157 articles – 193 references  [version française]
Detailed view Conference proceedings
Photonics West : Optical Components and Materials IX, San Francisco, California : United States (2012)
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A new vision of photodarkening in Yb-doped fibers
Romain Peretti1, 2, Anne-Marie Jurdyc1, Cedric Gonnet3, 4

Yb3+-doped fiber is one of the most promising hosts for high-power fiber lasers [1]. However, in the late 1990s, photodarkening effect, i.e., the creation of color centers induced by light, was observed and reported [2]. Like in other rare-earth-doped materials, a broad visible and near infrared absorption band appears during laser operation, which strongly lowers the laser efficiency. We have shown how thulium impurities, present at the parts-per-billion weights (ppb) level in the raw doping material, can induce UV emission which in turn creates defects responsible for photodarkening in ytterbium-doped continuous-wave fiber lasers [3]. This new vision is not in contradiction with others but it gives for the first time a possible explanation for UV defect creation by an infrared beam.
1:  LPCML - Laboratoire de Physico-Chimie des Matériaux Luminescents
2:  INL - Institut des nanotechnologies de Lyon - Site d'Ecully
3:  Draka Comteq
photodarkening – Yb-doped fiber – Tm upconversion