Research on NRZ-OOK and Duobinary Modulation formats for C and L band 25 Gbit/s WDM-PON Transmission Systems

The present paper aims to determine the best performing setup of 16-channel dense wavelength division multiplexed passive optical network (WDM-PON) employing two modulation formats, namely NRZ-OOK and duobinary (DB). One of the promising solutions to increase transmission system capacity and expand available bandwidth for WDM transmission system is to use optical L band. Therefore, in this paper we numerically compared the performance of 25 Gbit/s WDM-PON transmission systems operating over conventional optical C-band and extended L-band wavelengths. Dispersion compensation module with fiber Bragg grating (FBG) was implemented in both systems in order to compensate accumulated chromatic dispersion. We evaluated performance results in terms of bit error rate (BER) of received signal. The results of this research proved that L-band could be considered as a suitable solution for 25 Gbit/s WDM-PON systems.