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 mu m emission and energy transfer processes by codoping Ce3+ in ZBYA: Ho3+/Yb3+ 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+: I-4(13/2) to Ho3+: I-5(7) level. The 2.0 mu m emission from the Ho3+: I-5(7)-> I-5(8) 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 m emission by suppressing the upconversion processes. The Ho3+/Er3+/Ce3+ triply-doped ZBYA glass is a promising material for 2.0 m fiber laser applications. (C) 2014 Optical Society of America