Distribution measurement of Raman-gain and optical-loss characteristics in optical fibers

We propose a test method with which to measure the longitudinal distribution of Raman-gain characteristics in connected optical fibers. We describe a technique for obtaining the pump-loss distribution, knowledge of which is necessary for deriving the Raman-gain efficiency distribution, by the bidirectional measurement of Raman amplification. Based on this technique, we performed experiments and demonstrated that the Raman-gain efficiency distribution can be evaluated with the same equipment.