Dr. Renaud Foy Profile

Dr. Renaud Foy

Directeur de recherche at Observatoire de Lyon

SPIE Involvement:

Author

Publications (22)

Proceedings Article | 28 July 2010 Paper

Paper

Setting up ELP-OA: the polychromatic laser guide star demonstrator

N. Meilard, R. Foy, M. Langlois, M. Tallon, E. Thiébaut, A. Petit, A. Blazit, P.-E. Blanc, J. Chombart, O. Fouche, A. Laloge, A. Le Van Suu, X. Regal, J. Schmitt, M. Boër

Proceedings Volume 7736, 77361W (2010) https://doi.org/10.1117/12.858068

KEYWORDS: Projection systems, Adaptive optics, Telescopes, Data modeling, Laser guide stars, Stars, Interferometry, Mesosphere, Sodium, Chemical species

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Proceedings Article | 28 July 2008 Paper

Paper

VLTI-AMBER observations of Eta Carinae with the FINITO fringe tracker and spectral resolution 12000

Gerd Weigelt, Olivier Chesneau, Thomas Driebe, Renaud Foy, Didier Fraix-Burnet, Jose Groh, Karl-Heinz Hofmann, Stefan Kraus, Fabien Malbet, Alessandro Marconi, Philippe Mathias, Florentin Millour, Jean-Louis Monin, Romain Petrov, Frederik Rantakyrö, Andrea Richichi, Dieter Schertl, Markus Schöller, Philippe Stee, Leonardo Testi, Markus Wittkowski

Proceedings Volume 7013, 701303 (2008) https://doi.org/10.1117/12.796204

KEYWORDS: Visibility, Bromine, Spectral resolution, Phase measurement, Spectroscopy, Interferometry, Stars, Speckle, Telescopes, Binary data

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Proceedings Article | 28 July 2008 Paper

Paper

VEGA: a new visible spectrograph and polarimeter on the CHARA Array

D. Mourard, K. Perraut, D. Bonneau, J. M. Clausse, Ph. Stee, I. Tallon-Bosc, P. Kervella, Y. Hughes, A. Marcotto, A. Blazit, O. Chesneau, A. Domiciano de Souza, R. Foy, F. Hénault, D. Mattei, G. Merlin, A. Roussel, M. Tallon, E. Thiebaut, H. McAlister, T. ten Brummelaar, J. Sturmann, L. Sturmann, N. Turner, C. Farrington, P. J. Goldfinger

Proceedings Volume 7013, 701323 (2008) https://doi.org/10.1117/12.787505

KEYWORDS: Spectrographs, Visible radiation, Spectral resolution, Sensors, Polarimetry, Stars, Signal to noise ratio, Interferometry, Mirrors, Telescopes

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Proceedings Article | 10 July 2008 Paper

Paper

ELP-OA : status report of the setup of the demonstrator of the polychromatic laser guide star at Observatoire de Haute Provence

Renaud Foy, Pierre-Éric Blanc, Thierry Fusco, Andrée Laloge, Auguste Le Van Suu, Sandrine Perruchot, Alain Petit, Pierre Richaud, Michel Tallon, Éric Thiébaut, Michel Boër

Proceedings Volume 7015, 701517 (2008) https://doi.org/10.1117/12.789287

KEYWORDS: Telescopes, Mesosphere, Sodium, Adaptive optics, Laser guide stars, Mirrors, Projection systems, Wavefronts, Modulation, Dye lasers

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Proceedings Article | 24 September 2007 Paper

Paper

The Polychromatic Laser Guide Star for tilt measurement: progress report of the demonstrator at Observatoire de Haute Provence

Renaud Foy, Pierre Éric, Jérôme Eysseric, Françoise Foy, Thierry Fusco, Julien Girard, Auguste Le Van Suu, Sandrine Perruchot, Pierre Richaud, Yoann Richaud, Xavier Rondeau, Michel Tallon, Éric Thiébaut, Michel Boër

Proceedings Volume 6691, 66910R (2007) https://doi.org/10.1117/12.733997

KEYWORDS: Telescopes, Mesosphere, Projection systems, Sodium, Laser guide stars, Adaptive optics, Photons, Algorithm development, Stars, Wavefronts

