Multicolor upconversion of Er3+/Tm3+/Yb3+ doped oxyfluoride glass ceramics

Er3+/Tm3+/Yb3+ tridoped oxyfluoride glass ceramics was synthesized in a general way. Under 980 nm LD pumping, intense red, green and blue upconversion was obtained. And with those primary colors, multicolor luminescence was observed in oxyfluoride glass ceramics with various dopant concentrations. The red and green upconversion is consistent with 4F9/2 → 4I15/2 and 2H11/2, 4S3/2 → 4I15/2 transition of Er3+ respectively. While the blue upconversion originates from 1G4 → 3H6 transition of Tm3+. This is similar to that in Er3+/Yb3+ and/or Tm3+/Yb3+ codoped glass ceramics. However the upconversion of Tm3+ is enhanced by the energy transfer between Er3+ and Tm3+.