Mid-infrared 2.7 mu m emission properties of Er3+ sensitized by Nd3+ in fluorotellurite glasses

Er3+ singly doped and Er3+/Nd3+-codoped fluorotellurite glasses are prepared by melt-quenching method. The Judd-Ofelt intensity parameters (Omega(lambda),lambda = 2, 4, and 6), radiative transition rate (A(rad)), and radiative lifetime (tau(R)) of Er3+ are calculated based on the absorption spectra. The 2.7 mu m emission spectra of Er3+ ions in fluorotellurite glasses are investigated under 808 nm excitation. The enhancement of Er3+ 2.7 mu m emission shows that Nd3+ can be an effective sensitizer for Er3+: I-4(11/2) -> I-4(13/2) transition, and the energy transfer efficiency can be as large as 84%. The absorption and emission cross sections are calculated using Fuchtbauer-Ladenburg equation and McCumber theory with large values of 1.62 x 10(-20) cm(2) and 1.11 x 10(-20) cm(2), respectively. The results suggest that the present glasses have potential applications in 2.7 mu m laser materials. (C) 2013 Elsevier B.V. All rights reserved