Upconverting nanoparticles (UCNPs) compose a class of luminescent materials that utilize
the unique wavelength-converting properties of lanthanide (Ln) ions for light-harvesting …

The major challenge in the development of monolithic kW class CW fiber lasers is the
efficient conversion of pump photons into a high brightness laser beam under the constraints …

We show that the photodarkening resistivity of ytterbium-doped fiber lasers can be greatly
improved by cerium codoping. It is suggested that the coexistence of the redox couple Ce …

In this work we present experimental evidence that the valence instability of the ytterbium ion
play a key role for the observed photodarkening mechanism in Yb-doped fiber lasers …

Sustained progress in the development of optical fibers has led to the present state where
further improvements in performance are limited by intrinsic optical nonlinearities. In order to …

The radical suppression of the photodarkening effect and laser performance deterioration
via H_2 loading were demonstrated in high-power Yb-doped fiber (YDF) amplifiers. The …

In this paper we discuss recent progress in exploring short-term and long-term stability of
high power Yb-doped fiber lasers and amplifiers. Long-term stability is associated with …

Owing to its capability to produce large volume of glass while preserving a high degree of
purity and homogeneity, the suspension method was employed here to synthesize a Yb …

Ytterbium (Yb) doped silica fibers are widely used in high power fiber lasers where co-
doping the silica core material with other elements is pivotal for high efficiency, low …

In this work we measure how photodarkening affects the optical efficiency for three different
Yb/Al-doped silica fibers operating at 980 nm, one of which is codoped with cerium. A …