Active control of terahertz electromagnetically induced transparency metasurface using a graphene-metal hybrid structure
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摘要: 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。Abstract: 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.
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Key words:
- active control /
- electromagnetically induced transparency /
- graphene /
- metasurface /
- terahertz
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图 2 (a)模拟的CWR(明模),DUR (暗模)和EIT结构的透射谱;(b)模拟的EIT结构在透射窗口频率处的表面电流分布,其中黑色箭头表示电流流向
Figure 2. (a) Simulated amplitude transmission spectra of the CWR (bright mode), DUR (dark mode) and the EIT structure, respectively; (b) Simulated surface current distributions of the EIT structure at the transparency window frequency, the black arrows illustrate the directions of the surface currents
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[1] Boiler K J, Imamoglu A, Harris S E. Observation of electromagnetically induced transparency [J]. Physical Review Letters, 1991, 66: 2593-2596. doi: 10.1103/PhysRevLett.66.2593 [2] Wang Jing, Tian Hao. Terahertz flexible stretchable metasurface based on double resonance response [J]. Infrared and Laser Engineering, 2020, 49(12): 20201059. (in Chinese) doi: 10.3788/IRLA20201059 [3] Zhao Yun, Yang Yuanmu. Nonlinear metasurfaces: harmonic generation and ultrafast control [J]. Infrared and Laser Engineering, 2020, 49(9): 20201037. (in Chinese) doi: 10.3788/IRLA20201037 [4] Liu M, Yang Q, Xu Q, et al. Tailoring mode interference in plasmon-induced transparency metamaterials [J]. Journal of Physics D-Applied Physics, 2018, 51: 174005. doi: 10.1088/1361-6463/aab6fb [5] Li Q, Liu S, Zhang X, et al. Electromagnetically induced transparency in terahertz metasurface composed of meanderline and U-shaped resonators [J]. Optics Express, 2020, 28(6): 8792-8801. doi: 10.1364/OE.389292 [6] Singh R, Al-Naib I, Yang Yuping, et al. Observing metamaterial induced transparency in individual Fano resonators with broken symmetry [J]. Applied Physics Letters, 2011, 99: 201107. doi: 10.1063/1.3659494 [7] Mal K, Islam K, Mondal S, et al. Electromagnetically induced transparency and electromagnetically induced absorption in Y-type system [J]. Chinese Physics B, 2020, 29(5): 054211. doi: 10.1088/1674-1056/ab7ea0 [8] Gu J, Singh R, Liu X, et al. Active control of electromagnetically induced transparency analogue in terahertz metamaterials [J]. Nature Communications, 2012, 3: 1151. doi: 10.1038/ncomms2153 [9] Cao Yanyan, Li Yue, Liu Yuanzhong, et al. Tunable electromagnetically induced transparency based on T-shaped graphene metamaterials [J]. Journal of Terahertz Science and Electronic Information Technology, 2017, 15(2): 192-197. (in Chinese) [10] Chu Q, Song Z, Liu Q H. Omnidirectional tunable terahertz analog of electromagnetically induced transparency realized by isotropic vanadium dioxide metasurfaces [J]. Applied Physics Express, 2018, 11: 082203. doi: 10.7567/APEX.11.082203 [11] Tamayama Y, Kida Y. Tunable group delay in a doubly resonant metasurface composed of two dissimilar split-ring resonators [J]. Journal of the Optical Society of America B-Optical Physics, 2019, 36: 2694-2699. doi: 10.1364/JOSAB.36.002694 [12] Li Guangsen, Yan Fengping, Wang Wei, et al. Analysis of photosensitive tunable multiband electromagnetically induced transparency metamaterials [J]. Chinese Journal of Lasers, 2019, 46(1): 0114002. (in Chinese) [13] Sun H, Tang Y, Hu Y, et al. Active formatting modulation of electromagnetically induced transparency in metamaterials [J]. Chinese Optics Letters, 2020, 18(9): 092402. doi: 10.3788/COL202018.092402 [14] Zhou J, Zhang C, Liu Q, et al. Controllable all-optical modulation speed in hybrid silicon-germanium devices utilizing the electromagnetically induced transparency effect [J]. Nanophotonics, 2020, 9(9): 2797-2807. doi: 10.1515/nanoph-2020-0017 [15] Du C, Zhou D, Guo H, et al. Active control scattering manipulation for realization of switchable EIT-like response metamaterial [J]. Optics Communications, 2021, 483: 126664. doi: 10.1016/j.optcom.2020.126664 [16] Li Q, Tian Z, Zhang X, et al. Active graphene-silicon hybrid diode for terahertz waves [J]. Nature Communications, 2015, 6: 7082. doi: 10.1038/ncomms8082