【作者】 李军；

【导师】 郭玉彬；

【作者基本信息】 吉林大学 ， 通信与信息系统， 2004， 硕士

【摘要】 在波分复用（WDM）光纤通信技术中，为了提高码率和充分利用 1.55μm 波段的带宽，研究波长精确、性能优良的激光源一直是人们密切关注的课题。光纤光栅激光器的工作波长能通过光纤光栅精确确定，如 DBR 型 Er3+/Yb3+共掺光纤激光器，近年来在国外得到迅猛的发展，但目前国内对 Er3+/Yb3+共掺光纤激光器的有关报道很少，研究尚处于起步阶段。 随着未来全光纤通信器件不断向小型化，集成化发展，要求所用光纤激光源越短越好。同掺铒光纤激光器相比，Er3+/Yb3+共掺光纤激光器不但简化了光纤光源的结构，有效缩小了光源的结构尺寸，而且器件紧凑、小巧灵活，提高了其稳定性和实用性。该光纤激光器以其自身具有的诸多优势成为全光通信系统中一个研究热点，是适用于大容量全光纤通信系统的一种很有竞争实力、非常有前途的新型光源或信息源。 论文提出的 Er3+/Yb3+共掺光纤激光器以 1064nm Nd:YAG 激光器作为泵浦源，在国内属首次报道，填补了国内空白。设计中运用了原理设计与分析，装置建立和实验测量相结合的研究方法，以下是本文在该光纤激光器上完成的研究内容： 1. 在分析比对多种现在流行的方案的基础上，提出自己切实可 行的 DBR 型 Er3+/Yb3+共掺光纤激光器设计方案； 2. 通过大量检索，广泛收集资料及精心的原理设计，并计算输 出激光的各技术参数； 3. 在光纤光栅激光器原理设计的基础上，积极筹备建立实验装 置所需的设备，仪器和各种元器件并搭建实验装置； 4. 对所用 Er3+/Yb3+共掺光纤的长度进行了优化，找到了该种掺 杂光纤的最佳长度； 5. 对其进行调试并利用仪器设备对主要技术指标进行测定，然 83<WP=89>后验证其是否达到原理设计要求并进行综合评价。 本文介绍的 Er3+/Yb3+共掺光纤激光器采用长春新产业光电技术有限公司生产的 MIL-Ⅱ型号的 1064nmNd:YAG 激光器作为泵浦源。其(F-P)谐振腔由一对 Bragg 波长相同的光纤光栅 1 和 2 熔接在一段4.42m 长用以提供光增益的 Er3+/ Yb3+共掺光纤两端构成。与单纯掺铒 DBR型光纤激光器相比，所用增益介质长度大大缩短。采用宽带高反射光纤光栅 1 和用于耦合输出的窄带光纤光栅反射器 2 作为腔镜，其间接入长度为 4.42m 的 Er3+/Yb3+共掺光纤以提供光增益。1064 nm 泵浦光由1064nm 泵浦耦合尾纤导出,经一个 1064/1550 nm WDM、一个(1×2,99/1) 1064/1550nm 光纤耦合器的 1、2 端口和光纤光栅 1 耦合进入谐振腔，在 Er3+ /Yb3+共掺中形成粒子数反转产生受激发射光，经过窄带光纤光栅 2 和双光隔离器(Dual-ISO)得到所需波长的激光输出形成 DBR 型 Er3+/Yb3+共掺光纤激光器。 该光纤激光器的开发研制由吉林省科技发展计划项目——“基于光纤 Bragg 光栅的 Er3+/Yb3+共掺杂光纤激光器” 资助，其项目完成目标和主要研究、开发内容如下： 1. 完成基于光纤 Bragg 光栅的 Er3+/Yb3+共掺杂光纤激光器的原 理结构设计，由特定长度和掺杂浓度的 Er3+/Yb3+共掺杂光 纤、光纤光栅及功放等组成； 2. 开展特定反射率及带宽的光纤 Bragg 光栅制作及掺杂光纤的 研究； 3. 结合主振荡器和功率放大一体化技术，完成光纤激光器原理 实验及调试； 4. 测定光纤激光器输出特性参数并对其随泵源功率、驱动电流 等参量的变化规律展开研究； 5. 完成 Er3+/Yb3+共掺杂光纤激光器实验装置的研制。 84<WP=90>项目验收主要技术指标如下：1. 波长信道：1550nm；2. 光栅峰值反射率～60%；3. 边模抑制比>50dB；4. 输出光功率：5mW；5. 掺杂光纤转换效率：20%；6. 3dB 线宽<0.1nm。实验测得所研制光纤激光器的各项指标如下：7. 激光中心波长：1552.08nm；8. 光纤光栅 1 的峰值反射率为 99%，光纤光栅 2 的峰值反射 率为 60%；9. 边模抑制比：60dB；10. 输出光功率：80mW；11. 掺杂光纤转换效率：25.2%；12. 3dB 线宽：0.072nm，25dB 线宽：0.192nm。可见，本文提出的光纤激光器的各项指标均已达到或超过项目验收的要求。目前，该项成果已通过吉林省科技厅鉴定。更多还原

