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题名	2 μm 波段激光输出用掺铥硅酸盐激光玻璃与光纤研究
作者	王欣
学位类别	博士
答辩日期	2014
授予单位	中国科学院上海光学精密机械研究所
导师	胡丽丽
关键词	硅酸盐玻璃 光纤 2 μm发光和激光 Tm3+离子单掺 Ho3+/ Tm3+ 和Er3+ /Tm3+ 双掺
其他题名	The study on thulium doped silicate laser glass and fiber for realizing 2μm laser output
中文摘要	近年来， 因2 μm波段激光在军事、医疗和遥感探测等方面有着广阔的应用前景引起了广泛的关注。作为2 μm激光器核心工作物质的激光材料也成为研究的热点。其中该波段光纤激光器用的激光玻璃和光纤已经成为该领域的一个重要研究方向。目前，在石英光纤、锗酸盐玻璃光纤、氟化物玻璃光纤和碲酸盐玻璃光纤基质中已经实现了2 μm激光输出。但是上述几种光纤分别存在稀土掺杂浓度低、成本高、机械强度差等缺点。与石英光纤相比，硅酸盐玻璃稀土掺杂浓度高，与其他多组分玻璃光纤比，硅酸盐玻璃光纤机械强度高，化学稳定性好，原料成本低。虽然国外已经有硅酸盐玻璃光纤2 μm激光的报道，但是国内仍属空白。 本论文以2 μm波段激光输出用掺铥硅酸盐玻璃与光纤作为研究对象，对其相应性质进行了表征和分析。本论文总共包括六章，前两章分别为文献综述和实验方法及稀土发光理论，第三、四、五章为本论文核心内容，第六章是结论。 文献综述部分介绍了产生2 μm波段激光所用的方法和原理，概述了光纤激光器的构成和特点，总结了2 μm波段激光的应用，综述了各种玻璃在2 μm波段激光方面的研究进展，进而提出本文的研究内容和思路。 论文第二章介绍了研究过程中用到的实验和测试手段，概述了分析实验结果所需的理论，如Judd-Ofelt理论、多声子弛豫理论和能量传递理论等。 第三章分别讨论了网络外体离子和网络形成体离子对掺铥硅酸盐玻璃2 μm光谱性质的影响。文中研究的网络外体离子有Li+、Na+、K+、Mg2+、Ca2+、Sr2+和Ba2+，讨论了上述网络外体离子种类变化时，各种光谱参数的变化趋势。研究发现网络外体离子的改变会引起Tm3+离子周围局域环境的改变，从而导致各个光谱参数的变化。相对来说，Tm3+离子在大场强离子为网络外体的玻璃中，具有较大的受激发射截面、较小的多声子弛豫速率、较长的测试荧光寿命和较强的Tm3+离子间交叉弛豫过程，从而导致较强的1800 nm荧光。因此，设计硅酸盐激光玻璃配方时宜选用场强较大的网络外体离子。对比了不同网络形成体的掺铥激光玻璃的2 μm光谱性质，发现当玻璃中含有氧化硼和五氧化二磷时，会导致玻璃声子能量增大，从而使得玻璃的2 μm光谱性能急剧下降，而在掺铥硅酸盐玻璃中加入部分氧化碲、氧化锗、氧化铋等重金属氧化物时，会增强玻璃的2 μm光谱性能。因此在设计硅酸盐激光玻璃配方时，可以适当引入部分重金属氧化物。 第四章的主要工作是在第三章的研究基础上进行的，设计了掺铥硅酸盐玻璃配方，并对其2 μm光谱性质进行了表征。掺铥33Bi2O3-50SiO2-17PbO玻璃具有优异的2 μm光谱性质，其最大受激发射截面位于1845 nm处，为7.2×10-21 cm2，当Tm2O3掺杂浓度为0.1 mol%时，测试的3F4能级寿命为1534 μs，量子效率达58.5%。由于该玻璃在拉丝过程中容易析晶，所以在此基础上对配方进行了改进。最终获得的玻璃基质配方为15Bi2O3-50SiO2-10ZnO-15Al2O3-10La2O3，Tm3+离子在该玻璃中3F4能级到3H6能级跃迁的最大受激发射截面在1826 nm处，为4.7×10-21 cm2，Tm2O3掺杂浓度为0.1 mol%时，测试的3F4能级寿命为1139 μs，量子效率达35.5%。采用Tm2O3掺杂浓度为1 mol%的该种玻璃作为纤芯，制作了单包层光纤，由于玻璃中可能含有低价铋离子，导致光纤损耗高达17 dB/m，在用792 nm激光泵浦时产生强烈的热效应从而导致光纤损坏。在强氧化环境下对光纤进行处理，可将铋离子由低价氧化成高价，测试处理后光纤的损耗为7 dB/m，在792 nm激光泵浦下测试了光纤的荧光光谱，其中心波长为1900 nm。此外还开发了一种掺铥50SiO2-10Al2O3-25CaO-15SrO玻璃，其最大发射截面位于1882 nm处，为3.89×10-21 cm2，Tm2O3掺杂浓度为0.1 mol%时，测试的3F4能级寿命为858 μs，量子效率为16.5%。利用该材料制作了光纤，在1310 nm处损耗为15 dB/m。通过对光纤预制棒芯包界面进行酸处理使光纤损耗降为7~8 dB/m。采用处理后的光纤，在792 nm激光泵浦下获得了2 μm激光输出，中心波长为1980 nm。 第五章分析了Ho3+/Tm3+共掺和Er3+/Tm3+共掺硅酸盐玻璃的2 μm光谱性质。Ho3+/Tm3+共掺实验以50SiO2-10Al2O3-25CaO-15SrO玻璃为基质，探讨了不同Ho2O3掺杂浓度对2 μm光谱性质的影响。当掺杂1 mol% Tm2O3和0.1 mol% Ho2O3时，2 μm波段荧光峰半高宽可达345 nm；当掺杂1 mol% Tm2O3 和0.7 mol% Ho2O3时，Ho3+离子5I7能级向5I8能级跃迁产生的荧光最强。计算Ho3+离子5I7能级向5I8能级跃迁的最大受激发射截面为3.72 × 10-21 cm2。当掺杂1 mol% Tm2O3和1 mol% Ho2O3时，由Tm3+离子向Ho3+离子的能量传递效率可达95.4%。Er3+/Tm3+共掺实验以50SiO2-33Bi2O3-17PbO玻璃为基质，研究了Er2O3和Tm2O3含量的变化对2 μm光谱性质的影响。计算了Er3+离子和Tm3+离子之间能量传递的宏观和微观参数，结果表明Er3+离子4I13/2能级向Tm3+离子3F4能级的能量传递比Tm3+离子间的交叉弛豫更为有效。当Tm2O3含量大于1.5 mol%时，Er3+离子和Tm3+离子之间能量传递的效率可达90%以上。计算了实现粒子数反转所需要的泵浦速率和泵浦能量，结果表明，当Er3+离子浓度很高时，用980 nm激光泵浦Er3+/Tm3+共掺材料也是实现2 μm输出的一种有效途径。 最后是论文的结论部分，总结了全文的实验结果，指出了本论文的创新点和不足之处。
