Ultraviolet-induced paramagnetic centers and absorption changes in singlemode Ge-doped optical fibers

Marco Cannas, Fabrizio Messina, Aziz Boukenter, Youcef Ouerdane, Fabrizio Messina, Kader Médjahdi, Marco Cannas

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4 Citations (Scopus)


We investigated the laser-energy-density dependence of absorption changes and paramagnetic centers induced by a cw Ar+ laser operating at 5.1 eV, in both unloaded and H-2-loaded single mode Ge-doped optical fibers. The induced absorption is measured in the blue and near ultraviolet spectral range by using the 3.1 eV photoluminescence, ascribed to Ge lone pair center (GLPC), as an in situ probe source. We find that the Ge (1) center (GeO4-) is induced upon UV exposure by electron trapping on GeO4 precursors, where the free electrons are most likely produced by ionization of GLPC. Ge (1) is responsible of optical transmission loss of the fiber in the investigated range. Hydrogen loading strongly influences the generation efficiency of the several observed paramagnetic defects, leading in particular to passivation of radiation-induced Ge (2) centers. (c) 2006 Optical Society of America
Original languageEnglish
Pages (from-to)5885-5894
Number of pages10
JournalOptics Express
Publication statusPublished - 2006

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics


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