表面等离子体波在石墨烯中的传输与调控研究

Surface Plasmon Polaritons (SPPs) open the possibility to amplify, concentrate and manipulate light at the nanoscale, overcoming the diffracton limit of traditional optics.This could lead to miniaturized photonic circuits composed of miniaturized devices. Indeed, SPPs can serve as a basis for constructing nanoscale photonic circuits that will be able to carry optical signals and electric currents.Traditionally, noble metals such as gold and silver have been used to support SPPs. However, the difficulty in controlling and varying permittivity functions of noble metals and the existence of material losses constrain using metals for plamonics. Graphene has attracted an explosion of research interest for potential applications in various branches of engineering due to its exceptional electronic transport properties. Recently, Owing to its ability to support SPP waves, and capability to dynamically tune the conductivity, graphene may serve as a suitable platform for tunable metamaterials and transformation optics for plasmonics. In this project, we will find an approprate method for accurate analysis the electromagnetics of graphene, which will be verified by expriments. Using this simulation tool, we will study the characterics of SPP wave propagation in detail, and will try to find efficient way to manupulate SPP waves on the graphene monolayer besides gate voltage. Our work will pave the way for the application of graphene to planar subwave-lenth optical devices.

表面等离子体激元（Surface Plasmon Polaritons, SPPs），能突破衍射极限，为器件微型化和高度集成化，实现纳米全光集成电路提供了可能。传统支持SPPs的贵金属如金、银等存在损耗大并且调控困难等缺点，限制了其在SPP领域的应用。作为国际研究热点的石墨烯，因其损耗低并且能实现对SPP波的调控而吸引了更多科学家的关注。本项目针对微纳集成电路对SPP器件的需求，通过仿真与实验相结合的手段，开展对石墨烯SPP波准确电磁建模研究。在此基础上，重点开展对石墨烯SPP波传输特性分析，探索石墨烯对SPP波的调控机理及其实现途径，为石墨烯在平面亚波长光学器件中的应用奠定基础。

本项目开展表面等离子体波，（SPP）在石墨烯中的传输特性与调控研究。取得的主要成果有：（1）解决了石墨烯原子晶格形状、单原子厚等特点给电磁计算带来的困难，实现对石墨烯的准确电磁建模与计算；（2）证明了石墨烯对SPP波具有比金、银等贵金属具有更强的束缚性，石墨烯SPP波可以在任意弯曲的表面传播，甚至可以局域在纳米环上，为实现柔性光学变换SPP七届带来了希望；（3）给出了介质－石墨烯－介质三明治结构的等效电磁模型，提出了利用介质对石墨烯SPP波传输进行调控的新方法，实现了对石墨烯SPP波传输特性进行连续渐变的调控；为实现对SPP波调控提供了一种更简单有效的途径；（4）设计了一系列基于石墨烯的弯曲“Y”型波导、“S”型波导以及基于纳米谐振环的开关等平面亚波长光学器件。