KAPTEOS

Le Bourget-du-Lac, France
Le Bourget-du-Lac, France

Time filter

Source Type

Ayde R.,University Claude Bernard Lyon 1 | Gaborit G.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Jarrige P.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Duvillaret L.,Kapteos | And 3 more authors.
IEEE Sensors Journal | Year: 2013

In this paper, we demonstrate the use of a LiTaO3 crystal associated with a typical nuclear magnetic resonant loop coil to perform an optically remote radio frequency magnetic-field characterization. The whole transduction scheme is theoretically and experimentally studied. The measurement dynamics reaches 60 dB. The minimum detectable magnetic field is lower than 1 nT, which corresponds to an induced inner crystal electric field as low as 30 mV/m. To evaluate the spatial potentialities of the sensor, a 1-D mapping of the field along an asymmetric butterfly-shaped loop coil is performed. The result is in good agreement with finite-difference time-domain simulations and demonstrates the vectorial behavior of the sensor device. © 2001-2012 IEEE.


Perret E.,Grenoble Institute of Technology | Hamdi M.,University of Savoy | Vena A.,Grenoble Institute of Technology | Garet F.,University of Savoy | And 3 more authors.
Radioengineering | Year: 2011

This article presents two chipless RFID approaches where data are reading using electromagnetic waves and where the medium encoding the data is completely passive. The former approach rests on the use of RF waves. The tags are comparable with very specific, planar, conductive, radar targets where the relation between the tag geometry and its electromagnetic signature is perfectly known and is used to encode the data. The data storage capacity of the RF chipless tags is proportional to of the used frequency bandwidth. As radio spectrum is regulated, the number of possible encoding bits is thus strongly limited with this technology. This is the reason why we introduce a new family of tags radically different from the preceding one, where data is encoded in volume thanks to a multilayer structure operating in the THz domain. These two approaches although different are complementary and allow to increase significantly the data storage capacity of the chipless tags. Simulation and experimental results are reported in this paper for both configurations. We demonstrate a coding capacity of 3.3 bit/cm2 for RFID chipless tags and a potential 10 bits coding capacity in the THz domain.


Gillette L.,University of Savoy | Gaborit G.,University of Savoy | Grau A.,Électricité de France | Giraud F.,Électricité de France | And 2 more authors.
34th Electrical Insulation Conference, EIC 2016 | Year: 2016

We present herein a compact wattmeter clamp for measuring electric field and magnetic field in monoconductor and multiconductor cables. The clamp allows the diagnostic of low voltage and low frequency equipments. This device performs the electric and magnetic field measurement surrounding a multiconductor power cable and permits to deduce amplitude, phase and position of each conductor in the cable. Performances of this system and experimental results have been investigated and experimentally characterized in real industrial environment. © 2016 IEEE.


Gaeremynck Y.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Gaborit G.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Duvillaret L.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Ruaro M.,Kapteos | Lecoche F.,Kapteos
Applied Physics Letters | Year: 2011

Based on an isotropic electro-optic crystal, a two-port pigtailed electro-optic sensor has been built. The probe allows to measure two orthogonal components of the ambient electric field. The sensor intrinsically presents a temperature-dependent free response. The two measured electric field components are orthogonal to the sensor revolution axis, leading to a transverse electro-optic probe. Magnitude and orientation of the electric field are measured simultaneously with an accuracy of 0.5 dB and 2°, respectively. The rejection of orthogonal components to the electric field vector reaches 30 dB. © 2011 American Institute of Physics.


Warzecha A.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Gaborit G.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Ruaro M.,Kapteos | Duvillaret L.,Kapteos | Lassere J.-L.,Directorate General of Armaments
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Electro-optic measurement (EO) constitutes an efficient technique to characterize electrical (E) fields : indeed, the Pockel's effect properties (linear modification of refractive indices of some non-centrosymetric crystals induced by the E-field)1 leads to a vectorial measurement. Thus, it allows to map the E-field vector and its transient evolution, either in free space or inside guiding structures. Pigtailed EO sensors are naturally becoming a reliable and consistent mean of characterization for many applications, e.g. high power microwaves (HPM), electromagnetic interference (EMI), on chip diagnostic, bio-electromagnetism (e.g. influence of mobile phones on the human body). Even if these non-invasive sensors provide a greater temporal and spatial resolution (femtosecond and sub-millimeter, respectively) than commonly used sensors (antennas, bolometers), it remains temperature dependant and quite low sensitive. EO probes are based on the modification of a laser beam (either its polarization, phase or amplitude) crossing an EO crystal. We demonstrate here the last developments and improvements for EO probes as well as for whole EO setups, exploiting polarization state or amplitude modulation. The sensor is constituted by a polarization maintaining (PM) fiber carrying the beam to the crystal and taking it back once modulated, gradient index lense(s) managing the shape of the beam, half or quarter wave plate controlling the input and output polarizations and a crystal (either anisotropic: LiTaO3, LiNb03, DAST, KTP or isotropic : ZnTe, InP) converting the E-field into a modulation. Our probes are fully dielectric and cylindrically shaped (length ∼ 1 cm and diameter ∼ 2-3 mm). The setup is made of a 1.5 μm DFB laser, some photodiodes (low and high speed) added with a polarization state analyser arrangement in case of EO probes based on polarization state modulation scheme. The measurement bench is fully automated and compensate/measure the temperature deviation simultaneously. Sensitivity of our EO probe reaches 0.7 V.m-1Hz-1/2, the bandwidth covers an ultra wide frequency band (kHz - and more than 20 GHz), the selectivity (orthogonal E-field components rejection) is about 25 dB, and a spatial resolution greater than 100 μm is achieved. Transient and frequency measurements and 2D E-field mapping will be presented during the conference. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Gaborit G.,CNRS Institute for Microelectronics, Electromagnetism, and Photonics: Hyperfrequency and Characterization lab | Jarrige P.,Kapteos | Lecoche F.,Kapteos | Dahdah J.,Kapteos | And 3 more authors.
IEEE Transactions on Plasma Science | Year: 2014

