Terahertz wavefront control by tunable metasurface made of graphene ribbons
Terahertz wavefront control by tunable metasurface made of graphene ribbons
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DOI：
10.1063/1.4927824
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发表时间：
2015-08
影响因子：
4
通讯作者：
Takumi Yatooshi;A. Ishikawa;K. Tsuruta
中科院分区：
文献类型：
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作者：
Takumi Yatooshi;A. Ishikawa;K. Tsuruta
我们提出了一种可调的超颖表面组成的银镜与SiO2间隙层的石墨烯带阵列，以控制反射波阵面在太赫兹频率。石墨烯带表现出局部等离子体共振，这取决于它们的费米能级，以沿超颖表面沿着引入突然的相移。由于SiO2层中法布里-珀罗共振的干涉，系统中的相移会大量累积，覆盖0到2π范围，以完全控制波前。数值模拟结果表明，在5THz波段，在小于0.6ps的开关时间内，实现了53°的宽角度光束转向，反射效率高达60%。
We propose a tunable metasurface consisting of an array of graphene ribbons on a silver mirror with a SiO2 gap layer to control reflected wavefront at terahertz frequencies. The graphene ribbons exhibit localized plasmon resonances depending on their Fermi levels to introduce abrupt phase shifts along the metasurface. With interference of the Fabry-Perot resonances in the SiO2 layer, phase shift through the system is largely accumulated, covering the 0-to-2π range for full control of the wavefront. Numerical simulations prove that wide-angle beam steering up to 53° with a high reflection efficiency of 60% is achieved at 5 THz within a switching time shorter than 0.6 ps.