Dr. Olivier Lai Profile

Dr. Olivier Lai

Resident Astronomer at Lab JL Lagrange

SPIE Involvement:

Author

Publications (52)

Proceedings Article | 18 July 2018 Paper

Geometric distortion calibration using a pinhole mask

M. Service, M. Chun, J. Lu, F. Abdurrahman, O. Lai, D. Fohring, C. Baranec

Proc. SPIE. 10703, Adaptive Optics Systems VI

KEYWORDS: Astronomy, Data modeling, Cameras, Sensors, Calibration, Error analysis, Adaptive optics, Distortion, Astronomical imaging, Systems modeling

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Proceedings Article | 11 July 2018 Paper

Deconstructing turbulence and optimizing GLAO using imaka telemetry

Olivier Lai, Mark Chun, Fatima Abdurrahman, Jessica Lu, Max Service, Dora Fohring, Doug Toomey

Proc. SPIE. 10703, Adaptive Optics Systems VI

KEYWORDS: Point spread functions, Telescopes, Data modeling, Matrices, Wavefront sensors, Adaptive optics, Tomography, Domes, Turbulence

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Proceedings Article | 10 July 2018 Presentation + Paper

On-sky results from the wide-field ground-layer adaptive optics demonstrator 'imaka

Mark Chun, Jessica Lu, Olivier Lai, Fatima Abdurrahman, Maxwell Service, Douglas Toomey, Dora Fohring, Christoph Baranec, Yutaka Hayano, Shin Oya

Proc. SPIE. 10703, Adaptive Optics Systems VI

KEYWORDS: Point spread functions, Telescopes, Optical filters, Stars, Cameras, Matrices, Wavefront sensors, Adaptive optics, Image quality, Space telescopes

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Proceedings Article | 10 July 2018 Presentation + Paper

Ground layer adaptive optics for the W. M. Keck Observatory: feasibility study

J. Lu, M. Chun, S. Ammons, K. Bundy, R. Dekany, T. Do, D. Gavel, M. Kassis, O. Lai, C. Martin, C. Max, C. Steidel, L. Wang, K. Westfall, P. Wizinowich

Proc. SPIE. 10703, Adaptive Optics Systems VI

KEYWORDS: Point spread functions, Telescopes, Spectrographs, Spectroscopy, Adaptive optics, Image quality, Astronomical imaging, Galactic astronomy, Keck Observatory

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Proceedings Article | 9 July 2018 Paper

Intensity interferometry revival on the Côte d’Azur

Olivier Lai, William Guerin, Farrokh Vakili, Robin Kaiser, Jean Pierre Rivet, Mathilde Fouché, Guillaume Labeyrie, Julien Chabé, Clément Courde, Etienne Samain, David Vernet

Proc. SPIE. 10701, Optical and Infrared Interferometry and Imaging VI

KEYWORDS: Signal to noise ratio, Multimode fibers, Telescopes, Interferometers, Sensors, Interferometry, Photonics, Atmospheric Cherenkov telescopes

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Proceedings Article | 5 August 2016 Paper

Imaka: a ground-layer adaptive optics system on Maunakea

Mark Chun, Olivier Lai, Douglas Toomey, Jessica Lu, Max Service, Christoph Baranec, Simon Thibault, Denis Brousseau, Yutaka Hayano, Shin Oya, Shane Santi, Christopher Kingery, Keith Loss, John Gardiner, Brad Steele

Proc. SPIE. 9909, Adaptive Optics Systems V

KEYWORDS: Optical components, Telescopes, Mirrors, Stars, Cameras, Interfaces, Wavefront sensors, Adaptive optics, Image quality, Aluminum

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Proceedings Article | 27 July 2016 Paper

AIR FLOW: airborne interferometric recombiner fluctuations of light at optical wavelengths

Olivier Lai, Mark Chun, Kanoa Withington

Proc. SPIE. 9909, Adaptive Optics Systems V

KEYWORDS: Telescopes, Mach-Zehnder interferometers, Sensors, Interferometry, Optical testing, Domes, Turbulence, Phase measurement, Optical turbulence, Prototyping

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Proceedings Article | 27 July 2016 Paper

Correction of NIRI/ Altair non-common path aberrations using focal plane sharpening

Jesse Ball, Olivier Lai, Chadwick Trujillo, John White

Proc. SPIE. 9909, Adaptive Optics Systems V

KEYWORDS: Actuators, Point spread functions, Telescopes, Mirrors, Gemini Observatory, Cameras, Sensors, Calibration, Adaptive optics, Image quality

