Pis’ma v ZhETF, vol. 105, iss. 5, pp. 259 – 260 2017 March 10 c Performance investigation of suppression of four wave mixing using optical phase conjugation with different modulation format in DWDM soliton communication system G.Kaur+1), R. S.Kaler+, S. Singh∗ +Optical Fiber Communication Research Laboratory (OFCR Lab), ECE Department, Thapar University, Patiala, 147004 Punjab, India ∗Department of Electronics and Communication Engineering, Punjabi University, Patiala, 147004 Punjab, India Submitted 13 December 2016 Resubmitted 11 January 2017 DOI: 10.7868/S0370274X17050010 Optical fiber communication system are being extensively used in the world for telecommunication, data rate, and data transmission purpose. <...> The demand for transmission over the global telecommunication network will continue to grow at an exponential rate and only fiber optics will be able to meet the challenge [1–3]. <...> In a dense wavelength division multiplexed (DWDM) transmission system four wave mixing (FWM) is one of the major limiting factors and to suppress this undesirable effect the optical phase conjugation (OPC) is the best alternative [4, 5]. <...> By using OPC which change the phase of the signal in the middle of the link and it cancelled the impairment which occurred in the first part of the transmission link (before conjugation)with impairments that occurred in the second part of the link (after conjugation). <...> In this paper, the performance of DWDM soliton transmission system for return-to-zero (RZ) and nonreturn-to-zero (NRZ) modulation formats have been investigated. <...> The main aim of this paper is to estimate and mitigate the four wave mixing power by using inline optical phase conjugator. <...> In this work 32 channels DWDM soliton system is used. <...> The Q-factor is observed as a function of transmission distance for both RZ and NRZ and it is observed that the Q-factor is decreased with respect to transmission distance due to induced non-linearity in the fiber. <...> When the performance of data formats are compared then, as a result, RZ data format provides superior performance with good level of Q-factor. <...> To measure the 1)e-mail: gksumman@gmail.com Письма вЖЭТФ том 105 вып. 5 – 6 2017 259 Fig. 1 <...>