Frequency up-conversion properties of Er3+-doped TeO2-ZnO-PbCl2 oxyhalide tellurite glasses

This paper reports on the successful preparation and a detailed study on the up-conversion properties of Er3+-doped TeO2-ZnO-PbCl2 oxyhalide tellurite glasses. Three intense emissions centered at around 527, 549 and 666 nm have been clearly observed under 977 nm excitation and the involved mechanisms have been explained. The green emissions centered at 527 and 549 nm are due to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions, and the red up-conversion emission centered at 666 nm is associated with the 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The quadratic dependence of fluorescence on excitation laser power confirm that two-photons contribute to up-conversion of the green-red emissions.