石墨烯超材料与相干光场作用研究

Graphene has attracted considerable attention in micro/nano-photonics for: i) manipulating light on single/few-atomically thin scale; ii) ultrawide dynamical tunable optical response due to its novel charge-carrier properties. However, the extremely low charge-carrier density of graphene also limits its interaction with light, the pretty weak interaction with light led the poor-efficiency in manipulating optical fields. Our pre-research shows that metamaterial design as well as coherent modulation can be employed for effectively localizing optical fields to boost the light-graphene interactions. Aimed at the aforementioned prominent problem to apply graphene in practical nanophotonics and optoelectronics, we propose in this project to study the interactions of graphene metamaterials and coherent modulated optical fields for enhanced light-graphene interactions. We will theoretically and experimentally investigate the optical properties of graphene metamaterials in coherent optical fields, the physical mechanism in enhancing graphene's optical response with metamaterial design and coherent modulation will be elucidated. The loss-compensation or even optical amplification in optically pumped graphene metamaterials will also be explored for strong plasmonic response. The project is of great theoretical significance and practical value in providing high-efficiency dynamical manipulation on optical fields for the practical applications of graphene in photonics and optoelectronic devices.

石墨烯在微纳光学研究中得到越来越多的关注，其优势在于：i)使得单或者少原子层尺度光场调控成为可能；ii)不同于传统材料的载流子特性使其光性宽带大范围可调。但石墨烯的低载流子浓度导致其光学响应很弱，不能有效地调控光场。预先研究表明石墨烯超材料结构和相干调控均可以有效地局域光场进而增强石墨烯光场调控。针对石墨烯应用于光子学遇到的以上亟待解决的问题，本项目提出超材料结构与相干光场相互作用协调增强光与石墨烯相互作用的思路，将对石墨烯超材料与相干光场相互作用规律进行理论与实验结合的研究，阐明超材料与相干光场共同增强石墨烯光学响应的机理。同时也将理论探索光泵浦石墨烯超材料中的损耗补偿甚或光放大以获得强的石墨烯等离激元激励。本项目研究对石墨烯应用光学器件实现高效光场动态调控具有重要的理论意义与实际价值。

本课题利用超材料结构的合理设计或多路光场调控获得相干光场调制与石墨烯相互作用以增强其与光场的相互作用，获得强的石墨烯等离激元模式和相干完美吸收等。同时基于类似石墨烯的电可调光性，我们将可调相变材料及硅薄膜等于超材料结构结合构造了系列光性可高效动态调控的有源超表面。主要结果包括：系统地研究了石墨烯超材料与相干光场的相互作用，探索了石墨烯超材料与光相互作用的增强机理。基于CVD制备的大面积石墨烯尝试了微波波段石墨烯与超材料的杂化作用，发现相干耦合机制导致的超透射结构与石墨烯结合可以获得高效甚或双带和宽带的电磁透射调制或开关。此外合作进行了远红外波段高品质谐振模式的连续（模拟）调控实验研究。理论与实验研究结合掌握了基于电学、光学和热学方法对超材料性能调控的设计与调控方法。相关研究有望应用于高效动态太赫兹和红外波调制和开关等。项目执行过程中在微结构材料光子学方面主流期刊Advanced Materials，ACS Photonics Research，Advanced Optical Materials, Physical Review A, Photonics Research, Optics Express等著名期刊上发表SCI论文29篇，包括1篇AOM综述（封面论文），其中3篇入选ESI高被引论文,授权专利1项。发表英文专著章节1章。项目资助期间，培养毕业硕士3 人，在读硕士、博士4人。