| 摘要 |
PURPOSE:To make the attenuation of a propagation mode smaller and the attenuation of a cutoff mode larger by providing a conductive layer in a plane along the axis of a core or providing a couple of mutually parallel conductive layers along the outer periphery of the core. CONSTITUTION:For the cutoff mode, the conductive layer 6 as a constant potential plane is provided in parallel to a plane where an electromagnetic vector should vibrate, so the attenuation increases to disable propagation. For light in the propagation mode, on the other hand, the conductive layer 6 as the constant potential plane is provided perpendicularly to the vibration plane of the electric field vector, so the attenuation decreases to propagate the light. Accordingly, such constitution, therefore, comes to the absolute constant polarization fiber. In such a case, the conductive layer 6 is provided in a plane, so the attenuation of the propagation mode becomes smaller than that of conventional constitution equipped with a curved-surface conductive layer. The conductive layer 6 is provided in the center of a mold field distribution or nearby it, so the attenuation of the cutoff mode becomes larger than that of the conventional constitution. |
