| 摘要 |
PURPOSE:To make it possible to carry out easily the joining, by forming protruding ridges or grooves on the outer peripheral surface of an optical fiber by adjusting the internal pressure applied to hole parts in drawing a preform of the side pit type optical fiber having constant polarized waves. CONSTITUTION:A pair of holes (2a) and (2b) are provided in a core part in the long direction in a process for preparing a preform, which is then drawn while applying an internal pressure to the hole parts (2a) and (2b) not to collapse the holes (2a) and (2b) to prepare a side pit type optical fiber having constant polarized waves and the holes (2a) and (2b) on both sides of the core 1. The internal pressure applied to the hole parts (2a) and (2b) is set at a pressure for expansion or contraction to form protruding ridges (3a) and (3b) or grooves (4a) and (4b) on the outer peripheral surface in the long direction of the drawn optical fiber. In joining the optical fibers, a pair of the optical fibers are butted to make the protruding ridges (3a) and (3b) or grooves (4a) and (4b) in agreement with each other and further the plane of polarization of each other. The joining is then carried out by welding, etc. |
