基于矢量模式的全光纤模式选择耦合器  

All-Fiber Mode Selective Coupler Based on Vector Modes

作　　者：郭英豪 刘美 汤敏 任文华[1,2] 任国斌[1,2] Guo Yinghao;Liu Mei;Tang Min;Ren Wenhua;Ren Guobin(Institute of Lightwave Technology,Beijing Jiaotong University Beijing,100044,China;Key Laboratory of All Optical Network and Advanced Telecommunication Network of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学光波技术研究所,北京100044 [2]北京交通大学全光网络与现代通信网教育部重点实验室,北京100044

出　　处：《中国激光》2022年第3期83-91,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(62075008)。

摘　　要：提出了一种基于矢量模式的全光纤模式选择耦合器,该耦合器由一个单模光纤和一个空气芯环形少模光纤组成。基于耦合模理论,研究了不同参数对耦合特性的影响,并且详细分析了纤芯间距对高阶模式间的串扰和工作带宽的影响。结果表明,在相位匹配条件下,该矢量模式选择耦合器可高效地实现基模与特定高阶模的耦合;通过改变耦合器的纤芯间距,可以调控模式间的串扰和工作带宽之间的平衡关系。该模式选择耦合器可直接实现基模到高阶矢量模式的高效转换,能降低光通信系统的插损和复杂度,在光纤激光器、光镊和模分复用系统中具有潜在的应用价值。Objective Mode division multiplexing has gained considerable attention for its ability to increase the communication capacity.The individual mode in a fiber can act as a separate communication channel in the mode division multiplexing.Mode conversion devices are the key elements for mode division multiplexing.The fiber-based mode conversion devices mainly include long-period fiber gratings,fiber Bragg gratings,photonic lanterns,and mode selective couplers.Compared with other mode conversion devices,the mode selective coupler has inherent low crosstalk and high mode selectivity.However,the researches on mode selective couplers are mainly focused on the conversion of linear polarization modes by far.There are few reports on the conversion of vector modes,and the relationship between crosstalk among high order vector modes and working bandwidth has rarely been explored.In this paper,an all-fiber mode selective coupler based on vector modes is proposed.This vector mode selective coupler can directly realize the coupling between the fundamental mode and the high order vector modes with a high conversion efficiency.Moreover,there is a trade-off between depressing the crosstalk and extending the working bandwidth of the vector mode selective coupler.This work can find applications in the fields of fiber lasers,optical tweezers,and mode division multiplexing systems.Methods In this paper,an all-fiber mode selective coupler based on the vector modes is proposed,which consists of a single mode fiber and an air-core ring few mode fiber.Firstly,the phase matching condition means that two modes have the same mode propagation constant or mode effective index at a certain working wavelength.When the fundamental mode in the single mode fiber and the high order modes in the air-core ring few mode fiber satisfy the phase matching condition,the energy of the fundamental mode is fully coupled into the high order modes.We change the core radius of the single mode fiber to satisfy the phase matching of two modes at a certain working w

关 键 词：光纤光学 模分复用 相位匹配 矢量模式 模式选择耦合器 

分 类 号：TN253[电子电信—物理电子学]