Optical glass, optical element and process for the production thereof

摘要

Provided are an optical glass having high-refractivity, low-dispersion and anomalous partial dispersion properties, having excellent processability, being excellent as an anomalous partial dispersion glass for suppressing chromatic aberration, containing P⁵⁺, Al³⁺ and alkaline earth metal ions selected from the group consisting of Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺ as essential cationic components and F^- and O^2- as essential anionic components, wherein the ratio of content of Ba²⁺ to the total content R²⁺ of Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺, Ba²⁺/R²⁺, is 0.01 or more but less than 0.5 on the basis of cationic %, and having an Abbe's number (nud) of 68 or more, optical glass having an Abbe's number (nud) of 68 or more, a partial dispersion ratio of 0.535 or more and a frictional abrasion of 500 or less and an optical glass which is to be polished in a polishing step for producing an optical element and which is a fluorophosphate glass having a frictional abrasion of 500 or less.