2.7 µm emissions in Er<sup>3+</sup> doped transparent sodium tellurite glass ceramics

Transparent glass ceramics was obtained by heat-treating in 90TeO ₂ -10Na ₂ O glass. 2.7 μm emission of Er ³⁺ ions in the glass and glass ceramics matrix has been tested and compared, and the results suggest that nucleation is a possible way to enhance 2.7 μm emission. Er ³⁺ ions were embedded into the nano-crystals (Er ₂ Te ₅ O ₁₃ and Er ₆ Te ₅ O _19.2 ) evidenced by X-ray powder diffraction (XRD) spectra and the crystal size was calculated by Debye-Scherrer formula.