Abstract

Many current 10G optical systems need to be upgraded to higher data rates (for example 40G, 100G, etc…) in order to satisfy the increased demand for higher bandwidth. However, many system providers in the third world countries have limited budgets and could not just replace all equipment to upgrade their systems. Thus, it is important to investigate what equipment could still be used in the upgraded system. In other words, which equipment could be used for both 10G and higher data rate transmitters? The bandwidth of the passive modules is a crucial specification that enables optical communication systems. Therefore, the effect of multiplexer (MUX) and demultiplexer (DEMUX) bandwidth on the performance of hybrid 10G/40G optical communication systems is investigated in this work. Hybrid optical systems enable adding new channels with higher data rate on current 10G common equipment. Numerical simulations are conducted on eight consecutive dense wavelength division multiplexing (DWDM) channels selected on 100-GHz ITU-grid each carrying data rate of 10 Gbps or 40 Gbps. Different loading configurations of wavelengths with data rates are considered in this work. In addition, different MUX/DEMUX bandwidths of 40, 50, 60, and 70 GHz are used to investigate the performance of each selected hybrid system configuration. It is found that the optimal MUX/DEMUX bandwidth for all investigated hybrid configurations is 60 GHz. The hybrid system performance is evaluated for both return-to-zero (RZ) and nonreturn-to-zero (NRZ) pulses format. The maximum reach of a selected hybrid configuration is also investigated numerically using circulating loop configuration for both RZ and NRZ pulse formats.

Key words: Effect of MUX/DEMUX bandwidth on signal transmission, hybrid optical fiber communication, upgrading 10G to 40G systems, dispersion and nonlinearity interaction in optical fibers.