基于包层泵浦的4模掺铒光纤放大器的增益均衡  

Gain Equalization of 4-Mode Erbium-Doped Fiber Amplifier Based on Cladding Pump

作　　者：阮江冉 裴丽[1,2] 郑晶晶[1,2] 王建帅[1,2] 徐文轩 李晶[1,2] 宁提纲[1,2] Ruan Jiangran;Pei Li;Zheng Jingjing;Wang Jianshuai;Xu Wenxuan;Li Jing;Ning Tigang(Key Laboratory of All Optical Network and Advanced Telecommunication Network,Ministry of Education,Beijing,Jiaotong University,Beijing 100044,China;Institute of Lightwave Technology,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]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 [2]北京交通大学光波技术研究所,北京100044

出　　处：《光学学报》2022年第4期7-14,共8页Acta Optica Sinica

基　　金：国家重点研发计划课题(2018YFB1801003)。

摘　　要：少模掺铒光纤放大器(FM-EDFA)是长距离模分复用(MDM)光纤通信系统中必不可少的中继器件,其模间增益差(DMG)直接影响系统的通信质量。为实现FM-EDFA中不同模式的增益均衡,在包层泵浦条件下,提出了一种支持4模式组的铒离子分层掺杂环芯光纤,且无需考虑泵浦模式。对环芯光纤进行了设计,通过控制纤芯中心凹陷和外部凹槽折射率引起的模式分布变化,结合合理设计的铒离子掺杂半径及浓度来减小DMG。结果表明,当铒离子在环芯内分双层掺杂时,最大DMG从0.8 dB(单层均匀掺杂)降低至0.44 dB(环芯双层)。在全C波段(1530~1565 nm)中,4模式组增益超过22 dB,最大DMG低于0.45 dB,噪声系数小于5.3 dB。包层泵浦结构有利于实现FM-EDFA的全光纤连接,易于与MDM通信系统集成,并发挥掺铒光纤放大器的全光补偿优势。Few-mode erbium-doped fiber amplifier(FM-EDFA)is a necessary repeater for long-haul mode division multiplexing(MDM)optical fiber communication systems,and its differential modal gain(DMG)directly affects the communication quality of the systems.In order to realize the gain equalization of different modes in FM-EDFA,a layered erbium ion doped ring core fiber supporting 4-mode group in cladding-pumped condition is proposed,and the pump mode is not considered.The ring core fiber is designed,and the DMG is reduced by controlling the change of the mode distribution induced by the central recess and outer groove refractive index of the core,combining with the well-designed doping radius and concentration of erbium ion.The results show that when erbium ions are doped in double layers in the ring core,the maximum DMG is reduced from 0.8 dB(single layer and uniform doping)to 0.44 dB(double layers in the ring core).In the full C band(1530--1565 nm),the gain of the 4-mode group is higher than 22 dB,the maximum DMG is less than 0.45 dB,and the noise figure is less than 5.3 dB.The cladding pump structure is conducive to the realization of all-fiber connection of FM-EDFA,is easy to integrate with MDM communication system,and gives full play to the all-optical compensation advantages of erbium-doped fiber amplifiers.

关 键 词：光通信 光纤通信 少模掺铒光纤放大器 环芯光纤 增益均衡 包层泵浦 

分 类 号：TN929.11[电子电信—通信与信息系统]