DRAWING FURNACE FOR OPTICAL FIBER

• Main Authors: SAKAGUCHI SHIGEKI, NAKAHARA MOTOHIRO
• Format: Patent
• Language: English
• Published: 26.09.1983
• Subjects: CHEMISTRY; GLASS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

PURPOSE:To prevent the contamination of an optical fiber with SiC, etc. and to produce the optical fiber having high strength, by coating the surface of a carbon furnace core tube in a drawing furnace for optical fibers with the carbide or nitride of specific metals. CONSTITUTION:In the stage of drawing a quartz optical fiber, a base material 1 for an optical fiber 2 is put into a carbon furnace core tube 4 provided with heating elements 5 in a furnace body 3, where the material 1 is heated to soften. The softened base material is drawn to the fiber 2. The surface of the tube 4 in this case is coated with a high m.p. material such as carbide or nitride of Ta, Ti, Zr, etc. A gas such as N or Ar is supplied through an inflow port 6 into the tube 4 during the drawing. The formation of SiC by the reaction of the carbon of the tube 4 with the material 1 of quartz glass and the consequent decrease in the strength of the fiber 2 that may be resulted from sticking of such SiC on the fiber 2 as well as the consumption of the tube 4 by oxidation on account of the presence of slight O2 are prevented.