| 摘要 |
PURPOSE:To form an optical line which is excellent in its crosstalk characteristic by limiting a crosstalk, by containing a double core optical fiber having plural cores, in a double layer clad, and marking a refractive index of the clad of the inside larger than a refractive index of the clad of the outside. CONSTITUTION:When a double core optical fiber having plural cores 1 is contained in double layer clads 3, 4, and a refractive index of the clad 3 of the inside and a refractive index of the clad 4 of the outside are denoted as n1 and n2, respectively, and set as n1>n2, a light whose incident angle theta satisfies a condition of an inequality I is totally reflected, and not made incident on the adjacent core. Also, as for a part where the optical fiber has been bent by a radius of curvature (r), when a thickness of the clad 3 is denoted as t1 so as to satisfy a condition of an inequality II, a light 5 as indicated with an arrow is totally reflected at a point A, and not made incident on the adjacent core. In this way, a crosstalk is prevented, and an optical circuit whose characteristic is excellent is formed. |
