Four fiber ring network optical switching circuit using branched inputs

摘要

A four fiber ring network optical switching circuit capable of realizing the bridge function at times of the span switching and the ring switching economically by a very compact structure is disclosed. A four fiber ring network optical switching circuit is formed by a 10x8 optical matrix switch having ten input ports and eight output ports, and two branching elements adapted to branch each one of two optical signals among eight optical signals that are inputs of the four fiber ring network optical switching circuit, into two identical optical signals, and to enter the two identical optical signals into two input ports of the 10x8 optical matrix switch such that the eight optical signals are entered into the ten input ports of the 10x8 optical matrix switch as ten optical signals.