| 摘要 |
PURPOSE:To prepare the titled preform having improved characteristics easily, by arranging quartz tubes and quartz rods for clad on the outer periphery of a quartz rod for core, inserting stress providing rods having a low softening point into the quartz tubes, collapsing them so that they are integrated. CONSTITUTION:The quartz rods 11, 11... and the quartz tubes 12 are circumscribed about the quartz rod 10 for core, and one end of each of them are completely fused mutually. The stress providing rods 13 having a low softening point are inserted into the quartz tubes 12, the prepared composite rods are inserted into the quartz tube 14, to form the composite material. The composite material is collapsed under reduced pressure, and integrated to give a fiber preform of constant polarization. |
