Method of manufacturing an optical element blank and manufacturing method thereof and optical element optical glass, and press-molding glass gob

摘要

PPROBLEM TO BE SOLVED: To provide high-refractive index and low-dispersion optical glass which is stably supplied, has excellent glass stability and exhibits little coloration. PSOLUTION: The optical glass is characterized by including, in mass, 5-32% of the total of SiOSB POS="POST"2/SBand BSB POS="POST"2/SBOSB POS="POST"3/SB, 45-65% of the total of LaSB POS="POST"2/SBOSB POS="POST"3/SB, GdSB POS="POST"2/SBOSB POS="POST"3/SBand YSB POS="POST"2/SBOSB POS="POST"3/SB, 0.5-10% of ZnO, 1-20% of the total of TiOSB POS="POST"2/SBand NbSB POS="POST"2/SBOSB POS="POST"5/SB, 0-15% of ZrOSB POS="POST"2/SB, 0-12% of TaSB POS="POST"2/SBOSB POS="POST"5/SBand 0-5% of GeOSB POS="POST"2/SB(wherein, the mass ratio (SiOSB POS="POST"2/SB/BSB POS="POST"2/SBOSB POS="POST"3/SB) of the content of SiOSB POS="POST"2/SBto the content of BSB POS="POST"2/SBOSB POS="POST"3/SBis 0.3-1.0; the mass ratio (GdSB POS="POST"2/SBOSB POS="POST"3/SB+YSB POS="POST"2/SBOSB POS="POST"3/SB)/(LaSB POS="POST"2/SBOSB POS="POST"3/SB+GdSB POS="POST"2/SBOSB POS="POST"3/SB+YSB POS="POST"2/SBOSB POS="POST"3/SB) of the total content of GdSB POS="POST"2/SBOSB POS="POST"3/SBand YSB POS="POST"2/SBOSB POS="POST"3/SBto the total content of LaSB POS="POST"2/SBOSB POS="POST"3/SB, GdSB POS="POST"2/SBOSB POS="POST"3/SBand YSB POS="POST"2/SBOSB POS="POST"3/SBis 0.05-0.6; the refractive index nd is 1.90-2.0; the Abbe number νd is 32-38; and the degree of coloration λ70 is 430 nm or less). PCOPYRIGHT: (C)2013,JPO&INPIT