放大光纤可用于构建激光器、放大器、宽带光源等系统，在国民生产、军事国防、光纤通信等领域发挥着重要的作用。铋酸盐玻璃具有声子能量低和发射截面大等优势，是热门的光纤基质材料。但是较差的光学均匀性和较高的本征损耗是制约其应用的重要因素。与高温熔融法不同，本项目拟采用化学共沉淀法制备铒铥共掺铋硅玻璃与光纤，它能有效解决原料化合物中原子量不同而导致的扩散速度不一致问题，实现化合物原子尺度的复合。这有利于提高玻璃的均匀性与纯度，降低Bi元素的挥发与变价，降低玻璃的本征损耗。同时，引入近红外发光较强的PbSe量子点和Er、Tm构成宽带复合发光中心，通过改变量子点尺寸实现对宽带发光位置、强度、带宽的调控，打破稀土离子固有窄带能级的束缚，制备出具有不同放大特性的铋硅玻璃光纤。本课题将着重探讨复合发光中心内两种不同类型的发光离子的辐射行为和相互作用机制等科学问题，为重金属放大玻璃光纤的研制提供理论和实践支持。

Optical amplifier fiber can be used to assemble the lasers, optical amplifiers and broadband light sources, which play an important role in national production, military defense, fiber optic communications etc. Bismuth glass with the low phonon energy and high emission cross section is the hot fiber matrix. But the poor optical homogeneity and higher intrinsic loss prevent the application spread of this glass system. Different from the conventional melt quenching method, this item employs the chemical coprecipitation synthesis method to prepare the Er3+/Tm3+ co-doped bismuth silicate glass and fiber. This method will effectively resolve the inconsistence of diffusion speed of the starting compounds, making true the high optical homogeneity at atomic scale. Moreover, it will help improve the uniformity and purity of the prepared glass, reduce the volatilization of bismuth element and variable chemical valence of bismuth ions, increase the solubility of rare earth ions in glass, and reduce intrinsic loss of the sample. Meanwhile, the introduction of PbSe QD into the bismuth glass will enhance emission of Er、Tm ions. The emission spectral position, intensity and bandwidth will change with the modification of particle size of QD. Therefore, the optical fibers characterized by the different amplification properties are ultimately achieved. This item will focus on the amplification mechanism of the PbSe-Er/Tm Recombination broadband emission center in bismuth glass, providing the theoretical and practical support for the development of heavy metal oxide glass amplifier fiber.