Y.H.C. Kwan

Analytical design of densely dispersion-managed optical fiber transmission systems with Gaussian and raised cosine return-to-zero Ansatze

We propose an easy and efficient way to analytically design densely dispersion-managed fiber systems for ultrafast optical communications. This analytical design is based on the exact solution of the variational equations derived from the nonlinear Schrodinger equation by use of either a Gaussian or a raised-cosine (RC) Ansatz. For the input pulses of dispersion-managed optical fiber transmission systems we consider a RC profile and show that RC return-to-zero pulses are as effective as Gaussian pulses in high-speed (160-Gbits/s) long-distance transmissions.

Effect of group-delay ripples on dispersion-managed soliton communication systems with chirped fiber gratings

The effect of group-delay ripples in dispersion-managed soliton communication systems that use chirped fiber gratings for dispersion compensation is studied. Using both a reduced model and direct numerical simulation, we find that dispersion-managed solitons exist even in the presence of large dispersion variation caused by group-delay ripples. The dispersion-managed solitons suppress the growth of intersymbol interference induced by the group-delay ripples.

Analytical method for designing grating compensated dispersion-managed soliton systems

We show two useful methods to design grating compensated dispersion-managed systems. Our method is in good agreement with the numerical results even in the presence of group delay ripples in the gratings.

Gaussian pulse propagation in dispersion-managed systems using chirped fiber gratings with group delay ripples

We study the propagation of Gaussian-shaped pulses in grating-compensated dispersion-managed systems with group delay ripples (GDR). We show that the intersymbol interference caused by the GDR in gratings can be substantially reduced by nonlinear optical loop mirrors and the 40-Gb/s system performance can achieve transoceanic transmission in the presence of amplifier noise and random variations in ripple period of the gratings along the transmission line.

Method to find the stationary solution parameters of chirped fiber grating compensated dispersion-managed fiber systems

For any given dispersion-managed (DM) fiber system compensated by chirped fiber gratings, using the variational equations, we present an useful procedure to calculate the pulse widths and energies of all possible stationary solutions. We also show that same methodology can be extended for any desired DM fiber system with loss and periodic gain.

Reduction of intersymbol interference in dispersion-managed soliton systems compensated by chirped fibre gratings using nonlinear optical loop mirrors

We address the problem of group delay ripples in chirped fibre gratings on dispersion compensation in optical transmission systems. We show that the intersymbol interference, which is a highly harmful effect induced by the group delay ripples in transmission systems, can be substantially reduced by the use of nonlinear optical loop mirrors. This leads to an improvement of the system performance by more than one order of magnitude when compared with a grating-compensated dispersion-managed system without nonlinear optical loop mirrors. We find similar performances irrespective of whether the structure of group delay ripples is modelled by a sinusoidal function or the grating is modelled by the coupled-mode equations.

Reduction of intersymbol interference in dispersion-managed soliton systems compensated by chirped fiber gratings

We show that the use of nonlinear optical loop mirror can significantly reduce the intersymbol interference induced by group delay ripples in dispersion-managed soliton communication systems compensated by chirped fiber gratings.

Effectiveness of nonlinear optical loop mirrors in chirped fiber gratings compensated dispersion-managed transmission systems

We show that nonlinear optical loop mirrors can dramatically suppress the side peaks induced by the group delay ripples in chirped fiber gratings compensated dispersion-managed systems and significantly improve the system performance.

Effectiveness of Nonlinear Optical Loop Mirrors in Dispersion-Managed Fiber Communication Systems Compensated by Chirped Fiber Gratings With Group Delay Ripples

We examine the effectiveness of using nonlinear optical loop mirrors (NOLMs) to reduce the intersymbol interference in dispersion-managed (DM) fiber communication systems compensated by chirped fiber gratings (CFGs) with group delay ripples (GDR). We show that the use of NOLMs can enhance the transmission performance by more than one order of magnitude in the presence of amplifier noise and random variations in the parameters of the GDR in CFGs. We found that transoceanic transmissions can be achieved when NOLMs are included in the DM optical fiber transmission line compensated by CFGs with GDR whose parameters vary randomly along the transmission line.

Suppression of pulse pedestal using nonlinear optical loop mirrors in grating-compensated dispersion-managed fiber transmission systems

Pulse pedestal suppression by nonlinear optical loop mirrors is utilized to reduce the intersymbol interference caused by the group delay ripples of a real grating profile in dispersion-managed communication systems compensated by chirped fiber gratings.