LAUSR

Zirconium oxide (ZrO2) is a perspective co-dopant of rare-earth ions in silica fibers for use in fiber lasers. ZrO2 nanoparticles increase the solubility of rare-earth ions and enhance their luminescence properties. In this paper, we report on the fabrication of Zr-Tm codoped silica fibers using the MCVD method combined with modified solution-doping technique. Several fibers with different dopant concentrations were prepared and their optical properties were studied. It was found that increasing Zr concentration leads to the creation of larger ZrO2 nanoparticles which causes unwanted attenuation. Optimal Zr concentration was found to be 1 at. %. The fiber with optimal Zr concentration and Tm concentration of 260 ppm exhibited 1.8 µm fluorescence lifetime of 420 ± 10 µs. For the first time in literature, we have demonstrated laser operation in a Zr/Tm-codoped silica fiber. The threshold for laser operation was determined to be 233 mW and the slope efficiency of 72.7% was achieved. MCVD combined with modified solution doping proved to be a feasible method of preparation of Tm-doped SiO2-ZrO2 optical fibers for use in fiber lasers.