Intense upconversion luminescence in ytterbium-sensitized thulium-doped novel oxychloride bismuth–germanium glass

Abstract

Structural and up-conversion fluorescence properties in ytterbium-sensitized thulium-doped novel oxychloride bismuth–germanium glass have been studied. The structure of novel bismuth–germanium glass was investigated by peak-deconvolution of Raman spectrum, and the structural information was obtained from the peak wave numbers. The Raman spectrum investigation indicates that PbCl 2 plays an important role in the formation of glass network, and has an important influence on the up-conversion luminescence. Intense blue and weak red emissions centered at 477 and 650 nm, corresponding to the transitions 1G 4→ 3H 6 and 1G 4→ 3H 4, respectively, were observed at room temperature. The possible up-conversion mechanisms are discussed and estimated. This novel oxychloride bismuth–germanium glass with low maximum phonon energy (∼730 cm −1) can be used as potential host material for up-conversion lasers.