title: Photodarkening in Yb-doped aluminosilicate fibers induced by 488 nm irradiation.
abstract: Photodarkening of Yb-doped aluminosilicate fibers by continuous wave 488 nm irradiation was investigated. The irradiation induced significant excess loss in the UV-visible spectroscopy (VIS) region in Yb-doped aluminosilicate fibers while pure aluminosilicate fibers showed negligible induced loss. Ultraviolet-VIS-near-infrared spectroscopy revealed an absorption peak at 220 nm in unexposed Yb-doped aluminosilicate fiber preforms. The observed peak was attributed to Yb-associated oxygen deficiency centers (ODCs) and proposed as a precursor of the photodarkening. The proposed model was supported by measurements on oxygen-loaded Yb-doped aluminosilicate fibers. In these, the photodarkening could be significantly reduced, which we attribute to a smaller number of ODCs following oxygen loading.
authors.affiliation: Optoelectronics Research Centre, University of Southampton, UK. sey@orc.soton.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Yoo
authors.forename: C
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authors.lastname: Basu
authors.forename: A J
authors.initials: AJ
authors.lastname: Boyland
authors.forename: C
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authors.lastname: Sones
authors.forename: J
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authors.lastname: Nilsson
authors.forename: J K
authors.initials: JK
authors.lastname: Sahu
authors.forename: D
authors.initials: D
authors.lastname: Payne