石墨烯TE模表面等离子体波和表面等离子体波导的特性  

Properties of Graphene TE Mode Surface Plasmons and Surface Plasmon Waveguides

作　　者：万鹏 杨翠红 

机构地区：[1]南京信息工程大学物理与光电工程学院,江苏南京210044

出　　处：《光学学报》2017年第11期290-297,共8页Acta Optica Sinica

基　　金：江苏省自然科学基金(BK20131428);国家自然科学基金(11547030);江苏省高校"青蓝工程"

摘　　要：基于含石墨烯的双/三层介质结构中的光学色散方程,研究了覆层和基底层材料对石墨烯表面等离子体波横电(TE)模的影响。计算结果表明,近红外波段内,石墨烯表面等离子体波TE模的性质对覆层和基底层介电常数的差值极其敏感。当覆层和基底层介电常数出现微小差异时,TE模可以进行传输。随着两介电常数差值的增大,TE模的有效折射率显著增大,甚至超过覆层折射率,而传播损耗不断减小。对于三层介质结构,相邻两介质分界面间添加单层石墨烯形成了平板波导结构,研究该结构发现,当传导层和基底层介电常数相近时,其夹层的石墨烯对波导TE模的调控尤其显著,这种调控来源于电磁波耦合到石墨烯形成的表面等离子体波TE模。这些结果为设计调制器、检测器和过滤器等石墨烯表面等离子体波导器件提供了理论支持。The influence of the cladding and substrate materials on graphene transverse electric （TE） mode surface plasmonic properties have been theoretically investigated based on the optical dispersion equation in the two-layer/ three-layer dielectric system. It is found that the TE mode is highly sensitive to the dielectric contrast between the cladding and the substrate materials on both sides of graphene in the near-infrared regime. When the dielectric contrast between the cladding and the substrate is tiny, the TE mode surface plasmons can be transmitted. As the dielectric contrast increases, the TE mode dispersion curve behaves differently. The effective refractive index of the TE mode increases obviously and the propagation loss decreases continuously. For the three-layer parallel-plated waveguide structure with graphene embedded between two dielectric medium layers, the numerical results show that the control for the TE mode is significant especially when the dielectric constants for the propagation layer and the substrate layer is close to each other. It originates from the coupling between the electromagnetic wave and graphene leading to the surface plasmons between them. The results provide a theoretical support for the design of graphene surface plasmons based optoelectronic waveguides, such as modulators, detectors, and filters.

关 键 词：表面光学 表面等离子体波 石墨烯 平板波导 横电模 

分 类 号：O436[机械工程—光学工程]