Patent ID: 8053383

Claim:
A light-amplifying glass to be used for amplifying light having a wavelength of 1.0 to 1.2 μm, which comprises, as represented by mol % based on the following oxides, from 30 to 55% of Bi 2 O 3 , from 25 to 50% of either one, or both in total, of SiO 2 and B 2 O 3 , from 12 to 27% of either one, or both in total, of Al 2 O 3 and Ga 2 O 3 , from 0 to 4% of La 2 O 3 and from 0.1 to 4% of Yb 2 O 3 and which contains substantially no Er 2 O 3 .