Study on optical properties and luminescence of Er3+/Yb3+ co-doped La2O3-Nb2O5-Ta2O5 glasses prepared by aerodynamic levitation

Aerodynamic levitation method has been successfully used to prepare new Er3+/Yb3+ co-doped La2O3-Nb2O5-Ta2O5 glasses. 980 nm laser can be used to excite the glass for strong absorption of Yb3+ ions. The glass show high infrared transmittance of similar to 80%. Moreover, the OH- concentration is very low with the value of similar to 7 ppm, indicating excellent infrared transmission. The glass performs good optical properties with refractive index of near 2.3. The plane sweeping of EDS reveals that Er3+ and Yb3+ are distributed homogeneously in the glass. Strong down-conversion luminescence centered at 1530 nm has been achieved from the glass excited at 980 nm. The near-infrared emission is due to the transition of I-4(13/2) -> I-4(15/2) in Er3+ ions. After fitting the decay curve, the lifetime of the near-infrared emission can be decided to be similar to 5.517 ms. Such long lifetime is very helpful for rare earth ions to achieve strong emission.