Performance comparison of different dispersion management techniques in an all-optical closed-loop chaotic transmission system

Abstract

The performance of an all-optical closed-loop chaotic communication system in a transmission link consisting of single mode fibers (SMF) applying two different dispersion management techniques is numerically studied. The first technique is implemented by the usage of dispersion compensating fibers (DCFs), while the second utilizes optical phase conjugators (OPCs). The latter is implemented by means of four wave mixing (FWM) in a dispersion shifted fiber (DSF), where the chaotic carrier corresponds to the signal wave and a high power continuous wave corresponds to the pump wave. Calculation of the recovered message Q-factor values obtained from the corresponding eye diagrams has been carried out applying chaotic modulation (CM) and chaos shift keying (CSK) encryption techniques for two repetition rates (2.4Gbps, 5Gbps). It is shown that the optical phase conjugation is an effective dispersion and non-linear effects compensation technique even if high-bit rate message encoding is applied. The superiority of a transmission system including OPCs to that utilizing (DCFs) is presented. The influence of key system parameters such as optical power, OPC spacing, pump power level, etc. to the transmission performance has been investigated. Acceptable system performance is presented for approximately 600Km at 2.4Gbps and 400Km at 5Gbps.