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Proceedings Article | 22 August 2014 Paper

Extremely high-resolution ground-layer optical turbulence profile at Mauna Kea

Mark Chun, Olivier Lai, Timothy Butterley, Sean Goebel, Christoph Baranec, Douglas Toomey

Proc. SPIE. 9148, Adaptive Optics Systems IV

KEYWORDS: Telescopes, Stars, Cameras, Matrices, Wavefront sensors, Wavefronts, Adaptive optics, Domes, Turbulence, Optical turbulence

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Proceedings Article | 7 August 2014 Paper

Adaptive optics at the Subaru telescope: current capabilities and development

Olivier Guyon, Yutaka Hayano, Motohide Tamura, Tomoyuki Kudo, Shin Oya, Yosuke Minowa, Olivier Lai, Nemanja Jovanovic, Naruhisa Takato, Jeremy Kasdin, Tyler Groff, Masahiko Hayashi, Nobuo Arimoto, Hideki Takami, Colin Bradley, Hajime Sugai, Guy Perrin, Peter Tuthill, Ben Mazin

Proc. SPIE. 9148, Adaptive Optics Systems IV

KEYWORDS: Telescopes, Spectrographs, Visible radiation, Imaging systems, Cameras, Wavefront sensors, Imaging spectroscopy, Adaptive optics, Coronagraphy, Exoplanets

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Proceedings Article | 7 August 2014 Paper

`imaka: a path-finder ground-layer adaptive optics system for the University of Hawaii 2.2-meter telescope on Maunakea

Mark Chun, Olivier Lai, Douglas Toomey, Jessica Lu, Christoph Baranec, Simon Thibault, Denis Brousseau, Hu Zhang, Yutaka Hayano, Shin Oya

Proc. SPIE. 9148, Adaptive Optics Systems IV

KEYWORDS: Telescopes, Mirrors, Stars, Cameras, Calibration, Wavefront sensors, Adaptive optics, Image quality, Optical turbulence, Galactic astronomy

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Proceedings Article | 7 August 2014 Paper

ULTIMATE-SUBARU: simulation update

Shin Oya, Yutaka Hayano, Olivier Lai, Ikuru Iwata, Tadayuki Kodama, Nobuo Arimoto, Yosuke Minowa, Masayuki Akiyama, Yoshito Ono, Hiroshi Terada, Tomonori Usuda, Hideki Takami, Tetsuo Nishimura, Naruhisa Takato, Daigo Tomono

Proc. SPIE. 9148, Adaptive Optics Systems IV

KEYWORDS: Point spread functions, Telescopes, Mirrors, Astronomy, Adaptive optics, Turbulence, Atmospheric turbulence, Atmospheric modeling, Device simulation, K band

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Proceedings Article | 21 July 2014 Paper

Altair performance and upgrades

Olivier Lai, Jean-Pierre Véran, Glen Herriot, John White, Jesse Ball, Chad Trujillo

Proc. SPIE. 9148, Adaptive Optics Systems IV

KEYWORDS: Diffraction, Point spread functions, Telescopes, Gemini Observatory, Spatial frequencies, Signal attenuation, Wavefront sensors, Adaptive optics, Convolution, K band

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Proceedings Article | 21 July 2014 Paper

ULTIMATE-SUBARU: project status

Yutaka Hayano, Masayuki Akiyama, Takashi Hattori, Ikuru Iwata, Tadayuki Kodama, Olivier Lai, Yosuke Minowa, Yoshito Ono, Shin Oya, Koki Takiura, Ichi Tanaka, Yoko Tanaka, Nobuo Arimito

Proc. SPIE. 9148, Adaptive Optics Systems IV

KEYWORDS: Near infrared, Telescopes, Mirrors, Spectrographs, Stars, Imaging systems, Wavefront sensors, Adaptive optics, Space telescopes, Galactic astronomy

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Proceedings Article | 8 July 2014 Paper

Development and recent results from the Subaru coronagraphic extreme adaptive optics system

N. Jovanovic, O. Guyon, F. Martinache, C. Clergeon, G. Singh, T. Kudo, K. Newman, J. Kuhn, E. Serabyn, B. Norris, P. Tuthill, P. Stewart, E. Huby, G. Perrin, S. Lacour, S. Vievard, N. Murakami, O. Fumika, Y. Minowa, Y. Hayano, J. White, O. Lai, F. Marchis, G. Duchene, T. Kotani, J. Woillez

