Patent ID: 7515332

Claim:
A glass composition consisting of the following components, indicated by mol %: 30 to 80 SiO 2 ; 0 to 40 Li 2 O; 0 to 30 Na 2 O; 0 to 20 K 2 O; 0 to 40 MgO; 0 to 40 CaO; 0 to 30 SrO; 0 to 20 BaO; 0 to 40 Al 2 O 3 ; 0 to 40 ZnO; 0 to 30 TiO 2 ; 0 to 30 ZrO 2 ; 0 to 30 Y 2 O 3 ; 0 to 30 La 2 O 3 ; 0 to 20 B 2 O 3 ; 0.01 to 2 bismuth in terms of Bi 2 O 3 ; and 0.01 to 12 of at least one cation selected from the group consisting of Dy 3+ , Er 3+ , Yb 3+ , Nd 3+ , Tm 3+ , Ho 3+ , Ti 3+ , V 3+ , V 4+ , V 5+ , Cr 3+ , Cr 6+ , Mn 2+ , Mn 3+ , Fe 2+ , Co 2+ , Ni 2+ , Cu + , Cu 2+ , Mo 3+ , and Mo 4+ in terms of oxide of the at least one cation, wherein the total of Li 2 O+Na 2 O+K 2 O+CaO+SrO+BaO+ZnO+B 2 O 3 is in a range of 0.1 to 60 mol %, the glass composition emits fluorescence in an infrared wavelength region, with the bismuth functioning as a fluorescent source through irradiation of excitation light, and the total content by percentage of impurities is lower than 1 mol %.