Spectroscopic properties of Er3+ in LiErP4O12 and LiErYP4O12 single crystals

The electronic energy levels of Er3+ in flux-grown single crystals of LiErP4O12 and LiErYP4O12 have been determined from absorption spectra at 293 K in the range 185-3200 nm. The Slater-Condon integrals F k, the constant of spin-orbit interaction ζ 4f, and the intensity parameters Ω k, k = 2, 4, 6, have been obtained from 27 f-f transitions between the ground level 4I15/2 and the excited levels of configuration 4f11. Ω k have been compared with those of other solids and used in the calculation of the electric-dipole transition probabilities for the emissions at 1.3 and 1.5 μm