Ultra-Narrow-Spacing 10-Channel 1.12 Tb/s D-WDM Long-Haul Transmission Over Uncompensated SMF and NZDSF

We experimentally investigate the transmission of a 1.12-Tb/s Dense-WDM (D-WDM) system comprising 10 × 112 Gb/s polarization-multiplexed quadrature phase-shift-keying channels with ultra-narrow spacing (1.1 times the Baud rate). The D-WDM signal is generated by means of a recirculating frequency shifter. We used narrow optical filtering of channels at the transmitter to reduce interchannel crosstalk. With 100-km uncompensated spans and EDFA amplification, we reached 800 km over nonzero dispersion-shifted fiber (NZDSF) and 2300 km over standard single-mode fiber, at BER=3·10-3. By simulation, we also investigated transmission over large-effective area NZDSF fiber (LEAF) and pure silica-core fiber (PSCF). We found that the D-WDM channel should achieve a 40% longer reach with LEAF than with NZDSF and a 45% longer reach with PSCF than with standard single-mode fiber.