基于倏逝场耦合的石墨烯波导光传输相位特性仿真与实验研究

摘要

石墨烯材料应用到各种光波导器件中正成为新一代光子器件的重要发展方向之一，目前基于石墨烯的光纤和集成光子器件研究越来越受到国内外的重视。本文建立了一种由微纳光纤耦合光倏逝场，并在石墨烯薄膜中传输的模型。通过有限元分析法，研究了光在这种石墨烯波导中传输光场的强度分布和相位特性，并通过实验进行了验证。结果表明，沿着微纳光纤-石墨烯光波导传播的倏逝场的强度分布和相位均受石墨烯材料作用，石墨烯材料能有效聚集和导行波导中传输的高阶模，在单位传输长度上具有更密集的等相位面。本文提出了一种利用微纳光纤耦合光倏逝场研究石墨烯相位响应特性的新方法，对基于石墨烯波导的新型调制器、滤波器、激光器和传感器等光子器件的设计和应用具有一定的参考意义。%The applications of graphene-based optical waveguide devices have been demonstrated to be one of the important directions of development for a new generation of photonic devices, and the research of graphene-based optical fiber and integrated photonic devices has attracted a great deal of attention at home and abroad. In this paper, a graphene planar optical waveguide is proposed which could transmit light by the evanescent field coupling with a microfiber. Finite element method is adopted to simulate the optical field intensity distribution and phase features of light propagating along graphene planar optical waveguide, and an experiment is performed to verify these features. Experimental results show that the transmission distribution and phases of the evanescent field are modulated by graphene obviously, it could effectively gather and transmit the high-order modes, exhibiting denser equal-phase faces on unit propagating length. In this work, we propose a new method in which the microfiber is adopted to investigate the transmission phase feature of graphene by evanescent wave coupling, which could be used as references for the design and application of graphene-based optical devices, such as modulator, filter, laser and sensor.