THEORETICAL EVALUATION OF NONLINEAR EFFECTS ON OPTICAL WDM NETWORKS WITH VARIOUS FIBER TYPES

Abstract

A theoretical study is carried out to evaluate the performance of an optical
wavelength division multiplexing (WDM) network transmission system in the presence
of crosstalk due to optical fiber nonlinearities. The most significant nonlinear effects in
the optical fiber which are Cross-Phase Modulation (XPM), Four-Wave Mixing (FWM),
and Stimulated Raman Scattering (SRS) are investigated. Four types of optical fiber are
included in the analysis; these are: single-mode fiber (SMF), dispersion compensation
fiber (DCF), non-zero dispersion fiber (NZDF), and non-zero dispersion shifted fiber
(NZDSF). The results represent the standard deviation of nonlinearity induced crosstalk
noise power due to FWM and SRS, XPM power penalty for SMF, DCF, NZDF, and
NZDSF types of fiber, besides the Bit Error Rate (BER) for the three nonlinear effects
using standard fiber type (SMF). It is concluded that three significant fiber nonlinearities
are making huge limitations against increasing the launched power which is desired,
otherwise, lower values of launched power limit network expansion including length,
distance, covered areas, and number of users accessing the WDM network, unless
suitable precautions are taken to neutralize the nonlinear effects. Besides, various fiber
types are not behaving similarly towards network parameters.