Er³⁺-doped Na₂O · Cd₃Al₂Si₃O₁₂ glass for infrared and upconversion applications

Er³⁺-doped Na₂O · Cd₃Al₂Si₃O₁₂ glass suitable for making optical waveguide devices has been fabricated and characterized for the first time. The density, the refractive indices, the optical absorption, the Judd-Ofelt parameters and the spontaneous transition probabilities have been measured and calculated. Strong 1.535 μm fluorescence was observed under 973 nm excitation, and its emission cross-section has been determined from the line shape of the emission spectrum and the measured lifetime for the ⁴I_13/2 level. The maximum emission cross-section is obtained as 7.28 × 10^-21 cm² at 1.535 μm. Efficient green and weak red upconversion luminescence from Er³⁺ centers in the sample was observed at room temperature, and the upconversion excitation processes have been analyzed.