Research On PolMux Technique In Large Capacity And High Speed Optical Fiber Communication

Nowadays, with the urgent demand of the communication capacity, optical fibercommunication system is focused on the direction of high-speed, large-capacity andlong haul. While the transmission system at40Gb s is gradually come intocommercialize times, the research on100Gb s rates has made continuous progressalso. In WDM system, polarization multiplexing technology can double thecommunication capacity and raise the spectrum efficiency. Also, polarizationmultiplexing technique with advanced modulation format has becoming a keytechnique to the upgrade of system at low-cost. As polarization multiplexing techniqueemploys two orthogonal polarization channels of the single-mode optical fiber as twoindependent channels to transmission signal, however, the two orthogonal polarizationchannels are more susceptible to polarization mode dispersion (PMD), polarizationdependent loss (PDL) and various nonlinear effects during transmission, which causecrosstalk between the two orthogonal polarization channels. Therefore, choosing themodulation format with better nature can reduce PMD and restrain nonlinear effect,which can effectively improve the performance of the system.In this paper, an improved polarization multiplexing technology based on theadvanced modulation is proposed, which use different modulation format in the twoorthogonal polarization channels, and a simulation module of the improvedpolarization multiplexing system is made with VPI software. The simulation about theimproved and un-improved polarization multiplexing system is carried out. The resultsshows that one channel of the improved system has a better performance of resistnonlinear effect, and another can subserve BER improved. The improved system hasbetter adaptability in optical network with multi-node.