Investigations on Valence-Change Behaviors of Europium Ions in Eu-Doped Aluminate and Silicate Phosphors

Compounds of Sr3Al2O6∶Eu, Sr4Al14O25∶Eu, and BaZnSiO4∶Eu were synthesized by high-temperature solid state reactions. The doping Eu3 ions were partially reduced to Eu2 in Sr4Al14O25∶Eu and BaZnSiO4∶Eu prepared in an oxidizing atmosphere, N2 O2. However, such an abnormal reduction process could not be performed in Sr3Al2O6∶Eu, which was also prepared in an atmosphere of N2 O2. Moreover, even though Sr3Al2O6∶Eu was synthesized in a reducing condition CO, only part of the Eu3 ions was reduced to Eu2 . The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu3 to Eu2 .     

空芯光子晶体光纤的研究进展

综述了空芯光子晶体光纤（HC—PCF）的原理、制作方法和最新应用进展。详细介绍了HC—PCF在粒子传输、受激拉曼散射、激光频标、单模中红外光波导和高能超短激光脉冲领域的应用,讨论了HC—PCF的发展前景。     

铈掺杂钇铝石榴石纤维的电纺丝制备及光学性能

采用静电纺丝技术制备了铈掺杂钇铝石榴石(cerium doped yttrium aluminium garnet,YAG:Ce)纳米纤维,利用扫描电镜观测了电纺丝纤维的微结构与形貌,利用荧光光谱仪表征了YAG:Ce电纺丝纤维的荧光性能。结果表明:在还原气氛下热处理制备YAG:Ce电纺丝纳米纤维时,在纳米纤维表面出现了一层直径为50～100 nm的球形凸起物。相比于空气气氛中,在还原气氛中热处理制备YAG:Ce纳米纤维的荧光发射强度显著增强。并且随着Ce~3+掺杂含量增加,YAG:Ce电纺丝纤维的荧光发射带发生红移。     

具有超宽带近红外发光的铋激活光子玻璃

在铋掺杂的各种玻璃体系中能够产生覆盖1.2～1.6μm区间的超宽近红外发光；并对此类发光材料的发光机理进行了初步探讨，指出铬铋共掺的锌铝硅玻璃中的宽带近红外发光源于铋而不是Cr^4＋离子。     

超宽带光纤放大器用的新型掺铋发光材料

最近,一种新型的掺铋发光材料引起了人们的关注。这种发光材料有长的荧光寿命(τ>200μs),在800nm激光激 发下发射波长在1200-1600nm区间的超宽带荧光(荧光半高宽FWHM>200nm),其发光性质与以往文献中报道的Bi3+或 Bi2+掺杂的发光材料的性质截然不同;光发射截面(σem)是光掺铒光纤放大器玻璃(EDFAG)的2-3倍,其σem×FWHM值是 EDFAG的10倍左右,σem×τ值是掺Ti3+蓝宝石的3倍左右。