文档介绍：华中科技大学
硕士学位论文
2μm掺铥双包层光纤激光器研究
姓名:李尧
申请学位级别:硕士
专业:物理电子学
指导教师:杨振宇
2011-01-03
摘要
掺铥双包层光纤激光器采用包层泵浦技术对 Tm3+掺杂增益光纤进行抽运,能够
实现大功率的 2μm 波段的激光输出,因而受到广泛关注。2μm 波段处于人眼安全波
段,在工业、军事以及医疗方面有重要的应用,还可以作为 3~5μm 激光器的泵浦光。
因此 2μm 掺铥双包层激光器具有极高的研究价值。
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本文首先从铥离子能级结构的研究出发,分析了 H6→ H4 泵浦方式下激光产生
的具体过程,对其进行了深入的数值分析,得到了增益光纤中前后向泵浦光、信号
光的传输分布,并且计算了理论上光纤的最佳长度。而后对激光器的耦合系统进行
了设计,得到了透镜组的一个合适比例。
在这些理论研究基础上,我们确定了实验方案和相关关键器件,包括泵浦源、
非球面透镜组、双色镜等,搭建了光纤测试平台以及掺铥双包层光纤激光器平台,
完成了光纤吸收系数的测量,通过实验决定了最佳光纤长度,对不同光纤长度下的
输出激光进行了斜率效率的对比,并且最终获得了中心波长为 1909nm,激光线宽为
10nm,最大功率为的连续激光输出,阈值为 ,斜率效率为 %。
最后对实验方案进行了改进,在光纤上刻入布拉格光栅加强谐振腔的效果并起
到选频的作用,为今后的实验提出了一些改进方案。

关键词:双包层光纤激光器掺铥光纤耦合系统吸收系数
中心波长光纤布拉格光栅

I
Abstract
Cladding-pumped Thulium-doped double-clad fiber lasers which use the technology
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of cladding-pump to pump gain fiber can obtain the laser transition between F4 and H6 at
approximately laser near 2μm operates at eye-safe region, and the laser has a
great use in industry, medicine and military, it even could be used as the pump source of
3~5μm OPO. Therefore it is valuable to research Tm3+-doped fiber laser operating at 2μm.
The research of this paper starts from the energy level structure of Tm3+, then we
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analyzed the transition of H6→ H4 and the process of laser output including a detailed
numerical analysis. The forward and backward distributions of pump power and signal
power, the dependence of the fiber length and the transmission loss are also numerically
modeled. After that we designed the couple system of the laser system.
Based on all of these theories, we determine the program of our experiment. We
purchased the equipments related to the experiment, including pump sources, aspheric lens,
dichroic mirror, etc. We set up the fiber optic test platform and the fiber laser platform. We
tested the absorption coefficient of the fiber and determined the best length of fiber
through experiment. Finally we re