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73 results on '"El Hadi, K."'

1. The adaptive optics modes for HARMONI: from Classical to Laser Assisted Tomographic AO

Author

Neichel, B., Fusco, T., Sauvage, J. -F., Correia, C., Dohlen, K., El-Hadi, K., Blanco, L., Schwartz, N., Clarke, F., Thatte, N., Tecza, M., Paufique, J., Vernet, J., Louarn, M. Le, Hammersley, P., Gach, J. -L., Pascal, S., Vola, P., Petit, C., Conan, J. -M., Carlotti, A., Verinaud, C., Schnetler, H., Bryson, I., Morris, T., Myers, R., Hugot, E., and Gallie, A.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

HARMONI is a visible and NIR integral field spectrograph, providing the E-ELT's core spectroscopic capability at first light. HARMONI will work at the diffraction limit of the E-ELT, thanks to a Classical and a Laser Tomographic AO system. In this paper, we present the system choices that have been made for these SCAO and LTAO modules. In particular, we describe the strategy developed for the different Wave-Front Sensors: pyramid for SCAO, the LGSWFS concept, the NGSWFS path, and the truth sensor capabilities. We present first potential implementations. And we asses the first system performance., Comment: SPIE proceeding, 2016

Published
2018
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2. MOSAIC GLAO performance and system architecture: AO for the entire ELT focal plane

Author

Jackson, Kathryn J., Schmidt, Dirk, Vernet, Elise, Bharmal, Nazim Ali, Morris, Timothy J., Butterley, Timothy, Gill, Polly, Schmoll, Jürgen, Schwartz, Noah, Bramall, David, Davison, Christopher, Stephan, Jay, Artan, Raziye, Parr-Burman, Phil, Pello, R., Puech, M., Prieto, E., Rodrigues, M., Sanchez-Janssen, R., Dalton, G. B., Ducret, F., El Hadi, K., García-Vargas, M. L., and Lynn, J.

Published
2024
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3. MOSAIC on the ELT: front-end and instrument AITV planification

Author

Bryant, Julia J., Motohara, Kentaro, Vernet, Joël R. D., El Hadi, K., Chapuis, D., Prieto, E., Martin, L., Floriot, J., Dohlen, K., Challita, Z., Rodrigues, M., Larrieu, M., Dupieux, M., Castilho, B., Lewis, I., Dejonghe, J., Araujo, R., Thurneysen, M., Perez, A., Morris, Tim, Bharmal, A. N., Hottier, C., Janssen, A., Mohamed, M., Ducret, F., Puech, M., Pello, R., Dalton, G., Garcia Vargas, M., Lynn, J., and Sanchez-Janssen, R.

Published
2024
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4. Experimental implementation of a Pyramid WFS: Towards the first SCAO systems for E-ELT

Author

Bond, C., El Hadi, K., Sauvage, J. F., Correia, C., Fauvarque, O., Rabaud, D., Neichel, B., Fusco, T., Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Pyramid Wave-Front Sensor, [SDU]Sciences of the Universe [physics], Adaptive Optics
Abstract

International audience; Investigations into the Pyramid wavefront sensor (P-WFS) have experimentally demonstrated the ability to achieve a better performance than with a standard Shack-Hartmann sensor (SH-WFS). Implementation on the Large Binocular Telescope (LBT) provided the first operational demonstration on a facility-class instrument of a P-WFS on sky. The desire to implement a Pyramid on an Extremely Large Telescope (ELT) requires further characterisation in order to optimise the performance and match our knowledge and understanding of other wave-front sensors (WFSs). Within the framework of the European Extremely Large Telescope (E-ELT), the Laboratoire d'Astrophysique de Marseille (LAM) is involved in the preparation of the Single Conjugate Adaptive Optics (SCAO) system of HARMONI, E-ELT's 1st light integral field spectrograph (IFU). The current baseline WFS for this adaptive optics system is a Pyramid WFS using a high speed and sensitive OCAM2 camera. At LAM we are currently carrying out laboratory demonstrations of a Pyramid-WFS, with the aim to fully characterise the behaviour of the Pyramid in terms of sensitivity and linear range. This will lead to a full operational procedure for the use of the Pyramid on-sky, assisting with current designs and future implementations. The final goal is to provide an on sky comparison between the Pyramid and Shack-Hartmann at Observatoire de la Côte d'Azur (OCA). Here we present our experimental setup and preliminary results.

