| 摘要 |
PURPOSE:To manufacture the titled optical fiber having superior symmetry in the structure, superior uniformity in the longitudinal direction and superior properties of retaining linearly polarized light, by using a quartz glass tube having holes for inserting a glass base material for a core and an even number of glass base materials for stress applying parts. CONSTITUTION:A glass base material 2 for a core and glass base materials 3a, 3b for stress applying parts are regulated to desired sizes by drawing and external polishing. Holes are pierced in a quartz glass tube 7 by an ultrasonic working or other method and the holes are expanded by internal polishing to sizes enough to insert the base materials. The base materials 2, 3a, 3b are inserted into the holes 2', 3a', 3b' pierced in the tube 7, and after fixing the lower ends, the tube 7 is softened by heating in an electric furnace and drawn to manufacture an optical fiber having a desired outside diameter. |
