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题名	掺稀土氟化物玻璃中红外发光特性的研究
作者	黄飞飞
学位类别	博士
答辩日期	2015
授予单位	中国科学院上海光学精密机械研究所
导师	陈丹平
关键词	氟化物玻璃 2μm 3μm 中红外发光
其他题名	Spectroscopic properties of mid-infrared emissions in rare earth ions doped fluoride glass
中文摘要	近年来，输出波长为2-3 μm的中红外固体激光器，因在军事、医疗、光通信和环境监测等领域的应用前景而引起了广泛的关注。目前国内外对2 μm发光的稀土离子掺杂激光材料的研究主要集中在Tm3+离子掺杂的晶体、石英、硅酸盐、碲酸盐和锗酸盐玻璃及光纤中。3 μm的研究则主要集中在Er3+离子掺杂的氟化物ZBLAN玻璃光纤中。80年代后期，研究已表明氟化物玻璃具有较低的声子能量、较好的中红外透过性和较高的稀土离子溶解能力，使得氟化物玻璃作为中红外发光材料具有先天的优势。但是目前唯一成熟的氟化物ZBLAN玻璃的物化性能较差，发展受大了很大的限制。本论文的宗旨是在氟化物玻璃中探索物化性能及发光性能兼优的氟化物玻璃体系作为新型的中红外发光材料。同时研究2-3 μm波段发光的稀土离子(特别是目前研究较少的稀土离子)在不同条件下的发光机理。 本论文主要包括八章：前两章分别是文献综述、实验方法及理论基础；第三到七章是本论文的核心部分；第八章是结论。 论文首先在文献综述中简要的介绍了激光、激光器的应用及发展。综述了在2-3 μm波段发光的稀土离子及基质材料的研究。概述了氟化玻璃体系中几种玻璃基质的特点及研究进展，进而提出本论文的研究内容和思路。 论文的第二章，介绍了试验方法、氟化物样品制备、性能测试手段和光谱参数的理论计算等。 论文的第三章通过高温熔融法制备了不同体系的氟化物玻璃。研究了氟锆酸盐ZBYA玻璃的各项热学性能。最终获得了Tg在330 ℃左右及ΔT在90 ℃左右的抗析晶性能较好的55ZrF4-33BaF2-10YF3-7AlF3组分。通过改变制备浇注工艺获得了无析晶的氟铝基AYF玻璃，玻璃的转变温度比氟锆酸盐玻璃高了100 ℃以上，抗水性能高了一个数量级。在本章的后两小节，主要是通过在纯氟铝酸盐AYF玻璃的基础上加入少量具有挥发性的氧化物来增加成玻性能，减少羟基系数。 论文的第四章主要研究和对比了Er3+离子掺杂的氟化物玻璃（氟锆酸盐ZBYA体系、氟铝酸盐AYF体系及氟铝氧AYFT和AYFP体系）的中红外发光特性。Er3+离子在ZBYA玻璃中的掺杂浓度可以达到6 mol%，且2.7 μm处的荧光强度随着稀土离子浓度的增加而增加，其中2.7 μm处的荧光发射截面达到0.98×10-20 cm2，计算得到的增益性质符合典型的三能级激光系统的特征。Er3+离子在AYF玻璃中的发光性质与在ZBLAN玻璃中基本一致，但2.7 μm处的发光强度要弱一些，这是因为氟铝酸盐玻璃中的羟基含量较大。本章另一个重点是研究Er3+离子在含少量氧化物的氟铝酸盐玻璃中的发光性能，氧化物的加入很大程度上降低了玻璃中的羟基含量，所以2.7 μm处的荧光强度均得到大幅增强。但是在氟铝磷系列玻璃中，磷酸盐的引入降低了玻璃中的羟基含量；但是磷酸根离子的声子能量较大，较大的声子对稀土离子3 μm发光也有很大的抑制作用，所以氟铝磷玻璃中的磷酸盐的含量需要控制。 论文的第五章设计和制备了多系列Er3+离子与敏化离子共掺杂的氟化物玻璃，研究氟化物玻璃中敏化离子对Er3+离子2.7 μm发光的影响及其机理。首先制备了不同浓度的Ho3+/Er3+离子共掺杂的氟化物ZBYA玻璃，在980 nm 泵浦下Ho3+离子能有效的增加Er3+离子的2.7 μm发光，抑制1.5 μm处的荧光，同时Er3+与Ho3+离子的最佳掺杂浓度比例为1:1。另外，计算得到共掺杂样品的2.7 μm的自发辐射跃迁几率从单掺时的23.87 S-1增加到了25.11 S-1，在此处也拥有大的发射截面（16.5×10-21 cm-2）。根据Forster-Dexter理论计算得的能量传递系数显示：Ho3+离子的加入能够有效地降低Er3+离子的4I13/2能级上的粒子数而对4I11/2能级的影响甚微，从而有效的增加Er3+离子的2.7 μm发光。另外，研究在800 nm泵浦源下，Nd3+离子对Er3+离子2.7 μm发光的影响。Nd3+离子不但能像Ho3+离子那样减少Er3+离子4I13/2能级上的粒子数(Er3+:4I13/2→Nd3+:4I15/2)；还能有效地吸收800 nm泵浦源的能量，并将其传递给Er3+离子的4I9/2能级，4I9/2能级通过无辐射过程弛豫到4I11/2能级上，有利于Er3+离子的2.7 μm的发光。另外也研究了Yb3+与Er3+离子共掺杂的AYFT玻璃在不同波长泵浦源下的发光性质：980 nm激发下，Yb3+离子能有效的吸收泵浦源的光并将能量传递给Er3+离子的4I11/2能级，从而增加2.7 μm的发光；1550 nm泵浦下，受主离子Yb3+离子则接受Er3+离子的能量，增加1.0 μm处的上转换发光。在不同的激发条件下，两离子间的能量传递效率均在Er3+：Yb3+离子的浓度比为1：1.5时最大。 论文的第六章主要是研究了在1550 nm泵浦下，Er3+离子对Ho3+离子2 μm发光的敏化作用。Er3+离子对Ho3+离子2 μm的敏化作用主要是由于Er3+离子可以吸收泵浦光的能量，并通过Er3+:4I13/2→Ho3+:5H7过程将能量传递给Ho3+离子。与980和800 nm泵浦源相比，Er3+离子在1550 nm处的吸收截面更大，并且基态的粒子吸收泵浦源的光子可以直接跃迁至Er3+离子的4I13/2能级，这两方面都可以有效地提高Er3+:4I13/2→Ho3+:5H7能量传递过程的效率。荧光峰的变化说明Er3+离子的加入可以有效地增强Ho3+离子的2 μm发光。理论计算了此条件下Er3+:4I13/2能级到Ho3+:5I7能级的能量传递过程的微观系数为10.1×10-41cm6/s，比在980 nm激发条件下计算得到的数值要大。进一步的工作是研究Ce3+离子的引入对Er3+/Ho3+离子共掺杂的氟化物体系2 μm发光的影响。Ce3+离子能分别与Er3+和Ho3+离子发生能量传递过程：Er3+:4I11/2+Ce3+:2F5/2→Er3+:4I13/2+Ce3+:2F7/2和Ho3+:5I6+Ce3+:2F5/2→Ho3+:5I7+Ce3+:2F7/2，有效地抑制激发态再吸收，使得更多的粒子积累在Ho3+离子的5I7和Er3+离子的4I13/2能级上，增加了Ho3+离子的2 μm发光的效率。随着Ce3+离子的加入，由三光子再吸收过程产生的红光得到了明显的抑制；同时Er3+离子的2.7 μm发光强度随着Ce3+离子的浓度的增加而线性降低，这直接说明了Er3+:4I11/2+Ce3+:2F5/2→Er3+:4I13/2+Ce3+:2F7/2过程的存在。结果显示：Ho3+/Er3+/Ce3+离子三掺氟化物很有希望作为性能优异的2 μm激光材料 第七章设计和制备了不同浓度Dy3+离子掺杂的AYFT玻璃。研究了其在1310 nm泵浦下2.8 μm的发光性质。在荧光光谱中明显观察到了由Dy3+离子的6H13/2→6H15/2跃迁产生的位于2.8 μm附近的荧光峰，由于Dy3+离子在此波长处存在自吸收，荧光峰的位置随着加入稀土含量的增加发生了红移，荧光峰的强度则保持增加。计算得到Dy3+离子掺杂的AYFT样品在2.8 μm处具有较大的发射截面（0.67×10-20 cm2）。 最后是本论文的结论部分，总结了全文的实验结果，同时指出了本论文的不足和需要进一步改进研究之处。
