Spectroscopic properties and thermal stability of Er3+-doped TeO2-B2O3-Nb2O5-ZnO glass for potential WDM amplifier

A series of novel 70TeO2-(15 − x)B2O3-xNb2O5-15ZnO-1 wt.% Er2O3 (TBN x = 0, 3, 6, 9, 12 and 15 mol%) tellurite glasses were prepared. The thermal stability, absorption spectra, emission spectra, and the lifetime of the 4I13/2 level of Er3+ ions were measured and investigated. Three Judd-Ofelt intensity parameters Ωt (t = 2, 4 and 6) (Ω2 = (5.42-6.76) × 10−20 cm2; Ω4 = (1.37-1.73) × 10−20 cm2; Ω6 = (0.70-0.94) × 10−20 cm2) of Er3+ ions were calculated by Judd-Ofelt theory. It is found that the Ω6 first increases with the increase of Nb2O5 content from 0 to 6 mol% and then decreases, which is mainly affected by the number of non-bridging oxygen ions of the glass network. The high peak of stimulated emission cross-section (σepeak=(0.77-0.91)×10−20cm2) of Er3+: 4I13/2 → 4I15/2 transition were obtained according to McCumber theory and broad full width at half maximum (FWHM = 65-73 nm) of the 4I13/2 → 4I15/2 transition of Er3+ ions were measured. The results indicate that these new TBN glasses can be used as a candidate host material for potential broadband optical amplifiers.