Enhanced 2.7 μm mid-infrared emission and energy transfer mechanism in Er3+/Nd3+ codoped tellurite glass

• Er3+/Nd3+ codoped tellurite glass was prepared by conventional melt-quenching method.
• The prepared tellurite glass exhibited good thermal stability with ΔT > 170 °C.
• The 2.7 μm fluorescence enhanced greatly owing to the energy transfers from Nd3+.
• Quantitative study of energy transfer mechanism and phonon contribution was presented.

Nd3+ was introduced into Er3+ doped tellurite glass with composition of TeO2Nb2O5ZnONa2O to improve the 2.7 μm band fluorescence upon the excitation of 800 nm LD. The DSC curve and Raman spectrum were measured to characterize the thermal stability and vibration nature of glass host. The absorption spectra, visible, near- and mid-infrared fluorescence emission spectra were measured to evaluate the effects of Nd3+ introduction on the spectroscopic properties especially the 2.7 μm band fluorescence of Er3+. It is shown that the prepared tellurite glass exhibits a large glass transition temperature and no obvious crystallization peak is observed in the measured temperature range of 200–550 °C. Moreover, the introduction of Nd3+ significantly improves the 2.7 μm band fluorescence intensity through joint energy transfer processes between the relevant excited levels of Er3+ and Nd3+, and the energy transfer mechanisms are further investigated in detail by calculating energy transfer micro-parameters and efficiency. The excellent thermal stability and strong 2.7 μm fluorescence emission aroused by adopting codoping scheme indicate that the prepared Er3+/Nd3+ codoped tellurite glass is a potential glass medium applied for the 2.7 μm mid-infrared band lasers.