Raman-induced optical shocks in nonlinear fibers

It is demonstrated that the stimulated Raman scattering in optical fibers supports kink solitons (shocks) not only in the recently considered case of anomalous dispersion but also in the normal-dispersion regime. In both cases there is a family of the kinks depending on an arbitrary (positive) wave number of the carrying wave. Although all the kinks are unstable because of the inherent instability of the cw background behind them, in the normal-dispersion regime the instability, induced solely by the stimulated Raman scattering, is essentially weaker than that in the case of anomalous dispersion.

Analytical solution to soliton switching in nonlinear twin-core fibers

We give an approximate analytical solution to the coupled nonlinear Schrödinger equations that govern the soliton switching in a nonlinear fiber coupler. We have derived, in simple analytical form, the switching condition by which solitons can be switched from one core to another. The analytical result has been checked against the numerical results, and it is found that there is close agreement.

Dissipative damping of dark solitons in optical fibers

The adiabatic evolution of the parameters of a dark soliton in the presence of dissipative fiber losses is considered. It is shown that the rate at which a dark soliton decays and spreads is only half the corresponding rate for a bright soliton.