(2)E-](4)A(2) FLUORESCENCE OF CR-3+ IN HIGH AND INTERMEDIATE FIELD GARNETS

A new comprehensive approach to the radiative processes in octahedrally coordinated Cr3+ is presented. According to the adiabatic approximation the system is described by the electronic manifolds defined by total electronic energies dependent on the positions of the ions, calculated with inclusion of spin-orbit and electron-phonon interactions, and related to them discrete oscillation states. The elaborated model is used for calculations of the fluorescence kinetics, the doublet 2E-quartet 4T2 energy separation and the temperature dependence of the fluorescence line shapes for high and intermediate field garnets. The results are compared with experimental data for a series of garnets and also with predictions of other models existing in the literature.