基于石墨烯超表面的光学双稳态研究

光学双稳器件由于能实现对光波非线性特性的操控而被广泛应用在光开关、光限幅、光逻辑器件及光调制器等广泛的领域。但是，高阈值、不易主动调控和窄带响应等都限制了光学双稳器件的应用。石墨烯由于其独特的光电性质使得它在各种光电子器件中得到了极大的关注，尤其是石墨烯超大的三阶非线性极化率（高于介质的5-6个数量级），使其在非线性光学和光子学方面具有潜在的应用价值。本项目将重点研究石墨烯超表面结构中非线性效应增强和调控机理，研究光学双稳态的形成机理和可控的光学双稳态行为及其在光开关等领域的应用，设计低阈值、高速、高效率和低功耗的双稳态和光开关器件。石墨烯超表面结构的双稳特性和光开关行为将为未来的集成光学和数字全光网络提供基本模块。

Optical bistability devices are widely used in the areas of optoelectronics such as optical switching, optical limiting, optical logic device and optical modulator due to their ability of manipulating optical nonlinear characteristics. However, high threshold value, not easy to control dynamically and band limited have limited the practical application of optical bistability devices. Graphene has unique properties that make it attractive for a range of optoelectronic devices. In particular, experiments and theories show that the graphene sheets possess large nonlinear susceptibilities and exceed values for typical dielectrics by 5-6 orders of magnitude, which makes graphene a promising material for nonlinear optics and photonics. This project will investigate the nonlinear enhancement and adjusting mechanism in graphene-based metasurface structures, and further investigate the basic principle on how the optical bistability forms and discuss theoretically the controllable optical bistable and optical switching behaviors, and their applications in optical switching. Our purpose is in order to design a kind of optical bistability and optical switching with low switching threshold, high speed, high efficiency and low power consumption based on graphene metasurface structures. Graphene-based metasurface optical devices with intrinsic optical bistability allow us to explore the promise of using such elements as the building block of future integrated optics and digital all-optical circuitry.