Spectroscopy and Judd-Ofelt analysis of Er3+ ions in Li5La3Nb2O12 garnet-type ceramic powder

The optical spectroscopy of Er3+ activated Lanthanum Lithium Niobium Garnet ceramic powder is presented. The absorption and photoluminescence spectra have been both obtained at room temperature. Emission bands related to transitions starting at 4I13/2, 4I11/2, 4F9/2, (4S3/2, 2H(2)11/2) and 2H(2)9/2 manifolds are presented. Efficient excitation of the luminescence bands is obtained under ultraviolet excitation (270 nm) using a Mercury Xenon arc lamp. The Judd-Ofelt intensity parameters of Er3+ in this garnet are calculated using the absorption spectra. The obtained results Ω2 = 7.67 × 1020 cm2; Ω4 = 0.84 × 1020 cm2; Ω6 = 0.60 × 1020 cm2 are used to calculate the radiative lifetimes of the Er3+ luminescence originated up to 4G11/2 manifolds and the branching ratios of the radiative transitions on them. The luminescence decays from the main emission lines (2H(2)11/2:4S3/2), 4I11/2, and 4I13/2 excited levels to the 4I15/2 ground state of Er3+ have also been obtained. Experimental decay time values are compared with the radiative lifetime values obtained from the Judd-Ofelt analysis.