JP2018052763A5 - - Google Patents

Claims (7)

In mass%,
6.0% or more and 30.0% or less of B ₂ O ₃ components,
25.0% or more and 50.0% or less of La ₂ O ₃ components,
6.0% or more and 25.0% or less of TiO ₂ component,
2.0% or more and 23.0% or less of ZnO component,
Contains 4.0% or more and 22.0% or less of the BaO component,
An optical glass having a refractive index (n _d ) of 1.85 or more and an Abbe number (ν _d ) of 25 or more and 35 or less. The weight ratio _{(TiO 2 + ZnO + BaO)} / La 2 O 3 is 0.50 to 1.50 claim 1 Symbol placement of the optical glass (Wherein, Ln is La, Gd, Y, 1 or more selected from the group consisting of Yb) mass ratio BaO / _Ln 2 _{O 3} is according to claim 1 or 2, wherein at 0.0400 or 0.5000 or less Optical glass. The optical glass according to any one of claims 1 to 3 , wherein the mass ratio (SiO ₂ + BaO) / ZnO is 8.00 or less. The preform material which consists of an optical glass in any one of Claims 1-4 . An optical element comprising the optical glass according to any one of claims 1 to 4 . An optical apparatus comprising the optical element according to claim 6 .