OPTICAL RELAY AMPLIFIER, OPTICAL COMMUNICATION SYSTEM AND OPTICAL RELAY AMPLIFIER MONITORING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical relay amplifier capable of giving a sufficient power budget to a monitoring optical signal, an optical communication system with the same, and an optical relay amplifier monitoring method for monitoring the optical relay amplifier in the optical communication system.SOLUTION: An optical relay amplifier 1 includes: a relay amplifying section 5 for amplifying an optical signal bidirectionally; a first optical directional coupler 7a oriented in a direction (OLT2 direction) away from the relay amplifying section 5 at one side of the relay amplifying section 5; a second optical directional coupler 7b oriented in a direction (OLT2 direction) toward the relay amplifying section 5 at the other side of the relay amplifying section 5; an ONU 6 for transmitting and receiving the monitoring optical signal relating to the relay amplifying section 5; an optical switch 9 for selecting whether to pass the monitoring optical signal which is transmitted and received by the ONU 6 through the first optical directional coupler 7a or through the second optical directional coupler 7b; and a control section 10 for controlling the switching of the optical switch 9 based on the operational state of the relay amplifying section 5 and the communication link state of the ONU 6.