1 min

In cooperation with Toshiba, Single Quantum has made the technology suitable for more than 300 kilometres of fibre-optic connections.

In Quantum Key Distribution (QKD), high-performance and quantum computers generate keys that are resistant to decryption. Toshiba’s QKD technology is delivered over fibre-optic networks and so far could reach a maximum distance of 150 kilometres. Researchers are trying to increase the distance, but that is proving difficult since quantum signals weaken during the transmission process over fibre.

Tip: Quantum Key Distribution guarantees secure communication


To address this challenge, the two parties tried to validate the performance of Single Quantum’s superconducting nanowire single photon detectors (SNSPDs) working with Toshiba’s QKD systems. Single Quantum’s SNSPDs can detect single photons very accurately and efficiently, significantly extending the transmission distance of QKD.

The performance of Single Quantum and Toshiba is sustained for longer periods of time, as shown in a performance graph presented by the two companies. The graphic below shows the transmission performance.

Grafiek die de afname van de gemeten veilige bitsnelheid (bps) toont naarmate het kwantumkanaalverlies (db) toeneemt, met een genoteerd prestatiepunt over een verbinding van 300 km.

In addition to validating the ability to extend the distance of fibre QKD, Single Quantum and Toshiba are delivering a solution for longer-distance QKD transmission over a single fibre link by integrating SNSPDs with QKD technology in a compact rack-like solution.