【Abstract】 In order to enhance the bit rate and well use the bandwidth of 1.55μmwave band in WDM fiber-optic communications technology, the study onlasers of accurate wavelength and excellent performance has alwaysbeen the hot concern of people. The operation wavelength of fiber lasercan be determined by Fiber Bragg Gratings (FBG) precisely. For instance,DBR single frequency Er3+ doped especially Er3+/Yb3+ codoped fiberlasers have been rapidly developed. Yet, till now, there have been fewdomestic reports on Er3+/Yb3+ codoped fiber lasers. The research work isstill at the start. With the continuous miniaturization and integration of future fullfiber-optic component developments, the shorter is the better for thelaser source. In contrast with Er3+-doped fiber lasers, Er3+/Yb3+ codopedfiber lasers can not only simplify the lasers’ structure while shorteningtheir size, but can increase the stability and practicability for theircompactness and flexibility. The lasers, with their various advantages,have become one hotspot in full fiber-optic communications system.Therefore, the lasers, as a new laser or information source, have theirsharp competitiveness and promising future. The Er3+/Yb3+ codoped fiber laser put forward in the thesis, with itspump being 1064nm Nd:YAG is the first one ever reported and filled thedomestic blank. The paper integrated the theoretical design and analysisinto the configuration setup and experiment measurement researchmethod. The research contents accomplished can be described asfollows, 86<WP=92>1. Put forward the practical design of the DBR Er3+/Yb3+ codoped fiber laser on the basis of analyzing and contrasting various current popular schemes; 2. The technological parameters of the output laser were calculated after large scales of searches, extensive collection of data, prudent theoretical design and the optimization; 3. On the basis of theoretical design, the apparatus and components for the experiment were actively prepared and set up; 4. Optimized the length of the Er3+/Yb3+ codoped fiber and found the fit size of such type of Er3+/Yb3+ codoped fiber; 5. Debugged the experiment and measured the main technological indexes, then verified whether the fiber laser could meet the theoretical requirements. Meanwhile, gave comprehensive appraisal. The 1064nm pump whose model was MIL- Ⅱ was made byChangchun New Industries Optoelectronics Tech. Co., Ltd. Theresonant-cavity was constructed by splicing the FBG1 and FBG2(sharing the same Bragg wavelength, 1551.84nm Rpeak FBG1: 99%,1552.08nm Rpeak FBG2: 60%), to each side of the gain medium — a4.42-meter-long Er3+/Yb3+ codoped fiber. In contrast with the Er3+ onlyDBR fiber laser, the length of the gain medium was significantlyshortened. The broad bandwidth FBG1 and narrow bandwidth FBG2 forthe output were the cavity mirrors. The 1064nm light induced from the1064nm pump’s tail fiber was launched into the resonant-cavity via a1064/1550nm WDM, the port1 and port2 of a (1×2, 99/1) 1064/1550nmcoupler and FBG1. And then, a population inversion was formed in the 87<WP=93>Er3+/Yb3+ codoped fiber and the excited light was produced. The outputlaser with needed wavelength could be acquired via the light travelingthrough FBG2 and Dual-ISO. Thus, the DBR Er3+/Yb3+ codoped fiberlaser was constructed. The development of the fiber laser was supported by the Ji LinProvince Technology Development Scheme — The Er3+/Yb3+ codopedfiber laser based on FBGs. The target, main research and developmentcontents of the scheme can be described as follows, 1. Finish the theoretical and structural design of the Er3+/Yb3+ codoped fiber laser based on FBGs, which is made up of a certain length of Er3+/Yb3+ codoped fiber laser, FBGs, and更多还原