Ultra-high bandwidth optical data transmission with a microcomb

We report record data transmission over standard optical fibre using a single integrated chip source. We demonstrate a line rate of 44.2 Terabits per second (Tb/s) using the telecommunications C-band at 1550nm with a spectral efficiency - a critically important performance metric - of 10.4 bits/s/Hz. We use a new and powerful class of micro-comb called soliton crystals that exhibit robust operation and stable generation as well as a high intrinsic efficiency that, together with an extremely low spacing of 48.9 GHz enables a very high coherent data modulation format of 64 QAM. We demonstrate error free transmission over 75 km of standard optical fibre in the laboratory and a field trial over an installed metropolitan optical fiber network. This work demonstrates the capability of optical micro-combs to out-perform other approaches in demanding and practical optical communications networks.