Investigation of 2-b/s/Hz 40-gb/s DWDM transmission over 4/spl times/100 km SMF-28 fiber using RZ-DQPSK and polarization multiplexing

We have investigated transmission of 14/spl times/40 Gb/s dense wavelength-division-multiplexing channels with 20-GHz spacing over 4/spl times/100 km of SMF-28 fiber. A spectral efficiency of 2 b/s/Hz was demonstrated by 4-b (8-state) per-symbol coding using return-to-zero differential quadrature phase-shift keying (RZ-DQPSK) and polarization multiplexing using polarization bit interleaving. All 12.5-Gsymbols/s transmitted channels included 25% overhead bandwidth reserved for forward-error correction (FEC) and showed uncorrected bit-error rate below the FEC threshold required for error-free operation. Demodulation of the RZ-DQPSK signal at the receiver was achieved using a fiber-based asymmetric Mach-Zehnder interferometer as well as a packaged integrated lithium niobate optical 90/spl deg/ hybrid.

[1]  W. Chujo,et al.  1.6-b/s/Hz 6.4-Tb/s QPSK-OCDM/WDM (4 OCDM x 40 WDM x 40 Gb/s) transmission experiment using optical hard thresholding , 2002, IEEE Photonics Technology Letters.

[2]  Y. Achiam,et al.  Transmission of 25-Gb/s RZ-DQPSK signals with 25-GHz channel spacing over 1000 km of SMF-28 fiber , 2003, IEEE Photonics Technology Letters.

[3]  S. Banerjee,et al.  Ultra-high-capacity long-haul 40-Gb/s WDM transmission with 0.8-b/s/Hz spectral efficiency by means of strong optical filtering , 2003, IEEE Photonics Technology Letters.

[4]  Return-to-zero differential binary phase-shift-keyed multichannel transmissionwith 25-Gbit/s polarization bit interleaving and 25-GHz spacing , 2003 .

[5]  Yutaka Miyamoto,et al.  Performances of CSRZ-DPSK and RZ-DPSK in 43-Gbit/s/ch DWDM G.652 single-mode-fiber transmission , 2003, OFC 2003 Optical Fiber Communications Conference, 2003..

[6]  Enhanced suppression of nonlinearity-induced crosstalk in WDM systems using optical polarization-shift-keying , 2003, Conference on Lasers and Electro-Optics, 2003. CLEO '03..

[7]  P. Cho,et al.  Integrated Optical QPSK Modulator and Coherent Receiver , 2003 .

[8]  B. Lankl,et al.  High spectral efficiency 1.6-b/s/Hz transmission (8 x 40 Gb/s with a 25-GHz grid) over 200-km SSMF using RZ-DQPSK and polarization multiplexing , 2003, IEEE Photonics Technology Letters.

[9]  G. Raybon,et al.  25 x 40-Gb/s copolarized DPSK transmission over 12 x 100-km NZDF with 50-GHz channel spacing , 2003, IEEE Photonics Technology Letters.