| 摘要 |
PURPOSE:To eliminate the disturbance of phase even when mode coupling exists between two guided modes, by attenuating either of two guided modes. CONSTITUTION:A main core 1 consisting of a double refraction fiber and a subcore 2 which is adjacent to and in parallel with the main core 1 are provided. Two lowest modes having polarization directions orthogonal to each other are defined as an HE11<x> mode and an HE11Y mode, and either of two guided modes of the core 1 is coupled with the guided mode of the core 2, and a large loss is given to the core 2, and thus, the energy transferred from the core 1 to the core 2 by mode coupling is attenuated. As a result, one of the HE11<x> mode and the HE11Y mode is eliminated from the core 1, and only the other mode is guided to the core 1. |
