LOw-noise and REliable LAser sources for continuous-variable quantum keY distribution

Programm Indentification Code: QuNet+

(Funded by the German Federal Ministry of Education and Research)

Duration: December 2022 - November 2025


ADVA Network Security GmbH (Berlin), Fraunhofer HHI (Berlin), Fraunhofer IIS (Dresden), Friedrich-Alexander-Universität Erlangen-Nürnberg, TOPTICA Photonics AG (Gräfelfing), Rheinisch-Westfälische Technische Hochschule Aachen, ficonTEC Service GmbH (Achim)

Project description

Whether for the exchange of information between authorities or for the transmission of private data of citizens: With the increase in importance of digital infrastructures, the need for secure encryption methods to protect sensitive data has also increased significantly in recent years and will continue to increase in the future. In this context, the threat posed by future powerful quantum computers is particularly problematic, as the latter could break cryptographic algorithms that are considered secure today. However, quantum physics also offers possible solutions. For example, there are methods for exchanging cryptographic keys using light quanta, the so-called Quantum Key Distribution (QKD). It is demonstrably secure against quantum computers and can be integrated into both fibre-optic-based optical communication networks and free-radiation systems such as satellite communication. However, a great deal of research is still needed on the hardware in order to be able to use QKD in practice in the future.

Aims and procedure

The aim of the project "Low-noise lasers for quantum key exchange with continuous variables" (QuNET+LORELAY) is to develop a high-performance laser specially optimised for quantum communication and to demonstrate its performance in corresponding QKD systems. To this end, new approaches are being researched, both for the semiconductor-based optical laser chips and for the control electronics. This will make it possible to achieve extremely low-noise and stable laser emission. In addition, the researchers will develop a highly precise and reproducible automated manufacturing process to integrate the laser chips into a miniaturised module. In order to master the challenging tasks, a broad consortium of research institutions, universities and industrial partners are working together on solutions in the project.
In the project, a compact and high-performance laser for quantum communication is being developed. Compared to the current state of the art, the envisaged solution will allow the transmission distance of QKD systems to be significantly increased, enabling the widespread use of quantum-safe encryption methods in communication networks. At the same time, the research work of the project will lay the foundation for a completely national value chain, so that the reliable origin of the components used can be ensured in the future. As the project is embedded in the QuNET initiative, there are also significant synergies with other research projects in quantum communication. The project thus contributes to establishing Germany's technological sovereignty in the introduction and dissemination of quantum-based communication systems for socially and economically relevant use and applications.