| 摘要 |
PURPOSE:To monitor online the transmission condition of optical fiber communication by forming a flat surface along the longitudinal direction of an optical fiber for monitoring and providing light input and output means disposed with a prism having the refractive index higher than the refractive index of the optical fiber for monitoring on said flat surface. CONSTITUTION:A groove 14 is provided to prescribed depth to the upper part of a glass base plate 12 and the optical fiber 16 for monitoring is partly embedded therein. The optical fibers 30 on the transmission path are welded respectively to both ends 18, 20 of the fiber 16 and the prism 28 is closely adhered onto the flat surface 22 of the fiber 16, then the light introduced from the fiber 30 in the transmission path into the fiber 16 is partly propagated into the prism 28 and is detected by a photodetector 10 via a convergent lens 6 for output. On the other hand, the light from a light source 8 is inputted from a convergent lens 4 for input to the fiber 16 via the prism 28 and therefore the optional introduction of the light signal for test into the transmission path is made possible. |
