The study of spectroscopic and luminescence properties of disordered laser crystals calcium niobium gallium garnet doped with Er3+

The results of spectroscopy of disordered Er-doped calcium-niobium gallium garnets (CNGG: Er) are displayed. Based on the Judd-Ofelt theory, three intensity parameters Omega(t) (t=2, 4, 6) for Er ions concentration from 6 at. % in these crystals were obtained. The oscillator strength for hypersensitivity transition I-4(15/2)-> H-2(11/2) and intensity parameter Omega(2) of Er3+ ions in CNGG: Er crystals are higher than corresponding values for other Er-doped garnets. These results we explain by the presence in these crystals of optical centers Er with the environment symmetry lower than D-2. Gain cross-section for laser transition I-4(13/2) -> I-4(15/2) of Er3+ ions was obtained using absorption and emission cross-data for transition I-4(15/2) -> I-4(13/2) and I-4(13/2) -> I-4(15/2) respectively.