“管内熔体”法制备金属纳米晶复合铋酸盐玻璃光纤及其性能研究

Optical devices realized on the basis of nonlinear optical fibers, such as optical switchers etc., possess the concomitant advantages of high optical conversion efficiency and fast response. Meanwhile, they have tight structure, and easy to integrate with conventional optical communication networks, thus play a key role in constructing the all-optical communication networks. The bismuthate glass is acknowledged as one of the most promising candidates for fabricating high-performance nonlinear optical fibers, due to its very high nonlinear coefficient, excellent chemical and thermal stability, high mechanical strength and fiber drawing processibility. The doping of metal nanocrystals can dramatically enhance the optical nonlinearity of bismuthate glass fiber, thus shortening the length of fiber in practical applications, and effectively inhibit the signal deformation induced by group velocity dispersion. However, it is chellenging to control the crystalization of metal nanoparticles during fiber drawing by the conventional technique. This project will investigate the fabrication of bismuthate glass optical fibers doped with crystallization-controllable metal nanocrystals, test their optical properties, and study the crystallization behavior of metal nanocrystals in the constrained environment inside the fiber core, thus provide gist to the applications of bismuthate glass in future all-optical communication.

基于光纤和光波导自身非线性效应实现的光放大器、波长调制器件、全光开关等光学器件具有转换效率高、响应时间快等特点，同时结构紧凑，和光纤通信网络容易集成，是构建全光通信网络的关键元器件。铋酸盐玻璃具有极高的非线性系数，同时化学和热稳定性高、力学性能和拉丝性能好，是制造高性能非线性光纤的最佳候选材料。金属纳米晶掺杂可极大提高铋酸盐玻璃光纤的非线性系数，缩短实际使用长度，从而有效抑制群速度色散引起的信号畸变。然而采用传统方法制备的金属纳米晶复合铋酸盐玻璃光纤往往析晶不可控。本项目拟探索以“管内熔体”技术制备析晶可控金属纳米晶复合铋酸盐玻璃光纤的可能性，研究光纤的光学性能和纤芯内部受限环境中金属纳米晶的析晶行为及其与制备条件的关系，为铋酸盐玻璃光纤在未来全光通信中的应用提供依据。

基于光纤和光波导自身非线性效应实现的光放大器、波长调制器件、全光开关等光学器件.具有转换效率高、响应时间快等特点，同时结构紧凑，和光纤通信网络容易集成，是构建全光通信网络的关键元器件。铋酸盐玻璃具有极高的非线性系数，同时化学和热稳定性高、力学性能和拉丝性能好，是制造高性能非线性光纤的最佳候选材料。金属纳米晶掺杂可极大提高铋酸盐玻璃光纤的非线性系数，缩短实际使用长度，从而有效抑制群速度色散引起的信号畸变。然而采用传统方法制备的金属纳米晶复合铋酸盐玻璃光纤往往析晶不可控。本项目首先探索了基础组分对玻璃性能的影响，提出了通过氧化磷共掺大幅度提升银掺杂浓度的全新策略，实现了掺杂浓度高达10mol%且具有良好光纤拉丝性能的磷铋酸盐体系玻璃，获得了高达-14×10-12 m W-1的可饱和吸收系数和4.94×10-12 m W-1的反饱和吸收系数。在银掺杂磷铋酸盐玻璃体系的基础上，针对Ag纳米晶复合铋酸盐玻璃光纤拉制过程中出现的玻璃析晶、光纤结构严重变形、光纤芯层不连续及Ag纳米晶沉降等问题，我们分析了其产生原因，开发了两种新的预制棒及光纤制备技术：“熔体真空吸入法”（制备光纤预制棒）及改良的“熔芯法”（制备光纤）。这两种方法可用于解决金属纳米晶复合（磷）铋酸盐玻璃光纤拉制中的特异性问题，并证明了其对玻璃析晶、光纤结构严重变形、元素扩散及纳米晶沉降等问题的明显抑制作用。