Patent ID: 7858546

Claim:
A mother glass composition for gradient-index lens, comprising following components, indicated by mol %: 40≦SiO 2 ≦65; 1≦TiO 2 ≦10; 0.1≦MgO≦22; 3≦ZnO≦15; 2≦Li 2 O≦18; 2≦Na 2 O≦20; 0≦B 2 O 3 ≦20; 0≦Al 2 O 3 ≦10; 0≦K 2 O≦3; 0≦Cs 2 O≦3; 0≦Y 2 O 3 ≦5; 0≦ZrO 2 ≦2; 0≦Nb 2 O 5 ≦5; 0≦In 2 O 3 ≦5; 0≦La 2 O 3 ≦5; and 0≦Ta 2 O 5 ≦5, wherein the mother glass composition further comprises at least two oxides selected from the group consisting of CaO, SrO, and BaO each in a range of 0.1 mol % to 15 mol %, where a total of MgO+ZnO is greater than or equal to 6 mol %, a molar ratio of ZnO/(MgO+ZnO) is in a range of 0.12 to 0.93, a total of Li 2 O+Na 2 O is in a range of 6 mol % to 38 mol %, and a total of Y 2 O 3 +ZrO 2 +Nb 2 O 5 +In 2 O 3 +La 2 O 3 +Ta 2 O 5 is in a range of 0 mol % to 11 mol %.