Study on optical properties of La2O3–TiO2–Nb2O5 glasses prepared by containerless processing

High refractive index glasses with the composition of 20La2O3–(80−x)TiO2–xNb2O5 (x=0–65) were successfully prepared by aerodynamic containerless processing. The glass transition temperature Tg and the onset crystallization temperature Tx gradually decreased with the increase of Nb2O5, and the maximum temperature difference between Tx and Tg (ΔT=Tx−Tg) was 81 °C. The glasses were colorless and optical transparent from 370 nm to 6500 nm. The refractive indexes of as-prepared glasses were higher than 2.29 and the maximum Abbe number was almost 18 in the visible light range. The Raman scattering spectra demonstrated that the maximum phonon energy was found to be 800 cm−1. These results indicate that a La2O3–TiO2–Nb2O5 ternary system would be a promising optical glass from visible to infrared region.