2.7µm emission properties of Er3+/Nd3+-codoped fluorotellurite glasses

Er<sup>3+</sup> singly doped and Er<sup>3+</sup>/Nd<sup>3+</sup>-codoped fluorotellurite glasses are prepared by melt-quenching method. The 2.7 μm emission spectra of Er<sup>3+</sup> ions in fluorotellurite glasses are investigated under 808nm excitation. The enhancement of Er<sup>3+</sup> 2.7 μm emission shows that Nd<sup>3+</sup> can be an effective sensitizer for Er<sup>3+</sup> : <sup>4</sup>I<sub>11/2</sub>→<sup>4</sup>I<sub>13/2</sub> transition, and the energy transfer efficiency can be as large as 84%. The absorption and emission cross sections are calculated using Füchtbauer-Ladenburg equation and McCumber theory with large values of 1.62×10<sup>-20</sup> cm<sup>2</sup> and 1.11×10<sup>-20</sup> cm<sup>2</sup>, respectively. The results suggest that the present glasses have potential applications in 2.7 μm laser materials.