title: Concentration dependence and self-similarity of photodarkening losses induced in Yb-doped fibers by comparable excitation.
abstract: We report on an extensive investigation of photodarkening in Yb-doped silica fibers. A set of similar fibers, covering a large Yb concentration range, was made so as to compare the photodarkening induced losses. Careful measurements were made to ensure equal and uniform inversion for all the tested fibers. The results show that, with the specific set-up, the stretching parameter obtained through fitting has a very limited variation. This gives more meaning to the fitting parameters. Results tend to indicate a square law dependence of the concentration of excited ions on the final saturated loss. We also demonstrate self-similarity of loss evolution when experimental curves are simply normalized to fitting parameters. This evidence of self-similarity also supports the possibility of introducing a preliminary figure of merit for Yb-doped fiber. This will allow the impact of photodarkening on laser/amplifier devices to be evaluated.
authors: College of Engineering – Swansea University, Singleton Park, SA2 8PP, Swansea, UK. s.taccheo@swansea.ac.uk
authors: Stefano
authors: S
authors: Taccheo
authors: Hrvoje
authors: H
authors: Gebavi
authors: Achille
authors: A
authors: Monteville
authors: Olivier
authors: O
authors: Le Goffic
authors: David
authors: D
authors: Landais
authors: David
authors: D
authors: Mechin
authors: Denis
authors: D
authors: Tregoat
authors: Benoit
authors: B
authors: Cadier
authors: Thierry
authors: T
authors: Robin
authors: Daniel
authors: D
authors: Milanese
authors: Tim
authors: T
authors: Durrant
mesh_terms: D000669:Amplifiers, Electronic; D004867:Equipment Design; D005453:Fluorescence; D007259:Infrared Rays; D055095:Optics and Photonics / Q000295:instrumentation*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D015018:Ytterbium