Crystal fields and intensities of triply ionized rare-earth ions in cubic lanthanum oxyfluoride: an efficient 4 F 3/2 → 4 I 9/2 LaOF:Nd laser

TLDR: The first known completely a priori attempt to predict crystal-field splittings and luminescence properties of rare-earth impurity ions in a host crystal was reported in this article.

Abstract: We report the first known completely a priori attempt to predict crystal-field splittings and luminescence properties of rare-earth impurity ions in a host crystal. Starting with the reported crystal structure, we calculate crystal-field parameters Bkm (from the three-parameter theory) and intensity parameters Ωλ (from the Judd–Ofelt theory) for the 4fn configurations of the thirteen rare-earth ions Ce3+ through Yb3+ in cubic lanthanum oxyfluoride. The Stark-splitting schemes of the 4F3/2, 4I9/2, and 4L11/2 levels of Nd3+ in LaOF are presented, and possible laser emissions originating from the 4F3/2 level are examined. Multiplet-to-multiplet and line-to-line fluorescence branching ratios are given and compared with those calculated for existing Nd3+ lasers. It is predicted that cubic LaOF that is doped with Nd3+ may be a promising tunable, efficient laser material in the wavelength region from 850 to 950 nm, corresponding to optical transitions from 4F3/2 to 4I9/2.