| 摘要 |
PURPOSE:To obtain a noncrystallizing optical fiber having a waveguide structure by setting dies of double or triple structure and an extruding rod, forming a heating section enabling precise temp. control around the dies, and carrying out extrusion drawing. CONSTITUTION:Dies 4 provided with extruding rod 3 are held in the heat-insulated section having heater 16 in heat-insulated quartz tube 15 with trestle 10, motor 1 and vertically driving part 2. Dies 4 are filled with clad glass 13 and core glass 14. Inert gas is fed from inflow hole 18, and while heating heater 16 input feedback to heater 16 is applied by the electromotive force of thermocouple 12 to maintain the set temp. within + or -1 deg.C. Glass materials 13, 14 kept at a temp. near the deformation temp. are extruded from the tip of dies 4 with the extruding mechanism composed of motor 1, driving part 2 and rod 3 to draw optical glass fiber 11. The obtd. fiber does not crystallize and has a small loss and high strength. |
