Revisiting literature observations on photodarkening in Ybdoped fiber considering the possible presence of Tm impurities
نویسندگان
چکیده
Ytterbium (Yb) doped fiber lasers are known to be affected by the creation of color centers during lasing (socalled photodarkening (PD)). In a previous work, this defect creation was investigated from a spectroscopic point of view, showing the presence of traces (ppb) of thulium (Tm) in the Yb doped fiber. It was shown that Tm has a strong impact on the defect creation process involved in PD. In this paper, we compare the results from the literature with our Tm hypothesis, without finding any contradiction. Moreover, this hypothesis can be an explanation for the discrepancies in the literature.
منابع مشابه
Mitigation of photodegradation in 790nm-pumped Tm-doped fibers
The capability of Tm-doped silica fibers pumped at 790nm to efficiently produce high power emission in the 1.9~2.1μm region has been well documented to date but little has been presented on the reliability of this technology. Early experiments highlighted that photodarkening can be a significant concern when Tm-doped silica fibers are exposed to high intensity blue light. We present a discussio...
متن کاملMEASURING PHOTODARKENING FROM Yb DOPED FIBERS
OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNOLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Joona Koponen Name of the dissertation Measuring photodarkening from Yb doped fibers Manuscript submitted 12.9.2008 Manuscript revised 7.11.2008 Date of the defence 12.12.2008 Monograph Article dissertation (summary + original articles) Faculty Faculty of Electronics, Communications a...
متن کاملPhotodarkening Measurements in Large-Mode-Area Fibers
Yb-doped fibers are widely used in applications requiring high average output powers and high power pulse amplification. Photodarkening is one limiting factor in these fibers. In this paper, characterization of photodarkening in large-mode-area (LMA) fibers is presented building upon our previous work, which indicated that meaningful comparison of photodarkening properties from different fibers...
متن کاملTHE RELAXATION OF PHOTODARKENING IN Sn DOPED AMORPHOUS As2Se3 FILMS
Photodarkening relaxation under light exposure of a-As2Se3 amorphous films doped with 0.5-5.0 at.% Sn was studied for its dependence on the concentration of impurities and thermal treatment. Both factors reduce photodarkening with the degree of reduction dependent on the concentration of impurity. The relaxation process may be described by a stretched exponential with the dispersion parameter 0...
متن کاملPhotodarkening of 488nm-pumped Sm-doped germanosilicate fiber laser
Photodarkening in samarium doped germanosilicate fiber and laser by downconversion is studied. Appreciable photodarkening occurs in the fiber and we attribute the effect to color centres which are both related to Sm2O3 and GeO2. An energy level scheme has been illustrated to explain the photodarkening mechanism.
متن کامل