Efficient numerical model of stimulated Raman scattering in optical fibers

The paper proposes a novel efficient numerical model for simulation of spectral and temporal transformation of laser pulses due to interplay of Kerr and Raman nonlinearity and chromatic dispersion in the process of propagation through single-mode optical fibers. The model reproduces qualitatively the spectral shape of Raman gain within the approximation of slowly varying amplitudes using a pair of meshes (for pump and Stokes waves) with a reduced number of points. Nonlinear propagation of 100-ps-long laser pulses along an optical fiber is used as a test bed for the new model. It is shown that the proposed model provides accuracy better than 10% in Stokes wave energy growth speed, while being up to eight times more efficient in memory usage and computation speed compared to the generalized nonlinear Schrödinger equation.