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Proceedings Article | 29 June 2006 Paper

Paper

VEGA: a visible spectrograph and polarimeter for CHARA science cases description

Philippe Stee, Denis Mourard, Daniel Bonneau, Paul Berlioz-Arthaud, Armando Domiciano de Souza, Renaud Foy, Petr Harmanec, Slobodan Jankov, Pierre Kervella, Pavel Koubsky, Stéphane Lagarde, Jean-Baptiste Le Bouquin, Philippe Mathias, Antoine Mérand, Nicolas Nardetto, Romain Petrov, Karine Rousselet-Perraut, Chantal Stehlé, Gerd Weigelt

Proceedings Volume 6268, 62683R (2006) https://doi.org/10.1117/12.684479

KEYWORDS: Stars, Visible radiation, Spectral resolution, Spatial resolution, Interferometry, Interferometers, Visibility, Signal to noise ratio, Magnetism, Spectroscopy

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Proceedings Article | 28 June 2006 Paper

Paper

VLTI-AMBER observations of Eta Carinae with high spatial resolution and spectral resolutions of 1,500 and 10,000

Gerd Weigelt, Romain Petrov, Olivier Chesneau, Kris Davidson, Armando Domiciano de Souza, Thomas Driebe, Renaud Foy, Didier Fraix-Burnet, Ted Gull, John Hillier, Karl-Heinz Hofmann, Stefan Kraus, Fabien Malbet, Alessandro Marconi, Philippe Mathias, Jean-Louis Monin, Florentin Millour, Keiichi Ohnaka, Frederik Rantakyrö, Andrea Richichi, Dieter Schertl, Markus Schöller, Philippe Stee, Leonardo Testi, Markus Wittkowski

Proceedings Volume 6268, 62682S (2006) https://doi.org/10.1117/12.671582

KEYWORDS: Visibility, Bromine, Spectral resolution, K band, Stars, Spatial resolution, Phase measurement, Observatories, Interferometry, Near infrared

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Proceedings Article | 15 June 2006 Paper

Paper

Performances of CPNG: a new generation photon-counting camera with real-time dedicated optimal processing

X. Rondeau, E. Thiébaut, A. Blazit, R. Foy

Proceedings Volume 6276, 62760L (2006) https://doi.org/10.1117/12.671950

KEYWORDS: Charge-coupled devices, Cameras, Image filtering, Quantum efficiency, Microchannel plates, Photons, Ions, Spatial resolution, Sensors, Signal to noise ratio

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Proceedings Article | 20 October 2004 Paper

Paper

Science program of the AMBER consortium

Fabien Malbet, Thomas Driebe, Renaud Foy, Didier Fraix-Burnet, Philippe Mathias, Alessandro Marconi, Jean-Louis Monin, Romain Petrov, Philippe Stee, Leonardo Testi, Gerd Weigelt

Proceedings Volume 5491, (2004) https://doi.org/10.1117/12.550667

KEYWORDS: Stars, Telescopes, Beryllium, Interferometry, Spectral resolution, K band, Phase measurement, Interferometers, Spatial resolution, Astatine

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Proceedings Article | 7 March 2003 Paper

Paper

CPng: a high-sensitivity photon-counting camera

Eric Thiebaut, L. Abbe, Alain Blazit, Jean-pierre Dubois, Renaud Foy, Michel Tallon, Farrokh Vakili

Proceedings Volume 4841, (2003) https://doi.org/10.1117/12.462608

KEYWORDS: Cameras, Quantum efficiency, Optical amplifiers, Image intensifiers, Charge-coupled devices, Sensors, Photons, Microchannel plates, Amplifiers, CCD cameras

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Proceedings Article | 21 February 2003 Paper

Paper

Astrophysical potential of the AMBER/VLTI instrument

Fabien Malbet, Thomas Bloecker, Renaud Foy, Didier Fraix-Burnet, Philippe Mathias, Alesssandro Marconi, Jean-Louis Monin, Romain Petrov, Philippe Stee, Leonardo Testi, Gerd Weigelt

