Raman threshold pump power and optical amplification band calculations adjusted for attenuation dispersion in the range of total S+C+L telecom window of silica fibers (roughly from 1.46 to 1.62 мm) are presented. It has been shown that wavelength nonuniformity of signal attenuation coefficient essentially effects on amplification bandwidth and leads to the bandwidth decrease from 0.9 to 2.5 THz depending on a pump spectral position and fiber type. Offered has been the technique of analytical approximation of attenuation coefficient as a basis for pump power threshold determination and for preceding data correction with reference to an optical amplification band. Simulation results for three widely used fibers, namely, DCF, TrueWaveRSTM and SMF have been presented. However, the technique allows estimating the optimal pump power in fiber Raman amplifiers for other fiber types as well.
