Patent attributes
An optical glass consisting essentially of B2O3 in an amount of 10-40 wt %, SiO2 in an amount less than or equal to 5 wt %, ZnO in an amount less than or equal to 15 wt %, SrO in an amount less than or equal to 9 wt %, ZrO2 in an amount less than or equal to 9 wt %, La2O3 in an amount of 15 to 45 wt %, BaF2 in an amount of 1 to 10 wt %, BaO in an amount less than or equal to 5 wt %, HfO2 in an amount of 0.1 to 7.5 wt %, Gd2O3 in an amount less than or equal to 16 wt %, CaO in an amount less than or equal to 7 wt %, ZrF4 in an amount less than or equal to 5 wt %, Na2O in an amount less than or equal to 2 wt % and Y2O3 in an amount less than or equal to 16 wt %. The optical glass has a glass transition temperature in a range of 500-670° C. and a refractive index (nd) in a range of 1.60 to 2.00.