MATERIAL FOR INFRARED TRANSMITTING GLASS FIBER AND MANUFACTURE OF SAID FIBER

摘要

PURPOSE:To stably manufacture a glass fiber capable of transmitting infrared rays in a longer wavelength region by mixing BaF2, GdF3 and ZrF4 in a restricted molar ratio, melting the mixture under specified conditions, cooling the melt by furnace cooling, and drawing the resulting glass rod after polishing. CONSTITUTION:BaF2, GdF3 and ZrF4 are mixed so as to obtain a final composition consisting of 28-38mol% BaF2, 2-7mol% GdF3 and 58-69mol% ZrF4, and the mixture is melted at about 800-1,000 deg.C. This melt is poured in a metal mold having a cylindrical hollow part heated to 100 deg.C - below the glass deforming temp., and then it is annealed at 200 deg.C - below the glass deforming temp. and cooled to room temp. by furnace cooling to form a glass rod. After optically polishing both edges of the rod, while applying about 1.0-50mg/mm.2 tension to the tip of the rod, the rod is heated, kept at a constant temp., drawn, and crystallized.