| 摘要 |
The optical glass of the present invention comprises a composition in terms of weight ratio within the range of 0 to 14.8 wt% of SiO2, 30 to 60 wt% of B2O3, 0 to 17.5 wt% of Al2O3, 0 to 0.4 wt% of Li2O, 0 to 3 wt% of Na2O, 0 to 3 wt% of K2O, 0 to 5 wt% of MgO, 0 to 30 wt% of CaO, 0 to 30 wt% of SrO, 0 to 35 wt% of BaO, where RO (MgO + CaO + SrO + BaO) is 8 to 35 wt%, 0 to 20 wt% of ZnO, 0 to 6.5 wt% of La2O3, 0 to 15 wt% of Gd2O3, 0 to 15 wt% of Y2O3, 0 to 10 wt% of Ta2O3, 0 to 9.5 wt% of ZrO2, 0 to 1 wt% of As2O3, and 0 to 0.5 wt% of Sb2O3; and has a refractive index (nd) of 1.52 to 1.65, an Abbe number ( nu d) of 55 to 61, and an 80% transmission wavelength (at a thickness of 10 mm including no reflection loss) of 330 nm or shorter. <IMAGE> |
