表面等离子体激元在涂覆石墨烯的领结型纳米线光波导中的传输特性研究

Study of Propagation Characteristics of a Plasmonic Waveguide Formed of Graphene Coated Bow-tie Type Nanowires

本文设计并研究了一种关于介质板对称的涂覆石墨烯的领结型纳米线波导结构,利用有限元法(FEM)对波导所支持的表面等离子体激元的传输特性进行研究。通过调整结构的几何参数和电磁参数研究了表面等离激元模式的有效折射率、模式传播长度、归一化模式面积、品质因数以及模式的场分布特性。研究发现,该结构对电磁场模式具有良好的模式束缚特性,传播长度大于2μm,归一化的模式面积接近10-5的量级,并且具有较高的品质因数。这种结构在未来微纳光电器件领域实现超紧密光学集成中具有潜在的应用前景。

A type of plasmonic waveguide composed of a bow-tie type graphene-coated nanowire pair with a high-index dielectric slab in-between is proposed in this paper.The propagation characteristics of plasmonic mode supported by this waveguide are investigated with the finite element method（FEM）.By tuning the geometric parameters and electromagnetic parameters,the mode effective index,propagation length,normalized mode area,figure of merit and mode distribution properties of supported fundamental plasmonic mode is studied detailedly.The results reveal that the proposed waveguide structure has better mode confinement ability and higher figure of merit,that is to say,the propagation length is greater than 2μm and the normalized mode area is closer to an order of magnitude of 10^-5.This type of plasmonic waveguide structure will have a potential application in high density integration of photonic circuit for the future micro and nano optoelectronic devices.