| 摘要 |
PURPOSE:To ensure the adhesive properties and the smoothness of interface for the core and cladding, by forming the cladding of ion crystal by using an extruder having a crosshead die for a core fiber which is previously formed with the ion crystal. CONSTITUTION:A core fiber 1 of ion crystal is led into a pierced hole 5 of a mandrel 4 provided at the center part of a crosshead die 3 of an extruder 2. At the same time, the ion crystal powder 7 which is turned into a cladding is filled into a barrel 6. The powder 7 is pressed by a ram 9 heated by a heater 8 up to a temperature lower than the melting point to be plasticized, flows into the die 3 through the tip of the barrel 6, sticks to the outside of the fiber 1 which is led through the hole 5 at a lip part 10 to form a cladding 11. In this case, an end of the mandrel 4 is connected to a vacuum pump 14 through a pipe 13 to reduce the pressure within the mandrel 4. |
