Demonstration of 4 lanes of 4 × 100 Gbps DMT transmission with channel spacing of 50-GHz compatible with DWDM

We experimentally demonstrate 4 lanes of 416-Gb/s discrete multi-tone (DMT) transmission with 50-GHz channel spacing. This is the first demonstration of 4 × 100 G transmission with less than 100-GHz channel spacing and it can be compatible with dense wavelength division multiplexing (DWDM).