影响提高双包层光纤激光器输出功率的两个因素的研究
文献类型：学位论文
| 作者 | 王常安 |
| 学位类别 | 硕士 |
| 答辩日期 | 2002 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 陆雨田 |
| 关键词 | 光纤激光器 半导体激光器 光束整形 双包层光纤 光束耦合 微型棱镜 内包层形状分析 |
| 中文摘要 | 该论文分为六章,第一章为引言.简单介绍了光纤激光器的特点和它的用途以及目前的耦合技术现状.第二章为文献综述.首先介绍了光纤激光器的发展过程和它的现状,从最早的闪灯泵浦的光纤激光器到现在的LD泵浦的双包层高功率光纤的发展都做了介绍.并且介绍了常用的泵浦光源——半导体激光器(LD),介绍了它的基本工作原理和阵列LD的输出光束特性以及目前常用的光束整形技术的原理和它们的整形效果.第三章是LD与光纤之间的耦合理论与技术.在这一章,首先介绍了分析光束耦合的两种基本理论——模式理论和几何光学理论.同时介绍了目前LD与双包层光纤之间耦合的常用技术——端面耦合技术、侧面V形槽耦合技术和圆盘(圆管)耦合技术.分别介绍了这些耦合技术的技术实例以及这些耦合技术各自的优点和缺点.第四章是微型棱镜耦合新技术.在该章中,首先介绍了微型棱镜耦合新技术的技术原理并且从理论上计算了这种耦合技术的耦合效率(>90%).接着对这种技术对泵浦光源的要求、对大功率阵列LD作光源的处理,对各种内包层形状的处理、入射光束倾斜对耦合效率的影响等相关问题进行了讨论;根据微型棱镜耦合技术的本身特点提出了碟形光纤激光器结构;分析了这种耦合新技术的优点;最后得出结论——这种耦合技术能够有效地将泵浦光耦合进光纤.第五章是泵浦光在双包层光纤中的传播与吸收的分析.首先在提出了在二维平面内对内包层形状最佳化分析的分析方法;接着用蒙特卡罗方法分析了泵浦光在内包层中的传播和吸收,分析了吸收效率与纤芯/内包层面积比的关系、吸收效率与纤芯系数的关系以及吸收效率与内包层数值孔径的关系;最后得出了这种分析方法的适用范围和优点.第六章对上述工作进行了总结. |
| 英文摘要 | A critical reason that limits the improvement of fiber lasers is how to couple high power pumping light into the doped fiber efficiently. The double-cladding fibers (DCF) proposed by E.Snitzer et al. offer a clever solution to this problem. With the appearance of double-cladding fibers, how to couple LD pumping light into this kind of fiber becomes a key of improving the output features of a DCF fiber laser. All the coupling techniques that have been developed to this problem, such as end pumping technique, V-groove side-pumping technique and disc (or tube)-coupling technique, have their limitations. For these reasons, a new coupling technique is expected. Optimizing the inner shape and length of DCF is another factor that influences the improvement of the output of double-cladding fiber lasers. Most of the methods that have been developed can only work for a certain inner shape or too complexly. So a new analyzing method is also expected. This thesis consists of six chapters. The first chapter is the introduction. The second chapter is the review to the related research works. We first describe the evolution and its status quo of the fiber lasers, from the first flash tube pumped fiber lasers to LD pumped double-cladding fiber lasers. Then the introduction to the common pumping source-laser diode (LD) and its basic theory, and the characters of the output beam of array LD and beam shaping technique are given. The third chapter givens out the theory and techniques on the coupling of LD energy into fibers. We first present two theories used for light coupling analysis-mode-coupling theory and geometrical optics theory. Then we present the common coupling techniques used for coupling LD pumping light into DCF-end pumping technique, V-groove side-pumping technique and disc (or tube)-coupling technique. The limitations of these methods are also reviewed. The forth chapter is the study of the new micro-prism coupling technique proposed by us. The basic principle and the theoretical coupling efficiency of this technique are discussed. Then the problem such as requirement for the pumping source, the treatment of the high power LD and the shape of the inner clad, and the influence of pumping beam inclination to the coupling efficiency are discussed based on our calculations. Based on the technique, we also proposed a new double-cladding fiber laser configuration-disc fiber laser. The fifth chapter is the analysis of transmission and absorption of the pumping light in the inner clad of DCF. We first propose a two-dimension analysis method for optimizing the shape of inner clad. Then by using Monte Carlo method, we analyze the transmission and absorption of the pumping light in the inner clad of DCF. The influence of core/inner clad area ratio, absorption coefficient of the core and numerical aperture to the coupling efficiency are discussed based on our calculations. The last chapter summarizes the work mentioned above. In a word, in this thesis, we propose a new coupling technique-micro-prism coupling technique and analyze it. This technique is simple, efficient and does nearly no harm to the fiber. The mechanism and the application method were first introduced, and then the theoretical coupling efficiency was given (-90%). Finally, the requirement on the LD source and the application limit of this technology was given based on the analysis. Considering the trait of this coupling technique, we propose disc fiber laser coupling configuration, it can couple LD pumping light into DCF simply and efficiently. Furthermore, we also propose a new method used for analyzing the transmission and absorption of the pumping light in the inner clad of DCF. Using this method, we analyze the relation between the absorption and the inner shape and length of the double clad fiber. By using this method, we can optimize the inner shape and length of the double clad fiber. This is very useful for improvement of output of double-cladding fiber lasers. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16553]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 王常安. 影响提高双包层光纤激光器输出功率的两个因素的研究[D]. 中国科学院上海光学精密机械研究所. 2002. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。