Effective photodarkening suppression in Yb-doped fiber lasers by visible light injection.
Opt Express
; 22(7): 7638-43, 2014 Apr 07.
Article
en En
| MEDLINE
| ID: mdl-24718139
ABSTRACT
Al-silicate fibers have excellent manufacturing quality. Unfortunately, high-Yb doping concentration may be limited by severe losses induced by photodarkening phenomenon. In this paper we demonstrate for the first time that Al-silicate Yb-doped fibers with high-inversion and doping concentration above 1 wt% can be successfully used by implementing a simple optical bleaching scheme. A co-injection into the active fiber of a few mW of light at around 550 nm wavelength successfully eliminates almost all photodarkening induced losses. We demonstrate operation at above 90% of the pristine output power level in several lasers with up to 30% Yb ions in the excited state. These results may allow using Yb-doped Al-silicate fibers with doping level increased by one order of magnitude. Finally, we provide a comprehensive picture of main parameters affecting photobleaching performance and, to the best of our knowledge, we report the first quantitative measurement of the Ytterbium excited state absorption cross-section in the visible range.
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Colección:
01-internacional
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MEDLINE
Idioma:
En
Revista:
Opt Express
Asunto de la revista:
OFTALMOLOGIA
Año:
2014
Tipo del documento:
Article