具有四模式的低串扰及大群时延多芯微结构光纤的设计  

Analysis of a novel four-mode micro-structured fiber with low-level crosstalk and high mode differential group delay

作　　者：徐闵喃 周桂耀[1,2] 陈成[1,2] 侯峙云[1,2] 夏长明[1,2] 周概 刘宏展[1,2] 刘建涛[1,2] 张卫[1,2] 

机构地区：[1]华南师范大学广东省微纳光子功能材料与器件重点实验室广东高校特种功能光纤工程技术研究中心,广州510006 [2]广东省微结构功能光纤与器件工程技术研究中心,广州510006

出　　处：《物理学报》2015年第23期127-133,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61377100;61575066);国家自然科学基金重大仪器专项项目(批准号:61527822);高等学校博士学科点专项科研基金(批准号:20134407120014);广东省自然基金项目(批准号:S2013040015665)资助的课题~~

摘　　要：针对光纤空分复用及模分复用传输系统中大容量和耦合串扰问题,本文提出了一种具有四模式特性低串扰及大群时延的大容量多芯微结构光纤,通过有限元法计算该光纤电磁场分布进而对其他参数进行分析.结果表明:合理的选定光纤结构参数,可使得该光纤在C+L波段内同时实现19芯的LP_(01),LP_(11),LP_(21),LP_(02)四个偏振模式的传输.同时,利用空气孔对电磁场较好的隔离作用来优化芯间串扰并得到较大的模式差分群时延及较为平坦的色散.此外,这种结构的光纤制作简单,在短距离大容量的信息传递系统中具有重要应用.In this paper,a novel four-mode micro-structured fiber with low-level crosstalk and high mode differential group delay is proposed to solve the large transmission capacity and low crosstalk problems in the mode division multiplexing system.Electromagnetic field distribution,crosstalk,mode differential group delay and dispersion of the fiber are studied by using the full-vector finite element method.To determine the particular parameters of the micro-structured fiber,the performances of the inter-core crosstalk and mode differential group delay（MDGD） are considered comprehensively under different conditions.Simulation results show that this fiber can support four-mode transmission with 19 cores over the whole C＋L wavelength band when the cladding diameter is 125 μm.The inter-core crosstalks of LP01 mode,LP11mode,LP21 mode and LP02 mode are-131.01,-96.36,-63.32,-49.96 d B respectively and the mode differential group delays are high as all of them are more than 160 ps/m.Therefore,compared with the previous work,this fiber has the lower inter-core crosstalk and larger MDGD.Owing to the large index difference between core and cladding,the neff differences between the linearly polarized modes are all larger than 10-3 across the whole operating wavelength band,which is beneficial to low inter-mode corsstalk.Furthermore,the fabrication of this fiber is simple due to its preforming only need stacking technique to adjust the hexagonal structure geometry size without complex modified chemical vapor deposition process involved.The designed fiber can be used in short-distance and large-capacity transmission system,and it has potential applications in making the corresponding high power devices.

关 键 词：微结构光纤 多芯光纤 低串扰 大群时延 

分 类 号：TN253[电子电信—物理电子学]