| 摘要 |
The present invention relates to glass, a glass material for press molding, an optical element blank, and an optical element. Provided in the present invention is the glass, having a refractive index (nd) in the range of 1.790-1.830 and an Abbe′s number (νd) in the range of 45-48, having excellent thermal stability, and having absorption properties desirable to manufacture a cemented lens. The glass comprises: 20-35 mass% of the sum of SiO_2 and B_2O_3 contents; 50-70 mass% of the sum of La_2O_3, Gd_2O_3, Y_2O_3, and Yb_2O_3 contents; 37-69 mass% of La_2O_3 contents; 0-3 mass% of Gd_2O_3 contents; 3-30 mass% of Y_2O_3 contents; greater than or equal to 0 mass% and less than 2 mass% of Yb_2O_3; 2-15 mass% of ZrO_2 contents; 1-6 mass% of the sum of TiO_2, Nb_2O_5, and Ta_2O_5 contents; 0-4 mass% of ZnO contents; and 0-2 mass% of WO_3 contents. |
