| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical glass having high refractive index (n) and low Abbe number (ν), low in glass transition point and suitable for press molding and high in devitrification resistance, a lens preform and an optical element using the same.SOLUTION: An optical glass contains, by mol%, a POcomponent of 15.0% to 45.0%, a NbOcomponent of 5.0% to 50.0%, a ZnO component of 0.5% to 30.0% and a LiO component of 0.5% to 30.0% and has refractive index (n) of 1.80 or more and glass transition point of 650°C or less.SELECTED DRAWING: None |
