4.3μm中红外激光光源在国防和民用领域有着极好的应用前景。本项目针对目前制约4.3μm光纤激光光源发展的瓶颈问题，提出开展高性能Dy掺杂的硫系玻璃及光纤制备研究，通过实验探明硫系玻璃拓扑结构和化学计量比对稀土离子溶解度以及激光损伤阈值的影响机理，确定具有高稀土离子溶解度、高激光损伤阈值的玻璃组成，结合新型物理-化学综合动态开放除杂方法制备得到兼具高稀土溶解度、高激光损伤阈值、高纯等综合特性的硫系玻璃；通过低损耗、带结构、高掺杂硫系玻璃光纤制备技术瓶颈的突破，获得高质量Dy掺杂单模双包层增益光纤；在此基础上，通过4.3μm中红外光纤放大器理论模型的建立以及泵浦关键技术、增益光纤泵浦吸收和4μm以上放大的自发辐射（ASE）光谱特性调控机理的探索，初步建立4.3μm中红外光纤放大器原型。本项目的实施有望实现自主可控的中红外增益硫系光纤制备，促进4μm以上中红外光纤激光光源的进一步发展。

The 4.3μm mid-infrared laser has broad and important application prospects in national defense and civil fields. Aiming at the bottleneck problem restricting the development of 4.3μm fiber laser, this project studies high-performance Dy-doped chalcogenide glass and fiber materials. The influence mechanism of topological structure and stoichiometric ratio of chalcogenide glasses on the solubility of rare earth ions and laser damage threshold will be proved, and the glass composition with high solubility of rare earth ions and high laser damage threshold will be determined. Combined with the new physical-chemical comprehensive dynamic open impurity removal method, the chalcogenide glass with high solubility of rare earth, high laser damage threshold and high purity will be prepared. Through the breakthrough of the bottleneck of the preparation technology of low loss, band structure and high doping chalcogenide glass fiber, the high quality Dy-doped single-mode double-clad gain fiber will be obtained. On this basis, through the establishment of the theoretical model of 4.3 μm mid-infrared fiber amplifier and the exploration of the key technology of pumping, the regulation mechanism of ASE spectral and pumping absorption characteristics, the prototype of 4.3 μm mid infrared fiber amplifier will be initially established.The implementation of this project is expected to realize the self-controlled preparation of mid-infrared chalcogenide gain fiber, and promote the further development of mid infrared fiber laser source above 4 μm.