Impact Statement:Holmium-doped silica fibers for fiber lasers were prepared in wide concentration ranges by solution-doping and nanoparticle-doping methods. We studied the effects of fibe...View more
Abstract:
Efficient holmium fiber lasers have been studied as attractive laser sources operating around 2.1 μm. We report on holmium-doped silica fibers prepared by the modified ch...View moreMetadata
Impact Statement:
Holmium-doped silica fibers for fiber lasers were prepared in wide concentration ranges by solution-doping and nanoparticle-doping methods. We studied the effects of fiber composition and preparation method on laser properties. In the best-performance fibers, we measured slope efficiencies up to 83%, laser thresholds under 200 mW and fluorescence lifetimes up to 1.35 ms, which is a record value in silica-based glass. Significant differences between the doping methods were not observed.
Abstract:
Efficient holmium fiber lasers have been studied as attractive laser sources operating around 2.1 μm. We report on holmium-doped silica fibers prepared by the modified chemical vapor deposition in combination with either a solution-doping method or a nanoparticle-doping method. A set of 15 fibers with various compositions was characterized and compared with respect to their fluorescence lifetime, laser slope efficiency and laser threshold. This set of fibers in wide concentration ranges allowed us to assess reliably the influence of material composition and the influence of doping method. The best-performance fibers exhibited slope efficiency 83.1%, laser threshold 155 mW and a record value of upper laser level lifetime of 1.35 ms. These results were achieved in fibers with holmium concentration lower than 800 molar ppm and Al/Ho molar ratio greater than 70. Significant differences between fibers prepared by solution doping and nanoparticle doping were not observed. The behavior of Al2O3 nanoparticles during fiber preparation is discussed in details.
Published in: IEEE Photonics Journal ( Volume: 11, Issue: 5, October 2019)