To obtain fluoride glass containing fluorides having a specific composition, having a high refractive index excellent in weather resistance, and to obtain an optical fluoride glass fiber comprising the same.
This fluoride glass comprises 10-40% (by atomic molar fraction) of InF3, 1.5-40% of GaF3, 5-40% or ZnF2, 0-35% of BaF2, 0-35% of SrF2, 0-50% of PbF2, 0-7% of CdF2, 0-7% of MgF2, 0-15% of AlF3, 1.5-15% of one or more kinds of LaF3, ScF3, YF3, GdF3 and LuF3, and 0-30% of one or more kinds of LiF, NaF, CsF and RbF in the total amount of 100%. The composition is obtained e.g. by weighing anhydrous InF3, GaF3, ZnF2, RbF2, BaF2, SrF2, YF3, LaF3 and LiF so as to give a desired composition, mixing the weight compounds, adding acidic ammonium fluoride, melting the mixture at 900°C in a gold crucible in an argon atmosphere in an electric oven for 1hr, and subsequently quenched and solidified the melted mixture in a template.
KANAMORI TERUHISA
OISHI YASUTAKE