Published
2022

8. HARMONI at ELT: towards a final design for the Natural Guide Star Sensors system

Author

Angeli, George Z., Dierickx, Philippe, Dohlen, K., Vola, P., Challita, Z., Morris, T., Sauvage, JF, Jocou, L., Estrada, A., Louth, T., Bon, W., Dubbeldam, M., Montgomery, D., Gimenez, J-L, Viera Cuberlo, T., Charles, Y., Le Mignant, D., Carlotti, A., Pequeiras, J., El Hadi, K., Humphreys, W., Neichel, B., Fusco, T., Clarke, F., Melotte, D., and Thatte, N.

Published
2022
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9. In depth analysis of Fourier-based wavefront sensors with the adaptive optics testbed LOOPS

Author

Janin-Potiron, P., Chambouleyron, V., Schatz, L., Fauvarque, O., Bond, C. Z., Eduard Muslimov, El-Hadi, K., Sauvage, J. -F, Dohlen, K., Neichel, B., Correia, C. M., Villard, N., Aïssani, S., Taheri, M., Fusco, T., Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), University of Arizona, Institute for Astronomy, University of Hawai'i at Manoa, University of Victoria [Canada] (UVIC), André, Cécile, and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], pyramid wavefront sensor, Fourier-based wavefront sensors, ComputerSystemsOrganization_PROCESSORARCHITECTURES, spatial light modulator, [PHYS] Physics [physics], adaptive optics, optical bench
Abstract

International audience; The development and study of new, more robust and powerful wavefront sensors plays an important role in the improvement of the wavefront sensing capabilities of adaptive optics systems. The LAM-ONERA On-sky Pyramid Sensor is a R&D bench dedicated to study and characterize these new wavefront sensors. In this paper, we give a glance at the current status of the bench in terms of hardware and at the most recent results obtained using new flavours of Fourier filtering wavefront sensors.

Published
2019

10. Relationships between structural and optical properties of proton-exchanged waveguides on Z-cut lithium niobate

Author

Korkishko, Yu. N., Fedorov, V.A., Micheli, M.P. de, Baldi, P., El Hadi, K., and Leycuras, A.

Subjects
Waveguides -- Research, Protons -- Research, Photorefractive materials -- Research, Astronomy, Physics
Abstract

By using x-ray diffraction and optical waveguide characterization, it has been shown that proton-exchanged layers on Z-cut LiNb[O.sub.3] can have as many as seven different crystallographic phases that are stable at room temperature. This study allows us to establish some correlation between fabrication parameters and the crystalline structure, the index profiles, and the propagation losses of waveguides prepared by this process. Key words: Lithium niobate, proton exchange, waveguides.