Proceedings Volume 4838, (2003) https://doi.org/10.1117/12.458907

KEYWORDS: Stars, Spectral resolution, Visibility, Interferometers, Telescopes, Phase measurement, Planets, Jupiter, Large telescopes, Spatial frequencies

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Proceedings Article | 7 February 2003 Paper

Paper

Feasibility study of the polychromatic laser guide star

Renaud Foy, Jean-Paul Pique, Veronique Bellanger, Patrick Chevrou, Alain Petit, Claudia Hogemann, Lothar Noethe, Matthias Schock, Julien Girard, Michel Tallon, Eric Thiebaut, Jerome Vaillant, Francoise-C. Foy, Marcos Van Dam

Proceedings Volume 4839, (2003) https://doi.org/10.1117/12.460080

KEYWORDS: Telescopes, Sodium, Mesosphere, Laser guide stars, Wavefronts, Modulation, Adaptive optics, Doppler effect, Chemical species, Stars

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Proceedings Article | 17 November 2000 Paper

Paper

ELP-OA: measuring the wavefront tilt without a natural guide star

Matthias Schoeck, Jean-Paul Pique, Alain Petit, Patrick Chevrou, Vincent Michau, Gilbert Grynberg, Arnold Migus, Nancy Ageorges, Veronique Bellanger, Francois Biraben, Ruy Deron, Hayden Fews, Francoise-Claude Foy, Claudia Hoegemann, Markus Laubscher, Daniel Mueller, Celine d'Orgeville, Olivier Peillet, Mike Redfern, Renaud Foy, Patricia Segonds, Richard Soden, Michel Tallon, Eric Thiebaut, Andrei Tokovinin, Jerome Vaillant, Jean-Marc Weulersse

Proceedings Volume 4125, (2000) https://doi.org/10.1117/12.409304

KEYWORDS: Telescopes, Stars, Sodium, Wavefronts, Adaptive optics, Modulation, Laser guide stars, Oscillators, Astronomy, Chemical species

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Proceedings Article | 16 August 2000 Paper

Paper

Polychromatic guide star: feasibility study

Renaud Foy, Jean-Paul Pique, Alain Petit, Patrick Chevrou, Vincent Michau, Gilbert Grynberg, Arnold Migus, Nancy Ageorges, Veronique Bellanger, Francois Biraben, Ruy Deron, Hayden Fews, Francoise-Claude Foy, Claudia Hoegemann, Markus Laubscher, Daniel Mueller, Celine d'Orgeville, Olivier Peillet, Mike Redfern, Matthias Schoeck, Patricia Segonds, Richard Soden, Michel Tallon, Eric Thiebaut, Andrei Tokovinin, Jerome Vaillant, Jean-Marc Weulersse

Proceedings Volume 4065, (2000) https://doi.org/10.1117/12.407359

KEYWORDS: Telescopes, Sodium, Stars, Oscillators, Adaptive optics, Modulation, Wavefronts, Chemical species, Photons, Laser guide stars

Read Abstract +

Adaptive optics at astronomical telescopes aims at correcting in real time the phase corrugations of incoming wavefronts caused by the turbulent atmosphere, as early proposed by Babcock. Measuring the phase errors requires a bright source located within the isoplanatic patch of the program source. The probability that such a reference source exists is a function of the wavelength, of the required image quality (Strehl ratio), of the turbulence optical properties, and of the direction of the observation. It turns out that the sky coverage is disastrously low in particular in the visible wavelength range where, unfortunately, the gain in spatial resolution brought by adaptive optics is the largest. Foy and Labeyrie have proposed to overcome this difficulty by creating an artificial point source in the sky in the direction of the observation relying on the backscattered light due to a laser beam. This laser guide star (hereinafter referred to as LGS) can be bright enough to allow us to accurately measure the wavefront phase errors, except for two modes which are the piston (not relevant in this case) and the tilt. Pilkington has emphasized that the round trip time of the laser beam to the mesosphere, where the LGS is most often formed, is significantly shorter than the typical tilt coherence time; then the inverse-return-of-light principle causes deflections of the outgoing and the ingoing beams to cancel. The apparent direction of the LGS is independent of the tilt. Therefore the tilt cannot be measured only from the LGS. Until now, the way to overcome this difficulty has been to use a natural guide star to sense the tilt. Although the tilt is sensed through the entire telescope pupil, one cannot use a faint source because $APEX 90% of the variance of the phase error is in the tilt. Therefore, correcting the tilt requires a higher accuracy of the measurements than for higher orders of the wavefront. Hence current adaptive optics devices coupled with a LGS face low sky coverage. Several methods have been proposed to get a partial sky coverage for the tilt. The only one providing us with a full sky coverage is the polychromatic LGS (hereafter referred to as PLGS). We present here a progress report of the R&D program Etoile Laser Polychromatique et Optique Adaptative (ELP-OA) carried out in France to develop the PLGS concept. After a short recall of the principles of the PLGS, we will review the goal of ELP-OA and the steps to get over to bring it into play. We finally shortly described the effort in Europe to develop the LGS.

