Similariton spectrums application for high bit rate WDM communication systems

Abstract

In this paper, Continuum sources based on similariton spectrums formed in low normal and high nonlinear dispersion photonic crystal fiber (PCF) are generated to achieve high capacity transmission, high channel count, and wavelength division multiplexing multiple access systems (WDM). A wavelength band of 40-nm continuous signal band in the C wavelengths of optical communication window is generated; this continuum allows generating at least 32 channels separated by 100 GHz in ITU-T WDM grid after spectral slicing by optical demultiplexer, where each channel is a pulses train and whose duty cycle relates to the bandwidths of the demultiplexer. Because the continuum is generated while flatness and coherent characteristics are maintained, the peak power variation in the 32 WDM channels is shown to be very small, so that similar powers are transmitted in each channel. Furthermore, because a pulse train of 10 GHz is a signal source, a 10- GHz–based 32-channel -wavelength–division multiplexing is simultaneously generated. These channels are modulated by 27-1 Pseudo Random Binary Sequences (PRBS) signal of the user data. As a result, a 320-Gb/s (32-channel × 10-Gb/s) WDM system is established. To investigate the system performance, Eye-diagrams and Q factors have been calculated. The impact of duty cycle on the system performance is taken into account.