Optical glass and use thereof

摘要

An aspect of the present invention relates to optical glass, which is oxide glass, having a refractive index nd ranging from 1.95 to 2.50 and an Abbé number νd ranging from 18 to 40, including essential components in the form of Si4+, B3+, La3+, Ti4+, Nb5+, and at least one from among Gd3+, Y3+, and Yb3+, including, denoted as cation %, 1 to 30% of Si4+, 1 to 50% of B3+, wherein a total of Si4+ and B3+ ranges from 5 to 55%, a total of 11 to 70% of La3+, Gd3+, Y3+, and Yb3+, with 10 to 50% of La3+, a total of 23 to 70% of Ti4+, Nb5+, Ta5+, and W6+, with equal to or greater than 1% of Nb5+ and greater than 22% of Ti4+.

主权项

1. Optical glass, which is oxide glass, having a refractive index nd ranging from 1.95 to 2.50 and an Abbé number νd ranging from 18 to 40;
comprising essential components in the form of Si4+, B3+, La3+, Ti4+, Nb5+, and at least one from among Gd3+, Y3+, and Yb3+; comprising, denoted as cation %, 1 to 30% of Si4+; and 1 to 50% of B3+, wherein a total of Si4+ and B3+ ranges from 5 to 55%; a total of 21 to 70% of La3+, Gd3+, Y3+, and Yb3+, with 20 to 50% of La+; total of Ti4+, Nb5+, Ta5+, and W6+ ranges from greater than 23% to 70% with equal to or greater than 1% of Nb5+ and greater than 22% of Ti4+; and 0 to 6% of Ba2+; wherein
the refractive index nd and Abbé number νd satisfy the following expression: nd≧2.54−(0.02×ν);a cation ratio of a content of Ti4+ to a content of B3+, Ti4+/B3+, is equal to or greater than 0.85;a cation ratio of a content of Y3+ to a total content of Gd3+, Y3+, and Yb3+, Y3+/(Gd3++Y3++Yb3+), is equal to or less than 0.60; and a cation ratio of a content of W6+ to a total content of Ti4+, Nb5+, Ta5+, and W6+, W6+/(Ti4++Nb5++Ta5++W6+), is less than 0.10.