Proceedings Article | 7 July 2000 Paper

Paper

SPID: a high spectral resolution diffraction-limited camera

Michel Tallon, Andre Baranne, Alain Blazit, Francoise-Claude Foy, Renaud Foy, Isabelle Tallon-Bosc, Eric Thiebaut

Proceedings Volume 4007, (2000) https://doi.org/10.1117/12.390390

KEYWORDS: Spectral resolution, Telescopes, Adaptive optics, Cameras, Signal to noise ratio, Stars, Sensors, Diffraction, Wavefront sensors, Spatial resolution

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Proceedings Article | 7 July 2000 Paper

Paper

ELPOA: toward the tilt measurement from a polychromatic laser guide star

Renaud Foy, Jean-Paul Pique, Alain Petit, Patrick Chevrou, Vincent Michau, Gilbert Grynberg, Arnold Migus, Nancy Ageorges, Veronique Bellanger, Francois Biraben, Ruy Deron, Hayden Fews, Francoise-Claude Foy, Claudia Hoegemann, Markus Laubscher, Daniel Mueller, Celine d'Orgeville, Olivier Peillet, Mike Redfern, Matthias Schoeck, Patricia Segonds, Richard Soden, Michel Tallon, Eric Thiebaut, Andrei Tokovinin, Jerome Vaillant, Jean-Marc Weulersse

Proceedings Volume 4007, (2000) https://doi.org/10.1117/12.390401

KEYWORDS: Telescopes, Sodium, Oscillators, Adaptive optics, Modulation, Laser guide stars, Photons, Chemical species, Wavefronts, Atmospheric optics

Read Abstract +

Adaptive optics at astronomical telescopes aims at correcting in real time the phase corrugations of incoming wavefronts caused by the turbulent atmosphere, as early proposed by Babcock. Measuring the phase errors requires a bright source, which is located within the isoplanatic patch of the program source. The probability that such a reference source exists is a function of the wavelength of the observation, of the required image quality (Strehl ratio), of the turbulence optical properties, and of the direction of the observation. Several papers have addressed the problem of the sky coverage as a function of these parameters (see e.g.: Le Louarn et al). It turns out that the sky coverage is disastrously low in particular in the short (visible) wavelength range where, unfortunately, the gain in spatial resolution brought by adaptive optics is the largest. Foy and Labeyrie have proposed to overcome this difficulty by creating an artificial point source in the sky in the direction of the observation relying on the backscattered light due to a laser beam. This laser guide star (hereafter referred to as LGS) can be bright enough to allow us to accurately measure the wavefront phase errors, except for two modes which are the piston (which is not relevant in this case) and the tilt. Pilkington has emphasized that the round trip time of the laser beam to the mesosphere, where the LGS is most often formed, is significantly shorter than the typical tilt coherence time; then the inverse-return- of-light principle causes deflections of the outgoing and the ingoing beams to cancel. The apparent direction of the LGS is independent of the tilt. Therefore the tilt cannot be measured only from the LGS. Until now, the way to overcome this difficulty has been to use a natural guide star to sense the tilt. Although the tilt is sensed through the entire telescope pupil, one cannot use a faint source because approximately equals 90% of the variance of the phase error is in the tilt. Therefore, correcting the tilt requires a higher accuracy of the measurements than for higher orders of the wavefront. Hence current adaptive optics devices coupled with a LGS face low sky coverage. Several methods have been proposed to get a partial or total sky coverage for the tilt, such as the dual adaptive optics concept, the elongation perspective method, or the polychromatic LGS (hereafter referred to as PLGS). We present here a progress report of the R&D program Etoile Laser Polychromatique et Optique Adaptative (ELP-OA) carried out in France to develop the PLGS concept. After a short recall of the principles of the PLGS, we will review the goal of ELP-OA and the steps to get over to bring it into play.

