基于光栅辅助双层石墨烯混合结构的太赫兹频率双可调谐电磁诱导透明

Dual Tunable Electromagnetically Induced Transparency Based on a Grating-Assisted Double-Layer Graphene Hybrid Structure at Terahertz Frequencies.

作者信息

Zhong Xu, Wu Tiesheng, Liu Zhihui, Yang Dan, Yang Zuning, Liu Rui, Liu Yan, Wang Junyi

机构信息

Guangxi Key Laboratory of Wireless Broadband Communication and Signal Processing, School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China.

Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.

出版信息

Nanomaterials (Basel). 2022 Nov 1;12(21):3853. doi: 10.3390/nano12213853.

DOI:10.3390/nano12213853

PMID:36364629

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9654115/

Abstract

We propose a graphene plasmonic structure by applying two graphene layers mingled with a thin gold layer in a silicon grating. By utilizing the finite-difference time-domain (FDTD) method, we investigate the optical response of the system, and observe that the design achieves dual tunable electromagnetically induced transparency (EIT)-like effect at terahertz frequencies. The EIT-like effect arises from the destructive interference between the grapheme-layer bright modes and the gold-layer dark mode. The EIT-like phenomenon can be adjusted by the Fermi level, which is related to the applied voltage. The results show that the group delay of the present structure reaches 0.62 ps in the terahertz band, the group refractive index exceeds 1200, the maximum delay-bandwidth product is 0.972, and the EIT-like peak frequency transmittance is up to 0.89. This indicates that the device has good slow light performance. The proposed structure might enable promising applications in slow-light devices.

摘要

我们通过在硅光栅中应用两层与薄金层混合的石墨烯层，提出了一种石墨烯等离子体结构。利用时域有限差分（FDTD）方法，我们研究了该系统的光学响应，并观察到该设计在太赫兹频率下实现了双可调谐电磁诱导透明（EIT）类效应。这种EIT类效应源于石墨烯层亮模式与金层暗模式之间的相消干涉。这种EIT类现象可以通过与施加电压相关的费米能级进行调节。结果表明，该结构在太赫兹波段的群延迟达到0.62 ps，群折射率超过1200，最大延迟带宽积为0.972，EIT类峰值频率透过率高达0.89。这表明该器件具有良好的慢光性能。所提出的结构可能在慢光器件中具有广阔的应用前景。