METHOD FOR PRODUCING FLUOROPHOSPHATE OPTICAL GLASS, AND METHOD FOR PRODUCING OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for producing fluorophosphate optical glass by melting a glass raw material, clarifying and homogenizing the molten glass and quenching, where bubbles are not generated in the glass even if the glass is flown from a clarifying tank that is set to a high temperature to a working tank that is set to a low temperature.;SOLUTION: The content of Fe in terms of Fe₂O₃ and the content of Cu in terms of CuO are controlled so that the total of the contents of Fe and Cu is 20 ppm or more, and the obtained fluorophosphate optical glass has such a transmittance property that the internal transmittance in terms of a thickness of 10 mm becomes 98% or more in a wavelength region at least from 400 to 500 nm.;COPYRIGHT: (C)2012,JPO&INPIT