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 highinversion 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 to use 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. © 2014 Optical Society of America.
Effective photodarkening suppression in Yb-doped fiber lasers by visible light injection / Piccoli, R.; Robin, T.; Brand, T.; Klotzbach, U.; Taccheo, S.. - In: OPTICS EXPRESS. - ISSN 1094-4087. - ELETTRONICO. - 22:7(2014), pp. 7638-7643. [10.1364/OE.22.007638]
|Titolo:||Effective photodarkening suppression in Yb-doped fiber lasers by visible light injection|
|Data di pubblicazione:||2014|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1364/OE.22.007638|
|Appare nelle tipologie:||1.1 Articolo in rivista|