An experimental and theoretical study on Dy³⁺-doped ZBLAN fiber laser, core-pumped at 1.1 μm

An experimental and theoretical investigation into a core-pumped Dy³⁺-doped ZBLAN fiber laser with 1.1 μm pumping was conducted to figure out a configuration for better slope efficiency. First, the laser was experimentally constructed with a simple Fabry-Pérot cavity incorporating AlF₃ no-core fiber endcaps. The maximum output power of 607 mW was obtained readily with a slope efficiency of 25%. Next, a 5-energy level model was adopted for a numerical simulation to figure out the optimum output mirror reflectivity for the particular experimental laser setup in terms of slope efficiency. The best slope efficiency of 30% was shown to be obtainable with an output mirror of a 22% reflection.