Ho3+/Er3+ doped fluoride glass sensitized by Ce3+ pumped by 1550 nm LD for efficient 2.0 μm laser applications.

We present a detailed characterization of enhanced 2.0 μm emission and energy transfer processes by codoping Ce3+ in ZBYA: Ho3+/Er3+ glasses under 1550 nm excitation. The measured absorption and emission spectra show that Er3+ ions are efficiently excited by pumping and energy transfer from Er3+: 4I13/2 to Ho3+: 5I7 level. The 2.0 μm emission from the Ho3+: 5I7→5I8 transition is enhanced by codoping Ce3+ (< 0.5 mol %) ions in the Ho3+/Er3+ doped glasses. However, excess Ce3+ ions in the glass network negatively affect the mid-infrared emission. The upconversion luminescence is dominated by Er3+ (667 nm) red emission in the Ho3+/Er3+ doped sample, which is suppressed after introducing Ce3+ ions. The red emission is abnormally dominated by the Ho3+ (650 nm) emission when the ratio of the three ions (Ho3+/Er3+: Ce3+) is 1:1:0.5. These results indicate that Ce3+ ions can enhance Ho3+: 2.0 μm emission by suppressing the upconversion processes. The Ho3+/Er3+/Ce3+ triply-doped ZBYA glass is a promising material for 2.0 μm fiber laser applications.