过渡金属掺杂II-VI纳米晶-硫系玻璃复合光纤及中红外激光性能研究

中红外光纤激光器在民事和军事领域具有广泛的用途，已成为国内外研究的热点。针对目前中红外有源光纤材料缺乏、硫系玻璃中稀土离子溶解度低、量子效率低；过渡金属掺杂中红外晶体激光性能好，却又不能拉制成光纤等基础问题。本课题拟利用损耗最低、热性能最稳定的As2S3和As2Se3玻璃为基质，以激光性能优良、量子效率接近1、发射截面是稀土离子的100倍、宽半高宽的Cr2+/Fe2+掺杂四配位闪锌矿结构Ⅱ-Ⅵ族纳米晶为发光中心；通过热等静压的方式研制高效中红外光纤激光用复合玻璃芯棒及光纤。阐明复合玻璃的成型机理；探明玻璃种类、粒度分布、折射率、热压工艺和缺陷等参数对光纤激光性能的调控机理；利用传输方程和速率方程结合粒子群优化等算法优化设计谐振腔，实现中红外光纤激光的测试分析；解决当前中红外有源光纤掺杂浓度低、量子效率低、发射截面小、损耗高等科学难题，为中红外光纤激光器更广泛应用奠定坚实的科学和材料基础。

Mid-infrared fiber lasers have a wide range of applications in civil and military fields and have become a research hotspot at home and abroad. The current mid-infrared active glass fibers have lots of basic problems, such as lack of materials, low solubility of rare earth ions in chalcogenide glass, low quantum efficiency. Although transition metal doped mid-infrared crystals have good laser performance, they cannot be drawn into fibers. This project intends to use As2S3 and As2Se3 glass with the lowest loss and the most stable thermal properties as the matrix and use Cr2+/Fe2+ doped tetra-coordinated sphalerite structured II-VI nanocrystals with excellent laser performance, the quantum efficiency is close to 1, the emission cross-section is 100 times of the rare earth ions and the wide half height is wide as the luminescent centers. The composite preform core rod and optical fiber for high-efficiency mid-infrared fiber laser are developed by hot isostatic pressing. This project will explain the forming mechanism of composite glass and find out the optimal fiber laser performance by regulating the parameters, such as glass type, nanoparticle distribution, refractive index difference, hot pressing process, and defects. The fiber lasers will be optimized by using the transfer equation, rate equation, and particle swarm simulation. Then we will build the cavity to realize the test and analysis of the mid-infrared fiber laser. This project can solve the current scientific problems, such as low doping concentration of the mid-infrared fiber, low quantum efficiency, small emission cross section and high loss, which will lay a solid scientific and material foundation for the wider application of mid-infrared fiber lasers.