Calculating line intensities of 1S0 emission through standard and modified Judd-Ofelt theories in Pr3+-doped CaAl12O19 and SrAl12O19

A modified Judd-Ofelt theory is used in this paper to treat the electric dipole transitions within the 4f2 configuration of Pr3+ by considering two main perturbing components of 4f5d and 4fn'g. Through the energy-level calculation and standard tensorial analysis, the explicit distance between the 4f5d configuration and the 1S0 state and other lower 4f2 energy levels are determined. The rare-earth ion Pr3+ substituted at Sr2+ sites in SrAl12O19 (SAO) and Ca2+ sites in CaAl12O19 (CAO) has the site symmetry of D3h. The standard Judd-Ofelt parameters A332, A334, A534, A536, A736 are included in the calculation, together with odd-λ parameters A333 and A535. The emitting line intensities originating from 1S0 and 3P0 are then calculated. Compared with the experimental measurements, the modified model yields better results than the standard Judd-Ofelt theory.