Mid-infrared 2.7 μm emission properties of Er3 + sensitized by Nd3 + in fluorotellurite glasses

• Er3 + and Er3 +/Nd3 +-codoped flourotellurite glasses are fabricated and investigated.
• The present glasses show better thermal stability with high △T.
• Codoping Nd3 + in present glasses can be an effective way for Er3 + 2.7 μm emission.
• The emission cross section of the Er3 + 2.7 μm in present glasses are larger.
• The gain coefficient of the Er3 + 2.7 μm in present glasses are larger.

Er3 + singly doped and Er3 +/Nd3 +-codoped fluorotellurite glasses are prepared by melt-quenching method. The Judd–Ofelt intensity parameters (Ωλ,λ = 2, 4, and 6), radiative transition rate (Arad), and radiative lifetime (τR) of Er3 + are calculated based on the absorption spectra. The 2.7 μm emission spectra of Er3 + ions in fluorotellurite glasses are investigated under 808 nm excitation. The enhancement of Er3 + 2.7 μm emission shows that Nd3 + can be an effective sensitizer for Er3 +: 4I11/2 → 4I13/2 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− 20 cm2 and 1.11 × 10− 20 cm2, respectively. The results suggest that the present glasses have potential applications in 2.7 μm laser materials.