Optical glass, preform, and optical element

• Main Authors: OGINO, MICHIKO, NAGAOKA, ATSUSHI
• Format: Patent
• Language: Chinese; English
• Published: 01.05.2018
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; METALLURGY; MINERAL OR SLAG WOOL; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

The purpose of the present invention is to provide an optical glass that has optical characteristics including a high refractive index and low dispersion, that exhibits a low value with respect to the temperature coefficient of the relative refractive index thereof, and that can contribute to correcting the impact of changes in temperature on image formation characteristics. This optical glass contains, in mass%, more than 0% but no more than 30.0% of a SiO2 component, more than 0% but no more than 35.0% of a B2O3 component, 20.0-63.0% of a BaO component, and at least one Ln2O3 component (in the formula, Ln is one or more substances selected from the group consisting of La, Gd, Y, and Yb). The optical glass has a refractive index (nd) of 1.63 or more and an Abbe number ([nu]d) of 40-62. The temperature coefficient (40-60 DEG C) of the relative refractive index (589.29 nm) is within the range of +3.0*10-6 to -10.0*10-6 (DEG C-1).