HEAT TREATMENT OF POROUS OPTICAL FIBER BASE MATERIAL

摘要

PURPOSE:To sharply improve the strength and the transmitting performance of an optical fiber produced from the base material by treating the porous optical fiber base material in an atmospheric gas containing carbon monoxide in a furnace core tube. CONSTITUTION:Carbon monoxide is supplied to atmospheric gas in a furnace core tube 10 when a porous optical fiber base material 15 is inserted into the furnace core tube 10 made of carbon. Owing to the presence of carbon monoxide, the reaction of the oxygen and water discharged from the porous optical fiber base material 15 with the carbon of the furnace core tube 10 is restrained, and the wear of the furnace core tube 10 is lowered.