Published
1996

11. MOSAIC: the ELT multi-object spectrograph

Author

Jagourel, P., Fitzsimons, E., Hammer, F., De Frondat Laadim, F., Puech, M., Evans, C.J., Sanchez, R., Guinouard, I., Chemla, F., Frotin, M., Yang, Y., Parr-Burman, P., Morris, T., Dubbeldam, M., Close, M., Middleton, K., Rousset, G., Gendron, E., Kelz, A., Janssen, A., Pragt, J., Navarro, R., Larrieu, M., El Hadi, K., Dohlen, K., Dalton, G., Lewis, I., Rodrigues, M., Morris, S., Kaper, L., Barbuy, B., Cuby, J.-G., Le Fèvre, O., Simard, L., Takami, H., Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), UK Astronomy Technology Centre, Royal Observatory Edinburgh (UKATC), Duke University [Durham], STFC Rutherford Appleton Laboratory, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Haute résolution angulaire en astrophysique, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Leibniz-Institut für Astrophysik Potsdam (IAP), TNO/TPD-Space Instrumentation, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Univ. of Oxford (United Kingdom), Amsterdam, Departamento de Astronomia, Universidade de São Paulo, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Computer science, business.industry, media_common.quotation_subject, Near-infrared spectroscopy, Phase (waves), Mosaic (geodemography), 01 natural sciences, 010309 optics, Optics, Conceptual design, Sky, 0103 physical sciences, Extremely Large Telescope, business, Adaptive optics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Spectrograph, media_common
Abstract

International audience; Following a successful Phase A study, we introduce the delivered conceptual design of the MOSAIC1 multi-object spectrograph for the ESO Extremely Large Telescope (ELT). MOSAIC will provide R 5000 spectroscopy over the full 460-1800 nm range, with three additional high-resolution bands (R 15000) targeting features of particular interest. MOSAIC will combine three operational modes, enabling integrated-light observations of up to 200 sources on the sky (high-multiplex mode) or spectroscopy of 10 spatially-extended fields via deployable integral-field units: MOAO6 assisted high-definition (HDM) and Visible IFUs (VIFU). We will summarise key features of the sub-systems of the design, e.g. the smart tiled focal-plane for target selection and the multi-object adaptive optics used to correct for atmospheric turbulence, and present the next steps toward the construction phase.

Published
2018

12. The ELT-MOS (MOSAIC)

Author

Morris, S., Hammer, F., Jagourel, P., Evans, C.J., Puech, M., Dalton, G.B., Rodrigues, M., Sanchez-Janssen, R., Fitzsimons, E., Barbuy, B., Cuby, J.-G., Kaper, L., Roth, M., Rousset, G., Myers, R., Le Fèvre, O., Finogenov, A., Kotilainen, J., Castilho, B., Ostlin, G., Feltzing, S., Korn, A., Gallego, J., Castillo Morales, Á., Iglesias-Páramo, J., Pentericci, L., Ziegler, B., Afonso, J., Dubbledam, M., Close, M., Parr-Burman, P., Morris, T.J., Chemla, F., De Frondat, F., Kelz, A., Guinouard, I., Lewis, I.J., Middleton, K., Navarro, R., Larrieu, M., Pragt, J., Janssen, A., Dohlen, K., El Hadi, K., Gendron, É., Yang, Y., Wells, M., Conan, J.-M., Fusco, T., Schaerer, D., Bergin, E., Taburet, S., Frotin, M., Berkourn, N., Simard, L., Takami, H., Department of Physics [Durham University], Durham University, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ISIS Neutron and Muon Source (ISIS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Universidade de São Paulo (USP), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Universiteit van Amsterdam (UvA), Leibniz-Institut für Astrophysik Potsdam (AIP), University of Helsinki, Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Laboratorio Nacional de Astrofisica, Oskar Klein Centre [Stockholm], Stockholm University, Lund University [Lund], Uppsala University, Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), INAF - Osservatorio Astronomico di Roma (OAR), Istituto Nazionale di Astrofisica (INAF), Universität Wien, Observatório Astronómico de Lisboa, University of Oxford [Oxford], Netherlands Research School for Astronomy, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), University of Michigan [Ann Arbor], University of Michigan System, High Energy Astrophys. & Astropart. Phys (API, FNWI), Universidade de São Paulo = University of São Paulo (USP), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, University of Oxford, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Université de Genève = University of Geneva (UNIGE)

