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Information obtained from optical absorption, excitation, and emission experiments on erbium doped crystalline CsCdBr3 is analyzed, using a semiempirical Hamiltonian, to calculate atomic and crystal-field interaction parameters and electronic state wave functions. A majority of the Er3+ ions substitute at a Cd2+ site giving C3v point group symmetry and forming an Er3+ ion dimer center. This dimerization, together with the material’s low phonon energies, and the specific positioning of states in the Er3+ (4f11) configuration, produce the interesting and useful emission properties of the material. Comparisons are made with other erbium halide crystals, and interaction parameter and energy-level results for Nd3+:CsCdBr3 are also presented. The inclusion of second order correlation crystal-field interaction parameters is shown to be essential for accurately characterizing splittings of several J multiplets important in visible emission pathways.

As many as thirty-seven ' +'LJ multiplet manifolds of Nd'+(4f') have been analyzed in the garnets Y3A1)012 (YAG), Y3Sc~A1,0"(YSAG), Gd3Sc~Ga30l2 (GSGG), and LagLu2Ga30]2 (LLGG).The majority of Nd'+ ions substitute for Y'+, Gd'+, or La'+ ions in sites of D2 point-group symmetry in the lattice. Individual Stark levels within each manifold have been identified experimentally up to 40000 cm ' and compared with results obtained from a theoretical calculation. The modelHamiltonian includes Coulombic, spin-orbit, and interconfiguration interaction terms for the 4f atomic configuration of Nd'+ and crystal-field terms in D2 symmetry, including spin-correlated crystal-field (SCCF) contributions. The Hamiltonian was diagonalized within the complete 4f SLJMJ basis set which includes 364 states. Comparison between 148 (Nd: YAG), 140 (Nd: YSAG), 143 (Nd:GSGG), and 107 (Nd:LLGG) observed and calculated Stark levels (without SCCF) yields rms deviations of 18, 19, 17, and 16 cm, respectively. Results indicate that SCCF contributions yield modest improvement in the calculated value of the overall crystal-field splitting of the energy levels.

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