石英基L波段扩展掺铒光纤及其放大性能  

Silicate-based erbium-doped fiber extended to L-band and its amplification performance

作　　者：何乐 褚应波 戴能利 李进延 He Le;Chu Ying-Bo;Dai Neng-Li;Li Jin-Yan(Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学,武汉光电国家研究中心,武汉430074

出　　处：《物理学报》2022年第15期137-143,共7页Acta Physica Sinica

基　　金：国家自然科学基金青年科学基金(批准号:61805093)资助的课题。

摘　　要：掺铒光纤放大器的增益带宽是限制光纤通信系统传输容量提升的重要因素.受铒离子激发态吸收所限,常规L波段掺铒光纤难以实现更长波段的带宽扩展.本文基于改进的化学气相沉积工艺成功制备了P/Al共掺石英基L波段扩展掺铒光纤,研究了共掺离子对于铒离子4I13/2能级到4I9/2能级激发态吸收的影响.通过分别搭建单级前向泵浦和多级的放大结构,测试了其宽带放大性能.基于前向980 nm泵浦的单级结构,当输入信号功率为–9 dBm,泵浦功率为530 mW时,该光纤在1625.3 nm处增益达10.5 dB,最大噪声指数为5.9 dB.多级放大结构下,该光纤在1625.3 nm处增益可达23.4 dB.实验结果表明P/Al共掺石英基掺铒光纤可以有效抑制铒离子的激发态吸收,为进一步扩展L波段增益带宽提供了强有力的可行方案.With the continuous development of mobile internet,cloud computing,Internet of things,and 5G,the annual growth rate of the existing communication transmission capacity is far from meeting the growing demand.The gain bandwidth of L-band erbium-doped fiber amplification(EDFA) has become the main factor for limiting the bandwidth extension.Owing to its negative effect on the gain and noise figure after 1580 nm,the excited state absorption(ESA) is regarded as a key factor that directly limits the L-band expansion of EDFA.If the ESA coefficient has the same value as the stimulated emission coefficient,the net gain coefficient becomes zero.At the same time,signal amplification cannot be obtained no matter how the pump power and fiber length are adjusted.Improvements from the perspective of erbium-doped fibers,such as changing the host glass and doping components,are extremely beneficial to L-band extension based on simple amplifier configurations.In the present study,an erbium-doped fiber extended to the L-band is fabricated by the modified chemical vapor deposition technology.The saturation curve of the fiber is measured,and then the rate of clustering is obtained.In addition,the absorption coefficient and emission coefficient of the fiber are tested by the truncation method,then the effect of ESA is studied.We demonstrate that modulating the ratio of P to Al in the fiber core has a significant inhibitory effect on the ESA of Er3+.To better characterize the amplification performance of the fiber,a single-stage and a multi-stage amplifier system are built respectively.At an input signal injection with a power value of –9 dBm,the fiber exhibits a gain of 10.5 dB with a maximum noise figure of 5.9 dB at 1625.3 nm,based on a single-stage amplifier system under a 980 nm forward-pumping excitation.It indicates that the amplification performance of the fiber in the long-wavelength has improved,which is consistent with the conclusion of the suppression effect on the ESA.By optimizing the fiber length for the first,second an

关 键 词：光纤通信 L波段扩展掺铒光纤放大器 掺铒光纤 激发态吸收 

分 类 号：TN929.11[电子电信—通信与信息系统] TN722[电子电信—信息与通信工程]