Solitons Interaction and their Stability Based on Nonlinear Schrödinger Equation

Optical solitons are considered as natural bits for telecommunications as they have the tendency to maintain their shape over transoceanic distances because of interaction between nonlinearity and anomalous group velocity dispersion. However, depending upon the individual pulse width, inter-pulse spacing and loss in the fiber, co-propagating solitons do interact and share energy. It is therefore imperative to investigate the soliton pulse interaction before implementing them in a high speed optical communication system. Incorporating the mathematical model based on the Nonlinear Schrodinger (NLS) equation and using the split-step Fourier transform method; we have conducted various simulation experiments to investigate the interaction between adjacent pulses of equal amplitude, in-phase solitons copropagating in dispersion shifted fibers. The simulation results show that, solitons after traveling a certain distance get attracted and evolve as a giant pulse of double the amplitude of the individual pulse and if propagated further, simply get separated as if they have walked through each other. The simulation results reveal that, a careful choice of the pulse and fiber parameters can be helpful in avoiding the soliton interaction which limits the channel capacity.