| 摘要 |
PROBLEM TO BE SOLVED: To provide a channel inserting/extracting device that reinserts a channel of the same wavelength as that of a channel extracted from a 2-way optical link, so as to be sent in the opposite direction. SOLUTION: This device is provided with four optical circulators 21, 22, 23, 24 each having at least three ports, and major circulators 21, 22 among the circulators 21-24 are inserted to a line buffer 1, so that two of the ports 211, 213; 221, 223 are connected to the line buffer 1. The other two circulators called auxiliary circulators 23, 24 are inserted to 1st auxiliary optical fiber 6 and a 2nd auxiliary optical fiber 7, so that two of ports 232, 234; 242, 244 are connected to the auxiliary optical fibers 6, 7 respectively. |