英文摘要	Recently, 2 μm laser has drawn considerable attention due to its wide applications, such as military, surgery and remote sensing. Laser glass and fiber for lasing in this wavelength region is one of the hotest researches. Up to now, 2 μm lasers have been realized in silica fiber, germanate glass fiber, fluoride glass fiber and tellurate glass fiber. But these fibers have their disadvantages. The rare earth ions doping level is low in silica fiber; germanate glass is very expensive; fluoride and tellurate glass fibers are brittle. Silicate glass fiber can overcome these disadvantages. Although 2 μm laser has been realized using silicate glass fiber, similar results have not been reported by researchers in China. This dissertation topic is silicate glass and fiber for 2 μm laser. It includes six chapters. The first two chapters are literature review, experimental methods and theories about luminescence of rare earth ions. The chapters 3,4 and 5 are the core part of the dissertation. The last chapter is the conclusion. In chapter I, method and theory for realizing 2 μm laser have been briefly introduced. The construction and characters of fiber laser have been presented. Applications and research progresses have been reviewed. Then, the purpose and research contents of the dissertation were proposed. In chapter II, the experimental methods and test tools have been introduced. The theories for analyzing the experimental results, such as Judd-Ofelt theory, multi-phonon relaxation and energy transfer theory, are reviewed. In chapter III, compositional dependence of 2 μm spectral properties of thulium doped silicate glass have been studied. This research topic contains two aspects. Both network modifier cations and network former cations affect 2 μm spectral properties of glass. In this chapter, the studied network modifier ions include Li+, Na+, K+, Mg2+, Ca2+, Sr2+ and Ba2+. The dependence of spectral parameters on network modifier has been discussed. The result shows that the glass containing network modifier with high ion field strength has large emission cross section, low multi-phonon relaxation probability, strong cross relaxation process between Tm3+ ions, long lifetime of 3F4 energy level and high 2 μm emission intensity. So network modifier cation with high ion field strength should be chosen in glass composition design to improve 2 μm emission property. 2 μm spectral properties of thulium doped glasses with different network former cations have been studied. Glasses containing B2O3 and P2O5 which have large phonon energy show worse 2 μm emission properties. Glasses containing heavy metal oxide, such as TeO2, GeO2 and Bi2O3, show excellent 2 μm spectral property. So introducing heavy metal oxide to silicate glass for 2 μm emission may be favorable. Based on the result of chapter III, three kinds of glasses for 2 μm laser have been designed. In charpter IV, the 2 μm spectral properties of these glasses have been studied. Thulium doped glass with composition 33Bi2O3-50SiO2-17PbO has excellent 2 μm emission properties, the maximum emission cross section is 7.2×10-21 cm2 at 1845 nm. Lifetime of 3F4 energy level in this glass doped with 0.1 mol% Tm2O3 is 1534 μs, and the corresponding quantum efficiency is 58.5%. But this glass