平板光子晶体波导中慢光与石墨烯相互作用的研究

Recently, due to graphene’s distinctive optical and electrical properties, graphene optoelectronics becomes an interesting research topic. The research progress on this topic can help reveal novel optical phenomena in two-dimensional quantum confined system and develop high-performance optoelectronic devices. However, the single atomic layer of graphene limits its effective interaction with light, presenting a challenge for the development of graphene optoelectronics. The main purpose of this project is to study physical mechanism of the interactions between graphene and slow-light in planar photonic crystal (PPC) waveguides, which could provide a new method to effectively enhance the graphene-light interaction in a broad spectral range. The study results may indicate several new breakthroughs on the theories and technologies about graphene optoelectronics. To achieve these, following major studies will be carried out: (1) Physical phenomena and mechanism of the interactions between graphene and slow-light in PPC waveguides; (2) Enhancement effect on graphene’s photoelectric conversion based on the slow-light in PPC waveguides and its applications; (3) Mechanism of active modulations on slow-light in PPC waveguides by graphene and its applications. The key scientific problems to be solved are the theoretical model of the coupling between graphene and slow-light in PPC waveguides, and designs for high-performance graphene optoelectronic devices. The results obtained from above studies can not only help reveal novel phenomena in the coupling system of graphene and slow-light, but also promise developments of high-performance modulators and photodetectors, providing theory and experiment fundamentals for the new research and applications of graphene optoelectronics.

近年来，基于石墨烯优异光电特性的石墨烯光电子学已成为国际研究热点，其进展有助于揭示二维量子受限体系的新颖光学效应和开发高性能光电子器件。但石墨烯的单原子层厚度严重限制了其与光场的有效相互作用，使石墨烯光电子学的发展受到挑战。本项目旨在研究平板光子晶体（PPC）波导中慢光与石墨烯相互作用的物理机理，探索一种宽谱带、高效率增强石墨烯与光场相互作用的新手段，并在相关理论和技术上取得系列原创性成果。拟开展的主要研究有：①PPC波导中慢光与石墨烯相互作用现象及物理机理；②基于PPC慢光波导的石墨烯光电转换增强效应及应用；③石墨烯主动调控PPC波导中慢光特性的机制及应用。拟解决的关键科学问题是：PPC波导中慢光耦合石墨烯的理论模型和高性能石墨烯光电子器件的设计。研究成果不仅有助于揭示慢光耦合石墨烯系统中的新现象，还有助于发展新的高性能调制器和探测器，为石墨烯光电子学的研究和新应用提供理论和实验基础。

以石墨烯为代表的二维材料由于具有优异的光电特性，对其研究有助于揭示二维量子受限体系的新颖光学效应和开发高性能光电子器件。然而，二维材料仅具有单层或少层原子厚度，严重限制了其与光场有效相互作用，使二维材料光电子学的发展受到挑战。本项目围绕如何实现高效率、宽谱带增强光与二维材料相互作用展开研究，重点研究了二维材料与光子晶体慢光波导集成后所表现出的强烈光学响应，同时将二维材料与微纳光纤、光子晶体微腔等光子结构结合实现全光非线性器件及高性能传感器。. 取得结果如下：①制备和表征光子晶体慢光波导，得到带宽约为10纳米、群速度约为c/30的慢光模式，并在集成石墨烯后借助其光热效应验证了慢光增强吸收，实现了低功耗的热光非线性调制；在慢光波导上集成少层硒化镓实现了高效二次谐波，验证了慢光增强因子超过50倍；②将石墨烯与具有泄漏模的光纤波导集成，借助石墨烯的优良光热效应实现了多种全光主动器件，包括全光相移器（230 mW泵浦功率下相移超21π）、可调谐光纤光栅（调谐效率1.7 pm/mW）、微环腔等，并基于这些器件实现了光开关（消光比23dB）、光学双稳态、快慢光调节（210皮秒的群速度减慢和117皮秒的群速度加快）等全光效应；③将少层硒化镓二维材料集成于光子晶体微腔，实验上首次实现了微瓦量级连续激光泵浦的二维材料中二次谐波，获得微腔增强因子超过600倍；④借助光子晶体微腔中局域模场及二维材料的比表面积大、吸附能力强及反应活性高等特点，制备并原理性实现了高性能湿度、有机气体传感器，具有高灵敏度、高重复性、超快响应速度（百毫秒）；⑤实现了一种光子晶体微腔辅助的频率上转换探测器；⑥提出了一种新型聚合物平板光子晶体微腔制备工艺并基于其实现高性能应变传感器。. 项目所实现的利用光子结构增强二维材料与光场相互作用的结果不仅有助于揭示二维材料中新颖光学现象，还为高性能二维材料光电子器件开发提供思路。