Proc. SPIE. 9147, Ground-based and Airborne Instrumentation for Astronomy V

KEYWORDS: Point spread functions, Imaging systems, Speckle, Cameras, Sensors, Wavefront sensors, Wavefronts, Adaptive optics, Deformable mirrors, Coronagraphy

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Proceedings Article | 24 September 2012 Paper

FIRST - a fibered aperture masking instrument: on-sky results

Elsa Huby, Guy Perrin, Franck Marchis, Sylvestre Lacour, Takayuki Kotani, Gaspard Duchêne, Elodie Choquet, Elinor Gates, Julien Woillez, Olivier Lai

Proc. SPIE. 8446, Ground-based and Airborne Instrumentation for Astronomy IV

KEYWORDS: Optical fibers, Observatories, Diffraction, Telescopes, Stars, Speckle, Calibration, Adaptive optics, Phase measurement, Prototyping

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Proceedings Article | 13 September 2012 Paper

'Imaka: working towards very wide-field of view AO

M. Chun, O. Lai, J-C. Cuillandre, H. Richer, D. Toomey, D. Salmon, R. Carlberg, D. Andersen, D. Burgarella, K. Ho, J. Pazder, E. Bertin

Proc. SPIE. 8447, Adaptive Optics Systems III

KEYWORDS: Telescopes, Optical design, Astronomy, Stars, Wavefront sensors, Adaptive optics, Monte Carlo methods, Image quality, Relays, Optical turbulence

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Proceedings Article | 28 July 2010 Paper

Ῑmaka: a Lagrange invariant of ELTs

Olivier Lai, Mark Chun, John Pazder, Jean-Pierre Véran, Laurent Jolissaint, David Andersen, Derrick Salmon, Jean-Charles Cuillandre

Proc. SPIE. 7736, Adaptive Optics Systems II

KEYWORDS: Point spread functions, Telescopes, Mirrors, Stars, Wavefronts, Adaptive optics, Deformable mirrors, Monte Carlo methods, Image quality, Turbulence

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Proceedings Article | 22 July 2010 Paper

'OHANA-Iki: a test-bed for the 'OHANA beam combiner and delay line at CFHT

Marc Baril, Olivier Lai, George Zahariade, Flora Bouchacourt, Guy Perrin, Pierre Fedou, Julien Woillez

Proc. SPIE. 7734, Optical and Infrared Interferometry II

KEYWORDS: Optical fibers, Telescopes, Mirrors, Astronomy, Stars, Gemini Observatory, Interferometers, Cameras, Interferometry, Servomechanisms

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Proceedings Article | 22 July 2010 Paper

Development of a high-dynamic range imaging instrument for a single telescope by a pupil remapping system

Takayuki Kotani, Sylvestre Lacour, Elodie Choquet, Elsa Huby, Guy Perrin, Pierre Fedou, Franck Marchis, Gaspard Duchene, Éric Thiébaut, Julien Woillez, Jean-Philippe Berger, Pascal Bordé, Olivier Chesneau, Pierre Kervella, Olivier Lai, Stephen Ridgway, Daniel Rouan, Alain Lecavelier des Etangs, Alfred Vidal-Madjar

Proc. SPIE. 7734, Optical and Infrared Interferometry II

KEYWORDS: Observatories, Telescopes, Stars, Imaging systems, Wavefronts, Single mode fibers, Adaptive optics, Space telescopes, Range imaging, High dynamic range imaging

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Proceedings Article | 15 July 2010 Paper

'Imaka: a one-degree high-resolution imager for the Canada-France-Hawaii Telescope

Mark Chun, Raymond Carlberg, Harvey Richer, Yannick Mellier, Pierre Astier, Olivier Lai, Derrick Salmon, Jean-Charles Cuillandre, David Andersen, John Pazder, Jean-Pierre Véran, Gregory Barrick, Steven Bauman, Kevin Ho, Remy Avila, Richard Wilson, Timothy Butterley

Proc. SPIE. 7735, Ground-based and Airborne Instrumentation for Astronomy III

KEYWORDS: Telescopes, Mirrors, Optical design, Stars, Imaging systems, Wavefront sensors, Adaptive optics, Image quality, Optical turbulence, Galactic astronomy

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Proceedings Article | 14 July 2008 Paper

VASAO: visible all sky adaptive optics: a new adaptive optics concept for CFHT

Olivier Lai, Christian Veillet, Derrick Salmon, Kevin Ho, Marc Baril, Gregory Barrick, Jim Thomas, Douglas Teeple, Tom Benedict, Jean Paul Pique, Hugues Guillet de Chatellus