Proceedings Article | 7 July 2000 Paper

Paper

PASS-2: quantitative photometric measurements of the polychromatic laser guide star

Matthias Schoeck, Renaud Foy, Jean-Paul Pique, Patrick Chevrou, Nancy Ageorges, Alain Petit, Veronique Bellanger, Hayden Fews, Francoise-Claude Foy, Claudia Hoegemann, Markus Laubscher, Olivier Peillet, Patricia Segonds, Michel Tallon, Jean-Marc Weulersse

Proceedings Volume 4007, (2000) https://doi.org/10.1117/12.390338

KEYWORDS: Laser guide stars, Telescopes, Sodium, Stars, Global system for mobile communications, Oscillators, Wavefronts, Adaptive optics, Calibration, Photometry

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Proceedings Article | 5 July 2000 Paper

Paper

Science opportunities with AMBER, the near-IR VLTI instrument

Andrea Richichi, Thomas Bloecker, Renaud Foy, Didier Fraix-Burnet, Bruno Lopez, Fabien Malbet, Philippe Stee, Oskar von der Luehe, Gerd Weigelt

Proceedings Volume 4006, (2000) https://doi.org/10.1117/12.390266

KEYWORDS: Stars, Spatial resolution, Visibility, Interferometry, Interferometers, Telescopes, Exoplanets, Spectral resolution, Astatine, Data modeling

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Proceedings Article | 27 September 1999 Paper

Paper

PASS-2: photometry of the polychromatic laser guide star

Matthias Schoeck, Renaud Foy, Jean-Paul Pique, Michel Tallon, Patricia Segonds, Markus Laubscher, Olivier Peillet

Proceedings Volume 3762, (1999) https://doi.org/10.1117/12.363589

KEYWORDS: Laser guide stars, Sodium, Telescopes, Ultraviolet radiation, Pulsed laser operation, Mirrors, Wavefronts, Adaptive optics, Stars, Atmospheric corrections

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Proceedings Article | 14 September 1998 Paper

Paper

Polychromatic guide star

Renaud Foy, Michel Tallon, Herbert Friedman, Andre Baranne, Francois Biraben, Gilbert Grynberg, Miska Le Louarn, Alain Petit, Jean-Marc Weulersse, Arnold Migus, Jean-Pierre Gex

Proceedings Volume 3343, (1998) https://doi.org/10.1117/12.321566

KEYWORDS: Telescopes, Adaptive optics, Stars, Laser guide stars, Sodium, Atmospheric optics, Wavefronts, Diffraction, Wavefront sensors, Mesosphere

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Proceedings Article | 11 September 1998 Paper

Paper

Sky coverage and PSF shape with LGS AO on 8-m telescopes

Miska Le Louarn, Norbert Hubin, Renaud Foy, Michel Tallon

Proceedings Volume 3353, (1998) https://doi.org/10.1117/12.321752

KEYWORDS: Point spread functions, Stars, Adaptive optics, Systems modeling, K band, Performance modeling, Atmospheric modeling, Solids, Laser guide stars, Telescopes

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Proceedings Article | 17 October 1997 Paper

Paper

Performances of natural and laser guide star adaptive optics for 8-m class telescopes

Miska Le Louarn, Norbert Hubin, Renaud Foy

Proceedings Volume 3126, (1997) https://doi.org/10.1117/12.279039

KEYWORDS: Stars, Adaptive optics, Atmospheric modeling, Sodium, Laser guide stars, K band, Telescopes, Atmospheric propagation, Atmospheric optics, Phase modulation

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Showing 5 of 22 publications

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