| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical glass having a small partial dispersion ratio (θg, F), while a refractive index and an Abbe number are in each desired range, and hardly generating clouding during cleaning and polishing of the glass, and to provide a preform and an optical element using the optical glass.SOLUTION: This optical glass contains in mol%, a 10.0-60.0% SiOcomponent and a >0% TaOcomponent with respect to the glass whole material amount having a composition in terms of oxides, and the chemical durability (water resistance) thereof by a powder method is in the class 1-3. |
