Suppressing fiber tip failure: On the road to 100 W-level 3-μm fiber lasers (Conference Presentation)

We report on the use of OH diffusion barrier coatings to suppress fiber tip degradation in high-power 3 μm fiber lasers. To this extent, silicon nitride thin-films are sputtered on the endface of a 20 W erbium-doped fluoride fiber laser at 2.83 μm. By monitoring the temperature evolution of the output fiber tip over a 24 hour time period, we validate the effectiveness of silicon nitride thin films in mitigating fiber tip degradation. These results, along with previous demonstrations, underline the potential of 3 μm fiber lasers to reach 100 W of output power in the near future.