Distribution of Ce3+ Impurity Centers in Highly Doped LiCaAlF6 Crystals

Crystals of the UV lasers active media Ce3+:LiCaAlF6, which are characterized by the formation of several types of Ce3+ ion centers, have been studied. The presence of nonequivalent impurity centers was confirmed by detection of zero-phonon lines for two centers in low-temperature luminescence spectra, as well as from EPR spectra for various magnetic field orientations relative to the crystallographic axes of the samples. We have shown that for Ce3+:LiCaAlF6 crystals, with an increase in the concentration of Ce3+ ions in the melt , crystallization occurs in such a way that the concentration of impurity centers of lower symmetry increases to a greater extent than centers of higher symmetry . Moreover, laser oscillation belongs to precisely this type of center.