| 摘要 |
PROBLEM TO BE SOLVED: To amplify an input signal by a buffer amplifier, before the weakened signal light receives the loss by a light isolator, etc., by constituting a transmitter of a buffer light amplifier of low excitation in contact with a transmission path, and a core light amplifier in contact with this. SOLUTION: A transmission path 71 is connected to a buffer light amplifier 101 , and the buffer light amplifier 101 is connected to a core light amplifier 111 , and further the core light amplifier 111 is connected to a light wave multiplexed and divider 121 , and also it is connected to at least one light transmitter 1 and a light receiver 3. Moreover, the transmission paths 71 and 72 are connected to the buffer light amplifier 102 or 103 . The buffer light amplifier 102 or 103 is connected to the core light amplifier 112 through a monitoring light multiplexed or divider 92 or 93 , and also a middle relay device 62 is made constituted likewise. According to this constitution, the input signal can be amplified by the buffer amplifier before the signal light is weakened by the loss of transmission path receives the loss of an optical device. |
