Cascaded supercontinuum generation and rogue wave harnessing

Optical rogue waves in fiber systems always arise from soliton fission and supercontinuum generation, which are of great help to understand natural extreme events as well as to control them. Here, combined special fibers with zero dispersion points at different Raman Stokes wavelength regions were proposed to realize random lasing and to stimulate cascaded supercontinuum with improved spectral flatness. Moreover, an attempt to actively control rogue waves in supercontinuum generation through external periodical perturbation was carried out. The results show that a flat 2nd-order supercontinuum that pumped at a level of a few watts can have 3 dB bandwidth of up to 120 nm, and the chaotic output pulses can be obviously harnessed through small external perturbation, i.e., the power of externally injected light is only 1.5 % to the pump power. When external periodical perturbation of the injected light aligns to or deviates from the characteristic frequencies of the system, the probability of rogue waves can be inhibited by 1.28 % or increased by 0.49 %, indicating that the soliton behavior during supercontinuum generation can be effectively controlled. This work provides a simple and efficient way to stimulate supercontinuum and to control rogue waves in a complex system, which is also inspiring for the understanding and suppression of natural extreme events, such as ocean rogue waves etc.