Andrés Martínez, Andrea Melloni, and Francesco Morichetti from the Department of Electronics, Information and Bioengineering - Politecnico di Milano are among the developers of an innovative optical receiver capable of restoring chaotic signals distorted by atmospheric turbulence in free-space optical links. Thanks to a system of optical antennas integrated into a programmable photonic chip, the receiver adapts in real time, maintaining signal integrity even under challenging weather conditions.
The study, carried out in collaboration with Télécom Paris, has just been published in Light: Science & Applications and paves the way for chaos-based encryption, enabling secure and high-speed communications in hostile environments.
The principle behind secure communications using chaos involves encoding a secret message into a light signal that appears so unpredictable and complex that it becomes nearly impossible to decipher. However, when these chaotic signals travel through real-world wireless environments, they face a major challenge: atmospheric turbulence. The result? Distorted transmissions and compromised security.
This study has found a solution to this issue. The breakthrough lies in a next-generation receiver that combines a system of micro-optical antennas integrated into a programmable photonic chip. The micro-antennas act like multiple “intelligent eyes,” capturing light from various angles, while the photonic chip reconfigures itself in real time to reassemble these fragments into a reliable and secure chaotic signal. The result is remarkable: even in the presence of heavy rain, wind, and pollutants, the signal can be fully recovered.
Why is this important? Chaos-based systems have an intrinsic advantage: their unpredictability makes them naturally secure. However, the very nature of atmospheric turbulence has long represented the main obstacle to wireless optical communications. The impact of this advancement goes beyond technological applications, opening up new possibilities for confidential communications even in extreme conditions.
This work has been supported by the Italian National Recovery and Resilience Plan (PNRR) of NextGenerationEU, under the “Telecommunications of the Future” partnership (PE00000001—“RESTART” program, Structural Project “Rigoletto” and Targeted Project “HePIC”), by the Direction Générale de l’Armement (DGA), the European Office of Aerospace Research and Development (FA8655-22-1-7032), and the Chair in Photonics. The research activity also involved Polifab, the micro- and nanofabrication facility of the Politecnico di Milano.
