Reconfigurable Flat Optics with Programmable Reflection Amplitude Using Lithography-Free Phase-Change Materials Ultra Thin Films

We experimentally demonstrate a very large dynamic optical reflection modulation from a simple unpatterned layered stack of phase-change materials ultrathin films. Specifically, we theoretically and experimentally demonstrate that properly designed deeply subwavelength GeSbTe (GST) films on a metallic mirror produce a dynamic modulation of light in the near-infrared from very strong reflection (R>80%) to perfect absorption (A > 99,97%) by simply switching the crystalline state of the phase-change material. While the amplitude of modulation can lead to an optical contrast up to 10^6, we can also actively "write" intermediate levels of reflection in between extreme values, corresponding to partial crystallization of the GST layer. We further explore several layered system designs and provide guidelines to tailor the wavelength efficiency range, the angle of operation and the degree of crystallization leading to perfect absorption

A fabrication process for emerging nanoelectronic devices based on oxide tunnel junctions

Abstract : We present a versatile nanodamascene process for the realization of low-power nanoelectronic devices with different oxide junctions. With this process we have fabricated metal/insulator/metal junctions, metallic single electron transistors, silicon tunnel field effect transistors, and planar resistive memories. These devices do exploit one or two nanometric-scale tunnel oxide junctions based on TiO2, SiO2, HfO2, Al2O3, or a combination of those. Because the nanodamascene technology involves processing temperatures lower than 300°C, this technology is fully compatible with CMOS back-end-of-line and is used for monolithic 3D integration

Broadband Fourier-transform silicon nitride spectrometer with wide-area multiaperture input

4 pags., 5 figs.Integrated microspectrometers implemented in silicon photonic chips have gathered a great interest for diverse applications such as biological analysis, environmental monitoring, and remote sensing. These applications often demand high spectral resolution, broad operational bandwidth, and large optical throughput. Spatial heterodyne Fourier-transform (SHFT) spectrometers have been proposed to overcome the limited optical throughput of dispersive and speckle-based on-chip spectrometers. However, state-of-the-art SHFT spectrometers in near-infrared achieve large optical throughput only within a narrow operational bandwidth. Here we demonstrate for the first time, to the best of our knowledge, a broadband silicon nitride SHFT spectrometer with the largest light collecting multiaperture input (320 × 410 µm) ever implemented in an SHFT on-chip spectrometer. The device was fabricated using 248 nm deep-ultraviolet lithography, exhibiting over 13 dB of optical throughput improvement compared to a single-aperture device. The measured resolution varies between 29 and 49 pm within the 1260-1600 nm wavelength range.Spanish Ministry of Science and Innovation (MICINN) (RED2018-102768-T, RTI2018-097957-B-C33, TEC2015-71127-C2-1-R (FPI Scholarship BES-2016-077798)); Community of Madrid-FEDER funds (S2018/NMT-4326); Horizon 2020 Research and Innovation Program (Marie Sklodowska-Curie 734331); H2020 European Research Council (ERC POPSTAR 647342); European Commission (H2020- ICT-26127-2017 COSMICC 688516); French Industry Ministry (Nano2022 project under IPCEI program); Agence Nationale de la Recherche (ANR-MIRSPEC-17-CE09-004

Dual-band fiber-chip grating coupler in a 300 mm silicon-on-insulator platform and 193 nm deep-UV lithography

4 pags., 5 figs., 1 tab.Surface grating couplers are fundamental building blocks for coupling the light between optical fibers and integrated photonic devices. However, the operational bandwidth of conventional grating couplers is intrinsically limited by their wavelength-dependent radiation angle. The few dual-band grating couplers that have been experimentally demonstrated exhibit low coupling efficiencies and rely on complex fabrication processes. Here we demonstrate for the first time, to the best of our knowledge, the realization of an efficient dual-band grating coupler fabricated using 193 nm deep-ultraviolet lithography for 10 Gbit symmetric passive optical networks. The footprint of the device is 17 × 10 µm. We measured coupling efficiencies of −4.9 and −5.2 dB with a 3-dB bandwidth of 27 and 56 nm at the wavelengths of 1270 and 1577 nm, corresponding to the upstream and downstream channels, respectively.Spanish Ministry of Science, Innovation and Universities (MICINN) (RTI2018-097957-B-C33, TEC2015-71127-C2-1-R with FPI Scholarship BES-2016-077798); Community of Madrid - FEDER funds (S2018/NMT-4326); Horizon 2020 Research and Innovation Program (Marie Sklodowska-Curie 734331); H2020 European Research Council (ERC POPSTAR 647342); European Commission (H2020- ICT-26127-2017 COSMICC 688516); French Industry Ministry (Nano2022 project under IPCEI program); Agence Nationale de la Recherche (ANR-MIRSPEC-17-CE09-0041)

Optimization of an electret-based soft hybrid generator for human body applications

WOS:00048411360000

Système de mesure d'un niveau de puissance d'une source d'énergie ambiante

L'invention concerne un système comportant un ou plusieurs modules de mesure (101) comprenant chacun : - un générateur électrique (201) à récupération d'énergie ambiante ; - un élément capacitif (211) de stockage de l'énergie électrique produite par le générateur ; et - un circuit actif (221) adapté à émettre un signal radio d'indication d'évènement à chaque fois que la tension aux bornes de l'élément capacitif (211) dépasse un seuil, le système comprenant en outre une unité de réception adaptée à recevoir les signaux d'indication d'évènement émis par chaque module (101), et adaptée à mesurer une grandeur temporelle représentative de la cadence d'émission des signaux d'indication d'évènement par le module (101)

Générateur électrostatique embarqué à électret parylène et polymère électro-actif

International audienceDans ce travail, nous présentons un prototype de générateur électrostatique souple pouvant être incorporé au niveau du genou pour produire de l'énergie lors de la marche ou de la course à pied. Ce générateur, complètement autonome, s'appuie sur l'incorporation d'un électret qui joue le rôle de réservoir de charges et d'un polymère électroactif de type silicone. L'originalité vient du matériau électret constitué d'un polymère de la famille des parylènes fluorés et de la géométrie du dispositif permettant à la fois d'optimiser les performances mécaniques et électriques de la structure

Contribution to the design of soft hybrid generators: combination of electroactive polymers

International audienc

Coupling of Electro-active Polymers for Energy Harvesting Applications

International audienceHarvesting human kinetic energy to produce electricity is an attractive alternative to batteries for applications in wearable electronic devices and smart clothing. Among the different technologies, electrostatic converters represent one of the most promising method for this application. This paper presents a soft electret-based energy harvesting device which exploits human body movement as energy source to produce electricity. The device consists on an electret polymer coupled with an elastomeric deformable membrane. The impact of the characteristics and properties of materials on the power output of the device was evaluated leading to the best choice for materials: Sylgard 186 as elastomeric membrane and Parylene C as electret. The experimental results of the performance of Parylene C as electret polymer are presented and discussed

Harvesting human kinetic energy by electret-based soft generators

International audienc