Open AccessConcentration dependence and self-similarity of photodarkening losses induced in Yb-doped fibers by comparable excitation
Author(s) -
S. Taccheo,
Hrvoje Gebavi,
Achille Monteville,
Olivier Le Goffic,
David Landais,
David Méchin,
Denis Trégoat,
Benoît Cadier,
Thierry Robin,
Daniel Milanese,
Tim Durrant
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.019340
Subject(s) - photodarkening , materials science , doping , optics , figure of merit , ytterbium , fiber , fiber laser , molecular physics , optoelectronics , physics , composite material
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.