Yb3+/Er3+共掺杂TeO2-WO3-ZnO玻璃的光谱性质

制备了Yb³⁺/Er³⁺共掺杂的TeO₂-WO₃-ZnO玻璃,测量了Er³⁺在玻璃中的吸收光谱和970nmLD激发下的荧光光谱、荧光寿命和上转换光谱.计算了Yb³⁺/Er³⁺间的能量传递效率和Er³⁺离子1.5μm波段的吸收截面、发射截面,并研究了其荧光强度和上转换发光与Yb³⁺掺杂浓度间的关系.结果表明,Yb³⁺共掺杂可明显提高Er³⁺离子1.5μm发射的荧光强度,实验所得Yb³⁺离子的最佳掺杂浓度为Er³⁺离子浓度的3倍,在7.28×1020ions/cm³左右.Er³⁺离子1.5μm发射的荧光半峰全宽为67～72nm;上转换红、绿光均为双光子过程,随Yb³⁺掺杂浓度的增加,上转换红、绿光强度均增强.

Spectroscopic Properties of Yb3 +/Er3 + -Codoped TeO2-WO3-ZnO Glasses

Tellurite glass has attracted considerable attention and development effort as a host for broad EDFA and EDWA.But the phonon energy of tellurite glass is relatively low as 770 cm^-1,thus,the⁴I_11/2^→4I_13/2 nonradiative decay is too slow to allow pumping at 980 nm.Tungsten-tellurite glass has higher phonon energy of 930 cm^-1,which makes it possible pumping at 980 nm.The 1.5 μm emission bandwidth of Er³⁺ in tungsten-tellurite glass is also broad.The spectroscopic properties of Yb³⁺/Er³⁺-codoped TeO₂-WO₃-ZnO (TWZ) glasses were investigated,too. The Yb³⁺/Er³⁺-codoped TWZ glasses were prepared by traditional melting-quenching method.The absorption cross-section was calculated based on measured absorption spectra at room temperature.The emission cross-section was calculated by McCumber theory.The peak values of absorption cross-section and emission cross-section at 1.5 μm are 0.78 pm² and 0.90 pm²,respectively.The 1.5 μm emission spectra,upconversion emission spectra and fluorescence lifetimes of Er³⁺,excited at 970 nm,were also measured.The dependence of Yb³⁺ doping concentration on the 1.5 μm emission and upconversion luminescence of Er³⁺ was studied.The calculated energy transfer efficiency from Yb³⁺ to Er³⁺ in Yb³⁺/Er³⁺-codoped TWZ glasses is about 65%.Yb³⁺-codoping can enhance the 1.5 μm emission intensity effectively.The optimum Yb³⁺ doping concentration is about 7.28×10²⁰ ions/cm³,which is triple of the Er³⁺ doping concentration.The emission bandwidths of Er³⁺ at 1.5 μm in Yb³⁺/Er³⁺-codoped TWZ glasses are broad and the obtained full width at half maximum is between 67 nm and 72 nm.Three upconversion emission bands centered at about 533,547 and 668 nm,were observed.The three emission bands originate from the radiative transitions²H_11/2^→4I_15/2,⁴S_3/2^→4I_15/2 and⁴F_9/2^→4I_15/2,respectively.The green and red upconversion emission are both double-photon process.With the increasing of Yb³⁺ doping concentration,the green and red upconversion emission intensity both increase.This can be ascribed to the increased energy transfer rate from Yb³⁺ to Er³⁺.