Numerical simulations of collision behaviors of optical solitons in birefringent fibres

Vector-soliton collisions in birefringent nonlinear optical fibers are investigated. The multi-symplectic structure of the coupled nonlinear Schrödinger (CNLS) system was obtained directly from the variational principle. The multi-symplectic structure was discretizated by the multi-symplectic spectral method. Numerical experiment results showed that the multi-symplectic spectral method has the excellent behavior in the long-time numerical calculation. The collisions of the solitary waves are sensitive to the coupled constant ββ and the initial velocity V0V0.