引入石墨烯材料的光学异常透射现象机理研究与应用探索

The extraordinary optical transmission (EOT) refers to the strongly enhanced transmission of light through the subwavelength holes comparing with the value of classical theory. The EOT phenomenon has aroused intense interests due to the physical mechanism behind it, and becomes the landmark event in the plasmonics. Plenty of remarkable researches have been reported to reveal the mechanism and application of EOT by metallic nanohole array. However, further exploitation of EOT is prevented due to the high cost of noble metal and due to the high metal loss of surface waves. In the last decade, graphene has attracted considerable attention due to its unique physical, chemical, mechanical, electronic, and optical properties. Until now, The EOT phenomenon with graphene has not been widely investigated. This study is to introduce graphene in the metallic subwavelengh hole array, and explore the mechanism of EOT by this graphene-supported structure, as well as its novel applications, which facilitates the practicability of the EOT-based devices.

光学异常透射(EOT)现象是指当光通过亚波长金属孔阵列时，得到的透射率在特定波长位置会比经典的小孔透射理论预言的数值高若干个数量级。EOT一经提出，立刻引起了研究者们对这种现象背后所蕴藏的物理机制的广泛关注，成为表面等离激元光学(plasmonics)进入活跃发展期的标志性事件。目前，关于金属孔阵列实现EOT的机理与应用研究已较为成熟，但金属材料（金、银）的高成本以及对表面波的高损耗等特性限制了其在EOT应用中的进一步发展。近几年，石墨烯材料由于其良好的导热性、力学性能和超大的比表面积等特性，已引起了研究者们越来越广泛的关注。而关于引入石墨烯材料的光学异常透射现象，还缺乏广泛而系统的研究。本课题拟在传统EOT金属亚波长孔阵列结构中引入石墨烯材料，研究有石墨烯存在情况下，产生EOT的机制与传统EOT机制的共性与区别，并探索石墨烯材料的引入所带来EOT相关的新型应用，设计更实用的EOT器件。

本课题在原有光学异常透射（EOT）研究基础上，引入石墨烯材料，计算了金属-石墨烯结构的异常透射谱和表面电磁场分布，并计算了空气-石墨烯-空气结构的反对称模式场分布，对石墨烯层数、化学势、温度等参数对EOT峰和模式场分布的影响进行了分析。结果表明，EOT现象和表面波的激发存在相关性，化学势对介质-石墨烯结构的模式场分布具有显著调控效果。同时，本课题针对纳米天线结构建立了半解析模型，为引入石墨烯的纳米天线结构提供了理论基础。