| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical glass suitable for an optical element having refraction index (n) and Abbe number (ν) in a desired range and stable with contribution to weight saving of an optical device at low cost.SOLUTION: An optical glass contains, by mass% based on total mass of the glass in terms of oxide composition, a BOcomponent of 15.0 to 35.0% and a LaOcomponent of 20.0% to 60.0% with the content of a NbOcomponent of 5.0% or less and the content of a WOcomponent of 5.0% or less and having refractive index (n) of 1.75 or more and specific gravity of 4.80 or less.SELECTED DRAWING: None |