Proc. SPIE. 7015, Adaptive Optics Systems

KEYWORDS: Diffraction, Telescopes, Stars, Cameras, Sensors, Adaptive optics, Colorimetry, Sodium, Laser guide stars, Galactic astronomy

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Proceedings Article | 14 July 2008 Paper

IMAKA: imaging from Mauna KeA with an atmosphere corrected 1 square degree optical imager

Olivier Lai, Mark Chun, Jean Charles Cuillandre, Ray Carlberg, Harvey Richer, David Andersen, John Pazder, John Tonry, René Doyon, Simon Thibault, Jim Dunlop, Chris Pritchet, Jean Pierre Véran, Christ Ftaclas, Peter Onaka, Klaus Hodapp, Robert McLaren, Emmanuel Bertin, Yannick Mellier, Pierre Astier, Reynald Pain

Proc. SPIE. 7015, Adaptive Optics Systems

KEYWORDS: Point spread functions, Telescopes, Mirrors, Stars, Wavefront sensors, Adaptive optics, Deformable mirrors, Monte Carlo methods, Image quality, Turbulence

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Proceedings Article | 9 July 2008 Paper

The FIRST project: a single-mode fiber-based very high-dynamic range diffraction-limited imaging instrument at visible to near-infrared wavelengths

Takayuki Kotani, Guy Perrin, Sylvestre Lacour, Eric Thiébaut, Julien Woillez, Pierre Fedou, Jean-Philippe Berger, Pascal Bordé, Olivier Chesneau, Pierre Kervella, Olivier Lai, Alain Lecavelier, Stephen Ridgway, Daniel Rouan, Alfred Vidal-Madjar

Proc. SPIE. 7014, Ground-based and Airborne Instrumentation for Astronomy II

KEYWORDS: Diffraction, Point spread functions, Telescopes, Astronomy, Imaging systems, Exoplanets, Range imaging, High dynamic range imaging, Prototyping, Visibility

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Proceedings Article | 28 June 2006 Paper

VASAO: visible all sky adaptive optics

Christian Veillet, Olivier Lai, Derrick Salmon, Jean-Paul Pique

Proc. SPIE. 6272, Advances in Adaptive Optics II

KEYWORDS: Diffraction, Telescopes, Stars, Sensors, Photons, Adaptive optics, Sodium, Laser guide stars, Infrared telescopes, Mesosphere

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Proceedings Article | 15 June 2006 Paper

FlyEyes: integrating CCID-35 into PUEO AO system at CFHT

Kevin K. Y. Ho, Jean-Charles Cuillandre, Chueh-Jen Lin, Tom Benedict, Olivier Lai, Jeff Ward, Derrick Salmon, Gerry Luppino, James Beletic, Reinhold Dorn, Pascal Puget, Barry Burke, Shiang-Yu Wang

Proc. SPIE. 6276, High Energy, Optical, and Infrared Detectors for Astronomy II

KEYWORDS: Avalanche photodetectors, Sensors, Signal attenuation, Silicon, Quantum efficiency, Wavefront sensors, Amplifiers, Adaptive optics, Epoxies, Charge-coupled devices

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Proceedings Article | 20 October 2004 Paper

'OHANA phase I: adaptive optics and single mode fiber coupling

Julien Woillez, Guy Perrin, Jean Guerin, Olivier Lai, Francois Reynaud, Peter Wizinowich, Christopher Neyman, David Le Mignant, Katherine Roth, John White

Proc. SPIE. 5491, New Frontiers in Stellar Interferometry

KEYWORDS: Multimode fibers, Observatories, Telescopes, Gemini Observatory, Interferometers, Interferometry, Single mode fibers, Adaptive optics, Phase interferometry, Keck Observatory

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Proceedings Article | 20 October 2004 Paper

'OHANA

Guy Perrin, Olivier Lai, Julien Woillez, Jean Guerin, Takayuki Kotani, Sebastien Vergnole, Andrew Adamson, Christ Ftaclas, Olivier Guyon, Pierre Lena, Jun Nishikawa, Francois Reynaud, Katherine Roth, Stephen Ridgway, Alan Tokunaga, Peter Wizinowich

Proc. SPIE. 5491, New Frontiers in Stellar Interferometry

KEYWORDS: Optical fibers, Telescopes, Gemini Observatory, Interferometers, Dispersion, Glasses, Interferometry, Single mode fibers, Space telescopes, K band

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Proceedings Article | 20 October 2004 Paper

Tomography of active galactic nuclei broad line region: a science case for next-generation extremely long baseline optical interferometry

