Study on 2.0 μm fluorescence of Ho-doped water-free fluorotellurite glasses

Ho(3+-)doped water-free fluorotellurite glasses with composition of 60TeO(2)-30ZnF(2)-10NaF (mol%, TZNF60) were made by using specially-designed physical and chemical dehydration technique. 2.04 mu m fluorescence (Ho3+: I-5(7) -> I-5(8)) was observed experimentally and presented in this paper: A broad bandwidth of similar to 149 nm, large simulated emission cross-section of 7.2 x 10(-21) cm(2), and the longest reported fluorescence lifetime of similar to 10 ms among all the reported Ho3+-doped oxide glasses. Thanks to the absence of OH groups and low phonon energy with the addition fluorides into tellurite oxide glasses, 1.00Ho-TZNF60 glass demonstrates the maximum figure of merit (sigma(em) x tau(f)) of 7.13 x 10(-27) m(2) s, thus regarded as a promising optical material for the development of 2.0 mu m fiber lasers. (C) 2013 Elsevier B.V. All rights reserved.