Spectroscopy and Judd-Ofelt analysis of Er 3+ ions in Li 5 La 3 Nb 2 O 12 garnet-type ceramic powder

Abstract The optical spectroscopy of Er 3+ 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 4 I 13/2 , 4 I 11/2 , 4 F 9/2 , ( 4 S 3/2 , 2 H(2) 11/2 ) and 2 H(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 Er 3+ in this garnet are calculated using the absorption spectra. The obtained results Ω 2 = 7.67 × 10 20 cm 2 ; Ω 4 = 0.84 × 10 20 cm 2 ; Ω 6 = 0.60 × 10 20 cm 2 are used to calculate the radiative lifetimes of the Er 3+ luminescence originated up to 4 G 11/2 manifolds and the branching ratios of the radiative transitions on them. The luminescence decays from the main emission lines ( 2 H(2) 11/2: 4 S 3/2 ), 4 I 11/2 , and 4 I 13/2 excited levels to the 4 I 15/2 ground state of Er 3+ have also been obtained. Experimental decay time values are compared with the radiative lifetime values obtained from the Judd–Ofelt analysis.