MANUFACTURE OF CHALCOGENIDE GLASS FIBER

摘要

PURPOSE: To prevent a glass from being volatilized and changed in composition due to heating at the time of spinning the glass fiber by subjecting the whole region or the region other than the tip of the periphery of a clad glass tube housing a core glass material to adhesion coating. CONSTITUTION: In this manufacture, a clad glass tube 2 housing a core glass rod 1 and an evacuation pipe 3 provided in the inside with a core glass rod fixing part 6 for preventing the rod 1 from being pushed up during the spinning of the glass fiber are integrally coated with a thermally shrinkable tube 4 being an adhesion coating material so as to cover the whole region of the tube 2 including its tip of the side to be heated and spun. The lower parts of rod 1, tube 2 and tube 4 are heated from the surroundings with a ring heater 7 and spun while maintaining the pressure of the space between the rod 1 and tube 2 at <=10<-1> Torr by using a vacuum pump connected to an evacuation port 5 of the evacuation pipe 3 to produce the objective glass fiber 8 that has a three-layer structure consisting of the core glass, clad glass and thermally shrinkable tube.