Patent ID: 8769991

Claim:
A method for producing a fluorophosphate optical glass, comprising melting a glass raw material to give a molten glass, and refining, homogenizing, and forming the molten glass to prepare the fluorophosphate optical glass, wherein the glass raw material is melted to give the molten glass containing at least one of Fe and Cu, and the molten glass is refined and homogenized, the total of the content of Fe in terms of Fe 2 O 3 and the content of Cu in terms of CuO is 20 ppm or more, and the contents of Fe and Cu are controlled so that the obtained fluorophosphate optical glass has such transmittance property that the internal transmittance in terms of a thickness of 10 mm is 98% or more at a wavelength region of at least from 400 to 500 nm and is 90% or more over the wavelength range of more than 500 nm and 1000 nm or less.