基于高温等离子法制备掺镱微结构光纤光暗化机理研究

With development of rare earth doped optical fiber technology, the output power of fiber laser is required to be not only higher and higher, but also stable during intensive operations. In order to solve this problem, an effective way is to decrease the photodarkening effect of the Yb-doped optical fiber, which has attracted great attention recently. Regarding the photodarkening effect of the Yb-doped optical fiber, a lot of research has been done theoretically and experically, but there is, so far, no consensus achieved as to the photodarkening mechanism. In this project, we provide our recent research results on the photodarkening effect using the novel fabrication method of the Yb-doped microstrucure fiber, We investigate the photodarkening mechanism through Yb3+ clusters, the formation of Yb2+ color center, non-bridging oxygen hole centers defects in silica glass, then the photodarkening effect of the Yb-doped optical fiber can be effectively eliminated for fiber laser. The theoretical results with experimental data of the project will provide a thorough grounding in developing high-quality Yb-doped microstrucure fiber laser in the future.

随着稀土掺杂微结构光纤技术的不断发展，在光纤激光器研究领域中，不仅要求光纤激光器能输出高功率，还要求能保证在长时间运转过程中保持输出功率以及效率的稳定性，因此降低掺杂光纤光暗化效应是目前急需解决的重要课题。尽管世界上各研究小组对光暗化进行了大量的理论及实验研究，但是对光暗化产生的机理还没有统一而系统的认识。为此，结合课题组在掺杂微结构光纤光暗化效应研究的前期成果和掺杂微结构光纤先进制备工艺的优势，本项目将分别从Yb3+团聚、Yb2+色心形成、石英玻璃非桥氧心缺陷等方面进行研究，探索引起光暗化的机理，从而达到从源头上减少稀土掺杂微结构光纤光暗化效应对光纤激光器的影响，为研制高性能掺镱微结构光纤和光纤激光器打下扎实的基础。

为探索光子暗化的机理，达到有效抑制稀土掺杂微结构光纤光子暗化效应的目的。本项目通过优化J-O 理论，设计了理想的稀土掺杂石英玻璃组分配比。并采用激光烧结法研制出多种结构的大模场掺镱双包层微结构光纤。经实验检测表明：经过30小时的976 nm激光照射后，光纤的激光斜率效率由81.03%降至80.77%，下降幅度仅为0.26%，光暗化平衡损耗为1.07dB/m@633nm。相关结果分别发表在Optical Materials Express、J Lightwave Technol. Journal.、J Non-Cryst. Solids.等期刊34篇，申请专利6件（其中发明专利4件）。培养广东省珠江学者1名、博士生4名（其中在读2名）、硕士生23名（其中在读3名）。因此，本项目很好完成了原预定目标，为未来研制高性能镱离子掺杂微结构光纤提供具有实用价值的理论和方法，突破我国高功率激光器用镱离子掺杂光纤依靠进口的局面。