Zhang Baihui, Li Hongjian, Xu Hui, Zhao Mingzhuo, Xiong Cuixiu, Liu Chao, Wu Kuan
Opt Express. 2019 Feb 4;27(3):3598-3608. doi: 10.1364/OE.27.003598.
We propose a novel simple patterned monolayer graphene metamaterial structure based on tunable terahertz plasmon-induced transparency (PIT). Destructive interference in this structure causes pronounced PIT phenomenon, and the PIT response can be dynamically controlled by voltage since the existence of continuous graphene bands in the structural design. The theoretical transmission of this structure is calculated by coupled mode theory (CMT), and the results are highly consistent with the simulation curve. After that, the influence of the graphene mobility on the PIT response and absorption characteristics is researched. It is found that the absorption efficiency of our designed structure can reach up to 50%, meaning the structure is competent to prominent terahertz absorber. Moreover, the slow-light performance of this structure is discussed via analyzing the group refractive index and phase shift. It shows that the structure possesses a broad group refractive index band with ultra-high value, and the value is up to 382. This work will diversify the designs for versatile tunable terahertz devices and micro-nano slow-light devices.
我们提出了一种基于可调太赫兹等离子体诱导透明（PIT）的新型简单图案化单层石墨烯超材料结构。该结构中的相消干涉会导致明显的PIT现象，并且由于结构设计中存在连续的石墨烯能带，PIT响应可通过电压进行动态控制。利用耦合模理论（CMT）计算了该结构的理论透射率，结果与模拟曲线高度一致。在此之后，研究了石墨烯迁移率对PIT响应和吸收特性的影响。发现我们设计的结构的吸收效率可达50%，这意味着该结构有能力成为出色的太赫兹吸收体。此外，通过分析群折射率和相移来讨论该结构的慢光性能。结果表明，该结构具有一个具有超高值的宽群折射率带，其值高达382。这项工作将使多功能可调太赫兹器件和微纳慢光器件的设计多样化。
