Thermal, mechanical, and upconversion properties of Er3+/Yb3+ co-doped titanate glass prepared by levitation method

A novel Er3+/Yb3+ co-doped titanate glass sphere with diameter of 3.5 mm has been successfully fabricated by levitation method. Its thermal stability, mechanical property and upconversion behavior were investigated. The glass transition temperature Tg, onset crystallization temperature Tc, and peak crystallization temperature Tp, are as high as 820, 895 and 902 °C, respectively. Its Vickers hardness is found to be up to 7.85 GPa. Intense green and red upconversion emissions were obtained in this glassy sample upon 980 nm excitation. The results illustrate good potential of this class of material for practical application in frequency upconversion device. In addition, it is found that heating treatment above Tp can reduce the efficiency of upconversion fluorescence as well as deteriorate the mechanical property, due to the occurrence of La4Ti9O24 crystals.

► We fabricated one novel rare earth doped bulk titanate glass by levitation method.
► The glass performs excellent upconversion, mechanical and thermal properties.
► Two-photon processes are responsible for the upcoversion emissions mechanism.
► Upconversion efficiency and Vickers hardness are decreased by heat treatment.