| 摘要 |
An optical glass that is an oxide glass and comprises, by cationic %,
20 to 40 % of a total of Si 4+ and B 3+ ,
15 to 40 % of a total of Nb 5+ , Ti 4+ , W 6+ and Zr 4+ ,
0.2 to 20 % of a total of Zn 2+ , Ba 2+ , Sr 2+ and Ca 2+ , and
1.5 to 55 % of a total of Li + , Na + and K + ,
the cationic ratio of the content of B 3+ to the total content of B 3+ and Si 4+ being 0.01 - 0.5,
the cationic ratio of the content of Zr 4+ to the total content of Nb 5+ , Ti 4+ , W 6+ and Zr 4+ being 0.05 or less,
the molar ratio of the total content of Zn 2+ and Ba 2+ to the total content of Zn 2+ , Ba 2+ , Sr 2+ and Ca 2+ being 0.8 - 1,
the optical glass having a refractive index nd of 1.815 or more and an Abbe's number vd of 29 or less. |
