Erratum to ‘Sites structure and spectroscopic properties of Yb3+- and Yb3+, Na+-doped CaF2 laser crystals’ [Chem. Phys. Lett. 406 (2005) 254–258]

Reversible photo-darkening and resonant photo-bleaching of Ytterbium-doped silica fiber at in-core 977-nm and 543-nm irradiation

“…By the way notice that, according to the current point of view, in many highly-doped Ytterbium-doped materials (see e.g. [17,[20][21][22]), and particularly in YF [14,15,23], the effect of Yb 3+ -Yb 3+ ion pairs is noticeable. It is as well of importance that Ytterbium ion pairs possess not only the "cooperative" absorption/emission lines in the visible [14,15,23], but also the lines near ∼ 1 µm (latent under the Yb 3+ single ion band cover) [22], thus making relevant a suggestion that the observed in the present work resonant photo-bleaching (at 977-nm pumping) is due to a decrease of number of those Yb 3+ ions which compose Yb 3+ -Yb 3+ pairs (or even more complicate clusters).…”

Thermal, spectroscopic and laser properties of Yb3+,Na+:CaF2 single crystals

“…This shortcoming should not bring crucial restricts on our analyses and discussions. The three crystals with Na + dopant concentrations of 0%, 3.0%, and 20.0% have been reported in our previous papers [11]. As demonstrated earlier, codoping Na + can modulate the absorption spectra, photoluminescence properties, and fluorescence lifetime of Yb 3+ ions in CaF 2 host through alteration of the sites structure.…”

“…On the one hand, the fluorescence quenching effect could be weakened by the codoping of Na + , which can prevent the formation of Yb 3+ ion clusters and Yb 2+ ions, as reported in Ref. [11]. On the other hand, the emission cross-section, i.e.…”

“…[11], several remarkable and successive variations can be observed in the absorption and emission spectra of five crystals with increasing dopant concentration of Na + . First, the lowest absorption peak shifts to shorter wavelength (974-965 nm), while the highest one shifts to longer wavelength (912-921 nm).…”

“…Moreover, Yb 3+ introduced into CaF 2 lattice could be partly in divalent state because of the tendency to complete the full 4f-shell [10]. In our previous papers, codoping Na + as a charge compensator into Yb 3+ :CaF 2 crystal was just proved to be very effective for breaking the Yb 3+ ions clusters and suppressing the formation of Yb 2+ ions [11]. And the highly efficient self-Q-switched laser was achieved in 2.0 at% Yb 3+ -and 3.0 at% Na + -codoped CaF 2 crystal, operating with a relatively low-threshold pump power [12].…”