Patent ID: 8110513

Claim:
A glass composition satisfying the following conditions (A) to (L), and which does not contain PbO, the conditions being: (A) a content ratio of TeO 2 is in a range from 55.4 to 95 mol %; (B) a content ratio of B 2 O 3 is in a range from 1 to 33 mol %; (C) a content ratio of ZnO is in a range from 1 to 37 mol %; (D) a content ratio of Bi 2 O 3 is in a range from 1 to 18 mol %; (E) a content ratio of P 2 O 5 is 0 mol %; (F) a content ratio of R 2 O (where R represents at least one element selected from the group consisting of Li, Na, and K) is in a range from 0 to 13 mol %; (G) a content ratio of MO (where M represents at least one element selected from the group consisting of Mg, Ca, Sr, and Ba) is in a range from 0 to 13 mol %; (H) a content ratio of TiO 2 is in a range from 0 to 13 mol %; (I) a content ratio of Nb 2 O 5 is in a range from 0 to 10 mol %; (J) a content ratio of Ta 2 O 5 is in a range from 0 to 13 mol %; (K) a content ratio of L 2 O 3 (where L represents at least one element selected from the group consisting of yttrium and lanthanoids) is in a range from 0 to 11 mol %; and (L) a content ratio of a total amount of P 2 O 5 , R 2 O, MO, TiO 2 , Nb 2 O 5 , Ta 2 O 5 , and L 2 O 3 described in (E) to (K), respectively, is in a range from 0 to 15 mol %.