Mixed Chromatic Dispersion Compensation Methods for Combined HDWDM Systems

Abstract

The authors have investigated the most efficient realization of mixed chromatic dispersion (CD) compensation schemes for high speed combined high density wavelength division multiplexing (HDWDM) systems. This research is performed with OptSim 5.1 simulation software. In this research it is shown that chromatic dispersion compensation scheme has a crucial role for guaranteed performance in combined HDWM transmission channels. Dispersion management strategy is needed when increasing the bit rate per channel by a factor of four. Therefore, the most efficient CD compensation scheme must be found for realized combined fiber optical transmission system. Authors have revealed that implementation of asymmetrical CD compensation schemes in pre-compensation and post-compensation modules are the most efficient and that it enables the best possible channel's bit error ratio (BER) values.Keywords-high density wavelength division multiplexing (HDWDM), chromatic dispersion (CD) compensation methods.

Realization of Mixed WDM Transmission System

“…However in this case must take into the account total amount of optical power coupled into a fiber. Coupled power increase resulting in additional transmission impairments caused by nonlinear optical effects (NOE) and its combination with linear distortion mechanisms "in [4,6]". Generally it leads to distorted transmission in some channels of fiber optic transmission system (FOTS) or even to complete failure of system's channels.…”

“…Typical dispersion compensating fiber has small effective core area Aeff = 12 μm 2 whereas standard single mode optical fiber has Aeff = 80 μm 2 , and DCF has attenuation coefficient up to α = 0.6 dB/km, whereas standard single mode optical fiber has α = 0.2 dB/km. Impact of nonlinear optical effects can be reduced by lowering optical power "in [4]".…”

“…Material dispersion is dominant part of chromatic dispersion, and it is caused by change of optical fiber core and cladding refractive index with wavelength "in [4]".…”

“…In recent years the dramatic increase of demand for transmission capacity is observed and to secure an appropriate quality of service (QoS) level telecommunications services providers must constantly and continuously develop their transmission systems in use "in references [4,12]". Currently, as a study object of many scientific works have been chosen and focused directly on the fibre total transmission capacity increases, and this can happen in a three different ways.…”

“…SSMF length was chosen equal to 50 km, because it's better permissible length between two EDFA in an ultra -long haul transmission system, if fibre attenuation coefficient is 0.2 dB/km "in [4]". Large amplifier spacing in such system would result in a prohibitive increase in amplified spontaneous emission (ASE) noise and in order to achieve the greater range and information capacity, the amplifiers must be located close together with gain no greater than about 10 dB and preferably less "in [17]".…”