Compensating power depletion due to stimulated Raman scattering in high-power delivery fiber via spectral inversion

We report on a numerical investigation for compensating power depletion caused by stimulated Raman scattering (SRS) in high-power delivery fibers with the spectral-inversion approach. The spectral inversion is realized by four-wave mixing, considering the character of an optical fiber Raman gain profile. The power depletion of the signal by SRS can be effectively compensated using this method. The system parameters for the best compensation are optimized for the delivery of the laser beam with a power of 100 W in a 200-m-long standard single-mode fiber. The present method can be applied to higher-power delivery systems and longer fibers. The spectral-inversion method is compared with the alternative method to directly filtering Stokes waves for SRS cancellation. The influence of the initial phases of the Stokes waves on the compensating process is also discussed.