基于石墨烯超材料的可调谐电磁诱导透明

提出了一种基于石墨烯超材料的可调谐电磁诱导 透明(EIT)结构,该结构是由长条-半圆环形状的石墨烯层和 介质基底组成。通过频域有限差分法研究了该结构的特性,研究结果表明,由于石墨烯条和 石墨烯半圆环之间发生相互 作用,产生较弱的杂化,从而可以观察到EIT透明窗口。更重要的是,通过控制门电压,改 变石墨烯的费米能级,可以 在较宽的频率范围内实现透明窗口的动态调谐。通过调节石墨烯的费米能级,在透射峰附近 群延迟接近0.4ps。同时还研 究了石墨烯条和半圆环间的距离、圆环的半径、方位角等几何参数对EIT效应的影响,这些 因素的改变对EIT 效应产生 了不同的影响。本文设计的超材料结构可应用于调制器和慢光器件等,对光开关、光存储等 新型器件的设计有重要的指导意义。

Tunable electromagnetically induced transparency based on graphene metamaterial

A tunable electromagnetically induced transparency (EIT) structure based on graphene metamaterial is proposed in this paper.The structure is made up of the striphalf ring graphen e layers on the substrate.The characteristics of the structure are studied by the frequency domain method finite difference.The simu lation confirms that an EIT-like transparency window can be observed due to frequency detuning and the weak hybridization of t he strip and the half ring graphene layers.More importantly,the peak frequency of the transmission window can be dynamically controlled over a b road frequency range by varying the Fermi energy levels of the graphene layer through controlling the electrostatic gating.Corre spondingly,by adjusting the Fermi energy of the graphene,a group delay of 0.4ps is obtained in the vicinity of the transparency peaks.The effect of the distance between the strip and the ring,the radius of the ring and the azimuth angle on the EIT effect are als o studied.The changes of these factors have different impacts on the EIT.The metamaterial structure designed in this pape r can be applied in modulators and slow light devices,and has important guiding significance for the design of new devices,such as optical swi tching and optical storage.