| 摘要 |
PURPOSE:To simplify the constitution of a branching and inserting section of a transmission line and to perform reproduction and amplification of optical signals from optical fibers without special branching, by using a 4X4 acces coupler for branching and insertion of a transmission signal and two optical fibers as a data transmission line. CONSTITUTION:Two optical fibers are used as the transmission line, and transmission lines Dl1, Dl2 from the left hand of a figure and transmission lines Dr1, Dr2 from the right hand of the figure are connected to the 4X4 access coupler ACP for branching and insertion. In the normal usage where the 4X4 access couplers are connected in cascade, the same optical signals are transmitted to the transmission lines Dl1, Dl2 or the Dr1, Dr2 bidirectionally. The signals from the lines Dl1, Dl1, Dl2 are branched into a branch line R1 and those from the lines Dr1, Dr2 are branched to a branch line R2. Further, the signals to the lines Dl1, Dl2 are inserted from an insertion line S1 and those to the lines Dr1, Dr2 are inserted from an insertion line S2. As an example of the 4X4 access coupler ACP, a wavefront split type coupler made of a rod lens as shown in Figure is used. |
