Abstract:

Sphere transparent titanate glasses (La_0.94-xEr_0.06Yb_x)(Ti_0.95Zr_0.05)_2.25O₆ (x=0-0.24, in steps of 0.04) were prepared by containerless processing. The DTA curve shows that the glass(x=0) has high glass transition temperature(T_g=818℃) and onset temperature of crystallization(T_o=906℃). The thermal stability and the glass forming ability decrease with the Yb³⁺ concentration increasing. Strong absorption bands at 975 nm are observed, showing effective absorption of Yb³⁺ at 975 nm. The transmittance is almost 70% in 300-3000 nm except characteristic absorption of Er³⁺ and Yb³⁺. Three emission bands centered at 535, 554, 672 nm are obtained at the excitation of 980 nm laser. When the Yb³⁺ concentration x is 0.16, the glass sample performs the strongest upconversion luminescence, which emission intensity at 672 nm is almost 130 times as high as that of Er³⁺-doped glass at room temperature.

Key words: upconversion luminescence, containerless processing, titanate glass, Er3+/Yb3+ co-doped glass