基于化学气相沉积方法的石墨烯-光子晶体光纤的制备研究

Synthesis of photonic crystal fiber based on graphene directly grown on air-hole by chemical vapor deposition

本文利用常压化学气相沉积方法,在光子晶体光纤内孔壁上直接生长石墨烯薄膜,实现了石墨烯-光纤复合材料的直接制备.研究发现光纤中石墨烯层数和缺陷主要受生长温度、生长时间以及甲烷流量等参数影响.拉曼光谱和扫描电子显微镜等表征结果表明:石墨烯在光子晶体光纤孔内的生长均匀性良好,适当的高温、较长的生长时间以及合适的甲烷流量有利于生长高质量的石墨烯.石墨烯-光子晶体光纤复合材料的制备,对基于光纤平台的石墨烯光电器件的研究、开发和应用有着重要的推动作用,也为石墨烯全光纤集成应用提供了新的思路.

The integration of fiber with graphene has greatly expanded the two-dimensional functional materials in the field of photonics research.However,the growth method by using chemical vapor deposition with metal catalytic substrateis limited to the fabrication of a graphene-fiber composite due to inevitably transferring graphene flakes onto the optical fiber surface.In order to fully achieve the interaction between light and graphene material,optical fibers have to be treated with special structure,which greatly damages the fiber structure,resulting in inefficient and harmful manufacturing strategy for the mass production.In this paper,a graphene-photonic crystal fiber(G-PCF)composite is prepared by atmospheric chemical vapor deposition(APCVD),which can directly grow monolayer and multi-layer graphene into the air-hole of photonic crystal fiber.Furthermore,we randomly break a G-PCF and then conduct an electron microscope(SEM)test at the fractured section.It is obvious that a tube-like graphene protruding out of one hole in the fractured area of the G-PCF is observed,thus further demonstrating that a monolayer graphene is grown on the inner hole walls of the PCF as shown in Fig.2.By changing the process parameters such as growth temperature,duration and gas flow rate of carbon source,the law of the influence of different parameters on the graphene layers is explored.In addition,the uniformity of graphene and defects in the graphene-photonic crystal fiber(G-PCF)are experimentally analyzed.As illustrated in Fig.7,a 4-cm-long uniform graphene-photonic crystal fiber sample is achieved by controlling the gas flow rate,growth time and the growth temperature.The APCVD method of directly growing graphene onto the inner hole walls of the PCF is simple and effective.The flexible structure and optical control enable the G-PCF to have great potential applications in all-optical devices and photonics.The development of high-quality graphene synthesis and opto-electronics technology ensures its compatibility with the integrated electronics platform and existing optical fiber systems.Moreover,our results will pave the way for 2D materials and optical fiber applications,providing a new idea for the application of graphene to the integration of all-optical fibers.