Crosstalk in fiber Raman amplification for multi-channel WDM system

The paper produces the SIR (signal-interference-ratio) formula for fiber Raman amplification in an N-channel system based on the coupled equation of SRS (stimulated Raman scattering). It analyses the SIR of fiber Raman amplification in a three-channel system and the relations between the SIR and the pump wave power and signal wave power. Another topic discussed is the relationship between the SIR and the number of channels. The conclusion is drawn that there is obvious crosstalk in multi-channel Raman amplification, even if it works in linear amplification. The limiting condition for applying fiber Raman amplification is presented.