【作者】 杨芳；

【导师】 唐明；

【作者基本信息】 华中科技大学 ， 光学工程， 2014， 硕士

【摘要】 当前光通信网络正朝着大规模、大容量的方向迅速发展，传输带宽所面临的巨大增长压力对通信光纤提出了更高的要求。在此背景下，基于空分复用的多芯光纤逐渐受到关注，相比传统单芯光纤和光子晶体光纤，多芯光纤充分利用了空间维度，可以有效解决传统单模光纤的理论传输容量极限导致的容量紧缩问题。而大容量传输系统要求多芯光纤具有低串扰大模场面积等光学特性，基于此本论文对多芯光纤的结构和光学特性进行了研究与分析，主要内容为：研究多芯光纤与单模光纤的耦合系统，为后续的系统传输实验做好准备。通过对比多种耦合系统选取最适用、可行的方案——对单模光纤的包层进行化学腐蚀至与多芯光纤匹配的尺寸，再进行毛细管内堆积，该耦合器件简便可行、成本低、规格小，便于推广；利用模式耦合理论和功率耦合理论，详细研究了多芯光纤中的串扰特性，并利用matlab进行相应的理论计算，其中功率耦合理论能够更准确地描述多芯光纤中的串扰，另外特别分析了弯曲和沟道结构对串扰的影响；以七芯光纤为例进行多芯光纤结构设计，并分别采用光束传输法和有限元法模拟仿真了多芯光纤中各结构参量对芯间串扰和有效模场面积的影响关系，并进行参量优化，设计出在理论上实现串扰小于-45dB，模场面积大于130μm2的多芯光纤结构。并使用已拉制出的多芯光纤使用偏芯熔接方法进行串扰实验及其他光学性能参数测试。更多还原

【Abstract】 Currently, optical communication network is developing rapidly towards large scaleand large capacity, then higher request in optical fiber communication system is put forward,faced with the huge pressure of transmission bandwidth. Under this background, multi-corefibers (MCFs) based on space division multiplexing (SDM), can overcome the congestionproblem caused by the theoretical transmission limit of single mode fiber. Multicore fiberscannot be used in the transmission system only if they have the optical properties of lowcrosstalk and large effective mode field area. In this thesis, the structure and the opticalperformance of multi-core fiber for communication system are systematically researched andanalyzed.In the first section, after the investigation on multi-core optical fiber and single modeoptical fiber coupling systems, the characteristic of each is summarized. Then by comparingthe mentioned coupling systems, the most suitable and feasible method is selected tomanufacture, that is, using the chemical corrosion to reduce the single-mode optical fibers’cladding to the size that would be matched with the multi-core optical fiber, thenaccumulating the single-mode fibers in the capillary.In the second section, the coupled theory in multi-core fiber is studied in detail, and byutilizing the method of mode coupling theory and power coupling theory, the crosstalkproperty in multi-core optical fiber is calculated by the math-tool matlab.Finally, taking seven-core optical fiber for instance, multi-core fiber structure design isundertaken, and the beam propagation method (BPM) and finite element method (FEM) areused respectively for simulating the influence of multi-core optical fiber structure parameterson crosstalk and effective mode field areas. Then the structure is comprehensively optimized,theoretically achieving optical properties with low crosstalk less than-45dB and large arealarger than130μm2. In addition, the multi-core fibers which have already drawn are taken toproceed experimental test of crosstalk and other important optical parameters, in the processof which, offset splice is exploited for the coupling of multi-core fiber and single mode fiber.更多还原