Rare earth doped lead-free germanate glasses for modern photonics

Abstract

Lead-free germanate glasses doped with rare earth ions were synthesized and next studied using excitation and luminescence spectroscopy. Rare earths were limited to Pr3+, Eu3+ and Er3+ ions. Several luminescence bands correspond to transitions originating from the 3P0 and 1D2 states of Pr3+, the 5D0 state of Eu3+, the 4S3/2, 4F9/2 and 4I13/2 states of Er3+, respectively. The relatively long lifetime for the upper 4I13/2 laser state of Er3+ suggest that lead-free germanate glasses are promising materials for near-infrared optical amplifiers.