Changing the “color” of light to make future quantum communications more reliable. This is the idea behind a new study published in Advanced Quantum Technologies, which explores the use of mid-infrared light to distribute quantum information through the atmosphere. The research is the result of a collaboration between the National Institute of Optics of the CNR and the Italian Space Agency.
What if changing the color of light were enough to make future quantum communications more reliable? This is the perspective explored by a study conducted by the National Institute of Optics of the National Research Council (CNR-INO) in collaboration with the Italian Space Agency (ASI) , recently published in the journal Advanced Quantum Technologies . The research investigates the potential of mid-infrared light for transmitting quantum information through the atmosphere, opening up new possibilities for the development of more robust and reliable quantum links.
The mid-infrared is a particular region of the spectrum invisible to the human eye, characterized by longer wavelengths than visible light and the lasers used with fiber optics for telecommunications, with specific transmission “windows” where the atmosphere is less obstructive to the passage of light. This can offer potential advantages for optical communications over long distances and in certain weather conditions.
“The simulation results show that the mid-infrared can improve the reliability of the transmission of single photons, the elementary particles of light, even in challenging environmental conditions such as fog and smog, which can compromise light propagation,” explains Paolo De Natale, Director of CNR-INO. “Previously unexplored spectral regions are opening a new frontier for quantum technologies, not only for secure communications but also for next-generation sensors. In this field, the CNR is a leading player, and the technological advances explored together with ASI are increasingly bringing the applications of quantum sources and sensors closer to the spatial dimension.”
The research, conducted by scholars from the National Institute of Optics of the National Research Council (CNR) and the Italian Space Agency, with the University of Florence and QTI Srl, focuses on a challenge for future quantum networks: transmitting information securely not only through optical fibers, but also through the air, between buildings, ground stations, and potentially over large distances to satellites.
“The development of quantum communications represents one of the most advanced frontiers for the space sector, particularly for cybersecurity applications,” says Giancarlo Varacalli, head of the Italian Space Agency’s Telecommunications and Navigation Office. “The possibility of using new regions of the optical spectrum to transmit quantum keys from satellites opens up exciting prospects for making future secure telecommunications networks more flexible and efficient. Collaboration with CNR-INO is therefore essential for exploring new solutions and facilitating the transition from research to potential applications in the space sector.”
The findings are part of the European Quantum Infrastructure (EuroQCI) initiative, which aims to develop a network for secure quantum communications. The use of mid-infrared radiation could offer new opportunities to make quantum links more efficient and available, contributing to the distribution of cryptographic keys to secure communications.
The research stems from the collaboration between ASI and CNR-INO in the field of quantum technologies, consolidated in recent years through several national and European research projects. These include the PRIN QUAQK project, the Q-ASINO agreement, dedicated to joint ASI-CNR activities on quantum technologies coordinated by Dr. Mario Siciliani de Cumis, and the European project QUID – “Quantum Italy Deployment.”