涂覆石墨烯的三根电介质纳米线波导的模式特性

Mode Characteristics of Waveguides Based on Three Graphene-Coated Dielectric Nanowires

采用多极方法,通过改变工作频率、中间纳米线半径、中间纳米线高度、水平方向上纳米线之间的距离以及石墨烯的费米能,对涂覆石墨烯的三根轴心非共面的电介质纳米线波导所支持的5种低阶模的有效折射率实部和传播长度进行分析。当工作频率从30 THz增加到40 THz时,有效折射率实部增大,传播长度减小。当中间纳米线的半径从20 nm增加到55 nm时,有效折射率的实部增大,传播长度变化各不相同。当中间纳米线的高度从0增加到100 nm时,有效折射率的实部减小,除了模式5外,其他模式的传播长度都增大。当水平方向上纳米线之间的距离从160nm增加到200 nm,石墨烯的费米能从0.4 eV增加到0.8eV时,有效折射率的实部减小,传播长度增大。

We propose a waveguide based on three graphene-coated dielectric nanowires with a non-coplanar axis using the multipole method, and analyze the real part of effective refractive index and propagation length of five supported low-order modes by changing the operating frequency, radius and height of the central nanowires, the horizontal space between the nanowires, and the Fermi energy of graphene. When the operating frequency increases from 30 THz to 40 THz, the real part of the effective refractive index increases, whereas the propagation length decreases. When the radius of the central nanowire increases from 20 nm to 55 nm, the real part of effective refractive index increases;however, the corresponding propagation length varies. When the height of the central nanowire increases from 0 to 100 nm, the real part of effective refractive index decreases, whereas the propagation length increases, except for that of mode 5. When the horizontal space between the nanowires increases from160 nm to 200 nm or the Fermi energy increases from 0.4 eV to 0.8 eV, the propagation length increases, whereas the real part of the effective refractive index decreases.