Julien Woillez, Hélène Sol, Guy Perrin, Olivier Lai

Proc. SPIE. 5491, New Frontiers in Stellar Interferometry

KEYWORDS: Interferometers, Interferometry, 3D modeling, Tomography, Optical tomography, Spatial resolution, Astronomical imaging, Motion measurement, Bromine, Active galactic nuclei

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Proceedings Article | 29 September 2004 Paper

Update report on FlyEyes: a dual CCD detector system upgrade for PUEO

Kevin Ho, Jean-Charles Cuillandre, Pascal Puget, Derrick Salmon, Olivier Lai, James Beletic, Gerard Luppino, Reinhold Dorn, Barry Burke

Proc. SPIE. 5499, Optical and Infrared Detectors for Astronomy

KEYWORDS: Mirrors, Avalanche photodetectors, Clocks, Sensors, Wavefront sensors, Deformable mirrors, Data acquisition, Charge-coupled devices, Image storage, Real-time computing

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Proceedings Article | 3 March 2003 Paper

Simulations of high-order curvature adaptive optics

Olivier Lai, Thomas Craven-Bartle

Proc. SPIE. 4860, High-Contrast Imaging for Exo-Planet Detection

KEYWORDS: Point spread functions, Telescopes, MATLAB, Avalanche photodetectors, Sensors, Electrodes, Adaptive optics, High dynamic range imaging, Charge-coupled devices, CCD image sensors

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Proceedings Article | 21 February 2003 Paper

OHANA phase II: a prototype demonstrator of fiber-linked interferometry between very large telescopes

Guy Perrin, Olivier Lai, Julien Woillez, Jean Guerin, Francois Reynaud, Stephen Ridgway, Pierre Lena, Peter Wizinowich, Alan Tokunaga, Jun Nishikawa, Francois Rigaut, Andrew Adamson, Olivier Guyon

Proc. SPIE. 4838, Interferometry for Optical Astronomy II

KEYWORDS: Telescopes, Astronomy, Gemini Observatory, Interferometers, Interferometry, Single mode fibers, Space telescopes, Large telescopes, Astronomical imaging, Prototyping

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Proceedings Article | 21 February 2003 Paper

Injection into singlemode fibers for OHANA

Julien Woillez, Jean Guerin, Guy Perrin, Olivier Lai, Francois Reynaud, Claude Collin, Jean Cretenet, Claude Marlot, Sylvain Pau, Jean-Michel Reess, Denis Ziegler, Christophe Berthod, Bernard Brient

Proc. SPIE. 4838, Interferometry for Optical Astronomy II

KEYWORDS: Infrared detectors, Multimode fibers, Telescopes, Interferometry, Single mode fibers, Adaptive optics, Head, Astronomical telescopes, Infrared telescopes, K band

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Proceedings Article | 21 February 2003 Paper

OHANA Phase III: scientific operation of an 800-meter Mauna Kea interferometer

Olivier Lai, Stephen Ridgway, Pierre Lena, Guy Perrin, Gregory Fahlman, Andrew Adamson, Alan Tokunaga, Jun Nishikawa, Peter Wizinowich, Francois Rigaut

Proc. SPIE. 4838, Interferometry for Optical Astronomy II

KEYWORDS: Observatories, Telescopes, Astronomy, Data modeling, Interferometers, Interferometry, Infrared radiation, Astronomical telescopes, Astronomical imaging, Infrared telescopes

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Once the proof of concept of the OHANA Array has been demonstrated, the Phase II capabilities can be put into regular science operation, and the OHANA facility can be upgraded to extend interferometric operation to include all of the telescopes of the OHANA Consortium member observatories. This will constitute the Phase III of OHANA. The technical developments required will be relatively straight-forward. Longer fiber sets will be procured (fiber losses are not a limiting factor at the OHANA scale). An enhanced delay line capability will be needed in order to exploit longer baselines with good sky coverage and ample super-synthesis (several compact, multi-pass long optical delay concepts are under investigation). The scheduling and operation modes of an instrument such as OHANA present interesting opportunities and complications. We envision a place for both collaborative consortium science, based on mutual allocation of facility access, and PI-driven access, based on telescope access exchange between consortium members. The most potentially successful mode of operation would imply a community driven model, open to proposals from the different time allocation comittees. This poster looks at possible methods of allocation and operation, inspired by the UKIRT infrared survey (UKIDSS), the European VLBI, and the very interesting possibility of a Mauna Kea telescope time exchange scheme. The issue of data property is of course intimately tied with the proposal/operation system, and means of data availability and distribution are discussed, along with data interpretation tools, which may be modeled on existing systems such as the ISC at Caltech or the JMMC in France. when weighed against the UV coverage, the potential science and the uniqueness of this project, all these issues are worth an in depth study. Discussions are starting as to an OHANA Operation Committee, the goal of which would be to discuss, define and eventually carry out operational modes. The goal, of course, is for the Operation Committee to handle the details of multi-telescope scheduling in a way that will be transparent to the scientist who merely seeks the observational results.

