New graphene optoelectronic mixers boost high-speed telecommunications

By 2023, the world will see over 28 billion connected devices – more than double the number of gadgets we use today. This could have major effects on the environment, unless we develop technologies that are more sustainable and efficient than current solutions. Graphene-enabled optoelectronics could enable greener and faster communications.

Graphene Flagship researchers have developed a graphene-based optoelectronic mixer that operates at high frequencies and broad bandwidth – which could be implemented in future telecom and datacom devices, as well as RADAR and LIDAR systems, both useful for autonomous vehicles.

These results, just published in Nature Communications, are the result of an international collaboration between Graphene Flagship industrial partner Thales Research and Technology, France, with academic researchers at Graphene Flagship partner institutions the University of Lille and IEMN, France, and the University of Cambridge, UK. The collaborative ecosystem fostered by the EU-funded Graphene Flagship project was paramount to enable these discoveries, establishing Europe as a technological leader in the field of next-generation telecommunications.

“We have developed a graphene-enabled optoelectronic mixer that works very well at frequencies within the millimetre-wave spectrum, which are becoming more and more required in a wide range of applications such as telecommunication technologies, like 5G and the next 6G generation.” explains Alberto Montanaro, co-first author of the paper. Montanaro carried out the research at Graphene Flagship industrial partner Thales, France, and currently works at Graphene Flagship partner CNIT, Italy.

“Mixers are devices that combine two different signals into one,” adds Montanaro. Graphene was used to make a mixer that combines both electrical and optical signals into an electrical output. “This is possible thanks to the interactions of light with graphene” he says. “And because light allows the generation of very high frequencies in an easy way with respect to the fully-electronic counterpart, this mixer would enable new applications overcoming the hurdles of traditional electronics and leading to better communications.”

Thanks to the combination of electronics and photonics, devices like the new graphene-enabled mixer are made possible, paving the way to protocols with higher data-transmission rates, faster speeds, and broadband networks. Graphene-based technologies could accelerate the development and adoption of 6G, the successor of 5G. 6G wireless will provide connections 10 times quicker than 5G. 6G will support 10 times more connected devices than 5G with similar energy supplies – increasing efficiency, sustainability and reducing the environmental impact of telecommunications, a technology that currently accounts for almost 5% of all carbon emissions.

Marco Romagnoli, Graphene Flagship Division Leader for Electronics and Photonics Integration, says: “The photomixing technique developed in this work is a high impact technology for broad range of applications, such as generation of millimetre waves for future wireless systems and radars, or for ultra-stable frequency generation in all radio systems. In this high impact technology, graphene plays an important role. Thanks to its ultrafast nature, it enables all range of high frequencies and, thanks to its high electrooptical efficiency, graphene generates high frequency electromagnetic waves with unprecedented conversion efficiency that, with further developments, could state new records in performance.”

Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: “We are at the verge of the integration of graphene-based optolectronics into commercial devices. This work, spearheaded by the leading EU Graphene Flagship partner company Thales, shows the industry push for the technology. Our ambition is to see future 5G and 6G devices integrating graphene and layered materials technologies, enabling higher efficiency, speed, and lower power consumption.”

Reference

“Optoelectronic mixing with high frequency graphene transistors,” A. Montanaro, W. Wei, D. De Fazio, U. Sassi, G. Soavi, P. Aversa, A.C. Ferrari, H. Happy, P. Legagneux, E. Pallechi. Nature Communications, 2021, DOI: 10.1038/s41467-021-22943-1