MOTHER GLASS COMPOSITION FOR GRADIENT-INDEX LENS, GRADIENT-INDEX LENS, MANUFACTURING METHOD THEREOF, OPTICAL PRODUCT, AND OPTICAL DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a mother glass composition for gradient-index lens, from which a lead-free Li-based gradient-index lens that is excellent in weather resistance, in particular weather resistance in the presence of water, can be manufactured.;SOLUTION: The mother glass composition includes the following components, indicated by mol%: 40≤SiO₂≤65; 1≤TiO₂≤10; 0.1≤MgO≤22; 0.15≤ZnO≤15; 2≤Li₂O≤18; 2≤Na₂O≤20; 0≤B₂O₃≤20; 0≤Al₂O₃≤10; 0≤K₂O≤3; 0≤Cs₂O≤3; 0≤Y₂O₃≤5; 0≤ZrO₂≤2; 0≤Nb₂O₅≤5; 0≤In₂O₃≤5; 0≤La₂O₃≤5; and 0≤Ta₂O₅≤5. The mother glass composition further includes at least two oxides selected from CaO, SrO, and BaO each in a range of 0.1-15 mol%. The total of MgO+ZnO is greater than or equal to 2 mol%. The molar ratio of ZnO/(MgO+ZnO) is in a range of 0.07-0.93. The total of Li₂O+Na₂O is in a range of 6-38 mol%. The total of Y₂O₃+ZrO₂+Nb₂O₅+In₂O₃+La₂O₃+Ta₂O₅ is in a range of 0-11 mol%.;COPYRIGHT: (C)2009,JPO&INPIT