In the D-FACTO project, we propose to design and fabricate active optical windows based on nanostructured diamond, combining anti-reflective, superhydrophobic, anti-icing and anti-fouling properties. This research project is motivated by the very promising results obtained within the framework of the ANR ASTRID F-MARS project (2019-2022), coordinated by Thales Research & Technology (TRT). In this project, TRT has already shown its capability to simulate and manufacture “multifunctional” windows with broadband anti-reflective and large incidence, superhydrophobic and anti-rain properties in the range of Visible, Midwave InfraRed. and Longwave InfraRed, by developing nanostructuration processes of glass, silicon and germanium respectively. These optical windows aim to meet the needs of many optical and optronics systems used in civil and military fields: land and sea surveillance systems, airborne sensors for threat detection, autonomous train cameras, etc. However, the superhydrophobic nature of these windows, which is fundamental for some of these applications, does not protect these systems, for example, from the formation of various biofilms (marine, hydrocarbons, etc.), nor from the formation of frost. The aim of the D-FACTO project is to extend the multifunctionality of these optical surfaces, by developing robust “active” diamond windows allowing them to be get anti-fouling and anti-ince properties, by using a low current. electrical, coupled (or not) with adequate surface functionalization. Indeed, diamond has intrinsic qualities of interest: in addition to having very good mechanical properties, it is transparent in the ranges from visible to LWIR and it is an excellent thermal conductor. Once doped, it has remarkable electrochemical properties, among which the capacity for electrochemical self-cleaning of its surface and therefore anti-fouling properties. The work of the consortium, composed of two academic partners, CEA-LIST and ILV, and an industrialist (TRT), will first focus on the development of pre-industrial processes for producing optical windows based on synthetic diamond which will benefit from its optical, mechanical and physicochemical "flexibility" advantages for anti-fouling, anti-ince and anti-reflective applications. They will also focus on the understanding and optimizationof the phenomena involved in the self-cleaning and anti-icing mechanisms of these so-called "active" windows. The manipulation of surfaces by electrochemistry of diamond, or else by more conventional surface treatments, should make it possible to modulate its omniphobic capacities. The consortium will thus have various very original functionalization possibilities for optimal physicochemical adaptation. Considering the state of the art, the challenges of the D-FACTO project are the following: • to develop a large area (2-3 inches) process of diamond nanostructuring for anti-reflective applications in Vis, MWIR and LWIR. • to characterize and optimize the growth of doped diamond by taking into account the application constraints (compliance with optical specifications, nature of the substrates in the case of diamond / silicon, diamond / germanium “hydride” windows, etc.). • to optimize the physicochemical properties of the post-nanostructuring process diamond surface and to develop specific chemical engineering based on various surface treatments: “electroless” chemistry, electrochemical assistance, plasma process, etc. • Set up a robust characterization methodology, able of combining fine wettability analysis and chemical analysis by photoemission or Auger emission of diamond, in order to guide the consortium in optimizing the functionalization of nanostructures.

In PANASSE project, we aim at developing planar networks of nanowires as vacuum electron sources. By adopting a planar integration scheme, our approach will allow numerous technological bolts to be unlocked in order to produce efficient sources. Indeed, compared to classical tip emitter based cold cathode technology, planar nanowires based cold cathode would offer enhanced thermal management, variability control, efficiency, cost reduction, large surface production, etc. We already demonstrated proof-of-concept about such planar emission structures with main features being efficient backgate control of current emission and need for high permittivity material partial passivation of nanowires. In PANASSE project, we will focus on single nanowire device fabrication in order to define best routes for size reduction and control as well as passivation optimization. In parallel, this structure will allow for testing quantum confinement effect related with nanowire dimensions. Planar configuration will give access to a new panel of near field characterization, otherwise impossible considering tip emitter with out-of-plane configuration. Field emission characterization on single elements will be performed in parallel. Results combination on these two methods will be valuable for making decision about key features to be taken into account for rest of the project. After this first step, arrays of nanowires will be processed to form collective emission cathode components that will allow for ameliorating process routes on large emitter numbers. Device performances will be correlated with process in order to assess technological options. Progressive upscaling and cathodes emission performance will be continuously pursued and compared to single emitters performances in order to maximize chances to reach high current delivering cathodes. Post emission characterizations will be performed at different scale levels (from single emitters to full emission zone) with conclusions being highly valuable inputs for whole processes control and improvement. After this step reached,partners efforts will be dedicated to produce cathodes on large surface (4 inches) wafers while maintaining high performance on individual processed cathodes, paving the way to large production scheme. PANASSE work focuses on production of innovative field emission structure for future compact X-ray imaging systems, and in particular computed tomography equipment for 3D reconstruction. Various applications in industry, security and medicine could emerge from this concept with no alternative based on nowadays technologies. But if field emission is set as a user case for defining PANASSE framework, related results and developments can be basis for numerous other applications because we treat about generic topics of large area processing for planar nanoelements assemblies and high-quality thin dielectric films. These outputs will be valorized by each partners and the presence on a worldwide leader company in critical systems (electronics, optics, radiofrequency, etc.) such as Thales offers effective opportunities for technological transfer in industry with large impact on society.

