Performance evaluation and enhancement of DWDM systems under the impact of four waves mixing crosstalk in optical communications (original) (raw)
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Performance evaluation and analysis of four waves mixing in DWDM optical communications
Optical nonlinearities give rise to many ubiquitous effects in optical fibres. These effects are interesting in them and can be detrimental in optical communication. In the Dense Wave length division multiplexing system (DWDM) the nonlinear effects plays important role .DWDM system offers component reliability, system availability and system margin. DWDM system carries different channels. Hence power level carried by fiber increases which generates nonlinear effect such as SPM ,XPM, SRS, SBS and FWM. Four waves mixing (FWM) is one of the most troubling issues. The FWM gives crosstalk in DWDM system whose channel spacing is narrow. Wavelength exchanging enables data swapping between two different wavelengths simultaneously. These phenomena have been used in many applications in Wavelength Division Multiplexing (WDM) optical networks such as, wavelength conversion, wavelength sampling, optical 3R, optical interconnects and optical add-drop multiplexing.
Four-Wave Mixing Crosstalk in DWDM Optical Fiber Systems
Proceedings of the Twenty Third National Radio Science Conference (NRSC'2006), 2006
In this study, we introduce the third nonlinear optical effect known as four-wave mixing (FWM), its implications in optical fiber systems and finally a proposed technique for channel allocation to reduce its effect. Then, we investigate the channel crosstalk due to the FWM for various values of fiber length, core effective area, dispersion, channel spacing and channel power as a function of the number of multiplexed channels in a multi-channel system. Results show that, the ultimate factor, which degrades the system performance, is the FWM power.
ELIMINATING FOUR WAVE MIXING WITH DYNAMIC CHANNEL SHUFFLING IN DWDM OPTICAL NETWORK
Optical Fiber systems are major telecommunication base for worldwide broadband networks. The bandwidth capacity is increased by using DWDM optical networks. But in DWDM Optical Communication System, the nonlinear effects degrades the system performance. FWM is a nonline ar effect that appears at very high optical power and dense channel spacing. When the channels are equally spaced in a DWDM system, the new waves will be generated by FWM and these new waves will drop at channel frequencies, giving rise to crosstalk. Fou r - wave mixing (FWM) is a parametric approach in which distinct frequencies interact causing the generation of new spectral components. Coming generation optical networks insists on the use of the high input power and high bandwidth capacity to accomplish bigger data rates. However, enlarging input power and reducing channel spacing create nonlinear effects including Four Wave Mixing (FWM). So a technique using circular polarizers along with proposed algorithm namely Dynamic wavelength shuffling algorithm i s implemented which results in reduction of FWM to a greater extent and results are formulated in terms of Q - factor, SNR and BER.
Analysis of the Nonlinear Impairments on the DWDM Optical Communication Systems
In the dense wavelength division multiplexing (DWDM) there are many factors affecting their performance. These factors can be divided into linear and nonlinear effects. The linear effects such as chromatic dispersion (CD) and polarization mode dispersion (PMD) can be compensated easily by dispersion compensation fiber (DCF) or fiber Bragg gratings (FBG). The nonlinear effects are the major and most dangerous factors that affect the signal quality and the overall performance of the DWDM. The nonlinear effects can be divided into self-phase modulation, cross phase modulation, four waves mixing, stimulated Brillion scattering and stimulated Raman scattering. This paper discusses the nonlinear effects of the DWDM system and the different ways to overcome these effects to improve the overall signal quality. This simulation analysis was performed using Optisystem (7) simulator.
Mitigation of non-linear four-wave mixing phenomenon in a fully optical communication system
TELKOMNIKA Telecommunication Computing Electronics and Control, 2020
This paper aims to point out the nonlinear phenomenon occurring in coarse/dense wavelength division multiplex (C/D-WDM) systems. This phenomenon has to betaken into account during the design of the optical network itself, as wavelengthsin the optical fiber are constantly densified. The paper points out the emergence of the non-linear four-wave mixing (FWM) phenomenonand how it relates to the dispersion in the optical fiber together with the transmit power. The output of the paper is a proposed design of the system that points to the improvement of the bit error rate (BER) with a suitable choice of dispersion and suitable transmission power.
