| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarization holding optical fiber coupler that suppresses the fluctuation of a central wavelength when used under the environment of high temperature and high humidity. SOLUTION: In this polarization holding optical coupler 1, a first polarization holding optical fiber 10 and a second polarization holding optical fiber 20 are disposed parallel and fusion-stretched. In an optical coupled part 30 formed by fusion-stretching, the minimum value of a width D in a direction connecting the respective central axes of the polarization holding optical fibers 10 and 20 is≥80μm, and the minimum value of an aspect ratioη(=D/d) is≤1.85. In the optical coupled part 30, the shape of a cross section perpendicular to a longitudinal direction is preferably convex outward over the full circumference at a position to be a minimum width D<SB>min</SB>, and the shape of the cross section is preferably elliptical. COPYRIGHT: (C)2004,JPO |
