Nanoparticle and Solution Doping for Efficient Holmium Fiber Lasers

0518367 - ÚFE 2020 RIV US eng J - Journal Article
Kamrádek, Michal - Kašík, Ivan - Aubrecht, Jan - Mrázek, Jan - Podrazký, Ondřej - Cajzl, Jakub - Vařák, Petr - Kubeček, V. - Peterka, Pavel - Honzátko, Pavel
Nanoparticle and Solution Doping for Efficient Holmium Fiber Lasers.
IEEE Photonics Journal. Roč. 11, č. 5 (2019), č. článku 7103610. ISSN 1943-0655. E-ISSN 1943-0647
R&D Projects: GA ČR(CZ) GA17-20049S
Institutional support: RVO:67985882
Keywords : Fiber laser * infrared fibers
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 2.833, year: 2019
Method of publishing: Open access
https://ieeexplore.ieee.org/document/8831379

Efficient holmium fiber lasers have been studied as attractive laser sources operating around 2.1 mu m. 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
Permanent Link: http://hdl.handle.net/11104/0303523