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题名	高功率窄谱宽1918nm掺铥光纤激光技术研究
作者	张伟
文献子类	硕士
导师	叶锡生 余婷
关键词	掺铥光纤激光器（TDFL），1918nm，高功率，窄谱宽 TDFL, 1915nm, high power, narrow-bandwidth
其他题名	Investigation on the high-power narrow-bandwidth 1918nm thulium-doped fiber
英文摘要	2μm波段激光处于大气光学窗口并具有人眼安全等优点，因此，在激光测距、激光遥感、激光医疗和光电对抗等领域具有广泛的市场需求和重要的应用前景。此外，该波段激光器还是3~5μm宽带可调谐中红外光学参量振荡器的重要泵浦源。目前，2μm波段激光源主要有掺铥、掺钬以及铥钬共掺的光纤激光器与固体激光器。其中，光纤激光器由于结构紧凑、散热效果好、光束质量高等优点而广受关注。本文针对高功率窄谱宽1918nm掺铥光纤激光（TDFL）技术开展探索研究，并取得了以下主要进展： （1）基于主振荡功率放大（MOPA）结构，对TDFL实现窄谱宽输出进行了理论分析；基于铥离子速率方程和光纤中功率传输方程，建立数值模型，对掺铥光纤放大器输出功率与增益光纤长度的关系、种子光功率对放大器效率的影响等进行了模拟分析。 （2）开展了1918nm连续波输出TDFL相关实验研究。首先，基于不同尺寸光纤与光栅、进口光纤与国产光纤等分别搭建激光振荡器，对输出激光的光斑特性和光谱特性开展了相关实验研究。其次，采用国产光纤及器件开展了高功率国产化TDFL研究，基于一级振荡加两级放大的MOPA结构，得到了最高功率为171W的窄谱宽激光输出，中心波长为1917.82nm，3dB光谱宽度为80pm，斜率效率为33.5%，光-光转换效率为33.3%。接着，采用进口光纤基于同样结构得到了最高功率达206.5W的高功率窄谱宽激光输出；同时，对振荡和预放大两级进行了装机，得到了10小时稳定运行的90W输出TDFL整机系统；此外，开展了种子光功率对放大器效率影响的实验以及放大的自发辐射（ASE）产生的泵浦阈值功率随光纤长度变化关系的探索实验。最后，对进口光纤长度进行优化，得到了功率为285.5W的激光输出，中心波长为1917.79nm，3dB光谱宽度为80pm，斜率效率为55.8%，光-光转换效率为56.1%，系统在30分钟运行考核时间内稳定性良好，输出功率不稳定度为±0.4%。; The 2 μm region laser is in the atmosphere window, and has advantage of safe to eyes. Therefore, it has a wide range of market demand and important application prospect in the laser ranging, laser remote sensing, laser medical treatment and other fields. In addition, the 2μm pulsed laser is an important pump source of 3~5μm optical parametric oscillator, with which can achieve a broadband tunable mid-infrared laser output. Nowadays, 2 μm region laser sources mainly include Tm-doped, Ho-doped, Tm/Ho-codoped fiber lasers and solid-state lasers. The fiber lasers are widely concerned because of their compact structure, easy heat management and good beam quality. This paper mainly studies from the following aspects: (1) First, focusing on the theoretical analysis of narrow-width spectrum of thulium-doped fiber laser (TDFL) that based on master oscillator power amplifier (MOPA) structure. Then, a numerical model was established that based on the thulium ion rate equation and the power transmission equation in the fiber, and we analysed the relationship between the output power and the length of fiber of the thulium-doped fiber amplifier, the slope efficiency of thulium-doped fiber amplifier by changing the power of seed laser. (2) Experimental study of continuous wave (CW) 1918nm TDFL. Firstly, we studied on the oscillator with energy distribution of output spot and the characteristics of output spectral, and the oscillator based on thulium-doped fiber and fiber Bragg grating (FBG) which with different core sizes and produced by various counties’ companies. Secondly, based on MOPA structure, we studied on a high power narrow-width TDFL with homemade devices, and the laser maximum average power was 171 W, central wavelength measured at 1917.82 nm, 3 dB spectrum bandwidth keeped in 80pm, slope efficiency and optical-to-optical conversion efficiency reached 33.5% and 33.3%, respectively. Thirdly, we studied on a high power narrow-width TDFL used imported thulium-doped fiber to construct, the TDFL maximum output power was 206.5 W. Then, we packed the oscillator and preamplifier together as a 90 W output TDFL system. To confirm the stablity of this system, 10 hours test was passed, and no issue occured during this time. Finally, we did some experiments to verify the results of the theoretical simulation about the change of slope efficiency of thulium-doped fiber amplifier by increasing seed power, and also investigation on the relationship between threshold pump power of ASE and length of thulium-doped fiber. By optimizing the length of imported thulium-doped fiber, a high power narrow-width TDFL was obtained, which the maximum output achieved 285.5W, central wavelength was 1917.79nm, 3 dB spectrum bandwidth keeped in 80pm, slope efficiency and optical-to-optical coversion efficiency attained 55.8% and 56.1%, respectively. The stability of laser output of this system behaved well during the 30 minutes operation checking time, the instability of power is ±0.4%. Key words: TDFL, 1915nm, high power, narrow-bandwidth
学科主题	光学工程
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/31043]
专题	中国科学院上海光学精密机械研究所
作者单位	中国科学院上海光学精密机械研究所
推荐引用方式 GB/T 7714	张伟. 高功率窄谱宽1918nm掺铥光纤激光技术研究[D].

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