低串扰高密度复合型多芯光子晶体的光纤理论研究  

Theoretical Study on Low Crosstalk High-Density Composite Multi-Core Photonic Crystal Fiber

作　　者：张函 汪国瑞 张继伟 李曙光 闫欣 王方 张学楠 程同蕾 Zhang Han;Wang Guorui;Zhang Jiwei;Li Shuguang;Yan Xin;Wang Fang;Zhang Xuenan;Cheng Tonglei(State Key Laboratory of Process Industry Integrated Automation,School of Information Science and Engineering,Northeast University,Shenyang,Liaoning 110004,China)

机构地区：[1]东北大学信息科学与工程学院流程工业综合自动化国家重点实验室,辽宁沈阳110004

出　　处：《中国激光》2021年第7期149-156,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2019YFB2204001);国家自然科学基金(61775032,11604042);教育部基本科研业务费(N180406002,N180408018,N2004021);111引智基地(B16009)。

摘　　要：将传统阶跃型光纤与光子晶体光纤结构相结合,提出并研究了复合型7芯光子晶体光纤。该光纤可在有效降低芯间串扰的同时增大光纤的纤芯密度,为实现大容量、长距离的光纤空分复用技术提供了新思路。通过理论分析了掺锗纤芯以及纤芯周围空气孔的参数,结果表明,在1550 nm波长处中间纤芯与外围6个纤芯间的串扰低于-60 dB/km,有效模场面积大于90μm^(2),芯间距最小为31.7μm。以31芯光纤为例,其相对纤芯复用因子可达到8.78,可用于低串扰、大容量、长距离传输的网络系统,对用于空分复用的多芯光纤设计具有指导意义。Objective In this paper,a composite 7-core photonic crystal fiber is designed and investigated theoretically.By combining the step-index structure and the photonic crystal fiber structure,the inter-core crosstalk of the proposed fiber can be effectively reduced and the core density could be greatly improved,which provides a new opportunity for the realization of large-capacity and long-distance optical fiber space division multiplexing technology.The parameters of the fiber structure are analyzed by the theoretical analysis and research.At the wavelength of 1550 nm,the crosstalk between the intermediate core and the peripheral core is lower than-60 dB/km,the effective mode field area is over 90μm^(2),and the core spacing is up to 31.7μm.When increasing the core number to 31,the relative core multiplexing factor can reach 8.78,which effectively improves the core density.This work has a guiding significance for the design of multi-core photonic crystal fiber for space division multiplexing technology and can be used in the network system which demands low crosstalk and large capacity for long distance transmission.Methods Based on the theory of mode coupling and power coupling,the finite element method is used to calculate the crosstalk characteristics of the fiber.The cross-section and refractive index distribution of the composite multi-core photonic crystal fiber proposed in this paper are shown in Fig.1.In order to suppress the crosstalk and nonlinear effects in the fiber,analyze the influence of the fiber structure parameters on the crosstalk and the effective mode area of each core,and select a set of initial structure parameters,as shown in Table 1,the theoretical analysis is at the wavelength of 1550 nm,the crosstalk and the effective mode area variation law of L=1 km in fiber propagation.In order to show the advantages of composite multi-core photonic crystal fiber in suppressing XT when the core spacing is small,this paper compares the designed composite 7-core PCF with the traditional step multi-core f

关 键 词：光纤光学 多芯光纤 空分复用 串扰 

分 类 号：TN253[电子电信—物理电子学]