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AU Engineering Department of Electrical and Computer Engineering

Photonics engineers and physicists ally to make encryption completely secure

In our increasingly digitised society, exchanges of private and sensitive information are almost exclusively digital. Now researchers in a new project are working on photonic integrated circuits to make our digital data secure with unbreakable encryption.

[Translate to English:] I projektet forventer forskerne at komme et langt skridt hen imod at tage fotoniske kvanteteknologier ud af forskningslaboratoriet og anvende dem i virkeligheden. Strategien er at bruge modne teknologier, der allerede nu er tilgængelige. Foto: Colourbox

Over the next four years, researchers from the Department of Engineering at Aarhus University will collaborate with the Niels Bohr Institute, the Technical University of Denmark and four companies to translate decades of quantum research into commercial products that can forge completely secure, unbreakable telecommunication on the existing fibre-optic network.

The aim is to develop and implement so-called single-photon quantum hardware, and the project, which is named FIRE-Q (Field-Ready single-photon Quantum technology), received DKK 17.8 million (around EUR 2.4 mill.) from Innovation Fund Denmark’s Grand Solutions programme.

"By developing technology that bases communication on single photons and their intrinsic quantum properties, transmission of information can be encrypted with a very high level of security. However, because such a signal cannot be amplified, it has to propagate through a material that is extremely transparent so that it’s not lost,” says Nicolas Volet, assistant professor at the Department of Engineering, Aarhus University, and an expert in photonics.

Modern telecommunication takes place via laser beams passing through optical fibres that span the entire Earth. However, the signal loses strength as it is transmitted through the fibres due to scattering and absorption of the traveling photons.

Therefore, the entire fibre network depends on amplifiers, usually placed approx. every 100 km. An optical power of one milliwatt in the conventional telecom spectral band corresponds to a rate of a few millions of billions of photons (~1015) per second.

In contrast, for this new project, the researchers will work with devices that emit one and only one photon at a time.

“Our photonic integrated circuits will also include all-optical signal processing functionalities to encode information on the lightwave signal. This manipulation of single-photons will be achieved on the same chip, via optical nonlinearities, thus reducing the overall footprint and power consumption of the system,” says Nicolas Volet.

The researchers expect to achieve a significant step towards the deployment of photonic quantum technologies out of the research lab. Their strategy is to use mature technologies that are already now available through reliable foundry services. For a total of 15 years, Nicolas Volet and his colleague, Associate Professor Martijn Heck, have conducted research into photonic devices based on materials that are compatible with high-volume production capabilities.

The purpose of the project is therefore also to make the technology available at an affordable price using generic and 'ready-to-use' materials.

“We envision that our field-ready quantum technology will benefit many parts of society where network security is critical," says Nicolas Volet.

The companies Sparrow Quantum, SiPhotonIC, nanoPHAB (the Netherlands), and Swabian Instruments (Germany) are taking part in the project, as well as the Technical University of Denmark, Aarhus University and the Niels Bohr Institute at the University of Copenhagen.


Nicolas Volet
Assistant Professor, Aarhus University
Mail: volet@eng.au.dk
Tel.: +45 93522084