OPTICAL GLASS, PREFORM AND OPTICAL ELEMENT

• Main Authors: TSUDA TETSUYA, TSUCHIBUCHI NANA
• Format: Patent
• Language: English
• Published: 18.10.2012
• 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

PROBLEM TO BE SOLVED: To provide an optical glass having a refractive index (n) and an Abbe number (ν) which are in each desired range, a small partial dispersion ratio (θg, F), and heightened transparency to visible light, and to provide a preform and an optical element using the optical glass.SOLUTION: The optical glass contains in mol%, a ≤60.0% SiOcomponent and a ≤25.0% TaOcomponent to a total amount of a glass material of a composition in terms of oxides, and the partial dispersion ratio (θg, F) satisfies following relations with the Abbe number (ν): in the range of ν≤25, (-0.00160×ν+0.63460)≤(θg, F)≤(-0.00563×ν+0.75573), and in the range of ν>25, (-0.00250×ν+0.65710)≤(θg, F)≤(-0.00340×ν+0.70000).