Novel optical hybrid line configuration for quasi-lossless transmission by distributed Raman amplification

We propose a novel lossless transmission line configuration which exhibits significantly small signal power variation along the line by Raman amplification. A hybrid line consisting of two fibers with different Raman gain properties is theoretically investigated, and it is shown that signal power deviation can be suppressed to only 1.2 dB in a 50-km span. Validity of the proposed hybrid line is confirmed by experiments.