Abstract: The optical glass includes SiO2, B2O3, TiO2, Nb2O5, Y2O3, La2O3, and Gd2O3 as essential components, in which, on a mass basis, a mass ratio of a B2O3 content to a SiO2 content (B2O3/SiO2) is less than 1.000, a mass ratio of Y2O3 content to a total content of Y2O3, La2O3, Gd2O3 and Yb2O3 (Y2O3/(Y2O3+La2O3+Gd2O3+Yb2O3)) is more than 0.020, and a refractive index nd is more than 2.00000.

Abstract: The optical glass has a wavelength ?5, which provides a spectral transmittance of 5% for a thickness of 10 mm, of more than 370 nm and less than 410 nm, a difference (?70??5) between a wavelength ?70, which provides a spectral transmittance of 70% for a thickness of 10 mm, and ?5, of 70 nm or less, and a refractive index nd of 2.00000 or more.

Abstract: The optical glass has, in mass %, SiO2 content of 3.00% or more and 20.00% or less, B2O3 content of 1.00% or more and 18.00% or less, La2O3 content of 20.00% or more and 60.00% or less, Nb2O5 content of 8.80% or more, TiO2 content of 5.00% or more and 20.00% or less, total content (MgO+CaO+SrO+BaO+ZnO) of 2.00% or more, mass ratio ((MgO+CaO+SrO+BaO+ZnO)/(SiO2+B2O3)) of 0.300 or more, mass ratio ((Nb2O5+TiO2+ZrO2+WO3)/(SiO2+B2O3)) of 1.600 or more, mass ratio ((La2O3+Gd2O3+Y2O3)/(SiO2+B2O3)) of 2.750 or more, mass ratio ((MgO+CaO+SrO+BaO+ZnO)/(Nb2O5+TiO2+ZrO2+WO3)) of 0.290 or less, and mass ratio ((Nb2O5+TiO2)/(SiO2+B2O3)) of 1.400 or more.

Abstract: Provided is optical glass in which a refractive index nd is 1.900 or more, an Abbe number vd is 25.0 or less, an amount of P2O5 is 5.0 mass % or more, an amount of Bi2O3 is 20.0 mass % or less, an amount of TiO2 is 0.1 mass % or more, a mass ratio [TiO2/(Li2O+Na2O+K2O)] between the amount of TiO2, and a total amount of Li2O, Na2O, and K2O [Li2O+Na2O+K2O] is 2.5 to 10.0, a mass ratio [TiO2/(MgO+CaO+ZnO+SrO+BaO)] between the amount of TiO2 and a total amount of MgO, CaO, ZnO, SrO, and BaO [MgO+CaO+ZnO+SrO+BaO] is 1.25 to 10.0, and a mass ratio [(Li2O+Na2O+MgO+CaO+ZnO+SrO)/(K2O+BaO)] between a total amount of Li2O, Na2O, MgO, CaO, ZnO, and SrO [Li2O+Na2O+MgO+CaO+ZnO+SrO] and a total amount of K2O and BaO [K2O+BaO] is 0.8 or less.

Abstract: Provided is optical glass in which an amount of P2O5 is 10.0 to 40.0 mass %, an amount of TiO2 is 5.0 to 40.0 mass %, an amount of Nb2O5 is 20.0 to 60.0 mass %, an amount of K2O is 0.01 mass % or more, a total amount of Li2O, Na2O, K2O, MgO, CaO, ZnO, SrO, and BaO [Li2O+Na2O+K2O+MgO+CaO+ZnO+SrO+BaO] is 20.0 mass % or less, a total amount of TiO2 and Nb2O5[TiO2+Nb2O5] is 55.0 mass % or more, a mass ratio [K2O/(Li2O+Na2O+K2O)] between the amount of K2O, and a total amount of Li2O, Na2O, and K2O [Li2O+Na2O+K2O] is 0.5 or more, a mass ratio [(MgO+CaO+ZnO+SrO+BaO)/(Li2O+Na2O+K2O)] between a total amount of MgO, CaO, ZnO, SrO, and BaO [MgO+CaO+ZnO+SrO+BaO], and the total amount of Li2O, Na2O, and K2O [Li2O+Na2O+K2O] is 0.30 to 10.0, a mass ratio [TiO2/K2O] between the amount of TiO2 and the amount of K2O is 3.0 or more, and a mass ratio [(Li2O+Na2O+MgO+CaO+ZnO+SrO)/(K2O+BaO)] between a total amount of Li2O, Na2O, MgO, CaO, ZnO, and SrO [Li2O+Na2O+MgO+CaO+ZnO+SrO], and a total amount of K2O and BaO [K2O+BaO] is 0.

Abstract: Provided is optical glass in which a refractive index nd is 1.950 or more, an amount of P2O5 is 10.0 to 40.0 mass %, an amount of TiO2 is 5.0 to 40.0 mass %, an amount of Nb2O5 is 20.0 to 60.0 mass %, an amount of Bi2O3 is 20.0 mass % or less, a total amount of Al2O3 and SiO2 [Al2O3+SiO2] is 2.0 mass % or less, a total amount of Li2O, Na2O, and K2O [Li2O+Na2O+K2O] is 5.0 mass % or less, and a total amount of ZnO, SrO, and BaO [ZnO+SrO+BaO] is 0.01 to 12.0 mass %.