title: Photodarkening rate in Yb-doped silica fibers.
abstract: Yb-doped fibers are widely used in laser applications requiring high average output powers and high-peak-power pulse amplification. Photodarkening (PD) is recognized as one limiting factor in these fibers when pumped with high-intensity radiation. We describe an approach for performing quantitative PD studies of fibers, and we present measurements of the rate of PD in Yb-doped single-mode fibers with varying inversion levels. The method is applicable to large-mode-area fibers. We observed a seventh-order dependence of the PD rate on the excited-state Yb concentration for two different fibers; this result implies that PD of a Yb-doped fiber source fabricated using a particular fiber will be strongly dependent on the configuration of the device.
authors: Liekki Corporation, Sorronrinne 9, FIN-08500 Lohja, Finland. joona.koponen@liekki.com
authors: Joona
authors: J
authors: Koponen
authors: Mikko
authors: M
authors: Söderlund
authors: Hanna J
authors: HJ
authors: Hoffman
authors: Dahv A V
authors: DA
authors: Kliner
authors: Jeffrey P
authors: JP
authors: Koplow
authors: Mircea
authors: M
authors: Hotoleanu