Optical and magnetooptical properties of Ho3+:YGG

The luminescence and excitation spectra in the paramagnetic holmium‐yttrium gallium garnet Ho0.2Y2.8Ga5O12 (Ho3+:YGG) have been studied experimentally at temperatures T = 80 and 293 K. Identification of the radiative 4f → 4f transitions observed between 5S2, 5F4, and 5I8 multiplets of the ground 4f(10)‐configuration of Ho3+ in sites of D2 symmetry was performed on the base of the results of numerical crystal‐field calculations. Analysis of the features observed in the measured magnetic circular dichroism and magnetic circular polarization of luminescence spectra at T = 80 K confirms the correctness of the symmetry characterization of the Stark levels for several multiplets of Ho3+ in Ho:YGG. Significant contributions from quasidoublet states in the 5S2, 5G5, and 5I8 multiplets explain the magnetooptical measurements of the 4f → 4f transitions under consideration.