News : Engineering sciences

January 01 2023

Study of sidewall physical mechanisms involved in GaN µ-LEDs performance

In the Optics and Photonics division of CEA-LETI, The Emissive Components Laboratory designs and fabricates micro-displays based on GaN micro-LEDs. One of the major issue of GaN µ-LEDs is the decrease of their efficiency with the size reduction. In literature, this degradation is attributed to SRH (Shockley-Read-Hall) non-radiative recombinations on pixel sidewalls, in defects induced […] >>

January 01 2023

Development of Holographic Optical Elements Arrays with a micro-hologram printer

CEA Leti has conceived a holographic printer as part of its development of optical components and systems for the field of Augmented Reality. This printer allows us to record micro-holograms that encode elementary angular functions. The current application of the printer concern the development of pixelated holograms recorded with phase and angular matching for the […] >>

January 01 2023

Advanced side channel applied on post-quantum cryptography

The development of quantum computing threatens asymmetric cryptography. To address this threat, post-quantum cryptography (PQC) schemes, i.e. based on quantum computer resistant problems, have been proposed. The third round of the NIST PQC competition ended on July 5, 2022. The CRYSTALS-Kyber algorithm was selected for standardization. The history of cryptographic algorithms standardization shows that it […] >>

January 01 2023

Improvement of the contrast of photoplethysmographic measurements for the monitoring of physiological parameters

Photoplethysmography (PPG) is a non-invasive optical technique for detecting temporal variations in blood volume in tissues. PPG is used to monitor physiological parameters such as heart rate, pulse oximetry and blood pressure. PPG is a widely used method in physiological measurement systems, whether for consumer connected objects (smart watches, smartphones) or medical systems (oximeters). Even […] >>

January 01 2023

Programmable electromagnetic (meta)surfaces at sub-THz frequencies

Spatiotemporal manipulation of the near- and far-electromagnetic (EM)-field distribution and its interaction with matter in the THz spectrum (0.1-0.6 THz) is of prime importance in the development of future communication, spectroscopy, imaging, holography, and sensing systems. Reconfigurable Intelligent (Meta)Surface (RIS) is a cutting-edge hybrid analogue/digital architecture capable of shaping and controlling the THz waves at […] >>