Abstract:Er³⁺-doped TeO₂-ZnO-Na₂O-B₂O₃-GeO₂ (TZNBG) glasses were prepared by melt-quenching method. Differential scanning calorimetry (DSC) and thermal mechanical analysis (TMA) were used to calculate thermal parameters: crystallization temperature (T_x), glass transition temperature (T_g) and thermal expansion (α). Besides, Judd-Ofelt theory is applied to analyzing absorption spectra. Intensity parameters W_λ (λ=2, 4, 6), transition probabilities A_ed, radiative lifetime τ_i, and branching ratios β of Er³⁺ transitions were obtained. Emission cross-section σ_emis of ⁴I_13/2→⁴I_15/2 transition of Er³⁺ was calculated according to the theory of McCumber. All of the parameters indicate that the thermal stability and optical properties of Er³⁺-doped TZNBG glasses are improved effectively.

Key words: tellurite glasses; thermal stability; Judd-Ofelt theory; spectroscopic properties