On October 20th, 2023 at 11.00 am Frédéric Grillot, Full Professor at the Institut Polytechnique de Paris (France) and a Research Professor at the University of New-Mexico (USA). will hold a seminar on "Mid- and Long-Wave Infrared Optoelectronics for Free-Space Optical Communications" in DEIB Seminar Room "Nicola Schiavoni" (Building 20).

Free-space optics offer an attractive alternative for broadband data transmission when fiber optics are neither practical nor feasible. This technology has emerged as a strong candidate with a wide range of potential applications from everyday broadband internet to satellite links. Today, the availability of high-quality transmitters and detectors operating in the near-infrared window makes the 1.55-micron optical wavelength the natural choice for free-space optical systems. However, the atmospheric transmission spectrum has two other transparency windows that can be considered namely one between 3 and 5 microns and the other between 8 and 11 microns. In this context, mid-infrared quantum cascade devices have become prime candidates for data transmission applications, especially in fog or haze, where they significantly outperform near-infrared and visible light sources. In addition, atmospheric turbulence in the propagation path severely degrades the optical signal by causing beam spreading and wandering, scintillation or loss of spatial coherence. In this seminar, I will review our recent results on free-space optical communications, which have shown that quantum cascade lasers can be used as unpredictable light sources for data security, using complex photonic chaos for message encryption and synchronized chaos for message transmission. Between 8 and 11 microns, this technology is even more interesting because the random thermal background radiation of the blackbody further complicates the task of deciphering a potential spy, meaning that communication is even more secure.
My presentation will also cover our recent advances in multi-gigabit-per-second room temperature data transfer based on mid-infrared quantum optoelectronics. While these results can profoundly revolutionize the future of free-space laser communications, the ultimate goal, however, will be to implement this new optoelectronic technology in an actual outdoor testbed, especially to prove the superiority of the mid and long wave infrared domains.

Frédéric Grillot is currently a Full Professor at the Institut Polytechnique de Paris (France) and a Research Professor at the University of New-Mexico (USA). His research interests include, but are not limited to, advanced quantum confined devices using III-V compound semiconductors, quantum dots quantum dashes, light-emitters based on intersubband transitions, non-classical light, nonlinear dynamics and optical chaos in semiconductor lasers systems as well as microwave and silicon photonics applications. He strongly contributes to promote and support the development of the general optics community. He has served diligently and successfully Optica in particular as an Associate Editor of Optics Express, now as a Deputy Editor since September 2022. As of now, Professor Grillot has published more than 132 journal articles, 3 book chapters, and delivered many invited talks in major international conferences and workshops. He is also a Fellow Member of the SPIE as well as a Senior Member of Optica and the IEEE Photonics Society. In 2022, he received the IEEE Photonics Society Distinguished Lecturer Award which recognizes individuals who have made technical, industrial or entrepreneurial contributions to the field of photonics.