RingCryption: Scalable and Cooler-free Single-Photon Sources for Quantum-Secure Communication at Telecoms Wavelengths

The rapid advancement of quantum computing poses a significant threat to existing cybersecurity systems by undermining traditional encryption methods like RSA and ECC. This escalating risk has created an urgent demand for quantum-secure communication technologies that can protect sensitive data across industries. Quantum-ring single-photon light-emitting diodes (QR-SPLEDs) address this cybersecurity challenge by offering a scalable and cost-effective solution for quantum key distribution (QKD), providing a practical, market-ready pathway to unbreakable encryption. QR-SPLEDs emit single photons on demand at telecoms wavelengths, ensuring seamless integration with existing fibre-optic telecommunications network infrastructure. Unlike alternative sources that require cryogenic cooling or complex optical setups, QR-SPLEDs operate efficiently at room temperature through an all-electrical process. These unique semiconductor devices integrate GaSb quantum rings (QRs) in an optical cavity for photon emission at a specific wavelength. A quantum dot (QD) tunnelling layer enables precise electrical control over single-photon emission by injection of a single electron into the QRs. This concept is radically different to the conventional approach of trying to isolate a single light-emitting nanostructure, which is not scalable. Our QD single-electron filter layer dramatically simplifies the manufacturing process, facilitating scalable, high-yield production using standard semiconductor fabrication techniques that are already used to produce billions of vertical-cavity surface-emitting lasers (VCSELs) at very low cost. QR SPLEDs compact form factor and low power consumption make them ideal for real-world cybersecurity applications, particularly for industries such as telecommunications, finance, defence and healthcare, where secure data transmission is critical. Our technology has demonstrated strong proof-of-principle results with spectrally-pure (cavity-enhanced) photon emission at temperatures up to 80°C. Participation in the Innovate UK ICURe Explore Future Telecoms and NW CyberCom programmes has identified both the technological feasibility and market demand for QR-SPLEDs. The CyberASAP programme will further refine our cybersecurity commercialisation strategy, ensuring QR-SPLEDs meet the pressing needs of industries grappling with quantum-era cyber threats. Industry feedback highlights a pressing need for room-temperature, telecom-compatible and cost-effective single-photon sources, positioning QR-SPLEDs as a game-changing cybersecurity technology against the looming threat of quantum-enabled cyberattacks. The project will build on this, delivering robust value propositions and strong market validation in preparation for spinning-out within the next year. The global quantum communication market is projected to exceed $15 billion by 2030, driven by the need for quantum-secure encryption solutions. QR-SPLEDs fill a critical market gap by delivering compact, efficient, and affordable single-photon sources, uniquely suited for large-scale deployment in cybersecurity systems worldwide.