含Ag纳米颗粒稀土掺杂碲酸盐玻璃1-2μm宽带光辐射增强及光纤制备

Overcoming the limitation of low luminescent efficiency due to the electric-dipole forbidden transition of doped rare-earth ions in glass host, and realizing the high-gain and ultra-broadband light amplification of doped fiber is very urgent for the current WDM communication system which is now faced with the ultra-large capacity data transmission. To this end, the metal Ag nanoparticles (Ag NPs) are introduced into the rare-earth doped tellurite glass, and the studies of broadband optical emission enhancement in the range of 1-2 μm as well as the fiber preparation are presented. Based on the theoretical analyses, the effects of heat-treating technique on the concentration, size, shape and spatial distribution of metal Ag NPs in glass are investigated systematically. Furthermore, new type of heat-treating schemes such as the introduction of reducing agent to control the reduction rate of Ag+ ions, together with the adjusting of heat-treating temperature and time are carried out to realize the controlled fabrication of Ag NPs and meanwhile to tune the localized surface Plasmon resonance (LSPR) wavelength from the visible to near-infrared band, and finally obviously improve the 1-2 μm broadband optical emission intensity of doped rare-earth ions as well as draw the new tellurite glass fiber with Ag NPs. The aim of the project is to reduce the intrinsic confinement of low luminescent efficiency by mainly making use of the enhanced local electric field and the effect on the local structure around the doped rare-earth ions induced by Ag NPs, which has the important practical application and scientific research significances for the rare-earth doped tellurite glasses applied for the broadband optical fiber amplifiers.

克服玻璃中掺杂稀土离子因电偶极禁戒跃迁导致发光效率低下的局限性，实现掺杂玻璃光纤高增益超宽带光放大对于当前超大容量WDM通信系统非常迫切。为此，项目在稀土掺杂碲酸盐玻璃中引入金属Ag纳米颗粒，进行掺杂离子1-2μm范围内宽带光辐射强度提高和光纤制备研究：基于理论分析，实验上系统研究玻璃热处理工艺对于Ag纳米颗粒浓度、大小、形状和空间分布的影响。进一步，采取引入还原剂控制Ag+离子还原速度以及采取变温、变时等新型热处理工艺，实现Ag纳米颗粒的可控制备以及局域表面等离子体共振波长从可见到近红外波段的调谐，最终实现掺杂离子近红外波段宽带光辐射强度的显著提高并拉制出含Ag纳米颗粒的新型碲酸盐玻璃光纤。项目旨在利用金属Ag纳米颗粒的局域场增强效应以及对掺杂离子周围局域结构的影响，由此减小掺杂离子发光效率不高的固有制约，这对于推动稀土掺杂碲酸盐玻璃应用于宽带光纤放大器具有重要实际和科学研究意义。

项目针对玻璃中掺杂稀土离子因电偶极禁戒跃迁导致发光效率低下的局限性，在掺杂碲酸盐玻璃中引入金属Ag纳米颗粒，通过对Ag纳米颗粒的可控制备，进行掺杂离子1-2μm波长范围内宽带光辐射强度提高和光纤制备研究。项目取得了系列研究成果，主要包括：①通过不同稀土离子的优化组合，实现了1-2μm波长范围内的宽带荧光发射。例如，采用Er3+/Tm3+共掺方案，获得了1350−1650nm波长范围宽带且平坦的光发射，其荧光半高宽（FWHM）达到了160nm；采用Er3+/Tm3+/Ho3+三掺方案，获得了1350−1600nm和1600−2200nm波长范围的两个宽带光发射，1350−1600nm波长范围的FWHM达到了153nm，1600−2200nm波长范围的FWHM达到了374nm。②在稀土掺杂碲酸盐玻璃引入金属Ag纳米颗粒，实现了宽带光辐射强度的显著提高。例如，在Er3+/Tm3+共掺碲酸盐玻璃引入Ag纳米颗粒后，1350−1650nm波长范围的宽带荧光强度提高了91%，1600−2100nm波长范围的宽带荧光强度则提高了110%；在Er3+/Tm3+/Nd3+三掺碲酸盐玻璃引入Ag纳米颗粒后，1300−1650nm波长范围的宽带荧光强度提高了50%，1600−2100nm波长范围的宽带荧光强度提高了55%。③采用新型挤压法工艺开展了Er3+/Tm3+共掺碲酸盐玻璃光纤预制棒的制备研究，拉制得到了含Ag纳米颗粒的Er3+/Tm3+共掺宽带碲酸盐玻璃光纤，光纤包层直径125μm，纤芯直径6.50μm，传输损耗约3.15dB/m。对光纤放大自发辐射（ASE）光谱测试表明，引入Ag纳米颗粒后，ASE信号峰值功率提高约39%。项目研究成果对于稀土掺杂碲酸盐玻璃应用于宽带光纤放大器、红外激光器等光电子器件具有重要实际和科学研究意义。