Nd3+掺杂硅酸盐光子晶体光纤的制备及性质研究
文献类型：学位论文
| 作者 | 李萌 |
| 文献子类 | 博士 |
| 导师 | 陈丹平 |
| 关键词 | 硅酸盐玻璃 Silicate Glasses 大模场 Large-mode-area 全固态 All-solid 光子晶体光纤 Photonic Crystal Fiber 光纤熔接 Fiber Fusion Splicing |
| 其他题名 | Study on the fabrication and properties of neodymium doped silicate photonic crystal fibers |
| 英文摘要 | 稀土离子掺杂石英大模场光子带隙型光纤具有优异的高阶模抑制能力，以及独特的波长过滤与色散调控能力，因此成为了高功率激光光纤领域近年来的热点方向。相比于石英玻璃，硅酸盐玻璃则具有稀土离子掺杂浓度较高，拉丝温度较低，折射率易于调节，非线性阈值高，制备工艺简单，材料成本较低的特点，因此适合于需要较高增益的短光纤的研究，以及对于新的光纤结构的探索性研究。将大模场光子带隙型光纤的出色的高阶模抑制能力与硅酸盐玻璃光纤稀土离子掺杂浓度较高的特点相结合，则可在光纤较短的情况下实现稳定的单模激光输出。另一方面，包括硅酸盐玻璃光纤在内的多组分玻璃光纤，其实际应用范围主要是以短光纤实现单频激光的产生，或是以氟化物等光纤实现中红外波段的激光输出，而上述两种光纤的实用化，必然面临其与石英光纤熔接的问题。然而，由于多组分玻璃与石英玻璃在软化温度及热膨胀方面都有较大差异，石英光纤与多组分光纤的熔接问题一直未能较好的解决。因此，本文主要做了以下两个方面的研究：首先，研究了硅酸盐大模场光子带隙型光纤的理论设计与实验制备方法，以期实现在光纤长度较短的情况下，光子带隙型光纤的单模激光输出；之后，研究了硅酸盐玻璃光纤与石英光纤熔接的工艺及其可行性问题，为多组分玻璃光纤的实际应用打下基础。取得的主要成果与结论如下： 1. 研究了硅酸盐大模场光子带隙型光纤的理论计算与制备工艺。采用高阶模离域模型，设计并成功制备了钕离子掺杂硅酸盐大模场光子带隙型光纤，并分析了该种光纤的设计及制备误差。研究了采用六角形石英模具进行硅酸盐光纤预制棒烧结的工艺，获得了烧结质量较高，易于脱模的预制棒烧结方法。 2. 研究了在高折射率棒与背底玻璃的折射率差值较小的情况下，稀土掺杂大模场光子带隙型光纤产生激光的可行性。实验表明当在光纤内包层材料的相对折射率差为“任意小”时，仍可实现激光输出，因而扩展了该类光纤设计时材料折射率的选择范围。进一步研究了光纤制备工艺，证明了采用热膨胀较低的材料作为光纤的保护层，有助于在预制棒不采用烧结处理的情况下保持光纤的结构，并能够在一定程度上起到消除层间孔的作用。 3. 研究了硅酸盐玻璃光纤与石英光纤的熔接工艺。设计并制备了钕离子掺杂硅酸盐大模场折射率导引型光纤，并将其与双包层石英光纤光栅熔接，成功实现了硅酸盐光纤在1064 nm 的激光输出。另外，采用光束传播算法分析了熔接点的损耗。; Rare-earth doped large-mode-area silica photonic bandgap fibers have shown excellent potential for higher-order mode suppression, and presented unique properties of spectral filtering and chromatic dispersion control, thus having been widely studied in recent years in the scope of high power lasers. Compared with silica glass, silicate glasses have characteristics such as higher rare-earth solubility, low fiber fabrication temperature, easily adjustable refractive index, high non-linear effects threshold, mature fabrication technique, low cost, etc., therefore, are not only promising candidates for short fiber lasers where a high gain is needed, but can be used to investigate new structured fiber designs. The combination of photonic bandgap fiber designs and rare-earth doped silicate glasses can lead to robust single-mode laser output in fibers with short lengths. On the other hand, in practical use, soft glass fibers involving silicate glass fibers, are usually used to obtain single-frequency laser, or to generate mid-infrared lasers with fluoride fibers. For both cases, high-quality fusion splicing is requisite for the development of fiber laser systems. However, due to the significant differences in properties such as softening temperature and thermal expansion coefficient between soft glasses and silica glass, the fusion splicing technique between these two fibers have not been well studied. Therefore, two fields have been mainly studied in this work. First, the theoretical simulation and fabrication methods for silicate large-mode-area photonic bandgap fibers have been developed, in order to obtain single-mode laser emission in a photonic bandgap fiber with short length. For another, the fusion splicing technique between silicate and silica fibers have also been studied, which is important for the further development of practical soft glass fiber systems. The following three parts have been included in this thesis. Firstly, the theoretical simulation method and fabrication technique of large-mode-area silicate photonic bandgap fibers have been studied. Based on the power delocalization model, we have theoretically designed and experimentally demonstrated a neodymium doped silicate large-mode-area photonic bandgap fiber, and the errors in simulation and fiber fabrication have been discussed. Besides, we have also developed a preform sintering method by using silica mounds. The sintered preform has high quality and can be easily taken out from the mounds. Secondly, laser generation in photonic bandgap fibers with low cladding index contrast have been studied. In this study, we have demonstrated that laser emission can still be generated in photonic bandgap fibers when the fiber cladding has arbitrarily low index contrast, which will extend the choices of glass refractive indices in photonic bandgap fiber designs. Besides, we have further studied the fiber fabrication technique, and shown that by adopting glass which has low thermal expansion coefficient to fabricate fiber jacket, the fiber structure can be better maintained even when the preform is not sintered, and interstitial air holes can be better exhausted. Lastly, the fusion splicing technique between silicate and silica fibers has been studied. We have designed and fabricated a neodymium doped silicate large-mode-area index-guiding photonic bandgap fiber, which is fusion spliced with a double-cladding silica fiber grating. A laser output at 1064 nm has been obtained. In addition, the beam propagation method was used to analysis the loss at the splicing point. |
| 学科主题 | 材料学 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/31137]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 李萌. Nd3+掺杂硅酸盐光子晶体光纤的制备及性质研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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