| 摘要 |
PURPOSE:To hold linear polarized light stably against disturbance such as bending and temperature variation by applying a core which has a specific refractive index distribution to a polarized wave maintaining optical fiber and reducing abrupt stress variation caused on the boundary surface between a core and a clad. CONSTITUTION:There are two stress giving parts 3 formed on both sides of the core 1, which is circular; and the refractive index n(r) of the core 1 is as shown by an equation I, and 1<alpha<2 and 0.2%<DELTA<1.0%, where n1 is the refractive index in the center of the core and DELTA the difference in specific refractive index between the core 1 and clad 2. Then the core 1 with an alpha-power refractive index distribution at the time of the use of this polarized wave maintaining optical fiber is as shown in a figure A(a). In this case, alpha is set to 1-2 as shown in a figure (b) so as to remove deterioration in double refraction due to wire diameter variation at the time of the drawing of the optical fiber. Further, the difference DELTA in specific refractive index is set to 0.2-1.0% so as to reduce the loss due to the bending of the optical fiber. Deterioration due to crosstalk is eliminated by increasing the refractive index n3 of a stress inducing part 3 up to the refractive index n2 of the clad. |
