Patent ID: 7016582
Filing Date: 2006-03-21
Classification: C03B,G02B

Abstract:
1. A method of manufacturing a polarization maintaining optical fiber having a pair of stress applying regions on both sides of a core region existing in an axial direction within a cladding region surrounding this core region, the method comprising the steps of: preparing an intermediate including a cladding portion which constitutes the cladding region and surrounds a core portion constituting the core region, the cladding portion including a pair of holes existing in parallel with the axial direction on both sides of the core portion; manufacturing an optical fiber preform by inserting stress applying parts severally into the pair of holes of the intermediate, the stress applying parts having outer diameters slightly smaller than inner diameters of the holes; and manufacturing the polarization maintaining optical fiber by drawing and integrating the optical fiber preform with drawing tension from 1 g to 10 g inclusive while setting a non-circularity of cladding to 1% or less at a point where an outer diameter of a neck-down portion of the optical fiber preform becomes 3 mm.