基于石墨烯表面等离激元的亚辐射模式的研究

项目名称： 基于石墨烯表面等离激元的亚辐射模式的研究

项目编号： No.61505052

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 翟翔

作者单位： 湖南大学

项目金额： 20万元

中文摘要： 亚辐射模式为等离激元诱导透明系统提供亚稳态，其本身的超窄线宽在制备亚波长高品质谐振腔和无损耗纳米光波导方面具有很高的应用价值。然而基于金属共振结构的亚辐射模式的非辐射损耗受限于特鲁德极限，且无法实现共振频率的主动控制阻碍了他们的应用。本项目拟利用石墨烯表面等离激元损耗低、共振频率动态可调的特点，通过理论分析、数值计算与实验相结合的方法，研究石墨烯等离激元亚辐射模式的激发条件和形成机理；明确石墨烯载流子浓度和衬底结构对亚辐射模式透射谱的调控作用。研究基于多重亚辐射模式间接激发的Fano共振，阐释亚辐射模式对辐射和非辐射损耗抑制作用，揭示多重亚辐射模式的辐射方向和极化方向的敏感性，开展相关的器件研究。研究基于结构的对称破缺和对称匹配的亚辐射模式的直接激发问题，揭示两种方法在物理机制上的异同，探索不依赖模式间共振耦合效应激发石墨烯等离激元亚辐射模式的新方案。

中文关键词： 表面等离激元；纳米天线；微腔-表面等离子体耦合；表面等离子体增强吸收；SPP激发

英文摘要： Subradiant mode serves as the metastate of the plasmon-induced transparency system, and its inherent ultra-narrow linewidth exerts significant values in the designs of subwavelength high-Q optical cavities and losses nanoscale waveguide. However, nonradiative losses of the metal based subradiant mode is subject to the Drude damping limit, and passive control of the resonance frequency has largely blocked its application. In this project, we will utilize the lower loss and dynamical tunability of the graphene surface plasmon (GSP) combining the theoretical analyses, the numerical calculations and experiments to research the excitation condition and formation mechanism of the GSP subradiant mode. We will further study the influences of the carrier density of graphene and substrate structure on engineering the transmission spectrum of the subradiant mode. Meanwhile, we will explore the inhibition of the radiative and nonradiative damping through the researches of Fano resonance based on the indirect excitation of the multiple subradiant mode, and its sensitivity of radiation and polarization directions will also be researched, which will provide the principles of the related plasmonic devices. In addition, we will investigate systematically the direct excitation methods of GSP subradiant mode based on structural symmetry breaking and symmetry matching and reveal the differences and similarities between the two methods. Our studies will offer a new scheme of the direct subradiant mode excitation which is independent of the plasmon hybridization.

英文关键词： Surface plasmon;Nano-antenna;Micro-cavity surface plasmon coupling;Surface plasmon enhanced absorption;SPP excitation