Photodarkening and Photobleaching of an Ytterbium-doped Silica Double-clad LMA fiber
ABSTRACT We studied the temporal evolution of the photodarkening effect in an Yb-doped silica LMA fiber. The absorption spectra exhibit an increase in absorption in the visible and in the near infrared spectral range when the fiber is exposed to pump light around 980 nm. We show the influence of the photodarkening on the cw lasing properties of the fiber, and demonstrate photobleaching of the same fiber by exposure to UV light at 355 nm. The corresponding absorption spectra and lasing performances are shown and are entirely comparable to those of a new fiber.
Full-textDOI: · Available from: Francois Salin, Aug 25, 2015
- SourceAvailable from: Jianxiang Wen
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- "I.Manek-Hönninger et al  found that radiation-induced defects can be rehabilitated gradually themselves. This rehabilitating process can be also called " self-annealing " . "
ABSTRACT: Radiation-induced transmission loss in Low Water Peak Single Mode (LWPSM) fiber has been investigated. Formation and conversion processes of defect centers also have been proposed using electron spin resonance in the fiber irradiated with gamma rays. When the irradiation dose is low, Germanium electron center (GEC) and self-trapped hole center (STH) occur. With the increase of dose, E' centers (Si and Ge) and nonbridge oxygen hole centers (NBOHCs) generate. With the help of thermal-bleaching or photo-bleaching, the radiation-induced loss of pre-irradiation optical fiber can be reduced effectively. The obtain results also have been analyzed in detail.Proceedings of SPIE - The International Society for Optical Engineering 11/2013; DOI:10.1117/12.2036322 · 0.20 Impact Factor
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- "This hardly mitigated disadvantage becomes notable when dealing with a laser based on heavily-doped YF where high Yb 3+ population inversion is created, either at high-power continuous-wave or moderate-power pulsed lasing. A number of studies during the past years were aimed to understand the PD phenomenon which has remained unclear, although a few hypotheses have been proposed for its explanation         . Meanwhile, on one hand, the characterization procedures have been specified to quantify the PD phenomenon in YFs  , allowing a proper choice among YFs for a certain application. "
ABSTRACT: We report a comparative experimental study of the attenuation spectra transformations for a series of Yb doped alumino-germano silicate fibers with different contents of Yb3+ dopants, which arise as the result of irradiation either by a beam of high-energy electrons or by resonant (into the 977 nm absorption peak of Yb3+ ions) optical pumping. The experimental data obtained reveal that in the two circumstances, substantial and complex but different in appearance changes occur within the resonant absorption band of Yb3+ ions and in the off-resonance background loss of the fibers. Possible mechanisms responsible for these spectral changes are discussed.Optics and Photonics Journal 12/2011; 1(4):155. DOI:10.4236/opj.2011.14026
- "Recently, many efforts have been devoted to the research on fiber lasers all over the world, especially the problem of photodarkening (PD) in Yb 3+ -doped silica glass host  . "
Conference Paper: Photodarkening of 488nm-pumped Sm3+-doped germanosilicate fiber laser[Show abstract] [Hide abstract]
ABSTRACT: 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 Sm<sub>2</sub>O<sub>3</sub> and GeO<sub>2</sub>. An energy level scheme has been illustrated to explain the photodarkening mechanism.Lasers & Electro Optics & The Pacific Rim Conference on Lasers and Electro-Optics, 2009. CLEO/PACIFIC RIM '09. Conference on; 09/2009