Optical line switch device enabling connection of non-doubled optical transmission apparatus with doubled bidirectional optical link

摘要

An optical line switch device which contains: an optical switch which can input a transmission optical signal which is to be transmitted through one of first and second optical transmission lines, first and second optical coupling and branching units which can be connected with the first and second optical transmission lines, respectively, and an optical coupling unit which can output an input optical signal which is input from one of the first and second optical transmission lines. The transmission optical signal is supplied to one of the first and second optical coupling and branching units according to a switch control signal which is applied to the optical switch when the optical switch inputs the transmission optical signal. One of the first and second optical coupling and branching units transmits the transmission optical signal on one of the first and second optical transmission lines connected thereto when the transmission optical signal is supplied thereto. When one of the first and second optical coupling and branching units inputs an optical signal as the input optical signal, the input optical signal is suppled to the optical coupling unit. The optical coupling unit outputs the input optical signal when the input optical signal is suppled thereto.