Upconversion processes in Er3+-doped fluoroarsenate glasses

Abstract In this work we report the infrared to visible upconversion luminescence of Er 3+ -doped fluoroarsenate glasses with different ErF 3 concentrations (0.1, 0.5, 1, 3, and 5 mol%) under continuous wave excitation in the near infrared region inside the 4 I 11/2 level. Intense green emission was observed at room temperature due to the 4 S 3/2 → 4 I 15/2 transition. A weak blue emission at 408 nm corresponding to the 2 H 9/2 → 4 I 15/2 transition and a red emission corresponding to the 4 F 9/2 → 4 I 15/2 transition were also observed. These weak emissions increase with increasing ErF 3 concentration. The possible upconversion mechanisms responsible for these upconversion processes are discussed.