| 摘要 |
An optical glass that is an oxide glass and comprises, by cationic %, 20 to 40% of a total of Si4+ and B3+, 15 to 40% of a total of Nb5+, Ti4+, W6+ and Zr4+, 0.2 to 20% of a total of Zn2+, Ba2+, Sr2+ and Ca2+, and 15 to 55% of a total of Li+, Na+ and K+, the cationic ratio of the content of B3+ to the total content of B3+ and Si4+ being 0.01-0.5, the cationic ratio of the content of Zr4+ to the total content of Nb5+, Ti4+, W6+ and Zr4+ being 0.05 or less, the molar ratio of the total content of Zn2+ and Ba2+ to the total content of Zn2+, Ba2+, Sr2+ and Ca2+ being 0.8-1, the optical glass having a refractive index nd of 1.815 or more and an Abbe's number nud of 29 or less. |
