Ultra-high refractive niobate-based borate glasses with visible transparent and large elastic properties

Abstract

We have explored ultra-high refractive index over 2.05 in multi-component borate glasses with large optical bandgap (∼3.7 eV) and high Young’s modulus (∼130 GPa). The niobate-based borate glasses commonly contain highly electronic polarized oxides like Nb₂O₅ and TiO₂, chosen from transition metal oxides. Although these glasses have a large amount of Nb₂O₅, TiO₂, and La₂O₃, they are vitrified by melting at 1300 °C. The obtained borate glasses with internal transmissions of 99 % per 10 mm-thick estimated from the optical absorption coefficient for the visible light might be used for “Augmented Reality glass” devices.