| 摘要 |
PURPOSE:To manufacture an optical fiber efficiently and easily by putting glass with a lower m.p. for a core in a glass tube with a higher m.p. for a clad and carrying out melt-spinning using a heating furnace having a prescribed temp. distribution. CONSTITUTION:A core material 11 such as borosilicate glass with a lower m.p. is put in a clad material 12 such as a quartz glass tube with a higher m.p., and they are melted by heating with a heating furnace 10 having a continuous temp. distribution from the lower temp. range (a) to the higher temp. range (b). In the range (a) the core material 11 is first melted at a temp. above the softening point T1 of the material 11, and the clad material 12 is softened and melted in the range (b) kept at a temp. above the softening point T2 of the material 12. The molten materials 11, 12 are then spun to obtain a fiber 13. Thus, fibers each having a glass clad with a higher m.p. can be manufactured in large quantities without being restricted by the material, etc. of a crucible because no crucible is used. |
