Spectroscopic analysis of 10% Yb3+Yb3+:KYF4KYF4 crystal

A spectroscopic characterization of a KYF4 crystal doped with 10% Yb3+Yb3+ is presented. We report the analysis in two regions: from 870 to 1050 nm and from 520 to 580 nm. Because of the disordered KYF4 structure absorption spectra reveal a number of lines larger than the theoretical number predicted from the degeneracy lifting in Ytterbium-doped crystals. A discussion about the possible processes of energy transfer to impurity ions in the sample is also presented.