The role of a three-ion energy transfer process in the violet fluorescence in highly doped Er3+:ZB(L)AN glasses

Abstract The violet (∼400–410-nm) fluorescence in Er 3+ :ZB(L)AN glasses has been previously attributed to transitions originating from the 2 H 9/2 and 2 P 3/2 levels. The study reported here found that, in high Er 3+ concentrations and with 800-nm excitation, a significant source of violet fluorescence around 407-nm was due to the previously unreported 4 G 9/2 → 4 I 9/2 transition. The study also established that, under these conditions, a three-ion energy transfer process originating in the 4 I 9/2 level is responsible for populating of the fluorescing 4 G 9/2 level.