Proceedings Article | 21 February 2003 Paper

Extragalactic astronomy with the OHANA array

Julien Woillez, Helene Sol, Olivier Lai, Olivier Guyon, Guy Perrin

Proc. SPIE. 4838, Interferometry for Optical Astronomy II

KEYWORDS: Near infrared, Telescopes, Interferometers, Interferometry, Distance measurement, Spatial resolution, Astronomical imaging, Active galactic nuclei, Extragalactic astronomy, Visibility

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Proceedings Article | 21 February 2003 Paper

Optical delay for OHANA

Stephen Ridgway, Guy Perrin, Julien Woillez, Jean Guerin, Olivier Lai

Proc. SPIE. 4838, Interferometry for Optical Astronomy II

KEYWORDS: Optical fibers, Telescopes, Mirrors, Polarization, Reflection, Silver, Interferometry, Wavefronts, Space telescopes, Phase shifts

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Proceedings Article | 21 February 2003 Paper

OHANA: representative science objectives

Olivier Lai, Stephen Ridgway, Jean-Philippe Berger, Catherine Dougados, Vincent Coude du Foresto, Olivier Guyon, Regis Lachaume, Eugene Magnier, Fabien Malbet, Francois Menard, Denis Mourard, Guy Perrin, Helene Sol, Steve Warren, Julien Woillez

Proc. SPIE. 4838, Interferometry for Optical Astronomy II

KEYWORDS: Signal to noise ratio, Telescopes, Stars, Data modeling, Interferometers, Interferometry, Planets, K band, Visibility, Light

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In this poster, we examine the science potential of an 800 meter interferometer such as the OHANA Array. The working assumptions are a K = 12 limiting magnitude, a 0.5 milliarcsecond resolution at K band, and a small (diffraction limit of individual telescope) field of view. The science cases described herein are by no means exhaustive and perhaps not even the ones that will eventually be carried out, but serve to illustrate the potential of the array. We expect that operation of the array will be proposal driven, so the actual science will come from the Mauna Kea communities. Our philosophy is that any measurement that can be made at a dedicated interferometer facility should not be a strong driver for OHANA. Therefore the science areas discussed in the poster focus on very high angular resolution measurements of faint sources. In some cases, science which can be addressed with simpler or dedicated facilities at an exploratory level can be carried to a significant new capability with OHANA. A limitng magnitude of 12 was obtained by simple computations, but first tests on the sky with the injection module (See adjacent poster on Phase I) will help narrow down this figure. At such sensitivity, Cepheid pulsations can be studied in considerable detail for a wide range of stellar parameters, leading to enhanced confidence in the accuracy of their use for distance measurement with minimal extrapolation or inferrence. The disk/star interaction zone in young stellar objects can be resolved with unprecedented detail for a range of masses and ages, providing direct information about the jet formation region, accretion rates and disk conditions. The broad line region of active galactic nuclei can be studied in a large number of sources of differing characteristics, testing specific models for AGN nuclear structure. For OHANA Phase III, a dual-star phase tracking capability is planned. With the resulting increased sensitivity, direct brown dwarf diameter measurement will provide a strong check on evolution models. Microlensing events could be resolved and provide unique new information about the lensing and the lensed objects.

Proceedings Article | 7 February 2003 Paper

Optimal pupil mask geometries for large AO-compensated telescopes

David Tyler, Olivier Lai, H. Muralimanohar

Proc. SPIE. 4839, Adaptive Optical System Technologies II

KEYWORDS: Actuators, Signal to noise ratio, Optical transfer functions, Telescopes, Stars, Spatial frequencies, Sensors, Adaptive optics, Turbulence, Device simulation

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Proceedings Article | 7 February 2003 Paper

FlyEyes: a dual CCD detector system for CFHT PUEO NUI's wavefront sensor

Jean-Charles Cuillandre, James Beletic, Reinhold Dorn, Gerard Luppino, Sidik Isani, Nicolas Gorceix, Olivier Lai, Thomas Craven-Bartle, Barry Burke, Francois Menard