shows serious devitrification property at fiber drawing process. In order to improve the anti-crystallization property, the glass composition has been modified to 15Bi2O3-50SiO2-10ZnO-15Al2O3-10La2O3. The maximum emission cross section is 4.7×10-21 cm2 at 1826 nm. Lifetime of 3F4 energy level in the glass doped with 0.1 mol% Tm2O3 is 1139 μs, and the corresponding quantum efficiency is 35.5%. Using this glass doped with 1 mol% Tm2O3 as core, single cladding fiber has been prepared. The loss of this fiber is 17 dB/m. This comes from the absorption of low valence bismuth ion in the glass. Heat treatment on this fiber in the strong oxidizing atmosphere can lower the fiber loss to 7 dB/m. Peak position of emission spectrum of this fiber is at 1900 nm. Another kind of glass with composition of 50SiO2-10Al2O3-25CaO-15SrO shows maximum emission cross section of 3.89×10-21 cm2 at 1882 nm. Lifetime of 3F4 energy level in the glass doped with 0.1 mol% Tm2O3 is 858 μs, and the corresponding quantum efficiency is 16.5%. Double cladding fiber has been manufactured using this glass. The loss at 1310 nm is 15 dB/m. Through the acid surface treatment on core and cladding glasses, the loss of fiber decreased to 7~8 dB/m. Pumped with 792 nm LD, the 2 μm laser centered at 1980 nm has been realized. In chapter V, 2 μm spectral properties of Ho3+/Tm3+codoped and Er3+/Tm3+ codoped silicate glasses have been investigated. The effect of Ho2O3 concentration on 2 μm spectral properties in Ho3+/Tm3+ codoped 50SiO2-10Al2O3-25CaO-15SrO glass has been studied. The glass doped with 1 mol% Tm2O3 and 0.1 mol% Ho2O3 has a broadband spectrum with a FWHM value of 345 nm. The sample doped with 1 mol% Tm2O3 and 0.7 mol% Ho2O3 has the maximum emission intensity of Ho:5I7 to 5I8 transition. The maximum emission cross section of Ho:5I7 to 5I8 transition is 3.72 × 10-21 cm2. With 1 mol% Ho2O3, the energy transfer efficiency from Tm3+ to Ho3+ is as high as 95.4%. Er3+/Tm3+ codoped 50SiO2–33Bi2O3–17PbO glasses have been prepared, and the influence of Er2O3 and Tm2O3 contents on 2 μm spectral properties has been investigated. The microscopic and macroscopic energy transfer parameters between Er3+ and Tm3+ ions are calculated. The results show that the energy transfer from 4I13/2 energy level of Er3+ ion to 3F4 level of Tm3+ ion is more effective than the cross relaxation process between Tm3+ ions. When the Tm2O3 content beyond 1.5 mol%, the energy transfer efficiency from Er3+ ion to Tm3+ can be larger than 90%. When the Er3+ ion doping level is high, 980 nm LD pumping may be an effective way to realize 2 μm laser. The last chapter is the conclusion. All results of present work have been concluded in this chapter. The innovation and shortage of this dissertation have also been mentioned.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15871]
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	王欣. 2 μm 波段激光输出用掺铥硅酸盐激光玻璃与光纤研究[D]. 中国科学院上海光学精密机械研究所. 2014.

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