An analytical model for dispersion-managed 160 Gb/s OTDM transmission systems

Abstract

As the next generation of ultra-fast optical transmission systems, the optical time division multiplexing (OTDM) systems with a bit rate up to 160 Gb/s are actively being researched. Several experimental ultra-fast OTDM transmission systems with all-optical 3R-regeneration have been reported. With the development of ultra-fast OTDM technologies, techniques for rigorously evaluating the system performance through the calculation of bit error ratio (BER) have become increasingly important. We report a novel analytical model for estimating the performance of a 160 Gb/s OTDM receiver. The BER of the OTDM system is evaluated based on the calculation of the noise probability density function using the moment generating function. The optical pulse broadening by the fiber dispersion is compensated through the dispersion-managed approach and both nonlinearity and dispersion of the fiber channel are taken into account. Noise (ASE, shot and thermal) and performance-impairing factors (intrachannel interactions and timing jitter) are included in the calculation of the BER. A variational analysis approach is used to solve the optical pulse evolution over a periodical, dispersion-managed, nonlinear fiber channel as this yields an analytical expression for the received optical pulses. The OTDM demultiplexer is modeled as an optical gate controlled by an optical or electrical clock signal and the cyclostationary characteristic of the ASE noise after passing the OTDM demultiplexer is considered. Also the timing jittering between the signal pulse and the gate window and its effects on the signal decision are taken into account. Based on the proposed model, calculated results for the performance of the 160 Gb/s OTDM transmission systems are presented.