Abstract

There is currently intense research into extreme value fluctuations (optical rogue waves) in long pulse fibre supercontinuum (SC) generation [i]. This interest is motivated by the possibility to obtain important insights into related hydrodynamic instabilities, as well as by potential applications in generating stable SC [2], Optical rogue waves are generated under conditions where SC broadening develops from initial spontaneous modulation instability. Following the appearance of a noise-driven temporal modulation on the input pulse, a large number of distinct soldons emerge, a small number of which undergo extreme Raman frequency shifts to longer wavelengths. Although this suggests that Raman scattering plays a central role in their formation through inelastic energy exchange [3], here we revisit the dynamics of optical rogue wave formation in tenus of the well-known soliton turbulence description in which soldons play the role of statistical attractors in any non-integrable nonlinear Schrödinger equation (NLSE) model [4], Specifically, we show that Raman scadering is unnecessary for intense rogue pulses to emerge from SC generation, and third-order dispersion on its own is sufficient to stimulate a single large rogue soliton in the long distance limit. An additional novel result is that the rogue soliton undergoes a continuous frequency shift to longer wavelengths with propagation as a result of interaction with the turbulent background, even in the absence of Raman scattering.

© 2009 IEEE