Title :
1.14 b/s/Hz spectrally efficient 50/spl times/85.4-Gb/s transmission over 300 km using copolarized RZ-DQPSK signals
Author :
Yoshikane, N. ; Morita, I.
Author_Institution :
KDDI R&D Labs., Saitama, Japan
Abstract :
1.14 b/s/Hz spectrally efficient 50/spl times/85.4-Gb/s copolarized return-to-zero differential quaternary phase-shift keying (RZ-DQPSK) signals have been transmitted over 300 km of nonzero dispersion-shifted fiber (NZ-DSF), using optical prefiltering and conventional C-band erbium-doped fiber amplifier (EDFA) repeaters. In this study, in order to enhance the spectral efficiency, the impact of optical prefiltering on the RZ-DQPSK signal was experimentally investigated in comparison to the DQPSK signal, and we found that the RZ-DQPSK signal had better sensitivity with almost the same nonlinear tolerance than the DQPSK signal even with 65-GHz bandwidth optical prefiltering.
Keywords :
differential phase shift keying; erbium; optical fibre amplifiers; optical fibre communication; optical fibre dispersion; optical filters; optical repeaters; 300 km; 4270 Gbit/s; 50 Gbit/s; 65 GHz; C-band repeaters; RZ-DQPSK signals; copolarized signals; erbium-doped fiber amplifier; nonlinear tolerance; nonzero dispersion-shifted fiber; optical prefiltering; return-to-zero differential quaternary phase-shift keying; spectrally efficient transmission; Fiber nonlinear optics; Nonlinear optics; Optical crosstalk; Optical filters; Optical pulses; Optical sensors; Optical transmitters; Phase modulation; Phase shift keying; Wavelength division multiplexing; Copolarized signals; optical prefiltering; return-to-zero differential quaternary phase-shift keying (RZ-DQPSK); spectral efficiency; wavelength-division multiplexing (WDM);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2004.840343
