| 摘要 |
An optical glass comprising, by mass%, 12 to 30 % of total of B 2 O 3 and SiO 2 , 55 to 80 % of total of La 2 O 3 , Gd 2 O 3 , Y 2 O 3 , Yb 2 O 3 , ZrO 2 , Nb 2 O 5 and WO 3 , 2 to 10 % of ZrO 2 , 0 to 15 % of Nb 2 O 5 , 0 to 15 % of ZnO and 0 % or more but less than 13 % of Ta 2 O 5 , wherein the ratio of the content of Ta 2 O 5 to the total content of La 2 O 3 , Gd 2 O 3 , Y 2 O 3 , Yb 2 O 3 , ZrO 2 , Nb 2 O 5 and WO 3 is 0.23 or less, the ratio of the total content of La 2 O 3 , Gd 2 O 3 , Y 2 O 3 and Yb 2 O 3 to the total content of B 2 O 3 and SiO 2 is from 2 to 4, the optical glass having a refractive index nd of 1.86 or more and an Abbe's number vd of 38 or more, and a rod-shaped glass shaped material and an optical element formed of the above optical glass each. |
