Simultaneous amplification and channel equalization using Raman amplifier for 30 channels in 1.3-/spl mu/m band

A new technique is proposed to simultaneously amplify signals and equalize power unbalance caused by Raman-induced crosstalk among optical channels in the 1.3-/spl mu/m band. The crosstalk is induced in GeO/sub 2/-doped silica fibers due to the Raman-gain coefficient with a positive slope below the peak-frequency shift of 440 cm/sup -1/. Highly doped GeO/sub 2/ silica fiber, however, shows a negative slope across the band between 440 cm/sup -1/ and 490 cm/sup -1/. We propose expansion of the Raman-gain band with a negative slope over the bandwidth of 150 cm/sup -1/ using multiple pumps. Utilizing the negative gain slope of the proposed band, simultaneous amplification and power equalization was theoretically demonstrated for 30 channels in the 1.310-1.345 /spl mu/m region without external filters.

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