title: How do traces of thulium explain photodarkening in Yb doped fibers?
authors.affiliation: Université de Lyon, Université Lyon 1, CNRS/LPCML,Villeurbanne F-69622, France.
authors.forename: R
authors.initials: R
authors.lastname: Peretti
authors.forename: A-M
authors.initials: AM
authors.lastname: Jurdyc
authors.forename: B
authors.initials: B
authors.lastname: Jacquier
authors.forename: Cédric
authors.initials: C
authors.lastname: Gonnet
authors.forename: Alain
authors.initials: A
authors.lastname: Pastouret
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Burov
authors.forename: Olivier
authors.initials: O
authors.lastname: Cavani