英文摘要	Recently, 2-3 μm solid-state lasers have drawn considerable attention due to their wide applications, such as military, surgery, communication and remote sensing. Up to now，much work has been done on rare earth (RE) doped materials generated 2 μm emission，especially Tm3+ doped crystal，silicate, tellurite, and germanate glasses and fibers. As for 3 μm emission, the most fluoride glasses showed that it possesses low phonon energy, wide transmittance region, and high solubility for RE ions. These advantages make fluoride glass to be native better candidate for mid-infrared (MIR) material compared to oxide glasses. However, the only extensively used fluoride glass ZBLAN has poor physical and thermal properties, which limit its further application in the future. This paper aims to investigate new fluoride glasses that not only own good optical properties but also physical and thermal properties as MIR materials. Meanwhile, the luminous mechanism of MIR RE (especially expect Er3+ and Tm3+ ions) under different conditions should be studied. This dissertation includes the following eight chapters. The first two chapters are the literature review, experimental methods and theoretical basis. The middle five chapters are core parts of the dissertation. Chapter VIII is the conclusion. In Chapter I, the development and applications of laser have been briefly introduced firstly. The research progresses on 2-3 μm RE ions and its promising materials have been reviewed. In addition, the characteristics and development of fluoride glasses have been presented. Then, the purpose and research content of the dissertation were proposed. In chapter II, the experimental methods were introduced, including the preparation procedures of fluoride glasses, physical and spectroscopic properties measurement, and theory analysis. In chapter III, different component of fluoride glasses have been investigated and prepared using traditional high temperature melting method. For the ZBYA system, the thermal performance of glasses was studied. The glass with the composition of 50ZrF4–33BaF2–17(AlF3+YF3) has high temperature of glass transition (Tg: 330℃) and good thermal stability (ΔT: 90℃). Fluoroaluminate glasses without crystallization were prepared by optimizing preparation technology. The temperature of glass transition is almost enhanced 100 ℃ compared to that of ZBLAN and water resistance is improved an order of magnitude. In the next two sections, low content volatile oxides have been added into the pure AlF3-based glasses to improve its forming ability and low its OH- content. The efficient oxides are the tellurium oxide and phosphate. These two oxyfluoroaluminate glasses possess low OH- coefficient and better glass forming ability. In chapter IV, characteristic of Er3+ doped different fluoride systems in MIR region have been investigated, here the fluoride systems include ZBYA, AYF and oxyfluoroaluminate (AYFT and AYFP) glasses. Firstly, a series Er3+ doped ZBYA with different RE ions concentration