| 摘要 |
PURPOSE:To remove the deformation of the geometric shape in the section of optical fibers accompanying fusion drawing by removing a part of the clad of a polarization holding optical fiber and decreasing the interval between the cores of two optical fibers. CONSTITUTION:A part of a circular clad 4 or 5 is removed from an optical fiber which has strain inducing parts 8 and 9 or 10 and 11 arranged at symmetrical positions about a core 6 or 7 to form the polarization holding optical fibers 2 or 3. The central parts of the optical fibers 2 and 3 are welded to each other to form a fusion drawn part 12, thus obtaining a coupling element 1. Then linear polarized light 17 which enters the optical fiber 2 is propagated along a main axis 13 of double refraction and split at the drawn part 12 even to an optical fiber 3, so that linear polarized light beams 18 and 19 are emitted. Even when the linear polarized light is entered into this optical fiber 3, the same result is obtained. |
