Rogue waves in birefringent optical fibers: elliptical and isotropic fibers

Abstract

Rogue waves in elliptically polarized birefringent optical fibers are analyzed within the framework of a ‘non-integrable’ coupled nonlinear Schrödinger (CNLS) system, which can be used to describe pulse propagation in elliptically birefringent optical fibers. The modulation instability (MI) analysis of this system reveals that, in general, this coupled system is more unstable than its scalar (isotropic) counterpart. In fact, numerical simulations indicate that the generation of rogue events is comparable to the isotropic case. This implies that there is no 1-1 correspondence between rogue wave generation and MI, in these media. The birefringence angle for which the maximum number of rogue events is identified and the nature of the rogue wave is described for the different cases. Although the CNLS system is non-integrable in certain cases these rogue waves are well approximated by the rational solutions of the scalar integrable nonlinear Schrödinger (NLS) equation, while in other cases solitons of the scalar integrable NLS equation are better approximations of these rogue events. In every case, the relative solution of the isotropic system is found to be well suited to describe these waves.