| 题名 | 重金属氧卤铋锗玻璃结构和光谱性质研究 |
| 作者 | 孙洪涛 |
| 学位类别 | 博士 |
| 答辩日期 | 2006 |
| 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 | 重金属氧卤玻璃 铋锗玻璃 稀土离子 光谱性质 上转换发光 |
| 其他题名 | Structural and spectroscopic properties of rare-earth doped heavy metal oxyhalide bismuth germanate glasses |
| 中文摘要 | 蓝绿波段激光在高密度数据存储、大屏幕显示和激光医疗等领域有着广泛的应用价值。由于上转换蓝绿光纤激光器所采用的增益光纤一般为氟化物玻璃基质，在高功率红外泵浦光作用下，往往会在光纤内部产生光致变色破坏，造成光纤内部损耗逐步加大，在这种情况下很难获得高功率激光输出。此外，氟化物玻璃较差的化学稳定性和较低的机械强度也为其实际应用带来了困难。因而，开发上转换光纤激光器用高强度和高效率的有源玻璃和光纤对实现较高功率蓝绿激光输出具有重要意义。 在文献综述部分，首先对重金属和氟化物玻璃的研究情况、光纤激光和稀土离子的上转换发光的研究历史进行了概述，进而提出本文的研究内容和思路。 在论文的第二章，介绍了实验方法和理论计算，主要包括玻璃的制备、玻璃样品各种性质的测试和光谱理论计算。 论文的第三章是本文的核心之一，重点研究了掺铒和掺铥重金属氧卤铋锗酸盐玻璃结构和光谱性质。通过结构分析可知，卤化物引入到铋锗酸盐玻璃体系中，会对玻璃网络中的主要振动单元的具体结合方式产生影响，从而导致玻璃网络中的键振动削弱。同时，铋锗酸盐玻璃的析晶稳定性和显微硬度随着卤化物的逐步加入明显下降。通过对掺铒重金属氧卤铋锗酸盐玻璃光谱性质研究，得出以下结论：1）卤化铅加入到掺铒的铋锗酸盐玻璃中导致Er3+离子的配位环境发生变化，从而在整体上导致Er3+离子键合方式由共价性倾向于离子性；2）卤化铅替代PbO，铋锗酸盐玻璃的最高声子能、可见波段透过率、OH-含量、基质玻璃网络键振动会发生变化；3）卤化铅替代PbO后Er3+离子上转换发光增强与否，取决于以上因素的综合结果，仅凭某一因素的变化难以断定上转换发光是否增强。铋锗酸盐玻璃的透过性能的改善可以通过熔制工艺的改进来实现，改进工艺后熔制的铋锗酸盐玻璃的上转换发光增强，但透过性能仍弱于锗酸盐玻璃。对掺铒无铅铋锗镧玻璃的研究表明，随着La2O3含量的上升，铋锗镧玻璃的上转换发光稍微增强。最后，我们还系统研究了掺铥重金属氧卤铋锗酸盐玻璃光谱性质，并对上转换机制进行了简单的阐述。 论文的第四章也是本文的核心之一，重点研究了掺铒和掺铥重金属氧卤锗酸盐玻璃结构和光谱性质。通过对氧氟、氧氯锗酸盐玻璃的红外光谱和拉曼光谱分析，可知卤化物引入到锗酸盐玻璃体系中会对玻璃网络中的主要振动单元的局域环境产生影响，从而导致玻璃网络中的键振动削弱。同时，锗酸盐玻璃的析晶稳定性随着卤化物的逐步加入明显下降。PbCl2替代PbO，锗酸盐玻璃上转换荧光的明显增强应归因于玻璃最高声子能变小、OH-含量下降、基质玻璃网络键振动变弱及Er3+离子局域配位环境变化四个因素，并且这四个因素对上转换发光的增强效应要强于可见波段透过率下降对上转换发光的影响。Er3+和Tm3+掺杂锗酸盐玻璃的上转换荧光要强于同样掺杂的碲酸盐玻璃，主要原因是氧卤锗酸盐玻璃比碲酸盐玻璃具有更好的可见波段透过性能、更弱的网络键振动强度和更低的OH-含量。通过对Er2O3、Er2F6和Er2(NO3)6掺杂的氧氟锗酸盐玻璃的1.5μm荧光性能的研究，可知玻璃中稀土离子的局域环境会直接影响到Er3+激发态能级寿命，进而影响到光谱性质。通过对上转换荧光现象的研究可知在Er2O3、Er2F6和Er2(NO3)6掺杂的氧氟锗酸盐玻璃中，Er3+离子非近程的环境可能存在相似性，这种相似性表现在2H11/2到4I15/2的发射峰位发生轻微红移，同时Er3+离子近程环境在三种掺杂条件下是各不相同的，这种不同导致了三者的绿光发射变化无统一的规律。通过对荧光性能的讨论，我们得到以下两条结论：1）稀土引入方式的不同的，会导致光谱性质存在差异，稀土离子在近程键合可能仍然保持了晶体时的近程键合方式；2）稀土的光谱性质受近程配位环境及非近程环境的共同制约，研究稀土发光行为必须综合考虑稀土的近程和非近程配位环境情况。 论文的第五部分是全部实验的总结。 |
| 英文摘要 | Blue and green lasers have many applications in many areas such as high density data storage, large-scale screen display and laser therapy. In general, blue and green upconversion fiber lasers use fluoride fiber as gain media. When fluoride fiber is radiated by high power infrared lasers, it always induces photocromic phenomenon in glasses which increases fiber loss. Then it is difficult to obtain high power laser output in fluoride glass fiber. Moreover, fluoride glasses have poor chemical and mechanic properties which also hinder its pratical applications. Therefore, it is important to study the active glass and fiber with high efficiency and hardness for upocnversion fiber lasers to realize high power laser output. In the section of literature summarization, firstly the research history of heavy metal oxide glass, fluoride glass, fiber laser and upconversion luminescence of rare-earth ions are introduced in details. Then the research content and purpose of this dissertation are presented. In the second section of this dissertation, the experimental method and theory calculation, such as glass preparation, glass property measurement and spectroscopic theory are introduced. As one of the core sections of this dissertation, section 3 presents the results and discussions on structural and spectroscopic properties in Er3+ and Tm3+ doped heavy metal oxyhalide bismuth-germanate glasses. Based on the structural analysis, we observe that the exact bond methods and bond vibration strength of main vibrational groups in glass network change with the introduction of halide content. Meanwhile, the crystalline stability and micro-hardness of bismuth-germante glasses weaken with halide content introduction. Based on the spectroscopic properties analysis, we could draw the