Optical Parametric Oscillators, OPO’s, are mainly used as coherent sources, at wavelengths where no laser exists. They are also very useful when a tunable source is required. As they don’t exist in a compact form such as laser diodes, they have not found yet consumer applications, and they are mainly used for military or scientific applications. On chip, cm’s size Parametric Oscillator would be a game changer and should enable to address many additional applications in spectroscopy, communications, bio-medical studies and sensing. In the OPOINt project, we have gathered a consortium that has all the required expertise to realize such a source using the III-nitride platform and become a leader in the field. In the frame of the project we propose to develop the necessary technologies and demonstrate an integrated OPO pumped around 800 nm and covering all the telecom windows (1.2 – 1.7 µm). We will test different configurations with the objective of having threshold of a few Watts and an output power around 100 mW. This demonstration will be a world-first.

The issue of rapid global urbanization is seriously affecting all ecological systems, imposing new forms of mobility, production and distribution methods. Automotive and robotics are major segments of the industry that are today concerned with these important upheavals. The objective of this program is to participate to the development of these rapidly growing industrial sectors, by maturating imaging prototypes able to acquire 3D information on the landscape and the environment at high refreshing frame rates. The apparatus proposed herein provide real-time 3D vision to vehicles (both in civil and military context) and logistic equipment, addressing the needs of these growing markets, while employing newly accessible but scalable technological photonic solutions. The system of interest relies on a Metasurface-assisted Light imaging Detection and Ranging (LiDAR). It leverages on the light manipulation capabilities of active metasurfaces to improve the imaging frame rate, field of view and resolution. After exploring the basic possibilities offered by this new architecture, our proposal further extends knowledge and results obtained during an ERC PoC and a CNRS “prématuration” programs. Mapping the environment with ultrafast scanners allows to reach high frame rates and obtain fast response times. LiDAR techniques allow one to scan an environment to re-construct a point cloud that can be read or interpreted by robotic vision and defense systems. In this project, we introduce a new generation of LiDAR system, capable of outputting extremely high frame rates and outperforming the current technology. More specifically, we will mature a new solution for ultrafast, compact, and efficient LiDAR scanning modules, to reduce the size, weight, and high cost of traditional systems without sacrificing the imaging performances. We will pursuit the development leveraging from two distinct and patented technologies developed in our laboratory, namely GEN0 (passive) and GEN1 (active). The former GEN0 technology stems from a successful ERC proof-of-concept project in which we developed an ultrafast, high FoV metasurface-LiDAR. Such technology has been published in a high-impact journal and recognized by CNRS in the cnrs “letter of innovation”. The principle is to cascade a passive metasurface with an active beam scanner device (acousto-optical deflector) to generate an extremely wide field of view of 150X150 degrees. The latter GEN1, or the novel "dielectric metasurface" beam scanning modules are based on mature liquid crystal display (LCD) technology, modernized with a sub-wavelength pixel architecture to reach the metasurface regime. Our programmable metasurface can significantly outperform all conventional LC devices, which have traditionally been unsuitable for LiDAR applications. The combination of well-established Liquid Crystal display technology with sub-wavelength metasurface architectures is compatible with semiconductor foundries, thus providing a path to mass production of nanophotonic devices for large-scale markets such as automotive, robotics and compact devices. Our team has been recently honored by the iPhD award of innovation for our project “AUTONOM” dealing with an “Active Liquid Crystal Metasurface” for LiDAR scanning modules. The accomplishment of OCULAR project will mature our developed technology to be able to perform long-range LiDAR imaging device. These could be mounted on terrestrial an aerials vehicles, but also to be utilized in binoculars for compact, performant and robust in-field application.

