| 摘要 |
<p>PURPOSE: To prevent devitrification, bubble formation, etc., by housing a chalcogenide glass tube for a clad housing a chalcogenide glass material for a code into a quartz glass tube having a small aperture in its bottom, heating the bottom and drawing out the glass. CONSTITUTION: The clad glass tube 3 inserted with a core glass rod 2 is sealed into the quartz glass tube 1. The bottom 4 of the quartz glass tube 1 is provided with the aperture 5 of the bore smaller than the outside diameter of the clad glass tube 3. Ar is packed into a spacing 8 and the pressure in a spacing 9 is reduced. Next, the part near the aperture 5 is heated by a heater 13. A weight 16 is hung and a preform 11 is drawn out when the front end 15 of the preform 11 is brought to be extruded. The outer periphery of the preform 11 is coated with a hermetic coating material 12 and is heated by a ring heater 13 and thereafter, the preform is spun, by which a fiber 14 having the excellent adhesion property to the boundary between the core glass and the clad glass is obtd.</p> |
