FLUORIDE OPTICAL FIBER-PRODUCING APPARATUS AND PRODUCTION OF FLUORIDE OPTICAL FIBER

摘要

PURPOSE: To obtain a fluoride optical fiber having high strength by connecting surface treating part for carrying out dry etching of fluoride optical fiber preform to heat melting drawing part in a state blocked from outside air. CONSTITUTION: Plasma is generated into an ion gun 8 and beam accelerating voltage is applied to an argon ion drawn from the plasma and the argon ion is neutralized by a new trizer and irradiated into fluoride optical fiber preform. At this time, the preform is rotated in circumferential direction by a device 3 for rotating a preform-supporting rod. In a furnace center pipe 12, the optical fiber preform is feed into a heater 13 for preform heating and softened and drawn in the lower direction to provide the objective fiber. At this time, high- purity Ar gas is fed from a gas inlet 11 into the furnace center pipe 12. Since problem of surface crystallization of optical fiber preform can be solved according to the method, fluoride optical fiber having high strength and low loss can be prepared. Consequently, fluoride fiber can be practiced for mounting of optical amplifier, etc., and reduction of cost and high performance of optical communication system is performed.