PRODUCTION OF RADIATION-RESISTANT OPTICAL FIBER

摘要

PURPOSE:To obtain the titled optical fiber at a low cost by heating a porous glass base material obtained by a vapor-phase chemical reaction in the presence of moisture to remove the residual chlorine, then heating in the presence of dry oxygen to remove the moisture and then carrying out vitrification and wiredrawing. CONSTITUTION:Inexpensive SiCl4 is used as the raw material and the porous glass base material is formed by the vapor-phase chemical reaction. Then the porous glass base material is heated in the presence of moisture to remove the residual chlorine resulting from SiCl4 and a hydroxyl group is introduced. Then the base material is heated in the presence of a dry oxygen-contg. gas to remove the heated in the presence of a dry oxygen-contg. gas to remove the moisture, the oxygen defects are repaired and the material is vitrified to form a preform. The obtained preform is then wiredrawn to obtain the desire radiation-resistant optical fiber. Since the obtained optical fiber has a small content of chlorine and a large content of a hydroxyl group, the radiation resistance is excellent and the fiber is appropriately used in a radiated atmosphere in atomic power utilizing facilities, etc.