Graphene-supported tunable waveguide structure in the terahertz regime
Graphene-supported tunable waveguide structure in the terahertz regime
复制标题
DOI：
10.1364/josab.30.002461
复制
发表时间：
2013-09
影响因子：
1.9
通讯作者：
Xiaoyong He;Sangin Kim
中科院分区：
文献类型：
--
作者：
Xiaoyong He;Sangin Kim
利用有限元法 (FEM) 和传输矩阵法 (TMM) 研究了太赫兹范围内石墨烯支撑结构 Si-SiO2-石墨烯-电介质-石墨烯-SiO2-Si (SiSiO2GDGSiO2Si) 的可调谐波导特性。研究表明，FEM 和 TMM 获得的数值结果非常吻合。等值线结果表明，随着频率的增加，有效指数增大，损耗呈现峰值；随着费米能级的增加，有效指数减小，损耗减小。由于有效模式面积较小，SiSiO2GDGSiO2Si 结构的限制比 Si-电介质-石墨烯-电介质-Si 结构的限制要好得多。结构的传播特性可以通过使用施加的栅极电压来调制。传播损耗的调制深度可达90%以上。研究结果有助于可调谐石墨烯光电器件的设计，例如偏振器、调制器和超材料器件。
The tunable waveguide properties of the graphene supporting structure Si–SiO2–graphene–dielectrics–graphene–SiO2–Si (SiSiO2GDGSiO2Si) have been investigated in the terahertz regime by using the finite element method (FEM) and transfer matrix method (TMM). The study shows that the numerical results obtained from FEM and TMM agree well. The contour results show that as the frequency increases, the effective index increases, and the loss shows a peak; with the increase in the Fermi level, the effective index decreases, and the loss decreases. With a smaller effective mode area, the confinement of the SiSiO2GDGSiO2Si structure is much better than that of the Si–dielectrics–graphene–dielectrics–Si structure. The propagation properties of the structure can be modulated by using the applied gate voltage. The modulation depth of the propagation losses can reach more than 90%. The results are helpful to the design of tunable graphene optoelectronic devices, such as polarizers, modulators, and metamaterial devices.