ملخص البحث :

Abstract: To meet the growing needs of internet data, optical communication systems havebecome the backbone of modern communications networks. At the present time, the densewavelength division multiplexing (DWDM) technique has been used to increase the number ofchannels, but the nonlinear effects have a great impact that limits the performance of doublingthe DWDM system. The four wave mixing (FWM) is the most harmful and dangerous as theeffect of FWM increases on the system the greater the optical connection distances. The newapproach of pairing groups of different optical signals was investigated to suppress the FWMeffect. The simulation was conducted for an 8-channel system with a total data rate (80Gb/s).A comparative study was conducted on the suppression of FWM by the difference in the powerinputs (-0.5 to 20) dBm. The robustness of the proposed technique was examined using twoforms of modulation (Carrier Suppressed Return to Zero (CSRZ) and Duo Binary Modulationclass -1(DBM-1)) techniques, with optical fiber system of (1,2,5) spans, each of length 60 Km,with spacing between the channels 50GHz. The power of FWM was significantly reduced withthe CSRZ & DBM-1 techniques to less than (47.97%, 41.38 %) respectively, at an input powerof 12.5 dBm. The performance of the proposed system with the polarization technique wasimproved by the rate of the quality factor (Q-factor of (91.59%, 78.67%) for the same sequenceof modulation.