Propagation of Solitons in Quasi-periodic Nonlinear Coupled Waveguides

This paper is a tribute to Professor Mahir Saleh Hussein. It is motivated by two works which we published in collaboration in Cardoso et al. (Phys. Lett. A 374, 2356 2010, 374, 4594 2010). Here, we study the propagation of solitons in nonlinear coupled waveguides described by coupled nonlinear Schrodinger equations. In a specific case, these coupled equations behave as an exactly integrable nonlinear system known as the Manakov model. We introduce quasi-periodic nonlinear couplings by merging the components that allow changing the nonlinearities of the system, and study how the quasi-periodic nonlinearities modify the behavior of the solutions.