Title :
New techniques for the suppression of the four-wave mixing-induced distortion in nonzero dispersion fiber WDM systems
Author :
Neokosmidis, I. ; Kamalakis, T. ; Chipouras, A. ; Sphicopoulos, T.
Author_Institution :
Dept. of Informatics & Telecommun., Univ. of Athens, Greece
fDate :
3/1/2005 12:00:00 AM
Abstract :
The performance of a wavelength-division multiplexing (WDM) optical network can be severely degraded due to fiber nonlinear effects. In the case where nonzero dispersion (NZD) fibers are employed, the four-wave mixing (FWM) effect sets an upper limit on the input power, especially in the case of narrow channel spacing. In order to reduce FWM-induced distortion two new techniques, the hybrid amplitude-/frequency-shift keying (ASK/FSK) modulation and the use of prechirped pulses are investigated. It is shown that both techniques can greatly improve the Q-factor in a 10 Gb/s WDM system. This happens even for very high input powers (∼10 dBm), where the degradation of the conventional WDM system is prohibitively high. The proposed methods are also applied and tested in higher bit rates (40 Gb/s). It is deduced that although the hybrid ASK/FSK modulation technique marginally improves the system performance, the optical prechirp technique can still be used to greatly increase the maximum allowable input power of the system.
Keywords :
Q-factor; amplitude shift keying; channel spacing; chirp modulation; frequency shift keying; high-speed optical techniques; multiwave mixing; optical distortion; optical fibre dispersion; optical fibre networks; optical modulation; wavelength division multiplexing; 10 Gbit/s; 40 Gbit/s; FWM-induced distortion; Q-factors; WDM systems; amplitude-shift keying; fiber nonlinear effects; four-wave mixing; four-wave mixing effect; frequency-shift keying; high bit rate application; hybrid ASK/FSK modulation; narrow channel spacing; nonzero dispersion fiber; optical network; prechirped pulses; wavelength-division multiplexing; Amplitude shift keying; Degradation; Dispersion; Frequency shift keying; Nonlinear distortion; Optical distortion; Optical fiber networks; Pulse modulation; WDM networks; Wavelength division multiplexing; Chirp; nonlinear optics; optical crosstalk; optical fiber communications; wavelength-division multiplexing (WDM);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2004.841448