Long-haul DWDM/SCM transmission of 64- and 256-QAM using electroabsorption modulated laser transmitters

We report the first eight-wavelength hybrid dense wavelength-division multiplexing/subcarrier multiplexing (DWDM/SCM) transmission over 800 km (ten spans) of standard single-mode fiber, with 1.04-Gb/s payload on each wavelength in 35 6-MHz 64-quadrature amplitude modulated (QAM) channels, without dispersion compensation. Forward error-correction coding (FEC) was used to achieve error-free performance. Error-free performance on the majority of channels was also achieved for 64-QAM without FEC and for 256-QAM with FEC over 400 km. We used electroabsorption modulated laser transmitters.