Corning Incorporated
High index glasses

Abstract:

A glass composition comprising: Al.sub.2O.sub.3, ZnO, and SiO.sub.2; TiO.sub.2, in the amount of at least 10 mol % and not greater than 20 mol %; and alkaline metal oxide selected from the group consisting of MgO, CaO, SrO, BaO, or any combination thereof, such that the molar sum of MgO, CaO, SrO, BaO, and ZnO, in the amount in the glass composition is least 20 mol % and not greater than 35 mol %, and such that: the amount of BaO is 0 to 10 mol %; the amount of MgO is 0 to 10 mol % the amount of CaO is 0 to 10 mol %, and the molar sum of CaO and MgO in the glass composition is less than 12.5 mol %; and rare earth metal oxides (.SIGMA.RE.sub.mO.sub.n), in the amount of at least 1.5 mol % and not greater than 10 mol %; alkali metal oxides (.SIGMA.Alk.sub.2O), in the amount of greater than or equal to 0 mol % and less than or equal to 5 mol %; and not greater than 5 mol % of other components; and wherein -5 mol %.ltoreq.Al.sub.2O.sub.3 (mol %)-1.5 .SIGMA.RE.sub.mO.sub.n (mol %)-.SIGMA.Alk.sub.2O (mol %).ltoreq.+5 mol %.