Turbulent Spectral Broadening in Ultra-Long Raman Fibre Lasers

Abstract

The turbulent nature of the generation of multiple cavity modes in ultra-long Raman fiber lasers is demonstrated in this study. Observations show turbulence-induced broadening of the intra-cavity spectrum and formation of clearly pronounced exponential tails at the power level as small as ~0.1 W. This broadening is likely to occur due to nonlinear four-wave mixing.