Numerical investigation of the Raman instability in high-power CW ytterbium-doped fiber lasers

A numerical model of a high power CW ytterbium-doped fiber laser has been developed using the split-step Fourier method. Stimulated Raman scattering (SRS) is included in the model via the well-known Raman transfer function of silica fibers. The parameters of the gain fiber and of the fiber Bragg gratings are varied in order to minimize the impact of SRS on the spectral content of laser emission.