REVIEW ARTICLE ON THE MITIGATION OF FOUR WAVE MIXING IN OPTICAL COMMUNICATION SYSTEM

The main challenge faced in today's telecommunication is the ever increasing demand for bandwidth and data rates. The desire to expand the capacity of fiber optic communication to accommodate this demand accelerated the development of high capacity Dense Wavelength Division Multiplexing (DWDM) transmission equipment. However, nonlinear impairments are the fundamental limiting mechanisms to the amount of data that can be transmitted in DWDM. In DWDM, Four Wave Mixing is the most critical of nonlinear effects in fibre optics communication. This effect limits the DWDM’s channel capacity. There are numerous researches on nonlinear impairments that show the intricacy of FWM phenomena in DWDM system. This article present review of the several measures which have been carried out by researchers to overcome nonlinear effects in DWDM. Such measures include Modulation Formats, Channel Spacing, Channel Shuffling Algorithm and Electro-Optic Phase Modulation. The review provides insight into the methods, parameters and approaches used by other researchers. This will pave way for can thus lead to significant improvement in the design of DWDM system.

Probing of nonlinear impairments in long range optical transmission systems

Optical communication systems represent the backbone of modern long-haul communication networks. Nonlinear impairments such as the Kerr effect pose threat and deteriorate transmission in long-haul optical communication systems. At high launch powers, nonlinear effects become more important and their compensation is entailed to improve the transmission performance. In this paper, one of the major nonlinear effects of four waves mixing (FWM) is addressed using a theoretical model and validated through simulation in Optisystem. Two mechanisms with and without dispersion variation are investigated. The impact of FWM is investigated in terms of various values of launch power. The transmission performances of the proposed model are evaluated on the basis of bit error rate, optical signal to noise ratio, and quality factor using key parameters of effective area, nonlinear refractive index, nonlinear dispersion, and linear dispersion.

Simulation-Based Optical Threshold Component Design for Mitigating Four-Wave Mixing Effects in WDM Radio Over Fiber Systems

The gigantic demand on high bandwidth and capacity has triggered the need to use the radio over optical fiber (RoF) systems. RoF systems offer several attractive features such as low attenuation loss, large bandwidth, less interference, etc., which can improve the communication system reliability and achieve high data rates. However, the RoF system suffers from linear and nonlinear fiber impairments, which result in signal distortion. Several solutions have been proposed to overcome linear impairments; on the other hand, the nonlinear impairments issue is still a challenging problem in RoF communication systems. Four-wave mixing (FWM) is the most dominating nonlinear impairments that impacts the performance of optical fiber communication systems and the RoF systems as well. In this article, we present a strategy to mitigate the FWM effect in wavelength division multiplexing (WDM) RoF systems. Specifically, we study the effect of FWM under high transmit power levels over long transmission distances. This proposed strategy aligns the optical and radio link parameters to alleviate the FWM effects. To achieve this objective, the impact of WDM RoF system parameters such as wavelength ($\lambda_i$), transmitted power, etc., on system performance is investigated. The main performance metrics are the total signal-to-noise ratio (SNR), optical SNR (OSNR), Q-factor, and bit error rate (BER). Given these metrics, our proposed strategy defines an optical threshold level that applies to the optical threshold component to get rid of the undesired signals generated by the FWM effect.