1. Thermal bleaching of photodarkening-induced loss in ytterbium-doped fibers
- Author
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Joan J. Montiel i Ponsoda, Jeffrey P. Koplow, Seppo Honkanen, and Mikko Söderlund
- Subjects
Ytterbium ,Optical fiber ,Materials science ,business.industry ,chemistry.chemical_element ,Activation energy ,Atomic and Molecular Physics, and Optics ,law.invention ,Core (optical fiber) ,Optics ,chemistry ,law ,Attenuation coefficient ,Fiber laser ,Photodarkening ,Fiber ,business - Abstract
We study the thermal bleaching process of photodarkening-induced loss in ytterbium-doped fibers. The observed power-law time dependence of the normalized absorption coefficient is well represented by the thermal decay model of Erdogan et al. [J. Appl. Phys. 76, 73 (1994)]. Using this model, we derive the activation energy associated with thermal recovery of the induced loss to prephotodarkened state. For the studied commercial 20 microm core diameter large-mode-area fiber, the energy distribution consists of a single peak, located at 1.32 eV with a FWHM of approximately 0.31 eV. The results presented are of particular importance to understanding photodarkening and bleaching processes in high-power fiber lasers.
- Published
- 2009