Proc. SPIE. 4839, Adaptive Optical System Technologies II

KEYWORDS: Avalanche photodetectors, Cameras, Sensors, Image processing, Quantum efficiency, Wavefront sensors, Adaptive optics, Head, Charge-coupled devices, CCD image sensors

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Proceedings Article | 7 February 2003 Paper

PUEO NUI: a feasible and fast upgrade of the CFHT adaptive optics system for high dynamic range imaging

Olivier Lai, Francois Menard, Jean-Charles Cuillandre

Proc. SPIE. 4839, Adaptive Optical System Technologies II

KEYWORDS: Point spread functions, Telescopes, Stars, Sensors, Electrodes, Adaptive optics, High dynamic range imaging, Planets, K band, Asteroids

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Proceedings Article | 7 February 2003 Paper

Science with CFHT's future high dynamic range AO system PUEO NUI

Francois Menard, Olivier Lai, Jean-Charles Cuillandre

Proc. SPIE. 4839, Adaptive Optical System Technologies II

KEYWORDS: Point spread functions, Telescopes, Stars, Satellites, Imaging spectroscopy, Adaptive optics, High dynamic range imaging, Dynamical systems, Planets, Asteroids

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Proceedings Article | 7 July 2000 Paper

Performance of the W.M. Keck Observatory Natural Guide Star Adaptive Optic Facility: the first year at the telescope

Peter Wizinowich, D. Scott Acton, Olivier Lai, John Gathright, William Lupton, Paul Stomski

Proc. SPIE. 4007, Adaptive Optical Systems Technology

KEYWORDS: Human-machine interfaces, Telescopes, Mirrors, Stars, Cameras, Calibration, Wavefront sensors, Adaptive optics, Deformable mirrors, Galactic astronomy

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Proceedings Article | 7 July 2000 Paper

Initial performance of the Keck AO wavefront controller system

Erik Johansson, D. Scott Acton, Jong An, Kenneth Avicola, Barton Beeman, James Brase, Carmen Carrano, John Gathright, Donald Gavel, Randall Hurd, Olivier Lai, William Lupton, Bruce Macintosh, Claire Max, Scot Olivier, J. Shelton, Paul Stomski, Kevin Tsubota, Kenneth Waltjen, James Watson, Peter Wizinowich

Proc. SPIE. 4007, Adaptive Optical Systems Technology

KEYWORDS: Mathematical modeling, Telescopes, Mirrors, Data modeling, Diagnostics, Wavefronts, Adaptive optics, Control systems, Deformable mirrors, Keck Observatory

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Proceedings Article | 7 July 2000 Paper

eXtragalactic astronomy: the X-games of adaptive optics

Olivier Lai

Proc. SPIE. 4007, Adaptive Optical Systems Technology

KEYWORDS: Infrared imaging, Point spread functions, Telescopes, Stars, Sensors, Wavefront sensors, Adaptive optics, Deconvolution, Infrared radiation, Galactic astronomy

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Proceedings Article | 7 July 2000

Neptune and Titan observed with Keck Telescope adaptive optics

Claire Max, Bruce Macintosh, Seran Gibbard, Donald Gavel, Henry Roe, Imke de Pater, Andrea Ghez, D. Scott Acton, Peter Wizinowich, Olivier Lai

Proc. SPIE. 4007, Adaptive Optical Systems Technology

KEYWORDS: Infrared imaging, Point spread functions, Telescopes, Cameras, Wavefronts, Adaptive optics, Clouds, Neptune, Space telescopes, Infrared radiation

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Proceedings Article | 7 July 2000 Paper

MANO: the modal analysis and noise optimization program for the W.M. Keck Observatory adaptive optics system

Olivier Lai, Paul Stomski, Eric Gendron

Proc. SPIE. 4007, Adaptive Optical Systems Technology

KEYWORDS: Actuators, Mirrors, Stars, Wavefront sensors, Adaptive optics, Control systems, Deformable mirrors, Space mirrors, Modal analysis, Keck Observatory