MILAGaN aims at developing electrically pumped microdisk-lasers covering the UV-visible range based on group III-nitrides (Al,Ga,In)-N. Several applications are envisioned as a result of this project: water/air purification/disinfection, environmental sensing, and fabrication of ever more efficient white light sources. MILAGaN will focus his attention on solid state lighting because it is likely one of the most challenging issues of the century. Solid state lighting is rapidly expanding due to its better energetic efficiency compared to other technologies, and the huge energy savings that are expected. The only remaining limitation to its massive adoption is the price of light emitting diodes (LEDs). One solution is to reduce the number of LEDs in the lamp, and drive them under a larger current. Unfortunately, GaN-based LED have a reduced efficiency at larger currents, and then loose part of their energetic bonus and interest. While this effect is believed to be intrinsic, it is related to spontaneous emission and can be largely suppressed in stimulated emission sources, i.e. in lasers. Among the various laser geometries, the microdisk laser is well-suited for this application. Based on the consortium know-how on GaN-on-Si, we will develop electrical µdisk lasers emitting in the UV/blue, and pumping phosphors, as in conventional white LEDs, to emit white light. Microdisks will be fabricated in arrays and driven in parallel in order to achieve a high optical power. First prototypes will then help to assess very important issues such as cost of devices, thermal management, losses, lifetime and robustness of this new technology. But of course the main challenge is first to fabricate the electrical devices. Microdisks have been developed in nitrides for a long time for optical pumping, large resonance quality (Q) factors have been demonstrated and laser action has been achieved. The difficulty is to reproduce the same features with electrical pumping, which is completely novel and challenging. Our consortium gathers four partners with complementary expertise in France, and one partner in Hong Kong. French partners have been collaborating for a while on nanophotonics and have a good track record in producing state of the art photonic crystals, µdisks, and planar cavities in nitrides, with record Q factors, strong coupling and polariton lasers. However, they lack experience in electrically injected µdisks and white light sources, and for this reason, the help of a Hong Kong partner has been sought in the frame of a PRCI project. The University of Hong Kong has experience in µdisks, implementation of phosphors for white light sources and in electrically injected nanodevices. This complementarity allows one proposing a complete process from epitaxy to phosphor deposition, with state of the art players. The objective is to assess the potential of µdisks lasers for solid state lighting and identify problems and limitations. Obtaining high performance white sources based on µdisks competing with existing white LEDs, which have experienced 2 decades of optimization by large industrial companies, is obviously outside the scope of an ANR project. The impact of the project will be reinforced by the international nature of the project, and also by having all partners being members of GaNeX, which already supports MILAGaN’s objective. Also, the company Aledia and the startup EasyGaN, a young spin-off from CRHEA, both developing nitride-based technologies on silicon for optoelectronics, are interested in the project.

Flat panel displays constitute the basis of many mass-production optoelectronic devices, including smart phones, notebooks, laptops and flat screens in general. Most of these devices are based in liquid crystal displays or in organic light-emitting diodes, and employ active-matrix control based on thin-film transistors (TFTs). These transistors allow to address singular pixels with a faster response time and with a reduced power consumption compared to other competing solutions. In this field, the current materials solution is hydrogenated amorphous silicon (a-Si:H), which enables to fabricate TFTs exhibiting field-effect mobilities in the order of 1 cm2/V·s. Unfortunately, such low mobilities do not meet the actual industrial needs, which require TFT backplanes with mobilities in the order of 20 cm2/V·s. Besides an enhanced mobility, next-generation TFTs will also need to meet more stringent requirements in terms of threshold voltage stability. The goal of ZONE is to provide a new materials solution to these problems based on ZnMg-oxynitrides (ZnMgNO) and to demonstrate TFTs with figures of merit better than the best reported to date at the research laboratory level (i.e. TFTs based on amorphous ZnNO showing field effect mobilities of 100 cm2/V·s and published by SAMSUNG ELECTRONICS in 2016). To achieve this ambitious technological objective we plan to grow new oxynitride materials by molecular beam epitaxy and by sputtering, which is the technique of choice of TFTs industry, in both crystalline and amorphous forms: this will give us the opportunity to determine the fundamental physical properties of ZnMgNO compounds, which are barely known (in many cases unknown), and to assess their evolution when going from single-crystalline, to polycrystalline and finally to amorphous material. Indeed, it should be noted that only amorphous ZnNO has been studied and this because of its promising electronic properties. To carry out this phenomenal work, ZONE will bring together two complementary teams recognized as specialist of MBE growth (CRHEA-CNRS, in France) and sputtering deposition (U. Leipzig, in Germany). Furthermore, their complimentary expertises and experimental facilities in terms of materials characterization will enable to cover the whole range of physical properties, including structural, optical and electrical ones. In particular, the more advanced transistors will be fabricated in CRHEA’s clean-room while their thorough electrical characterization, including light/bias stress tests, will be done in U. Leipzig. Overall, ZONE is a timely a project marrying fundamental research on materials science and realistic technological implementation.