SOLITON INTERACTION AND STABILITY IN NONLINEAR DIRECTIONAL FIBER COUPLERS

The interaction of soliton pulses in the optical-fiber nonlinear directional coupler is studied theoretically and numerically. Using the Hamiltonian structure of the equations, a canonical perturbation theory is developed and the steady-state regimes of the two-soliton system are found. Linear stability analysis shows that, in general, none of these states are stable. Numerical simulations performed support, both qualitatively and quantitatively, the theoretical predictions.