QKD is a secure communication method that leverages the principles of quantum mechanics to generate and distribute cryptographic keys between two parties, ensuring that any attempt at eavesdropping can be detected.

The project aims to introduce two new OEM QKD receivers based on different technologies, which are interchangeable at the optical connection point. These receivers will be constructed using UK components, ensuring a robust domestic supply chain for critical quantum networking technologies.

For smaller setups and short-distance communications, a four-channel single photon avalanche detector (SPAD) system will feature Noiseless InGaAs technology from Phlux Technology, packaged by Bay Photonics. For larger, long-distance applications, a superconducting nanowire single photon detector (SNSPD) system will be employed, incorporating enhanced SNSPDs from the University of Glasgow, cooled by a novel 1K system from Chase Cryogenics, and coupled with a new compact timetagger from Redwave Labs. Redwave Labs will optimise the control electronics and timetaggers for both systems, which will be coupled with an optical receiver module from the Fraunhofer Centre for Applied Photonics (CAP).

The University of Cambridge will showcase these receivers in entanglement-based discrete variable-QKD transmission across both metro and long-haul networks, using the BBM92 protocol. This demonstration will highlight the scalability and performance of the MARCONI receivers.

The MARCONI project addresses two critical needs: establishing a UK-led supply chain for quantum networking components and enhancing the scalability of quantum networks. The project targets the rapidly growing QKD market, forecasted to reach approximately $5 billion by 2028. By developing high-performance OEM receiver modules for both small and large installations, MARCONI aims to disrupt the market and reduce reliance on single-source suppliers.

MARCONI's innovations promise significant economic and security advantages, including job creation and safeguarding within the UK supply chain, enhanced national security through the adoption of more secure QKD systems, reduced import dependency for high-performance photonics systems, and boosting the reputation and impact of the UK photonics industry. Redwave Labs, the system integrator, will lead the commercialisation efforts. The project is expected to generate substantial revenue and growth opportunities for all consortium partners.

Backed by funding from Innovate UK under the Scalable Quantum Network Technologies: Collaborative R&D programme, the MARCONI initiative not only strengthens the UK's position in addressing the challenge of bringing scalable quantum network technologies to market but also enhances national security and economic growth.