Subjects
Astrofísica, ASTRONOMICAL IMAGING, Age of the universe, Computer science, media_common.quotation_subject, Dark matter, FOS: Physical sciences, 01 natural sciences, 7. Clean energy, Cosmology, 010309 optics, [SPI]Engineering Sciences [physics], Optical Fibres, 0103 physical sciences, Adaptive optics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Spectrograph, Galaxy rotation curve, media_common, ADAPTIVE OPTICS, [PHYS]Physics [physics], Multi-Object, GALACTIC ASTRONOMY, Astronomy, Galaxy, NEAR INFRARED, Sky, TELESCOPES, SPECTROGRAPHS, VISIBLE RADIATION, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

When combined with the huge collecting area of the ELT, MOSAIC will be the most effective and flexible Multi-Object Spectrograph (MOS) facility in the world, having both a high multiplex and a multi-Integral Field Unit (Multi-IFU) capability. It will be the fastest way to spectroscopically follow-up the faintest sources, probing the reionisation epoch, as well as evaluating the evolution of the dwarf mass function over most of the age of the Universe. MOSAIC will be world-leading in generating an inventory of both the dark matter (from realistic rotation curves with MOAO fed NIR IFUs) and the cool to warm-hot gas phases in z=3.5 galactic haloes (with visible wavelenth IFUs). Galactic archaeology and the first massive black holes are additional targets for which MOSAIC will also be revolutionary. MOAO and accurate sky subtraction with fibres have now been demonstrated on sky, removing all low Technical Readiness Level (TRL) items from the instrument. A prompt implementation of MOSAIC is feasible, and indeed could increase the robustness and reduce risk on the ELT, since it does not require diffraction limited adaptive optics performance. Science programmes and survey strategies are currently being investigated by the Consortium, which is also hoping to welcome a few new partners in the next two years., 6 pages, 3 figures, Submitted to SPIE Proceedings, AS18

Published
2018

13. Current status of PAPYRUS: the pyramid based adaptive optics system at LAM/OHP

Author

Haverkamp, Nils, Sitarski, Breann N., Youngworth, Richard N., Muslimov, E., Levraud, N., Chambouleyron, V., Boudjema, I., Lau, A., Caillat, A., Pedreros, F., Otten, G., El Hadi, K., Joaquina, K., Maxime, M., El Morsy, M., Beltramo-Martin, O., Fétick, R., Ke, Z., Sauvage, J-F., Neichel, B., Fusco, T., Schmitt, J., Le Van Suu, A., Charton, J., Schimpf, A., Martin, B., Dintrono, F., Esposito, S., and Pina, E.

Published
2021
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14. Opto-mechanical design of a High Contrast Module (HCM) for HARMONI

Author

Hénault, François B., primary, Rabou, P., primary, Magnard, Y., primary, Sradler, E., primary, Mouillet, D., primary, Chauvin, G., primary, Bonnefoy, M., primary, Sauvage, J. F., primary, Dohlen, K., primary, Fusco, T., primary, El Hadi, K., primary, Vola, P., primary, Clarke, F., primary, Schnetler, H., primary, Vérinaud, C., primary, Carlotti, Alexis, primary, Vigan, A., primary, Thatte, N., primary, Bryson, I., primary, and Tecza, M., primary

Published
2018
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16. The adaptive optics modes for HARMONI: from Classical to Laser Assisted Tomographic AO

Author

Neichel, B., Fusco, T., Sauvage, J. -F., Correia, C., Dohlen, K., El-Hadi, K., Blanco, L., Schwartz, N., Clarke, F., Thatte, N., Tecza, M., Paufique, J., Vernet, J., Louarn, M. Le, Hammersley, P., Gach, J. -L., Pascal, S., Vola, P., Petit, C., Conan, J. -M., Carlotti, A., Verinaud, C., Schnetler, H., Bryson, I., Morris, T., Myers, R., Hugot, E., Gallie, A., Marchetti, Enrico, Close, Laird, Véran, Jean-Pierre, Le Louarn, M., Gach, L., Conan, M., Vérinaud, C., Gallie, M., Henry, M., Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ONERA - The French Aerospace Lab [Châtillon], ONERA-Université Paris Saclay (COmUE), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
Diffraction, Wavefront, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Computer science, FOS: Physical sciences, First light, Laser, 01 natural sciences, law.invention, 010309 optics, Optics, Laser guide star, Integral field spectrograph, law, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Pyramid (image processing), Astrophysics - Instrumentation and Methods for Astrophysics, business, Adaptive optics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics
Abstract