SPACESENSE project deals with the development of a strain sensor directly printed on structures for space applications. In this project, we will print sensors directly on the part that needs to be monitored over time. This technique enables a direct contact between the object and the sensor, avoiding any extra material that could alter measurements. Considering that we will achieve an autonomous sensor we will work also on a multimodal harvesting system based on efficient pyroelectric ceramic materials, perfectly adapted to the large temperature changes experienced by satellites, and photovoltaic cells. Space compatible Supercapacitor and Microbatteries will be developed in parallel (answering specific requirements in terms of radiation resistance and temperature interval). The integrated electronics, able to manage the sensor and the energy harvesting, will be embedded in the final sensors and will be compatible with harsh environment. This approach will enable a very compact design, which improves reliability and will allow to develop a new generation of completely autonomous sensors.

The goal of DIFOOL project is to demonstrate an ultra-low noise frequency synthesis based on coupled opto electronic oscillators (COESs) and high-frequency low-noise frequency dividers. MINOTOR project showed that passive or active optical resonators combined with an adapted laser source is a promising way to improve performances of OEOs as they allow a direct oscillation at high frequency within a significantly compact volume, especially when compared to optical-fiber-delay based OEOs. Within MINOTOR, we indeed demonstrated a COEO at 10 GHz, with performances close to that of OEwaves (best commercial product) using French- of European-only components. Quartz-based oscillators are now reaching their limits in terms of performances and availability of high-grade materials. As such, opto electronic oscillators represent a promising alternative for next generation civil or military RF systems (improvement of sensitivity for radar and electronic warfare systems, higher bandwidth for telecommunication and improved stability and precision for positioning and navigation). However, system analysis has shown that those OEOs could greatly benefit from the association with synthesis components well suited to their specificity. Within this “Astrid Maturation” project « DIFOOL », we will realize a compact high-frequency (up to 30 GHz) COEO demonstrator (TRL 4) and a low-noise high-frequency divider (TRL5), which, when combined, will allow the demonstration of a novel frequency synthesis principle with performances well above that of quartz synthesis. This project gathers all the required competencies through the following 5-partner consortium: Thales Research & Technology France (TRT - coordinator), one SME : OSAT, two academic labs (Laboratoire d’Analyse et d’Architecture des Systèmes and Laboratoire Aimé Cotton), and Thales Alenia Space. This project consists of 4 principal tasks. The first one will be devoted to the system analysis for a telecom payload application and the consequent requirements for oscillators and dividers. The 30 GHz COEO demonstrator will be designed and realized (TRL 4) within the second task, as well as, in parallel, a 10 GHz COEO, that will allow us to test different architectures. The third task is devoted to the analysis, design and realization of the high-frequency low-noise frequency divider (TFL 5). At last, the frequency division of the COEO will be demonstrated within the fourth task. Preliminary environmental tests and exploitation scheme will be conducted as well. Expected output for this project are : - Realization of 2 COEOs at 30 GHz and 10 GHz, as 2 compact breadboard at TRL4, exhibiting phase noise level of -120 to -125 dBc/H at 1kHz and -150 dBc/Hz at 100 kHz (floor) - Realization of several high-frequency low-noise frequency dividers, allowing to reach 1GHz (phase noise of 150dBc/Hz at 1 kHz, -170 dBc/Hz at 100 kHz) exhibiting TRL5 at the chip level and TRL4, when packaged in modules. - Demonstration at TRL4 of frequency synthesis combining COEOs and dividers. Those results will be exploited by OSAT -an SME which is specialized in technologies for RF synthesis for spatial applications- under the supervision of TAS -system makers in the space industry- and TRT which will bridge the gap with radar and electronic warfare applications that should benefit as well from those developments.