We discuss options for upgrading coarse wavelength-division multiplexed (CWDM) optical access links over standard single-mode fiber (SSMF) by increasing per-channel data rates from 2.5 to 10 Gb/s. We identify electronic equalization and forward error correction (FEC) as the enabling technologies to overcome the dispersion limit of SSMF. In addition, we show how FEC enhances the tolerance to in-band crosstalk, and paves the way toward fully bidirectional CWDM transmission. Due to the lack of CWDM sources rated for 10-Gb/s operation, we demonstrate full-spectrum (1310 to 1610 nm) 10-Gb/s CWDM transmission over standard-dispersion fiber using uncooled, directly modulated lasers specified for 2.5 Gb/s. All 16 CWDM channels could be transmitted over more than 40 km, yielding a capacity-times-distance product of 6.4 Tb/s/km. The longest transmission distance (80 km) was achieved at 1610 nm, equivalent to 1600 ps/nm of chromatic dispersion.
© 2005 IEEE
P. J. Winzer, F. Fidler, M. J. Matthews, L. E. Nelson, H. J. Thiele, J. H. Sinsky, S. Chandrasekhar, M. Winter, D. Castagnozzi, L. W. Stulz, and L. L. Buhl, "10-Gb/s Upgrade of Bidirectional CWDM Systems Using Electronic Equalization and FEC," J. Lightwave Technol. 23, 203- (2005)