摘要
设计了一种涂覆石墨烯的嵌套偏心空心圆柱的椭圆形电介质纳米线波导.采用多极方法得到了波导所支持的最低阶的3个模式的传输特性,即场分布、有效折射率的实部、传播长度和品质因数.结果显示:最低阶的3个模式都可由涂覆石墨烯的单根圆柱和椭圆柱所支持的最低阶模式合成.通过改变波导的结构参数,即圆柱的半径、椭圆柱半长轴、椭圆柱半短轴及两柱之间的最小间距,可以在一定程度上调节模式的传输性能.然而通过增大工作波长、费米能以及减小椭圆形电介质纳米线的介电常数,可以明显改善模式的传输性能.文中还与涂覆石墨烯的嵌套偏心空心圆柱的圆形电介质纳米线波导进行比较,可以发现本文所设计的波导具有更优的传输性能.这些结果都得到了有限元方法的验证.本文设计的波导可以为涂覆石墨烯的嵌套偏心空心圆柱的椭圆形电介质纳米线波导的设计、制作及应用提供理论基础.
An elliptical dielectric nanowire waveguide with a nested eccentric hollow cylinder is designed,the inner surface and the outer surface of the waveguide are both coated with graphene.The transmission characteristics of the three lowest order modes supported by the waveguide,i.e.the field distribution,the real part of the effective refractive index,the propagation length,and the quality factor,are obtained by multipole method.The results show that the three lowest order modes of the waveguide can be synthesized by the lowest order modes supported by a single cylinder and an elliptic cylinder coated with graphene.With the increase of the radius of the embedded cylinder,the three evaluation indexes of the waveguide increase slightly.The change of the semi major axis of the ellipse will slightly increase the real part of the effective refractive index,propagation length and quality factor of Mode 0 and Mode 1,while Mode2 will slightly decrease.When a = b = 170 nm,the performance of the circular nested circular waveguide becomes slightly worse than that of the structure in this paper.With the decrease of the semi minor axis of the ellipse,the real part of the effective refractive index,propagation length and quality factor for each of the three modes increase to a certain extent,and have the greatest impact on Mode 1.When b = a = 190 nm,the transmission performance of the circular nested circular waveguide is not so good as that of the structure in this paper.When the distance between the inner rod and the outer rod on the right side increases,the real part of the effective refractive index for each of the three modes decreases,the propagation length and quality factor of Mode 0 and Mode1 gradually decrease,while the propagation length of Mode 2 increases slightly,and the quality factor is basically unchanged.On the contrary,the mode transmission performance can be significantly improved by increasing the working wavelength and Fermi energy and reducing the dielectric constant of elliptical dielectric nanowires.Compared with the circular dielectric nanowire waveguide nested with an eccentric hollow cylinder coated with graphene,the waveguide designed in this paper can be found to have a good transmission performance.These results are verified by the finite element method.This waveguide can provide a theoretical basis for the design,fabrication and application of nested waveguides of the same type.
作者
李慧慧
薛文瑞
李宁
杜易达
李昌勇
Li Hui-Hui;Xue Wen-Rui;Li Ning;Du Yi-Da;Li Chang-Yong(College of Physics and Electronic Engineering,Shanxi University,Taiyuan 030006,China;State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第10期310-325,共16页
Acta Physica Sinica
基金
国家自然科学基金(批准号:61378039,61575115)
国家基础科学人才培养基金(批准号:J1103210)资助的课题。
关键词
石墨烯
纳米线
波导
多极方法
graphene
nanowires
waveguides
multipole method