HARMONI is a visible and NIR integral field spectrograph, providing the E-ELT's core spectroscopic capability at first light. HARMONI will work at the diffraction limit of the E-ELT, thanks to a Classical and a Laser Tomographic AO system. In this paper, we present the system choices that have been made for these SCAO and LTAO modules. In particular, we describe the strategy developed for the different Wave-Front Sensors: pyramid for SCAO, the LGSWFS concept, the NGSWFS path, and the truth sensor capabilities. We present first potential implementations. And we asses the first system performance., Comment: SPIE proceeding, 2016

Published
2016

17. Characterisation of a turbulent module for the MITHIC high-contrast imaging testbed

Author

Vigan, Arthur, Postnikova, M., Caillat, A., Sauvage, J.-F., Dohlen, K., El Hadi, K., Fusco, T., Lamb, M., N'Diaye, M., Marchetti, Enrico, Close, Laird, Véran, Jean-Pierre, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Space Telescope Science Institute (STSci), NRC Herzberg Institute of Astrophysics, and National Research Council of Canada (NRC)

Subjects
Wavefront, Continuous phase modulation, business.industry, Zernike polynomials, Computer science, Testbed, Phase (waves), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, 01 natural sciences, 010309 optics, symbols.namesake, Optics, 0103 physical sciences, symbols, Segmentation, business, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

Future high-contrast imagers on ground-based extremely large telescopes will have to deal with the segmentation of the primary mirrors. Residual phase errors coming from the phase steps at the edges of the segments will have to be minimized in order to reach the highest possible wavefront correction and thus the best contrast performance. To study these effects, we have developed the MITHIC high-contrast testbed, which is designed to test various strategies for wavefront sensing, including the Zernike sensor for Extremely accurate measurements of Low-level Differential Aberrations (ZELDA) and COronagraphic Focal-plane wave-Front Estimation for Exoplanet detection (COFFEE). We recently equipped the bench with a new atmospheric turbulence simulation module that offers both static phase patterns representing segmented primary mirrors and continuous phase strips representing atmospheric turbulence filtered by an AO or an XAO system. We present a characterisation of the module using different instruments and wavefront sensors, and the first coronagraphic measurements obtained on MITHIC., Comment: Presented at SPIE Astronomical Instrumentation + Telescope 2016

Published
2016

23. The adaptive optics modes for HARMONI: from Classical to Laser Assisted Tomographic AO

Author

Neichel, B., additional, Fusco, T., additional, Sauvage, J.-F., additional, Correia, C., additional, Dohlen, K., additional, El-Hadi, K., additional, Blanco, L., additional, Schwartz, N., additional, Clarke, F., additional, Thatte, N. A., additional, Tecza, M., additional, Paufique, J., additional, Vernet, J., additional, Le Louarn, M., additional, Hammersley, P., additional, Gach, J.-L., additional, Pascal, S., additional, Vola, P., additional, Petit, C., additional, Conan, J.-M., additional, Carlotti, A., additional, Vérinaud, C., additional, Schnetler, H., additional, Bryson, I., additional, Morris, T., additional, Myers, R., additional, Hugot, E., additional, Gallie, A. M., additional, and Henry, David M., additional

Published
2016
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24. Le site mégalithique du Monte Revincu à Santo-Pietro-di-Tenda (Haute-Corse)

