Abstract: An optical glass contains, based on a total weight of the optical glass: 12 to 30 weight percent of P2O5; 1 to 5 weight percent of B2O3; 1 to 8 weight percent of Li2O; 0.5 to weight percent of Na2O; 0.5 to 15 weight percent of K2O; 1 to 5 weight percent of CaO; 0 to 20 weight percent of BaO; 0 to 5 weight percent of SrO; 1 to 10 weight percent of TiO2; 1 to 20 weight percent of Bi2O3; 3 to 35 weight percent of Nb2O5; 13 to 60 weight percent of WO3; and 0 to 1 weight percent of Sb2O3, wherein a total weight of Na2O and K2O is in a range of 3 to 20 weight percent based on the total weight of the optical glass.

Abstract: An optical glass for press-molding contains as glass ingredients, by weight: 0.5-4% SiO2; 20-30% B2O3; 10-20% ZnO; 1-10% ZrO2; 30-45% La2O3; 5-12% Nb2O5; 1-15% WO3; 0.5-3.5% TiO2; 0.5-3% CaO; 0.1-0.5% Li2O; 0-0.4% Na2O (zero inclusive); and 0-0.4% K2O (zero inclusive), with the total content of Li2O+Na2O+K2O accounting for 0.1-0.5%.

Abstract: Optical glass which is suitable for press molding does not substantially contain a compound of lead or arsenic, and has intermediate refractive index, low dispersion properties, low Tg and small density. Concretely, the optical glass includes the glass components of SiO2: 20 to 45%, B2O3: 15 to 40%, Al2O3: 4 to 15%, MgO: 0 to 10% (including 0), CaO: 13 to 25%, MgO+CaO: 13 to 25%, Li2O: 12.5 to 25%, Na2O: 0 to 10% (including 0), K2O: 0 to 10% (including 0), Li2O+Na2O+K2O: 12.5 to 25%, SrO: 0 to 10% (including 0), BaO: 0 to 5% (including 0), and Sb2O3: 0 to 1% (including 0).

Abstract: An optical glass contains, based on a total weight of the optical glass: 12 to 30 weight percent of P2O5; 1 to 5 weight percent of B2O3; 1 to 8 weight percent of Li2O; 0.5 to weight percent of Na2O; 0.5 to 15 weight percent of K2O; 1 to 5 weight percent of CaO; 0 to 20 weight percent of BaO; 0 to 5 weight percent of SrO; 1 to 10 weight percent of TiO2; 1 to 20 weight percent of Bi2O3; 3 to 35 weight percent of Nb2O5; 13 to 60 weight percent of WO3; and 0 to 1 weight percent of Sb2O3, wherein a total weight of Na2O and K2O is in a range of 3 to 20 weight percent based on the total weight of the optical glass.

Abstract: An optical glass for press-molding contains as glass ingredients, by weight: 0.5-4% SiO2; 20-30% B2O3; 10-20% ZnO; 1-10% ZrO2; 30-45% La2O3; 5-12% Nb2O5; 1-15% WO3; 0.5-3.5% TiO2; 0.5-3% CaO; 0.1-0.5% Li2O; 0-0.4% Na2O (zero inclusive); and 0-0.4% K2O (zero inclusive), with the total content of Li2O+Na2O+K2O accounting for 0.1-0.5%.

Abstract: An optical glass contains glass constituents by wt % as follows; P2O5: 20 to 30%, B2O3: 0.1 to 10%, Nb2O5: 25 to 45%, WO3: 9 to 25%, Bi2O3; 0.1 to 10%, BaO: 3 to 15%, Li2O: 4 to 5.

Abstract: Optical glass which is suitable for press molding does not substantially contain a compound of lead or arsenic, and has intermediate refractive index, low dispersion properties, low Tg and small gravity. Concretely, the optical glass includes the glass components of SiO2: 20 to 45%, B2O3: 15 to 40%, Al2O3: 4 to 15%, MgO: 0 to 10% (including 0), CaO: 13 to 25%, MgO+CaO: 13 to 25%, Li2O: 12.5 to 25%, Na2O: 0 to 10% (including 0), K2O: 0 to 10% (including 0), Li2O+Na2O+K2O: 12.5 to 25%, SrO: 0 to 10% (including 0), BaO: 0 to 5% (including 0), and Sb2O3: 0 to 1% (including 0).

Abstract: An optical glass consists essentially, expressed in term of weight percent, of: P2O5: 20.0 to 30.0%, B2O3: 0.5 to 10.0%, Nb2O5: 5.0 to 50.0%, WO3: 15.0 to 27.0%, Bi2O3: 0.1 to 3.0%, ZnO: 1.0 to 7.0%, Li2O: 0 to 8.0%, Na2O: 0 to 15.0%, K2O: 0 to 15.0%, and Li2O+Na2O+K2O: 5.0 to 20.0%.

Abstract: An optical glass consists essentially, expressed in term of weight percent, of: P2O5: 20.0 to 30.0%, B2O3: 0.5 to 10.0%, Nb2O5: 5.0 to 50.0%, WO3: 15.0 to 27.0%, Bi2O3: 0.1 to 3.0%, ZnO: 1.0 to 7.0%, Li2O: 0 to 8.0%, Na2O: 0 to 15.0%, K2O: 0 to 15.0%, and Li2O+Na2O+K2O: 5.0 to 20.0%.