Enhanced 3 μm luminescence in Ho3+/Yb3+ co-doped bismuth-tellurite glass by controlled structure network topology

Abstract

Ho3+/Yb3+ co-doped bismuth-tellurite glasses (TeO2-Bi2O3-ZnO) have been investigated systematically according to the Raman, absorption, and mid-infrared luminescence spectra, contraposing 3 μm band. The evolution of luminescence and structure has been explored by modifying network topology based on the substitution of TeO2 with WO3 when the optimal concentration ratio of Ho3+/Yb3+ was determined in TBZ glass. The results show that WO3 entered the glass structure network as [WO4] and [WO6] units, contributing to the content of bridging oxygen and network connectivity increased, which can be enhanced effectively the luminescence properties. The gain cross-section is 1.51 × 10−20 cm2 (2884 nm) increasing by 11.85% compared with the glass without glass network modifiers. Moreover, the energy transfer micro-parameters have been calculated based on a spectral overlap method. The CD-A was augmented from 0.36 to 1.11 × 10−40 cm6/s. As mentioned above, the bismuth-tellurite glasses have the potential as the gain materials for mid-infrared fiber lasers.