Effect of Dispersion and Fiber Length on Four Wave Mixing in WDM Optical Fiber Systems
2015
This paper introduces the non linear optical effect known as four wave mixing (FWM). In wavelength division multiplexing (WDM) systems four wave mixing can strongly affect the transmission performance on an optical link. As a result it is important to investigate the impact of FWM on the design and performance of WDM optical communication systems. The main objective of this paper is to analyze the FWM power for different values of fiber length and dispersion by designing and simulating a model in Optisim. In this paper, we have simulated the FWM design for three waves. The results obtained show that when the optical fiber length and dispersion value is increased FWM effect reduces. This result confirms that the fiber nonlinearities play decisive role in the
Analysis of Four Wave Mixing in WDM Optical Sysytems
The efficiency of Wavelength Division Multiplexing (WDM) optical networks can be severely degraded due to fiber nonlinear effects. This paper deals with the analysis of nonlinear effect due to four wave mixing in Wave length division multiplexing optical fibre systems. The numerical analysis of the nonlinear effects is done by Nonlinear Schrödinger equation. The equation is solved using an algorithm called "Split-step algorithm" coded in Matlab. The analysis shows that FWM is independent of bit rate but depends on fibre dispersion and channel spacing. Thus, WDM systems upgrade channel capacity, transparency and enhances wavelength switching and routing.
Performance Analysis of Four Wave Mixing: A Non-Linear Effect in Optical Fibers
Non-Linear effects in Optical fibers are caused due to the refractive index of the optical medium's dependence on the intensity of light. One of the prominent non-linear effects in Optical fibers is the Four-wave mixing (FWM) phenomenon. FWM effect is resonant when the phase matching condition is satisfied. It only occurs for particular combinations of fiber dispersion and signal frequencies. The FWM is a very unpleasant transmission phenomenon occurring in a transparent optical network based on Dense Wave Division Multiplexing, but it could be used advantageously for implementing optical devices such as wavelength converters, parametric amplifiers, optical de-multiplexers, chromatic dispersion compensators, as well as signal to noise regenerators. This paper discusses the effect of channel spacing, laser power, and dispersion, length of the optical fiber and the variation of input power to compensate the effect of FWM when implemented in a short haul environment.
Applied …, 2004
Fiber nonlinearities can degrade the performance of a wavelength-division multiplexing optical network. For high input power, a low chromatic dispersion coefficient, or low channel spacing, the most severe penalties are due to four-wave mixing ͑FWM͒. To compute the bit-error rate that is due to FWM noise, one must evaluate accurately the probability-density functions ͑pdf ͒ of both the space and the mark states. An accurate evaluation of the pdf of the FWM noise in the space state is given, for the first time to the authors' knowledge, by use of Monte Carlo simulations. Additionally, it is shown that the pdf in the mark state is not symmetric as had been assumed in previous studies. Diagrams are presented that permit estimation of the pdf, given the number of channels in the system. The accuracy of the previous models is also investigated, and finally the results of this study are used to estimate the power limits of a wavelength-division multiplexing system.
Modeling and minimization of FWM effects in DWDM-based long-haul optical communication systems
Photonic Network Communications, 2020
Optical communication systems (OCSs) mainly represent the backbone of modern long-haul communication networks because of low loss transmission over long distances and ultra-high capacity. However high data-rate transmission through optical fiber suffers from deterioration due to nonlinear impairments, such as four-wave mixing (FWM) in particular. At high launch power levels, which are required for the long-haul transmission over hundreds of km, these nonlinear effects become more severe which imposes a challenge to achieve satisfactory transmission performance. In this paper, a theoretical model for the FWM effects and its mitigation is presented and validated through simulation results. Moreover, two other nonlinear effects, polarization mode dispersion and nonlinear dispersion variations are also investigated for various values of launch power level. The transmission performance of the proposed OCS model is evaluated on the basis of bit error rate, optical signal-to-noise ratio and quality factor using different transmission channel parameters such as effective area, nonlinear refractive index, nonlinear dispersion, and linear dispersion. Keywords Four-wave mixing (FWM) • Nonlinear dispersion management • Bit error rate (BER) • Optical signal-to-noise ratio (OSNR) • Dense wavelength division multiplexing (DWDM)