| 题名 | 掺Yb3＋、Nd3＋晶体和玻璃的激光光谱和激光性能研究 |
| 作者 | 毛艳丽 |
| 学位类别 | 博士 |
| 答辩日期 | 2002 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 干福熹 |
| 关键词 | Yb3+离子 Nd3+离子 晶体 玻璃 激光光谱 激光性能 |
| 其他题名 | Study on laser spectroscopy and laser performance of Yb3+ or Nd3+ -doped crystals and glasses |
| 中文摘要 | 本文选择近年来在激光应用方面发展较快和最具有应用价值的几种掺Yb3+的激光材料和掺Nd3-的激光材料，开展了常规光谱、选择激发荧光光谱、时间分辨荧光光谱和激光性能的研究，目的是从微观上揭示Yb3+离子和Nd3+离子在不同基质中的发光机理，为其在激光器中的实际应用提供实验和理论依据。我们首先研究了掺Yb3+和掺Nd3+激光材料的光谱特性。首次采用选择激发荧光光谱技术研究了Yb：VAG、Yb：FAP、YbC3S2-FAP、Yb：磷酸盐的格位变化特征。研究发现：Yb3-在YAG晶体中只占据一种格位；在Yb：FAP和Yb：C3S2-FAP晶体中存在两种类型的Ca（II）格位；在Yb3+离子掺杂的磷酸盐玻璃中Yb3+离子周围配位环境存在着连续性畸变；证明了相对于Nd3+离子，Yb3+在材料中的格位结构变化较小。Yb3+离子间强的相互作用导致明显的合作发光现象，并由此分析了掺Yb3+激光材料的浓度碎灭现象。首次提出Yb3十激光材料的浓度碎灭效应明显小于Nd3+激光材料的一个重要原因是Yb3+离子在激光介质中格位结构比较一致，交叉驰豫损耗较小。首次系统地研究了温梯法生长的高浓度Nd:YAG晶体的光谱特性，其低温吸收谱表现出多格位特征。Nd:YAG晶体荧光寿命的浓度碎灭明显存在，3at％Nd:YAG晶体的荧光寿命为124娜。从能量转移角度对高浓度Nd:YAG晶体荧光寿命随温度的变化进行了解释。Nd:YVO4晶体的荧光寿命随温度的变化较为反常，它随温度升高而升高。采用选择激发和时间分辨荧光光谱研了Nd3+磷酸盐玻璃的格位特性和激活离子间的能量转移。论文第四章研究了掺Yb3+和掺Nd3＋激光材料的激光性能。采用大功率的940nmInGaAsLD泵浦研究了Yb:YAG品体的激光性能，Yb：YAG品体的掺杂浓度分别为IOat％和5at％，斜率效率分别为37％和25.5％，最人输出功率分别为4.1W和2.7W:976nmLD泵浦Yb3+磷酸盐玻璃，获得的激光刹率效率为40％。Yb3+”磷酸盐玻璃中YbZO：的掺杂浓度为smol％。首次系统地研究了温梯法生长的高浓度Nd：YAG晶体的激光性能，并与提拉法生长的1.1at％Nd:YAG和2at％Nd:YVO4晶体的激光咨性能做了对比，研究发现高浓度Nd:YAG晶体的激光性能要优于低浓度的Nd：YAG晶体，并且2at%Nd:YAG晶体的激光性能与2at％Nd:YVO4品体的激光性能相当。另外采用闪光灯泵浦还对比了Nd:YAG晶体与Nd:KGW品体的激光性能。论文第五章对比讨论了基质对Yb3＋离子光谱特性的影响；离子一离子相互作用和掺杂离子的格位结构对Yb3+、Nd3+激光材料浓度碎灭效应的影响，以及高增益激光晶体和玻璃的激光特性。本文最后概括总结了全文的实验结果和结论。 |
| 英文摘要 | In this paper, the conventional spectra, site-selective fluorescence spectra, time-resolved fluorescence spectra and laser performance of several Yb+-doped or Nd+-doped laser materials have been investigated. The purpose of the dissertation is to reveal the microscopic luminescent mechanism of Yb3+ ions and Nd3+ ions in different hosts and to provide the experimental and theoretical basis for their practical laser applications. Firstly, we studied the spectroscopic properties of these Yb3+-doped and Nd3+-doped laser materials. The variation of sites of Yb:YAG, Yb:FAP, Yb:C3S2-FAP, Ylrphosphate glasses was investigated by site-selective spectroscopy techniques for the first time. Results show that there is only one type of site in Yb:YAG crystals which is occupied by the Yb3+ ions, and two types of Ca(II) site of Yb:FAP and Yb:C.- S2-FAP were discovered. There is a continuous distortion of the local environment of Yb3+ ion in Yb3+-doped phosphate glass. Results indicate the variation of site structure of Yb3+ ions in host is smaller comparing with the Nd3+ ions. The concentration quenching of YlrYAG was analyzed according to its cooperative luminescence caused by the strong interaction between the ytterbium ions. Comparing with the Nd3T-doped laser materials, the concentration quenching effect is weaker. One important reason was advanced for the first time, which is the uniform site structure of Yb3+ ions in host provides less cross-relaxation loss between Yb3+-Yb3+ ions and low concentration quenching of luminescence. The spectroscopic properties of high-doped Nd:YAG grown by temperature gradient technique(TGT) were studied systematically for the first time. The characteristic of multi-sites of Nd3+ was found in absorption spectra of Nd:YAG at low temperature. The concentration quenching effect of Nd:YAG crystals was obviously observed. From the point of the energy transfer, the variation of fluorescence lifetime of high-doped Nd:YAG with temperature was analyzed. The variation of fluorescence lifetime of Nd:YV04 with temperature is found to be anomalous, and its lifetime increases with the temperature increasing. The site-selective characteristic and energy transfer between the ions of Nd3+ in phosphate glass were studied by selective excitation and time-resolved spectroscopy technique. Secondly, we studied the laser performance of these Yb3+ doped or Nd3+ doped laser materials. Using 940nm InGaAs diode laser as pumping source, the laser performance of Yb:YAG crystals with different Yb3+ doping concentrations was investigated. The slope efficiency for 10at% Yb:YAG is 37%, and 25.5% for 5at% Yb:YAG. The maximum output power is 4.1W and 2.7W for 10at% and 5at% Yb:YAG, respectively. The slope efficiency of 40% was obtained for Yb3+ doped phosphate glass pumped by 976nm diode laser, and the Yb2O3 doping concentration is 5mol%. The laser performance of high-doped Nd:YAG crystals grown by TGT has been demonstrated systematically and compared with that of 1.1 at% Nd:YAG grown by Czochralski and 2at% Nd;YVO4. The high-doped Nd:YAG shows excellent performance, which is superior to the lower-doped Nd:YAG. The laser performance of 2.0at% Nd:YAG crystal is compared to that of 2at% Nd:YVO4 crystal. Additionally, the laser performance of the Nd:KGW and Nd:YAG laser crystals, which were pumped by flashlamp, were compared. Thirdly, the host effect on the spectroscopic properties of YbJ+ ions has been compared. The influence of ion-ion interaction and site structure on concentration quenching of Yb3+-doped or Nd3"-doped laser materials, and the influence of high-doped crystals and glasses on the laser performance have been discussed contastively. The experimental results and conclusions were summarized at the end of dissertation. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15358]  |
| 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 | 毛艳丽. 掺Yb3＋、Nd3＋晶体和玻璃的激光光谱和激光性能研究[D]. 中国科学院上海光学精密机械研究所. 2002. |
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