| 摘要 |
PURPOSE:A glass for optical fibers having a low refractive index and loss characteristics without the hygroscopicity, by incorporating a fluoride selected from MgF2, CaF2, SrF2 and BaF2 with YF3, AlF3 and BeF2 in a specific proportion. CONSTITUTION:A glass for optical fibers obtained by incorporating (A) 10- 65mol% fluoride powder selected from MgF2, CaF2, SrF2 and BaF2 with (B) 0.5-50mol% fluoride powder YF3, (C) 20-65mol% fluoride powder AlF3 and (D) 0.5-15mol% fluoride powder BeF2 in a heat and chemical-resistant vessel, e.g. a platinum crucible, melting the resultant mixture in an atmosphere of an inert gas, e.g. argon gas, under heating at about 1,000 deg.C, cooling the bottom of the vessel with water, etc., and vitrifying the mixture. |