have been prepared. Er3+ doping concentration can reach 6 mol% and the intensity of 2.7 μm emission increases with the Er3+ content. According to the Fuchbauer-Ladenburg theory, the emission cross section at 2.7 μm of Er3+ doped ZBYA reaches 0.98×10-20cm2. Meanwhile， the positive gain properties proves that it is a typical three-level laser system. Meanwhile, optical properties of series AYF glasses have been investigated and compared to ZBLAN. Luminescence rule between AYF and ZBLAN is similar except the intensity of 2.7 μm emission. The intensity of AYF glasses is slightly weaker than that of ZBLAN owing to its larger OH- content in the glass network. Another key focus of this chapter is the investigation of optical properties in the Er3+ doped oxyfluoroaluminate glasses. After modified by oxides, the OH- content in the fluoroaluminate glass was reduced to a great extent, which caused the increasing of the intensity of 2.7 μm emission. As for the fluoroaluminate glasses modified by phosphate, one point should be noticed that the phosphate introduces large phonon energy which is harmful for MIR emissions. So the content of the phosphate should be controlled no more than 1mol%. In chapter V, series Er3+/x codoped fluoride glasses ware prepared, the effect of sensitization ions on Er3+ ions and the energy transfer processes between them have been investigated. Firstly, Er3+ with different concentration Ho3+ codoped ZBYA glasses were prepared. Ho3+strengthens the Er3+: 2.7 μm emission under 980 nm excitation due to the energy from Er3+ to Ho3+, while the Er3+:1.5 μm emission decreases dramatically. The optimized concentration ratio of Er3+ to Ho3+ is found to be 1:1 in ZBYA system. The absorption and emission spectra were tested and the sample possesses large emission cross section (16.5×10-21 cm-2) around 2.7 μm along with larger radiative transition probability (25.11 S-1) on the basis of Judd-Ofelt and Fuchbauer-Ladenburg theories. Additionally, the energy transfer microparameters are calculated using F?rster-Dexter theory and the result shows the energy transfer coefficient of Er3+:4I13/2 →Ho3+:5I7 is 24 times larger than that of Er3+:4I11/2 → Ho3+:5I6. Our results show that Er3+: 2.7 μm emission can be sensitized by Ho3+ efficiently, and this Er3+/Ho3+- codoped ZBYA glasses might have potential application in MIR lasers. Part two in this chapter is spectroscopic property and energy transfer processes of singly doped and codoped Er3+ and Nd3+ AYFP glasses with low phosphate under an 800 nm excitation. The Er3+/Nd3+ system is particularly interested because Nd3+ can not only increase the pumping efficiency of 800 nm, and also can be a quenching center for the near-infrared (NIR) and the green upconversion emissions corresponding to the 4I13/2→4I15/2, 4S3/2, and 2H11/2 →4I15/2 transitions of Er3+. Optical mechanism between the two ions was discussed and the miscroparameters of the energy transfer between them ware calculated. There results indicated that Nd3+ can be an efficient sensitizer for Er3+ to obtain 2.7 μm emission. Part three, near to middle infrared luminescence and energy transfer process of Er3+/Yb3+ codoped AYFT glasses under 980, 1550 and 800 nm excitations were reported. Using a 980 nm laser diode pump, enhanced 1.5 and 2.7 μm emissions from Er3+:I13/2→4I15/2 and I11/2→4I13/2 transitions are observed, in which Yb3+ ions can increase pumping efficiency and be used as energy transfer donors. Meanwhile, Yb3+ can also be used as an acceptor and intensive upconversion luminescence of around 1000 nm is achieved from Er3+:I11/2→4I15/2 and Yb3+: F5/2→4F7/2 transitions using a 1550 nm excitation. In addition, the luminescence properties and variation tendency by 800 nm excitation is similar to that under 1550 nm excitation. The optimum Er3+ and Yb3+ ion ratio is 1:1.5 and excess Yb3+ ions decrease energy transfer efficiency under these two pumpings. These results indicated the two ions can be sensitized each other. In chapter VI, the 2.0 μm emission properties of Ho3+ codoped with Er3+ in the fluoride glasses under 1550 nm excitation have been investigated. The sensitization affect of Er3+ ions on Ho3+ is from the energy transfer process Er3+:4I13/2→ Ho3+:5I7. On the other hand, the energy transfer process can get a high efficiency under 1550 nm excitation compared to 980 or 800 nm excitations owing to lager absorption cross section at 1550 nm and ions were directly excited to the Er3+:4I13/2 level. Intensive 2.0 μm emission is observed from the fluorescence spectra. The microscopic interaction parameters of the phonon-assisted (Er3+: 4I13/2→Ho3+:5I7) process are calculated and the microparemeter reaches as high as 10.1×10-41 cm6/s, which is larger than the value calculated under 980 nm excitation. The further work focused on the effect of Ce3+ ions on the 2.0 μm emission when it was added into the Er3+/Ho3+ system. The enhanced 2.0 μm emission was obtained through CR processes (Er3+:4I11/2 + Ce3+ 2F5/2→Er3+:4I13/2 + Ce3+: 2F7/2 and Ho3+:5I6 + Ce3+: 2F5/2→Ho3+:5I7 + Ce3+: 2F7/2), which can efficiently suppress the excited state absorption. On this occasion, the obtained red upconversion at 667 nm belongs to three photon processes and the intensity reduces with the increasing of the Ce3+ content. Meanwhile, the intensity of Er3+:2.7 μm decreases linearly with the Ce3+ content, which directly demonstrated the existence of Er3+:4I11/2 + Ce3+ 2F5/2→Er3+:4I13/2 + Ce3+process. These results indicate that the Ho3+/Er3+/Ce3+ triply-doped fluoride glass is a promising material for 2.0 μm fiber laser applications. In chapter VII， series of Dy3+ doped fluoroaluminate glasses modified by TeO2(AYFT) have been prepared. The properties of 2.8 μm emission form Dy3+:6H13/2→6H15/2 transition were investigated under 1310 nm excitation. Intense emission around 2.8 μm is observed and the emission peak redshifts when >1 mol % RE ions are introduced into the glass network which can be explained by the self-absorption of Dy3+ ions. The calculated emission cross section at 2800 nm can reach as high as 0.67×10-20 cm2.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15925]
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	黄飞飞. 掺稀土氟化物玻璃中红外发光特性的研究[D]. 中国科学院上海光学精密机械研究所. 2015.

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