费米能级在价带、狄拉克点和导带之间移动。因此，可以通过传输光谱波动来评估狄拉克点的近似位置。在1V电压下测得最大调制深度为182%。这些发现为设计超灵敏太赫兹调制器件提供了一种方法。
