Inhomogeneity of Ho3+ activated SrLaGa3O7 and SrLaGaO4 crystals studied by fluorescence line narrowing technique

Spectroscopic properties of Ho3+ in SrLaGa3O7 (SLG) and SrLaGaO4 (SLO) are studied using non-resonant fluorescence line narrowing technique. Spectrally-different ions in inhomogeneous absorption line of holmium are selectively excited. The low temperature emission and fluorescence decays from the 5S2 level of Ho3+ ion after pulsed 5I8 → 5S2 excitation transition are investigated. The observed line-narrowed fluorescence is used to analyze the origin of spectral line broadening phenomenon in SLG and SLO hosts. Based on the experimental results an influence of the statistical distribution of La3+ and Sr2+ ions in crystal lattice on the spectroscopic properties of Ho3+ is discussed.