Improved Power Budget of 112 Gb/s/l Intra-Datacentre Links Using a Split-Carrier Transmitter Architecture

A split-carrier transmitter is proposed to improve loss budget for short distance 100 G-per-wavelength intra-datacentre links. By applying a low-complexity hardware modification to the transmitter, the proposed architecture reduces transmitter loss without sacrificing modulation quality. These benefits are demonstrated by implementing intensity modulated, direct-detection signals using a single-ended photodiode receiver. The architecture is evaluated using two formats: Nyquist-shaped 56 GBd PAM-4 and Nyquist-shaped double sideband 28 GBd 16-QAM. The results are compared against a conventional transmitter modulated with Nyquist-shaped 56 GBd PAM-4. Through simulation, the split-carrier transmitter is shown to achieve hard decision forward error correction ready performance after 2 km of transmission using a laser output power of just 0 dBm; a 5.2 dB improvement over the conventional transmitter.