| 题名 | 中红外激光材料光谱设计研究 |
| 作者 | 彭雅珮 |
| 学位类别 | 博士 |
| 答辩日期 | 2016 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 张龙 |
| 关键词 | 中红外激光 过渡金属离子 稀土离子 Cr2+:ZnS/ZnSe 氧氟镓玻璃 |
| 其他题名 | The design of spectrum in mid-infrared laser materials |
| 中文摘要 | 中红外2-5μm波段激光在军事和民用方面具有巨大的应用潜力。目前实现2-5μm中红外固体激光的主要方式中依靠离子(稀土离子和过渡金属离子)能级跃迁产生中红外激光的方式实现LD直接泵浦，将大幅度降低系统的复杂程度，提高效率，因此发展合适的中红外激光增益材料成为国内外研究学者们必须解决的研究难题。在众多红外激光材料中，Cr2+:ZnS/ZnSe具有室温量子效率较高、激发态吸收较小、吸收和发射截面较大等优点，而氧氟玻璃在该波段透明度高且声子能量低等优点，两者皆成为近几年中红外激光材料领域研究的热点。 第一章首先综述了中红外固态激光器的发展趋势，其发展核心关键在于激光增益材料的好坏，介绍了常用激光增益材料的基本特性和发展前景，并探讨分析目前激光增益材料遇到的发展的局限性与困境，最后根据此局限性设计提出课题选题依据和研究思路。 第二章介绍了本论文中使用的Cr2+:ZnS/ZnSe和氧氟玻璃制备方法和所需要使用的测试仪器和计算理论知识。 第三章，我们以Cr2+:ZnS/ZnSe和氧氟玻璃作为研究对象，首先采用典型热扩散法制备Cr2+:ZnS/ZnSe，即先在CVD+HIP生长的多晶ZnS/ZnSe表面沉积Cr金属膜，之后在真空密封氩气保护石英管中高温热扩散，制备高光学质量的Cr2+:ZnS/ZnSe激光陶瓷，并研究其基本的光谱特性。 在实验中发现样品存在Cr3+离子的特征吸收峰，铬离子价态的变化会造成有效离子掺杂浓度的降低，导致后期激光功率严重下降。另外，扩散过程中Cr2+离子掺杂浓度梯度分布也是材料制备工艺的一大难点。我们在不同温度和不同保温时间条件下进行一维方向的热扩散，建立扩散模型，结合菲克第二定律，计算其扩散机理参数。 第四章，我们成功采用热扩散制备的Cr2+:ZnSe激光陶瓷，在室温下分别使用Tm2+:YLF/ YAP固体激光泵浦和Tm:silica光纤激光泵浦，实现连续激光输出。另外，又采用钛宝石飞秒激光螺旋形直写在Cr2+:ZnS材料内部写入通道光波导结构，并实现中红外波导激光输出。 第五章中通过高温熔融法制备了氧氟镓玻璃。由于2.7-3.6μm处的OH-吸收带影响，会大大减少Er3+离子发光效率，因此，我们通过引入BaF2替代BaO组分来去除OH-基团，研究其玻璃结构和光谱特性。第二小节，研究Er3+离子掺杂氧氟镓玻璃的光谱学特性，并利用J-O理论计算光谱参数，结合计算发射截面和增益截面获得良好光谱特性。第三小节，研究敏化离子Yb3+对Er3+离子2.7μm发光的影响及其机理。在980nm泵浦下，Yb3+离子能有效增加Er3+离子2.7μm发光。同时Yb3+离子与Er3+离子的最佳掺杂浓度比例为0.5:1。 最后第六章是结论部分，总结全文的实验结果，同时指出本论文的不足和需要改进研究之处。 |
| 英文摘要 | There are various potential applications such as military and civilian fields in mid-infrared (IR) 2-5μm laser. Currently, the main methods of mid-infrared solid-state lasers rely on the levels transition of rare-earth or transition metal ions, which can realize the LD pump directly in laser system. It will greatly reduce the complexity of laser system and improve laser efficiency, so that the development of the suitable laser gain medium in mid-infrared regions is key problem for reasarchers. Among of mid-infrared laser materials, Cr2+:ZnS/ZnSe featuring high quanum efficicency at room temperature, low excited state absorption, large absorption and emission cross section and oxyfluoride glass with high transmittance and low phonon energy are the most popular candidate. Firstly, the background and the development of mid-infrared solid-state laser were revealed in the chapter 1. The key point of the development of mid-infrared solid-state laser was the laser gain medium. We introduced the development prospects and basic characteristics of commonly used mid-infrared laser gain materials, then analyzed the limitations and difficulties of the mid-infrared laser gain materials. Finally, we demonstrate the topic basis and the research content of this work. In chapter 2, we introduced the preparation method of Cr2+:ZnS/ZnSe and oxyfluoride glass. We also introduced the synthesis and characterization equipment and theoretical analysis of the samples we prepared. In chapter 3, we take both Cr2+:ZnS/ZnSe and oxyfluoride glass as our research objects. First, we adopted the typical thermal diffusion method in materials preparation. The CVD-HIP- grown ZnS/ZnSe hosts were deposited with Cr film, and then diffused under high temperature in sealed vacuum silica tubes in argon gas atmosphere to get high optical quality laser materials. The spectra characteristics were investigated. It was found that typical absorption band of Cr3+ ions in samples. The variation of valence state of Cr ions would reduce the effective doping concentration and lead to low laser power. And the concentration gradient of Cr ions in the diffused sample has been a severe problem in preparation process. We use thermal diffusion method on 1D direction in different temperature and holding time, together with a simplified Fick’s second law model, in researching the diffusion coefficient. In chapeter 4, we achieved continuous-wave Cr2+:ZnSe laser output at room temperature by Tm2+:YLF/ YAP or Tm:silica fiber laser pumped. Moreover, we also achieved Cr2+:ZnS channel waveguide laser output by fs laser spiral writing directly. In chapter 5, we investigated oxyfluorogallate glass by high temperature melting method. The content of OH- in glass will participate in the energy transfer of rare-earth ions and reduce the emission intensity. Therefore, we induce BaF2 to substitute for BaO to improve the OH- absorption at 3 μm of gallate glass system. The effect of BaF2/BaO ratio on the structure of Er3+-doped gallate glass were been investigated. In the second section, the 2.7 μm emission of Er3+ ions, optical absorption, Judd–Ofelt (J–O) intensity parameters, spontaneous transition probability, and stimulated emission cross-section were also calculated and discussed. In the third section, the spectroscopic properties of an Er3+/Yb3+-codoped oxyfluorogallate glass are investigated as a laser material with 2.7 μm emission. Yb3+ ion is widely used as sensitizer of Er3+ to improve the pump absorption and the quantum efficiency. The optimal doping concentration ratio of Yb3+ and Er3+ ions is 0.5:1. Finally, we give a summary of the experimental results, point out the shortage of this thesis, and need to improve the place of this study. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15981]  |
| 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 | 彭雅珮. 中红外激光材料光谱设计研究[D]. 中国科学院上海光学精密机械研究所. 2016. |
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