Syed Zafar ALI¹, Muhammad Khawar ISLAM^2*, and Muhammad ZAFRULLAH³

¹Department of Electrical Engineering, Air University, E-9 Islamabad, Pakistan
²Department of Telecommunication Engineering, University of Engineering and Technology, Taxila 47050, Pakistan
³Department of Electronic Engineering, University of Engineering and Technology, Taxila 47050, Pakistan

(Received November 29, 2011; Accepted June 22, 2012)

Optical chaos propagation has few constraints peculiar to itself which do not become as significant in conventional non-chaotic optical communication. We have investigated the effects of transmission fiber nonlinearities, dispersion and noise of erbium doped fiber amplifier (EDFA) on chaotic signal synchronization in lumped and distributed configuration. It is found that the effects of fiber dispersion can be easily compensated; however, the effects of fiber nonlinearity on chaos cannot be overdone and must be avoided. Three distinct configurations with different combinations of standard telecommunication fiber, dispersion compensation fiber and lumped and distributed EDF for amplification are analysed. The results are compared in terms of sync diagrams and noise figure. The chaos after propagation through distributed amplification performs better as compared to lumped amplification. Also, a new quantitative measure for the calculation of deviation in sync diagram of chaos is introduced.

Key words: optical chaos, secure communication, synchronization, transmission effects, EDFA

^*E-mail address: drmk.islam@uettaxila.edu.pk