US Patent 7514381 Optical glass and lens

To provide an optical glass which has a high transmittance and a high refractive index and shows little decrease in the transmitted light intensity when continuously irradiated with a blue-violet laser diode light, and which is less prone to a higher melting temperature and exhibits chemical durability being not low. An optical glass consisting essentially of, as represented by mol %, from 35 to 54% of TeO2, from 0 to 10% of GeO2, from 5 to 30% of B2O3, from 0 to 15% of Ga2O3, from 0 to 8% of Bi2O3, from 3 to 20% of ZnO, from 0 to 10% of MgO+CaO+SrO+BaO, from 1 to 10% of Y2O3+La2O3+Gd2O3, from 0 to 5% of Ta2O5+Nb2O5, from 0 to 1.8% of TiO2, and from 0 to 6% of Li2O+Na2O+K2O+Rb2O+Cs2O. A lens made of such an optical glass.