Optical amplification repeating system

摘要

Disclosed is an optical amplification repeating system having at least one repeater disposed in the middle of an optical transmission line connecting two terminal stations in which a light beam output from an optical amplifier is split into at least two split beams, one of the split beams is converted into an electric signal by optical/electrical conversion and the signal-to-noise ratio is detected on the basis of the electric signal. With such arrangement, the signal-to-noise ratio in the repeater can be measured in an in-service state, i.e., while the system is in operation.