Author

Leandri, F., La Collaboration De, Avec, Béraud, A., Bressy-Leandri, C., Demouche, F., Gilabert, C., Jorda, C., El Hadi, K., Lazard, N., Ottavi, A., Pinelli, C., Paolini-Saez, H., Pellissier, M., Santucci, J.-F., Thury-Bouvet, G., Economies, sociétés et environnements préhistoriques (ESEP), Université Joseph Fourier - Grenoble 1 (UJF)-Université de Provence - Aix-Marseille 1-Centre National de la Recherche Scientifique (CNRS), and SRA Corse

Subjects
[SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, Néolithique, Corse, Mégalithisme
Published
2005

26. Opto-mechanical design of a High Contrast Module (HCM) for HARMONI

Author

Evans, Christopher J., Simard, Luc, Takami, Hideki, Hénault, F., Carlotti, A., Rabou, P., Magnard, Y., Sradler, E., Mouillet, D., Chauvin, G., Bonnefoy, M., Sauvage, J. F., Dohlen, K., Vigan, A., Fusco, T., El Hadi, K., Vola, P., Clarke, F., Thatte, N., Bryson, I., Schnetler, H., Tecza, M., and Vérinaud, C.

Published
2018
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27. MOSAIC: the ELT multi-object spectrograph

Author

Evans, Christopher J., Simard, Luc, Takami, Hideki, Jagourel, P., Fitzsimons, E., Hammer, F., De Frondat, F., Puech, M., Evans, C. J., Sanchez, R., Guinouard, I., Chemla, F., Frotin, M., Yang, Y., Parr-Burman, P., Morris, T., Dubbeldam, M., Close, M., Middleton, K., Rousset, G., Gendron, É., Kelz, A., Janssen, A., Pragt, J., Navarro, R., Larrieu, M., El Hadi, K., Dohlen, K., Dalton, G., Lewis, I., Rodrigues, M., Morris, S., Kaper, L., Barbuy, B., Cuby, J-G., and Le Fèvre, Olivier

Published
2018
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47. Chromium(III) in Hypoglycemia and in Impaired Glucose Utilization in Kwashiorkor

Author

CARTER, J. P., KATTAB, A., ABD-EL-HADI, K., DAVIS, J. T., EL GHOLMY, A., and PATWARDHAN, V. N.

Abstract

Thirty-four children with kwashiorkor were admitted to the children’s ward, Ein Shams Medical School, Cairo, Egypt. Intravenous glucose tolerance curves done on admission showed impaired glucose utilization in all but one. The curves were repeated in nine patients after the oral administration of 250 µg of chromium(III) daily for 1–3 days. Curves were also repeated in 13 patients before and after milk feedings for 3 days and before and after complete dietary and therapeutic management. The chromium contents of foods, medicines, and plasma were determined. Ample amounts of chromium were found in some of the foodstuffs consumed by the patients prior to admission to the hospital, and variable, but sometimes quite large, amounts in therapeutic agents employed. The chromium content of the plasma was within normal limits in eight infants. The diabetic glucose tolerance curves returned to normal following treatment with a high-protein, high caloric diet for 1–2 weeks. Chromium deficiency did not appear to be responsible for the rapidly reversible impaired glucose utilization seen in patients with kwashiorkor in Cairo, Egypt, United Arab Republic.

Published
1968
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50. Difference-frequency generation and parametric fluorescence in quasi-phase-matched lithium niobate stripe waveguides

Author

Baldi, P., Sundheimer, M., El Hadi, K., Aschieri, P., Marc De Micheli, Ostrowsky, D. B., Delacourt, D., and Webjorn, J.

Abstract

Optical parametric oscillators (OPO) are excellent candidates for coherent tunable sources for many applications, such as telecommunications, spectroscopy and medicine, and optical parametric amplifiers (OPA) are interesting as amplifiers without spontaneous emission noise for generating squeezed states, etc… Integrated optical waveguide version1 of such devices could provide important additional features such as electrooptic tuning. Optical parametric fluorescence (OPF) and difference-frequency generation (DFG) are powerful techniques for characterizing the nonlinear waveguides without building the high-finesse cavity necessary to achieve the oscillation.

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