In this paper we illustrate the ability of electrooptic sensors to perform electric (E)-field vectorial measurements. Thanks to their frequency response spreading over nine decades and to their measurement dynamics reaching 120 dB, these sensors are of high interest for some applications (near field mapping, energy line monitoring, electromagnetic compatibility, and so on). Furthermore, due to their fully dielectric structure and millimetric size, almost no perturbation is induced on the E-field to be measured, even in the near field region. This paper is focused on high-intensity pulsed E-field characterization in different environments such as air, water (bioelectromagnetism applications), or plasmas (in situ assessment of the E-field associated to an electric discharge and to the induced plasma). The use of such a technology for electrical equipment and energy line monitoring is also investigated. © 1973-2012 IEEE.


Guyot C.,CNRS Femto ST Institute | Ulliac G.,CNRS Femto ST Institute | Dahdah J.,Kapteos | Qiu W.,CNRS Femto ST Institute | And 3 more authors.
Optics Letters | Year: 2014

In this Letter, we report a technique to etch giant aspect ratio nanostructures in lithium niobate. An 8 μm long Bragg grating on a Ti:LiNbO3 ridge waveguide was fabricated by combining optical-grade dicing and focused ion beam milling. The reflectivity was evaluated using an optical coherence tomography system: it is measured to be 53% for the TM wave and 47% for the TE wave. We study by 2D-FDTD the modeled behavior of the electromagnetic field when an angle exists between two consecutive sidewalls of the grating in order to understand the difference between ideal Bragg grating and experimental samples. These simulations allow us to optimize the parameters in order to increase the reflection of the grating up to 80%. © 2014 Optical Society of America.


Kone G.,University of Quebec at Chicoutimi | Volat C.,University of Quebec at Chicoutimi | Ezzaidi H.,University of Quebec at Chicoutimi | Duvillaret L.,Kapteos
34th Electrical Insulation Conference, EIC 2016 | Year: 2016

This paper presents an experimental investigation of semi-conductive internal defects present in a 69 kV composite insulator based on E-field measurements. For this purpose, an electro-optic sensor with compact E-field probe was used. In order to simulate the presence of internal defects, an experimental 69 kV composite insulator was specially developed using 3D printing. The results demonstrate that the proposed 69-kV experimental model obtained from 3D printing can be a new alternative for adequate simulation and study of internal defects present in composite insulators. Moreover, these results also show that the actual E-field method used for detecting internal defects can be considerably improved by measuring the radial E-field component close to the rod sheath surface, between insulator sheds. Using this approach, semi-conductive defects with a length equal to 3.5% of the insulator length can be detected both at the HV electrode and floating potential, with is a significant improvement of the sensitivity of actual E-field detection method. © 2016 IEEE.


PubMed | Kapteos, University of Rome Tor Vergata and ENEA
Type: | Journal: Scientific reports | Year: 2016

We describe the first electro-optical absolute measurements of electromagnetic pulses (EMPs) generated by laser-plasma interaction in nanosecond regime. Laser intensities are inertial-confinement-fusion (ICF) relevant and wavelength is 1054nm. These are the first direct EMP amplitude measurements with the detector rather close and in direct view of the plasma. A maximum field of 261kV/m was measured, two orders of magnitude higher than previous measurements by conductive probes on nanosecond regime lasers with much higher energy. The analysis of measurements and of particle-in-cell simulations indicates that signals match the emission of charged particles detected in the same experiment, and suggests that anisotropic particle emission from target, X-ray photoionization and charge implantation on surfaces directly exposed to plasma, could be important EMP contributions. Significant information achieved on EMP features and sources is crucial for future plants of laser-plasma acceleration and inertial-confinement-fusion and for the use as effective plasma diagnostics. It also opens to remarkable applications of laser-plasma interaction as intense source of RF-microwaves for studies on materials and devices, EMP-radiation-hardening and electromagnetic compatibility. The demonstrated extreme effectivity of electric-fields detection in laser-plasma context by electro-optic effect, leads to great potential for characterization of laser-plasma interaction and generated Terahertz radiation.


Patent
Électricité de France and Kapteos | Date: 2014-05-28

The invention concerns a method for measuring the voltage of at least one conductor (121, 122, 123) of an electrical power cable (10) comprising the following steps: providing a container (22) made from a conductive material around a portion of the cable and at least one electric field sensor (301, 302, 303, 304) between the container and the cable; bringing the container to a constant potential and measuring the electric field by means of the sensor; and determining said voltage by comparing the measured electric field with electric fields simulated for a plurality of configurations of punctual electric charges.

Loading KAPTEOS collaborators
Loading KAPTEOS collaborators