Stark level analysis for Er3+-doped ZBLAN glass

From the absorption and emission spectra recorded in a conventional way at 13 K, the Stark levels in manifolds from I-4(15/2) to (2)Hy(9/2) for Er3+-d oped ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass have been investigated by means of the effective crystal field model previously proposed to describe the av erage of local symmetries occupied by rare earth ions in oxide glasses [1]. This model, based on the principle of descending symmetry, used the symmet ry group chain scheme. Crystal field strength, homogeneous and inhomogeneou s widths of levels have been determined, and the former models and results about optical properties for rare earth ions in heavy metal fluoride glasse s are discussed. In fluoride glasses, the rare earth ions appear more evenl y distributed than in oxide glasses, and the crystal field strength is weak er than in oxide glasses. (C) 2001 Elsevier Science B.V. All rights reserve d.