表面芯光纤及其石墨烯被覆功能器件研究

This project proposes a kind of surface core fiber (SCF) and graphene-based SCFs devices. Comparing to the traditional optical fibers, the evanescent field leaked to the external will be stronger in a SCF and it will be more convenient to make chemical modification and physical changes on the core surface because the core of the fiber is close to the boundary of the cladding. Since the SCF is drawn directly, this fiber has many advantages including low insertion loss and low surface scattering loss compared with other fibers with extra processed surface. Graphene is a potential material in integrated fibre optic devices due to its unique photoelectric characteristics. This project is going to study the optical transmission mechanism of the SCF. The graphene-based SCF polarizer and fiber grating devices are proposed. The mechanism and performance parameters of the devices will be analyzed by using the finite element method. We will cover the surface of a SCF with graphene in practice. The performance test of the devises will be completed. We will realize on-line broadband TE/TM polarizers or tunable bandwidth polarizers. This project not only adds a new member to the optical fiber family, but also expands graphene's applications in fiber devices. With further researches and application needs, new devices based on SCF will be further researched and wildly applied in integrated all-fiber devices, optical fiber communications, fiber sensing and so on. Therefore the researches of graphene-based SCFs devices show important significance for promoting development of new optical fiber devices in China.

本项目提出一种表面芯光纤及其石墨烯被覆功能器件。光纤纤芯位于包层边界，泄漏到外界的倏逝场会较强，也使在纤芯表面做化学修饰和物理改变都非常方便。光纤结构直接拉丝成形，与额外加工光纤表面相比，其散射损耗小，器件插损会降低。石墨烯因具有独特的光电特性，使其成为纤维集成光器件中非常有潜力的材料。本项目拟深入研究该光纤的导光机理，利用有限元法设计石墨烯被覆表面芯光纤偏振器和光纤光栅器件，分析器件机理及性能参数，在此基础上在纤芯表面被覆石墨烯，实验研制器件并进行性能测试，实现TE/TM偏振宽带和窄带可调在线光纤偏振器。本项目既为光纤家族增添了新的成员，也拓展了石墨烯在光纤器件中的应用。随着研究的深入和应用的需要，表面芯光纤新元件必将在全光纤集成器件、光纤通信、光纤传感等领域获得进一步的发展和广泛的应用。因此，开展石墨烯被覆表面芯光纤功能器件的探索与研究，对促进我国新型光纤器件的发展具有十分重要的意义。

本项目提出了新型表面芯光纤和D形光纤及其石墨烯被覆功能器件。对于表面芯来说，光纤纤芯位于包层边界，D形光纤也类似，纤芯能直接与外界环境接触，所以泄漏到外界的倏逝场会较强，也使在纤芯表面做化学修饰和物理改变都非常方便。首先利用有限元法对表面芯光纤和D形光纤被覆石墨烯偏振器进行了理论研究，分析了器件机理以及优化了各类性能参数，理论结果显示2mm长表面芯被覆石墨烯可以实现消光比为25dB的起偏器，2.5mm长D形光纤被覆石墨烯起偏器消光比可以达到40dB。基于理论研究的基础，我们对表面芯和D形光纤也分别进行了被覆石墨烯的实验研究。根据不同的参数需求我们能很好的完成对表面芯光纤和D形光纤制备，也熟练掌握了单层石墨烯的被覆以及转移技术，最终得到了消光比为4dB的表面芯被覆石墨烯起偏器和36dB的D形光纤宽带起偏器。研究结果表明表面芯光纤与D形光纤新元件必将在全光纤集成器件、光纤通信、光纤传感等领域获得进一步的发展和广泛的应用。