| 摘要 |
An optical glass having high refractive index and low dispersion properties. There is provided an optical glass having an Abbe number (&ngr;d) and a refractive index (nd) in a region indicated by a shape bound by connecting three points, A(53, 1.70), B(53, 1.87), and C(40, 1.87) with straight lines on an orthogonal xy-coordinate system with the x-axis designating the Abbe number and the y-axis designating the refractive index; and comprising no less than 25% and no more than 65% of a combination of a SiO2 component and a B2O3 component, no less than 20% and no more than 55% of a Ln2O3 component (Ln represents at least one species selected from the group consisting of La, Gd, Dy, Yb, and Lu), and a ratio of a La2O3 component to a Ln2O3 component being no more than 0.6, by mol % on the basis of oxides. |
