Near-infrared luminescence property of Te-doped zinc phosphate glasses

Broadband near-infrared (NIR) emission has been observed from Te-containing glasses melted under reduced conditions in recent years. However, it has not been paid great attention compared with Bi-containing glasses, and there are few reports on the NIR emission property of Te-containing glasses. In this paper, we report tunable broadband NIR emission from 900 to 1500 nm in Te-doped zinc phosphate glasses. The emission intensity increases with increasing melting temperature, indicating the temperature-dependent formation of the related luminescent center. A red shift is observed when increasing the wavelength of excitation. The NIR emission intensity increases linearly with the increase of excitation power. Based on absorption, emission and Raman spectra of the glasses melt at various temperatures, Te2 clusters are suggested to be responsible for the NIR emission.