Excitation and dynamics of pulses in coupled fiber arrays

Abstract

We consider a system of nearest neighbor linearly coupled nonlinear Schrödinger equations. The system models a coupled array of optical fibers in the anomalous dispersion regime. In the infinite array case, a sharp power threshold for the excitation of a coupled array soliton (nonlinear ground state) is found. For the periodic array (ring geometry), a soliton is excited for arbitrary values of the power. Coupled array solitons are nonlinearly dynamically stable. As the power increases, the coupled array solitons become increasingly peaked in amplitude, localized on the lattice as well as temporally compressed. As the power tends to infinity, a rescaled limit of the ground state converges to a pure one-soliton. The results provide a mathematical theory for the observations of previous investigators made by computer simulations.