Judd–Ofelt analysis and improvement in thermal stability and optical properties of Er<sup>3+</sup> doped TeO<sub>2</sub>–ZnO–Na<sub>2</sub>O–B<sub>2</sub>O<sub>3</sub>–GeO<sub>2</sub> glassesYu Lei, Anxian Lu, F. Ren et al.|Materials Research Innovations|2014Cited by 2