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In the photon starved regime (which is usually the case in the real world), adaptive optics can benefit from advanced or innovative schemes such as modal control. The concept is quite natural, as one looks for the natural modes (eigen-modes, Karhunen-Loeve) that occur in the atmosphere and that the deformable mirror can produce; once these modes are identified, the loop gain that minimizes the residual phase variance is determined. Because the modes form an orthogonal and independent basis, optimizing each mode individually ensures that the global minimum is found, producing the highest Strehl ratio possible. In the case of Keck Adaptive Optics System, there were two fundamental difficulties that made the modal control scheme difficult. The first one is that the pupil is not circular but hexagonal. The second one is that being a the Nasmyth focus, the (non-circular) pupil rotates on the wavefront sensor. Some sub-apertures are gradually illuminated as others get extinguished, and the natural modes of the system evolve as a function of pupil rotation. In this poster, we describe the first step of building a modal control, which is to determine what the appropriate modes are, and whether they need to be computed in real time, to compensate for pupil rotation. We also show two methods that were tried to optimize the loop gain (random walk and modified Newton-Raphson). These methods were used in zonal control, as a proof of concept. On-sky trials with a modal scheme showed us that the real time mode determination was not practical or necessary, and a set of mode that worked well under any geometry was found: the covariance matrices of these modes had a diagonal that was factors of ten higher than non- diagonal elements indicating that the modes that we computed were in fact independent in the atmosphere. However, the optimizing schemes required too many samples to produce adequate statistics to find the minimum residual phase variance. Changes to the real time code to provide statistics in real time will help to produce a reliable and automatic modal control.

Proceedings Article | 7 July 2000 Paper

GriF: an infrared 3D spectroscopic mode for KIR/PUEO

Yann Clenet, Robin Arsenault, Jean-Luc Beuzit, Almas Chalabaev, Claude Delage, Gilles Joncas, Francois Lacombe, Olivier Lai, Etienne LeCoarer, David Le Mignant, Sylvain Pau, Patrick Rabou, Daniel Rouan

Proc. SPIE. 4007, Adaptive Optical Systems Technology

KEYWORDS: Optical filters, Fabry–Perot interferometers, Spectroscopy, Adaptive optics, Infrared spectroscopy, Spectral resolution, Field spectroscopy, Infrared radiation, Spatial resolution, Infrared telescopes

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Proceedings Article | 5 July 2000 Paper

Fibered large interferometer on top of Mauna Kea: OHANA, the optical Hawaiian array for nanoradian astronomy

Guy Perrin, Olivier Lai, Pierre Lena, Vincent Coude du Foresto

Proc. SPIE. 4006, Interferometry in Optical Astronomy

KEYWORDS: Telescopes, Astronomy, Interferometers, Interferometry, Single mode fibers, Adaptive optics, Spectral resolution, Astronomical imaging, K band, Visibility

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Proceedings Article | 11 September 1998 Paper

Laboratory calibration of the W.M. Keck Observatory Adaptive Optics Facility

D. S. Acton, P. Wizinowich, P. Stomski, J. Shelton, O. Lai

Proc. SPIE. 3353, Adaptive Optical System Technologies

KEYWORDS: Telescopes, Light sources, Stars, Interferometers, Calibration, Wavefront sensors, Adaptive optics, Image sensors, Turbulence, Device simulation

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Proceedings Article | 11 September 1998 Paper

Analytical model for Shack-Hartmann-based adaptive optics systems

Francois Rigaut, Jean-Pierre Veran, Olivier Lai

Proc. SPIE. 3353, Adaptive Optical System Technologies

KEYWORDS: Actuators, Point spread functions, Spatial frequencies, Sensors, Error analysis, Fourier transforms, Adaptive optics, Turbulence, Phase measurement, Systems modeling

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Proceedings Article | 11 September 1998 Paper

High angular observations of active galactic nuclei using PUEO, the CFHT adaptive optics system

Daniel Rouan, Olivier Lai, Francois Rigaut, D. Alloin

Proc. SPIE. 3353, Adaptive Optical System Technologies

KEYWORDS: Infrared imaging, Telescopes, Stars, Wavefront sensors, Adaptive optics, Infrared radiation, Spatial resolution, Galactic astronomy, Active galactic nuclei, Tin

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Proceedings Article | 21 March 1997 Paper

CFHT adaptive optics: first results at the telescope

O. Lai, Jean-Pierre Veran, Francois Rigaut, Daniel Rouan, Pierre Gigan, Francois Lacombe, Pierre Lena, Robin Arsenault, Derrick Salmon, James Thomas, David Crampton, J. Murray Fletcher, James Stilburn, Corinne Boyer, Pascal Jagourel

Proc. SPIE. 2871, Optical Telescopes of Today and Tomorrow

KEYWORDS: Point spread functions, Telescopes, Mirrors, Stars, Sensors, Electrodes, Adaptive optics, Control systems, Image quality, Turbulence

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Showing 5 of 52 publications

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