Er3+/Yb3+共掺杂铋酸盐玻璃的上转换发光和能量传递

用高温熔融法制备了Er³⁺/Yb³⁺共掺杂的45Bi₂O₃-45GeO₂-10PbO玻璃,对玻璃样品进行了光谱测试,分析了上转换发光机制和Yb³⁺→Er³⁺的能量传递效率。通过Yb³⁺离子浓度对Er³⁺离子在铋酸盐玻璃中的上转换荧光强度影响的研究,得到Er³⁺质量分数为0.5%以及Yb³⁺质量分数为2.5%时上转换发光强度最大。研究结果表明,在970nm泵浦激发下,Er³⁺/Yb³⁺共掺杂B₄₅G₄₅P₁₀玻璃在532,545,673nm处产生较强的上转换绿光和红光,是一种较为理想的上转换发光基质材料。

Energy Transfer and Upconversion Emission of Er3+/Yb3+ -codoped Bismuthate Glasses

In recent years,there has been a renaissance in the study of rare earth(RE) doped materials for applying in areas such as optical data storage,lasers,sensors and optical displays.Er³⁺ can originate the red and green upconversion emission under 975 nm excitation.The glass hosts with low phonon energy can reduce the nonradiative loss due to the multiphonon relaxation(MPR),therefore the choice of host material is quite important in the development of more efficient upconversion lasers.The intensity of red and green upconversion emission attribute to the absorption of Er³⁺,⁴I_15/2→⁴I_11/2(at around 980 nm),which present weak ground state absorption.The sensitization of Er³⁺ doped materials with Yb³⁺ ions is a well-known method for increasing the optical pumping efficiency.However,there has been a backward energy transfer when Yb³⁺ is more than certain concentration.So it is necessary to find the optimal doping concentration of Yb³⁺.The novel Er³⁺/Yb³⁺-codoped 45Bi₂O₃-45GeO₂-10PbO glasses were prepared by the technique of high temperature melting in an electronic furnace.The absorption spectra and fluorescence spectra of Er³⁺/Yb³⁺-codoped 45Bi₂O₃-45GeO₂-10PbO glasses were measured and investigated.The absorption near 980 nm becomes stronger with the increasing of Yb³⁺ concentration.The intense green(532 and 545 nm) and red(673 nm) emissions are observed at room temperature.The red(673 nm) emission is weaker than green(545 nm) emission while Yb³⁺ concentration is low,however it becomes much stronger when the Yb³⁺ concentration is high.The upconversion process involving the sequential two-photon absorption for the green and red emissions is analyzed. It is found that the optimal Yb³⁺ doping content is 2.5% when the Er³⁺ doping content is fixed at 0.5% according to the results of ET efficiency and upconversion fluorescence.The results suggest that this kind of glasses may be a suitable material for practical upconversion fiber optical devices.