Steady photodarkening of thulium alumino-silicate fibers pumped at 1.07  μm: quantitative effect of lanthanum, cerium, and thulium.
By pumping thulium-doped silica-based fibers at 1.07 μm, rapid generation of absorbing centers leads to photoinduced attenuation (PIA). This detrimental effect prevents exploiting laser emissions in the visible and near infrared. We report on the characterization of the PIA versus the fiber core composition, particularly the concentration of thulium (Tm), lanthanum (La), and cerium (Ce) ions. We show that UV emission induced by Tm-Tm energy transfers is the source of photodarkening and that lanthanum and cerium are efficient hardeners against PIA.
Jean-François
JF
Lupi
Manuel
M
Vermillac
Wilfried
W
Blanc
Franck
F
Mady
Mourad
M
Benabdesselam
Bernard
B
Dussardier
Daniel R
DR
Neuville