Coherent combining of spectrally broadened fiber lasers

We demonstrate that fiber lasers spectrally broadened by cross mode coupling can be coherently combined with high efficiency. The spectral broadening that it induces suppresses stimulated Brillouin scattering. Using long cavity length lasers, > 800 m, we induce spectral broadening of > 50 GHz and show mode by mode coherence in the output of four intracavity coupled fiber lasers.