All pages tagged four wave mixing

We report an original method enabling a non invasive characterization in phase and intensity of the longitudinal evolution of the main spectral components involved in the Fermi Pasta Ulam recurence process. We will show that it allows to evidence the symmetry breaking of the process. Future prospects and recent results will be presented.

We discuss propagation of ultrashort solitary pulses in nonlinear single-mode optical fibers. Each pulse creates a moving perturbation of the refractive index; the perturbation is capable to scatter co-propagating pulses. An ultrashort optical soliton serves, under suitable conditions, as an impenetrable mirror for the group-velocity matched small-amplitude waves. Reflection of such waves by a quickly moving mirror in dispersive media is a rich source of the intriguing phenomena including analogue event horizons and radiation at negative frequencies. On the other hand, energy exchange between the scattered pump waves and the soliton provides an effective way to manipulate the soliton, e.g., to fix its frequency or to compress it to a large extent.