Patent ID: 7371703

Claim:
An optical glass having optical constants of a refractive index (nd) within a range from 1.49 to 1.6, comprising, in mass %, P 2 O 5 4-39% Al 2 O 3 0-9% MgO 0-5% CaO 0-6% SrO 0-9% BaO 0-10% Y 2 O 3 + La 2 O 3 + Gd 2 O 3 + Yb 2 O 3 0-20% in the total amount of Where Y 2 O 3 0-10% La 2 O 3 0-10% and Yb 2 O 3 0-10% TiO 2 0-0.1% SnO 2 0-1% As 2 O 3 0-0.5% Sb 2 O 3 0-0.5% AlF 3 0-29% MgF 2 0-8% CaF 2 0-27% SrF 2 0-27% BaF 2 10-47% YF 3 0-10% LaF 3 0-10% GdF 3 0-10% LiF 0-3% NaF 0-0.1% KF 0-1% the total amount of F in one or more of the fluorides being 22-45% and the total amount of one or more of MgF 2 , CaF 2 , SrF 2 and BaF 2 being 30-70%.