Spectroscopic Properties and Energy Transfer Mechanism of Er^3＋/Yb^3＋/Ce^3＋ Codoped Tellurite-based Glasses

为进一步揭示多稀土离子共掺低声子能量玻璃中Er3＋的光谱特性及其发光机理,采用高温熔融法制备了Er3＋/Yb3＋/Ce3＋共掺组分为（72.5–x）TeO2–20ZnO–5La2O3–0.5Er2O3–2Yb2O3–xCe2O3（x=0,0.4,0.7,1.0,摩尔分数x%）的碲酸盐玻璃,通过测量吸收光谱、荧光光谱和无掺杂样品的Raman光谱,以及计算相应能级间的吸收截面和受激发射截面,研究并分析了Yb3＋和Ce3＋离子掺杂对于Er3＋的1.55μm波段荧光特性的影响。结果显示：Yb3＋和Ce3＋的引入能显著增强975nm泵浦下Er3＋的1.55μm波段荧光强度。分析表明：Er3＋在1.55μm波段荧光强度的增强主要归结于Yb3＋/Yb3＋、Yb3＋/Er3＋离子间的共振能量传递过程以及基于单声子和双声子辅助的Er3＋/Ce3＋离子间的能量传递过程,并通过计算得到了相应稀土离子间的能量传递微观参数和声子所作的贡献比。

Spectroscopic Properties and Energy Transfer Mechanism of Er3+/Yb3+/Ce3+ Codoped Tellurite-based Glasses

In order to demonstrate the Er3+ ion spectroscopic properties and its fluorescence mechanism of multi-rare earth ion codoped glass with a low phonon energy,Er3+/Yb3+/Ce3+ codoped tellurite glasses with the composition of(72.5–x)TeO2–20ZnO– 5La2O3–0.5Er2O3–2Yb2O3–xCe2O3(x = 0,0.4,0.7,1.0,mole fraction x%) were prepared by a melt–quenching method.The effect of Yb3+ and Ce3+ ions doping on the 1.55 μm band spectroscopic properties of Er3+ was investigated via the measurements of absorption spectra,fluorescence spectra and Raman spectra of undoped glass.The absorption and stimulated emission cross-sections were calcu-lated based on the relevant energy level transitions.The results showed that the 1.55 μm band fluorescence intensity under the 975 nm pump could be improved when Yb3+ and Ce3+ were introduced.It was indicated that the improvement of fluorescence intensity was mainly ascribed to the resonant energy transfers between Yb3+/Yb3+ and Yb3+/Er3+ ions,and then followed the single-phonon and two-phonon assisted energy transfer between Er3+/Ce3+ ions.In addition,the energy transfer micro-parameters between rare earth ions and the contribution ratio of phonons played in the energy transfer process were also analyzed.