Su Zhaoxian, Chen Xuan, Yin Jianbo, Zhao Xiaopeng
Opt Lett. 2016 Aug 15;41(16):3799-802. doi: 10.1364/OL.41.003799.
We design a tunable terahertz metasurface, which consists of two different trapezoid graphene ribbons patterned in opposite directions on a gold film, separated by a thin dielectric spacer. The two kinds of graphene ribbons can cover a nearly 2π phase shift with high reflection efficiency in different spectral regions so that the metasurface can reflect different frequency waves to totally different directions. By changing the Fermi level of the graphene ribbons, the response frequency of the proposed metasurface can be adjusted, and as a result, tunable spectrum splitting can be realized. The present metasurface provides a powerful way to control terahertz waves and has potential applications in wide-angle beam splitters.
我们设计了一种可调谐太赫兹超表面，它由在金膜上沿相反方向图案化的两种不同梯形石墨烯带组成，中间由一层薄的电介质间隔层隔开。这两种石墨烯带在不同光谱区域能够以高反射效率覆盖近2π的相移，从而使超表面能够将不同频率的波反射到完全不同的方向。通过改变石墨烯带的费米能级，可以调节所提出的超表面的响应频率，进而实现可调谐的光谱分裂。这种超表面为太赫兹波的控制提供了一种强有力的方法，并且在广角分束器方面具有潜在应用。
