Combating the effect of nonlinearities in DWDM system

Abstract

In Fiber optic communication, Dense Wavelength Division Multiplexing system (DWDM) is used to increase the capacity and to satisfy the need of enormous bandwidth utilization. In this system more number of channels with different wavelength passed through Single Mode Fiber (SMF). Eventhough, there is an impact of parameters such as input power, channel spacing and frequency response. To achieve high data rates for long haul communication the launching power for transmission should be high. Due to this, the system behave from linear to nonlinear response leads to the unwanted effects. Generally the DWDM system affects by nonlinear effects such as Simulated Raman Scattering (SRS), Cross-Phase Modulation (XPM) and Four-Wave Mixing (FWM). These effects severely degrade the system performance. In this paper, the impact of FWM and SRS effects were analyzed for different number of channels with power level varied from -10 dBm to 10 dBm. The FWM effect was suppress by introducing the Circular Polarizers (CP) alternatively in each channel before multiplexing and the SRS effect was reduced by using Super Gaussian Filter after optical fiber.