Four-wave mixing in multispan dispersion-managed transmission links
ABSTRACT We report the first experimental measurement of resonances in four-wave mixing (FWM) fields caused by lumped amplification in wavelength-division-multiplexed systems. Our numerical model allows us to predict the FWM characteristics in great detail. We also show that the FWM is reduced by more than 20 dB when two channels are launched with orthogonal polarizations.
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ABSTRACT: We show, using simulations, that a combination of orthogonal frequency division multiplexing (OFDM) and optical single sideband modulation can be used to compensate for chromatic dispersion in ultralong-haul wavelength-division multiplexed (WDM) systems. OFDM provides a high spectral efficiency, does not require a reverse feedback path for compensation, and has a better sensitivity than nonreturn to zero. This paper provides design rules for 800-4000-km optical-OFDM systems. The effects of WDM channel number and spacing, fiber dispersion, and input power per channel on the received Q are studied using extensive numerical simulations. These effects are summarized as a set of design rulesJournal of Lightwave Technology 02/2007; 25(1):131-138. · 2.78 Impact Factor
Article: Linear and Nonlinear Crosstalk Evaluation in DWDM Networks Using Optical Fourier Transformers[show abstract] [hide abstract]
ABSTRACT: A novel DWDM channel monitoring technique based on the conversion from wavelength domain to time domain by performing a real-time optical Fourier transform over the whole DWDM system bandwidth is proposed and experimentally demonstrated. The use of chromatic dispersion-based optical Fourier transformers has been validated in the case of a spectrum comprising light from different uncorrelated sources. Linear and nonlinear crosstalks between the DWDM channels appear as amplitude noise at specific time positions. The correspondence of this amplitude noise with the crosstalk spectral distribution is evaluated theoretically and experimentally.EURASIP Journal on Advances in Signal Processing. 01/2005;
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ABSTRACT: Four-wave mixing (FWM) in wavelength-division multiplexed systems with strong dispersion management and loss–amplification is comprehensively studied. The methods described apply to both soliton and quasi-linear return-to-zero systems. A linear model is introduced that describes the resonant growth and saturation of the FWM products. The model yields a resonance condition between the channel separation and the am-plifier spacing that, in certain parameter regions, reproduces for strongly dispersion-managed systems the phase-matching condition that is valid for classical solitons. As the dispersion map's strength increases, the residual FWM decreases, but the FWM amplitude is found to increase inversely to the average dispersion in the system. A reduced linear model is also introduced that contains the basic features of FWM processes. Comparisons of both models with direct numerical simulations of the full nonlinear system demonstrate ex-cellent agreement. © 2003 Optical Society of America OCIS codes: 060.0060, 190.4380.