Analytical study on the stimulated Raman scattering threshold in distributed-pumped fiber amplifiers.

In this paper, the stimulated Raman scattering (SRS) threshold of the distributed-pumped fiber amplifier consisting of multiple sub-amplifiers is analytically studied based on the rate-equation model. The SRS threshold formula is presented where the predictions agree well with the numerical results. With the help of the formula, the effect of the pumping scheme on the SRS suppression of the distributed-pumped fiber amplifier is systematically investigated.