Er3+/Tm3+共掺碲酸盐玻璃光谱特性及能量传递

采用高温熔融法制备了两系列不同掺杂比的Er³⁺/Tm³⁺共掺的碲酸盐玻璃,测试了样品的吸收光谱和在980 nm LD激发下的发光光谱、上转换发光光谱及发光寿命。讨论了Er³⁺与Tm³⁺掺杂浓度对样品光谱性质的影响,Tm³⁺离子的掺入会减弱Er³⁺的1.53 μm发光强度,但通过共振能量传递可以获得Tm³⁺的1.8 μm发光,并随着Tm³⁺离子浓度的增加而增强。同时表明Tm³⁺离子的增加会减弱Er³⁺离子在528 nm和545 nm附近的上转换绿光强度,而上转换红光出现了先增强后减弱的现象。研究了Er³⁺/Tm³⁺共掺杂碲酸盐玻璃的能量传递机制与传递效率,分析了Tm³⁺/Er³⁺离子掺杂浓度比对上转换发光的影响。

Luminescence and Mechanism of Energy Transfer of Er3+/Tm3+-codoped Tellurite Glass

The Er~(3+)/Tm~(3+)-codoped tellurite glasses were prepared by high-temperature melting. The absorption spectra, fluorescence spectra, upconversion emission, and the fluorescence lifetime of samples were investigated under 980 nm LD excitation. Spectral properties of the samples with different concentration of Er~(3+)-Tm~(3+) ions were analyzed, the 1.53 μm fluorescence intensity of Er~(3+) reduces with increasing Tm~(3+) ions concentration, but the 1.8 mm emission of Tm~(3+) increases. The Tm~(3+)-~3H_6→~3F_4 absorption cross-section and Er~(3+)-~4I_(13/2)→~4I_(15/2) emission cross-section were calculated based on Dexter theory, the energy transfer process from Er~(3+)-~4I_(13/2) level to Tm~(3+)-~3F_4 level can occur. The measured lifetimes of Er~(3+)-~4I_(13/2) level was decreased from 2.05 ms to 0.8 ms with increasing the mol fraction of Tm_2O_3 from 0.1% to 0.5% where Er_2O_3 mol fraction is fixed at 0.5%, while the energy transfer rate, at first, from Er~(3+) to Tm~(3+) increases rapidly and then tardily does. The upconversion luminescence of Er~(3+) and Er~(3+)/Tm~(3+) ions doped tellurite glasses was investigated. The green light of 530 nm and 545 nm, and the red light of 657 nm can be observed in Er~(3+) doped tellurite glass, moreover the 545 nm light intensity is stronger than the 530 nm light. But the green upconversion emission intensity decreases with Tm~(3+)-ions doping, otherwise the red upconversion emission intensity increases firstly and then decreases with increasing Tm~(3+)-ions concentration. In addition, the intensity of red light is strongest when the Tm~(3+)/Er~(3+) concentration ratio is 1/5 approximately.