Quasi-linear optical pulses in strongly dispersion-managed transmission systems

Asymptotic analysis of collision-induced timing shifts in return-to-zero quasi-linear systems with predispersion and postdispersion compensation

An asymptotic method for calculating the collision-induced frequency and timing shifts for quasi-linear pulses in return-to-zero, wavelength-division multiplexed systems with predispersion and postdispersion compensation is developed. Predictions of the asymptotic theory agree well with quadrature and direct numerical simulations. Using this theory, computational savings of many orders of magnitude can be realized over direct numerical simulations.

Reduction of collision-induced timing shifts in dispersion-managed quasi-linear systems with periodic-group-delay dispersion compensation

Periodic-group-delay (PGD) dispersion-compensation modules were recently proposed as mechanisms to alleviate collision-induced timing shifts in dispersion-managed (DM) systems. Frequency and timing shifts in quasi-linear DM systems with PGDs were obtained, and it is shown that significant reductions are achieved when even a small fraction of the total dispersion is compensated for by PGDs.

Incomplete collisions in strongly dispersion-managed return-to-zero communication systems

Incomplete collisions in wavelength-division-multiplexed return-to-zero transmission systems are analyzed by asymptotic methods. Formulas for frequency and timing shifts are obtained. The results agree with direct numerical calculations.

Collision-induced timing shifts in dispersion-managed soliton systems

The frequency and timing shifts associated with dispersion-managed solitons in a wavelength-division multiplexed system are computed by the numerically efficient Poisson sum technique. Analytical formulas are attainable by use of this approach with a Gaussian approximation for the soliton. The results are favorably compared with known results for the frequency shift. The method also applies to quasi-linear return-to-zero transmission formats.

Intrachannel pulse interactions in dispersion-managed transmission systems: energy transfer

Energy transfer between adjacent pulses as a result of nonlinear intrachannel interactions in a transmission system with strong periodic dispersion management is analyzed. With small average dispersion, the energy change between nonzero bits grows linearly with respect to distance in the presence of loss and lumped amplification, whereas in a lossless system the energy change is found to be significantly suppressed. The analytical results compare favorably with the results of direct numerical simulation of the full system.

Intrachannel pulse interactions in dispersion-managed transmission systems: timing shifts

Nonlinear intrachannel interactions responsible for timing shifts in a transmission system with strong periodic dispersion management are investigated. Formulas describing the evolution of the timing shift are obtained for general bit patterns. When average dispersion is negligible, the timing shift is shown to grow linearly in distance in a system with loss and lumped amplification, whereas in a lossless system the timing shift is sufficiently small at every chirp-free point. The analysis agrees with direct numerical simulations.

Nonlinear chirp of dispersion-managed return-to-zero pulses

Applying variational methods, we derive a reduced system of equations from the nonlocal equation that governs the average dynamics in dispersion-managed systems. These equations, which apply for any type of return-to-zero pulse, describe the stroboscopic evolution of the pulse parameters and bypass the fast variations inside each dispersion map. In the limit of large map strength we integrate the equations to obtain explicitly formulas for the parameters of a chirped return-to-zero pulse as well as the amount of post-transmission compensation needed to restore the initial pulse width.