Patent ID: 8642490

Claim:
A fluorophosphate glass comprising more than 3 cationic % and 30 cationic % or less of a phosphorus ingredient in terms of P 5+ , the glass having a ratio) I (1) /I (0 of equal to or less than 0.08 in which I (0) is a strength of a resonance peak generated near a reference frequency of 31 P in a nuclear magnetic resonance spectrum and I (1) is a strength of a first-order side band peak of the resonance peak, wherein a molar ratio (O 2− /P 5+ ) of a content of O 2− to a content of P 5+ is equal to or more than 3.5, the content of B 3+ is from 0 to 3%, and wherein the glass is an optical glass which does not contain ions having absorption in the visible region.