Characterization of defect luminescence in Yb doped silica fibers: part INBOHC

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. (c) 2008 Optical Society of America.