Soliton interaction in a two-core optical fiber

In this paper, we study the interaction of two temporally separated soliton pulses in a two-core optical fiber by solving numerically a pair of linearly coupled nonlinear wave equations. In the absence of coupling coefficient dispersion, two soliton pulses launched into one core of the fiber coalesce after propagating a distance along the fiber. This coalescence distance increases with the initial pulse separation and is insensitive to the coupling coefficient of the fiber, namely, the physical separation of the two fiber cores. Beyond the initial coalescence distance, the pulses may undergo periodic separation and coalescence along the fiber with a spatial period depending on the initial pulse separation and the coupling coefficient of the fiber. In the presence of coupling coefficient dispersion, the pulse evolution dynamics becomes asymmetrical and complicated. Significant pulse break-up effects can be observed. © 2003 Elsevier B.V. All rights reserved.