following conclusions: 1) the Er3+ local environment change with the halide introduction, and the bond manner is inclined to electrovalent bond; 2) the maximum phonon energy, the transmission in visible wavelength, OH- content and network bond vibration intensity of bismuth-germanate glasses change with the replacement of PbO by lead-halide; 3) the property of upconversion luminescence depends on all the above factors, and it is hard to estimate whether the upconversion luminescence enhance only by one of the aspects. The transmission property of bismuth-germanate glasses can be improved by revised melting method; however, the glass transmission property prepared by revised melting method is still worse than that of germante glasses. We also investigate the Er3+ doped lead-free bismuth-germanate-lanthanum glass. With increasing La2O3 content, the upconversion luminescence increase slightly. Finally, we systematically investigate the spectroscopic properties of Tm3+- doped oxhalide bismuth-germanate glasses and simply explain the upconversion mechanism. The fourth section is also one of the core sections of this dissertation. In this section, we mainly study the structural and spectroscopic properties in Er3+ and Tm3+ doped heavy metal oxyhalide germanate glasses. Based on the IR and Raman spectra analysis, we observe that the exact bond methods of main vibrational groups in glass network change with the introduction of halide content. Meanwhile, and bond vibration strength and the crystalline stability of germante glasses become weakening with halide content introduction. With replacement of PbO by PbCl2, the upconversion luminescence increases notably, which is due to the decrease of maximum phonon energy, OH- content and glass network vibration intensiy and the change of Er3+ ion local environment. Moreover, the influence of the above four aspects on upconversion luminescence is stronger than that of decreasing visible transmission. The upconversion of Er3+ and Tm3+ ions in germanate glass is stronger than that in tellurite glass, because the former has better visible transmission, weaker network vibration and lower OH- content than the latter. Based on the investigation of 1.5μm luminescence property of Er2O3, Er2F6 and Er2(NO3)6 doped oxyfluoride germante glasses, we observe that the lifetime of excited level of Er3+ ion can be affected by the local environment of Er3+. Based on the investigation of upconversion luminescence in Er2O3, Er2F6 and Er2(NO3)6 doped oxyfluoride germante glasses, we could deduce that the non-short-range environment of Er3+ ion in the above three doping manners might exist similarity, which represent the emission peak of 2H11/2→4I15/2 shift towards long wavelength. Meanwhile, the short-range environment of Er3+ ion in the above three doping manners is quite different, which represent the change of green emissions has no unified law. Based on the detailed discussion of luminescence property, we could draw two conclusions: 1) the short range bond of rare earth ion in glasses might preserve the short-range bond manner in crystal, which induce the difference of spectroscopic propery; 2) the spectroscopic properties depend on the short-range and non-short-range environment of rare-earth ions, and one must sysmetically take into account the above aspects when studying the spectroscopic properties. The fifth section of this dissertation is the summarization of all the experiments. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15395]  |
| 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 | 孙洪涛. 重金属氧卤铋锗玻璃结构和光谱性质研究[D]. 中国科学院上海光学精密机械研究所. 2006. |
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