P.D. Dragic, C.G. Carlson, A. Croteau "Characterization of defect luminescence in Yb doped silica fibers: part I NBOHC" Optics Express, 16 (7):4688-4697, 2008
Abstract: We present an analysis of non-bridging oxygen hole center (NBOHC) defects in Yb-doped silica fibers. Red photoluminescence is observed when several fiber samples are irradiated with green light (532nm). Both highly Ge-doped and moderately P-doped Yb fibers exhibit red-shifted NBOHC emission spectra while highly Al-doped Yb fibers seem to exhibit NBOHC spectra closer to that of pure silica. NBOHC centers may play a role in the photodarkening process of Yb doped fibers.
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