支持10个模式的空气孔辅助型偏振保持少模光纤  

Air Hole-Assisted Polarization-Maintaining Few-Mode Fiber Supporting 10 Modes

作　　者：薛宇勃 李海粟 刘亚静[1] 揭璐 张宇[1] 姜有超 任国斌[1] 裴丽[1] Xue Yubo;Li Haisu;Liu Yajing;Jie Lu;Zhang Yu;Jiang Youchao;Ren Guobin;Pei Li(Key Laboratory of All Optical Network and Advanced Telecommunication Network of EMC,Institute of Light leave Technology,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学光波技术研究所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17期83-94,共12页Chinese Journal of Lasers

基　　金：国家重点研发计划(2018YFB1801003);国家自然科学基金(62075007,62005013)。

摘　　要：提出了一种空气孔辅助型偏振保持少模光纤,在椭圆环芯中心引入一个椭圆形空气孔,并在水平和竖直方向分别引入4个不同尺寸的圆形空气孔,以提高模式间的有效折射率差,实现多阶模式间无串扰偏振保持传输。通过数值仿真研究了4个圆形空气孔的尺寸和位置、环形纤芯的尺寸和椭圆率以及椭圆形空气孔的尺寸和椭圆率对偏振保持传输性能的影响。经过参数优化设计,所提光纤在1520~1600nm波段内满足所有相邻模式间的有效折射率差Δn_(eff)均高于1.0×10^(-4),色散为17.6~51.3ps/(nm·km)。所提光纤在大容量空分复用通信技术中具有良好的应用前景。Objective With the emerging social media age,mobile communications,and cloud computing,the ever-increasing consumer demand for network capacity has exploded,which has brought enormous challenges to optical fiber communication systems.To enhance data transmission and all-optical network switching capabilities,an upgrade of the optical fiber is imperative.Multiplexing technologies like wavelength-division multiplexing and time-division multiplexing are currently being employed to expand the capacity of traditional single-mode fiber(SMF)based optic-transmission systems.However,the SMF has merged all degrees of freedom of light(including amplitude,phase,frequency,and polarization),achieving the nonlinear Shannon limit’s maximal capacity.To solve the capacity barrier,space-division multiplexing(SDM)transmission has been studied in the recent decade.SDM technology has two efficient solutions:multicore fiber(MCF)and few-mode fiber(FMF).The MCF integrates numerous independent cores into a single fiber for parallel transmission and the multicore design increases manufacturing costs.Due to the intermode coupling,it is challenging to attain high core density.For FMF,each mode is a channel for independent signal transmission,which increases the single fiber’s transmission capacity.In particular,polarization-maintaining FMF supporting several orthogonally polarized modes with a large separation of effective indices would realize low-crosstalk high-capacity communications.In this study,we report an air hole-assisted polarization-maintaining FMF,where high birefringence is attained using air holes assisted structure.The numerical simulation results revealed that a low-index core fiber can realize 10 polarization-maintaining modes.In the future,the proposed fiber can find applications in large-capacity SDM communication technology.Methods The numerical model,i.e.,the FMF’s cross-sectional structure,was established by exploiting COMSOL Multiphysics based on the complete vector finite element approach.The perfectly matched l

关 键 词：光纤光学 偏振保持 空气孔辅助 空分复用 少模光纤 

分 类 号：TN252[电子电信—物理电子学]