title: Ultra-high bandwidth quantum secured data transmission.
abstract: Quantum key distribution (QKD) provides an attractive means for securing communications in optical fibre networks. However, deployment of the technology has been hampered by the frequent need for dedicated dark fibres to segregate the very weak quantum signals from conventional traffic. Up until now the coexistence of QKD with data has been limited to bandwidths that are orders of magnitude below those commonly employed in fibre optic communication networks. Using an optimised wavelength divisional multiplexing scheme, we transport QKD and the prevalent 100 Gb/s data format in the forward direction over the same fibre for the first time. We show a full quantum encryption system operating with a bandwidth of 200 Gb/s over a 100 km fibre. Exploring the ultimate limits of the technology by experimental measurements of the Raman noise, we demonstrate it is feasible to combine QKD with 10 Tb/s of data over a 50 km link. These results suggest it will be possible to integrate QKD and other quantum photonic technologies into high bandwidth data communication infrastructures, thereby allowing their widespread deployment.
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: James F
authors.initials: JF
authors.lastname: Dynes
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Winci W-S
authors.initials: WW
authors.lastname: Tam
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Plews
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Bernd
authors.initials: B
authors.lastname: Fröhlich
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Sharpe
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Lucamarini
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: ADVA Optical Networking SE, Maerzenquelle 1-3, 98617 Meiningen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Radig
authors.affiliation: ADVA Optical Networking, York, Advantage House, Tribune Way, Clifton Moore, Tribune Way, York, YO30 4RY, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Straw
authors.affiliation: ADVA Optical Networking, York, Advantage House, Tribune Way, Clifton Moore, Tribune Way, York, YO30 4RY, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Edwards
authors.affiliation: Toshiba Research Europe Ltd, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Shields