Transmission of 25-Gb/s RZ-DQPSK signals with 25-GHz channel spacing over 1000 km of SMF-28 fiber

We report transmission of nine 25-Gb/s return-to-zero differential quadrature phase-shift keyed (RZ-DQPSK) dense wavelength-division-multiplexing signals with 25-GHz channel spacing over 1000 km of single-mode fiber (SMF-28) in a recirculating loop. The loop uses all erbium-doped fiber amplifiers (EDFAs) and has an amplifier spacing of 100 km with an average loss of 25 dB between EDFAs and a maximum span loss of up to 30 dB. All channels were copolarized launched. No precompensation or postcompensation was employed. To the best of our knowledge, this is the first transmission test of multichannel RZ-DQPSK signals operating at 25 Gb/s with a spectral efficiency of 0.8 b/s/Hz. The transmission distance is limited by amplified spontaneous emission noise due to the high span losses. Nevertheless, our result indicates that upgrading the capacity of long-haul terrestrial systems using RZ-DQPSK modulation format should be feasible.

[1]  D. M. Boroson,et al.  Sensitivity of optically preamplified DPSK receivers with Fabry-Perot filters , 1996 .

[2]  J. Gordon,et al.  Phase noise in photonic communications systems using linear amplifiers. , 1990, Optics letters.

[3]  Gabriel Charlet,et al.  1.6 Tb/s (40 × 40 Gb/s) DPSK Transmission with Direct Detection , 2002 .

[4]  G. Raybon,et al.  2.5 Tb/s (64/spl times/42.7 Gb/s) transmission over 40/spl times/100 km NZDSF using RZ-DPSK format and all-Raman-amplified spans , 2002, Optical Fiber Communication Conference and Exhibit.

[5]  U. Gliese,et al.  DPSK 32 x 10 Gb/s transmission modeling on 5 x 90 km terrestrial system , 2000, IEEE Photonics Technology Letters.

[6]  P. V. Mamyshev,et al.  Pulse-overlapped dispersion-manageddata transmission and intrachannel four-wave mixing , 1999 .

[7]  S. Ryu,et al.  Signal linewidth broadening due to nonlinear Kerr effect in long-haul coherent systems using cascaded optical amplifiers , 1992 .

[8]  Frank Kerfoot.  Forward error correction for optical transmission systems , 2002, OFC 2002.

[9]  C. Wree,et al.  RZ-DQPSK Format with High Spectral Efficiency and High Robustness Towards Fiber Nonlinearities , 2002, 2002 28TH European Conference on Optical Communication.

[10]  F. Kerfoot.  Tutorial: forward error correction for optical transmission systems , 2002, Optical Fiber Communication Conference and Exhibit.

[11]  Takashi Mizuochi,et al.  Third generation FEC employing turbo product code for long-haul DWDM transmission systems , 2002, Optical Fiber Communication Conference and Exhibit.

[12]  Robert A. Griffin,et al.  10 Gb/s optical differential quadrature phase shift key (DQPSK) transmission using GaAs/AlGaAs integration , 2002, Optical Fiber Communication Conference and Exhibit.

[13]  P. Mamyshev,et al.  Pulse-overlapped dispersion-managed data transmission and intrachannel four-wave mixing. , 1999, Optics letters.

[14]  G. Raybon,et al.  Intra-channel cross-phase modulation and four-wave mixing in high-speed TDM systems , 1999 .

[15]  X. Liu,et al.  Nonlinear phase noise in pulse-overlapped transmission based on return-to-zero differential-phase-shift-keying , 2002, 2002 28TH European Conference on Optical Communication.

[16]  S. Chandrasekhar,et al.  Influence of Optical Filtering on Return-to-Zero Differential Phase Shift Keying (RZ-DPSK) , 2002, 2002 28TH European Conference on Optical Communication.