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Your search keyword '"T. ten Brummelaar"' showing total 7 results
Start Over Author "T. ten Brummelaar" Journal optical and infrared interferometry and imaging vii
7 results on '"T. ten Brummelaar"'

1. Looking into the future of interferometry using free-space beam propagation

Author

F. Baron, T. ten Brummelaar, Arturo O. Martinez, Caleb G. Abbott, and Stuart M. Jefferies

Subjects
Wavefront, Physics, Spatial light modulator, Optical fiber, business.industry, Turbulence, Astrophysics::Instrumentation and Methods for Astrophysics, Phase (waves), law.invention, Interferometry, Optics, law, Astrophysics::Solar and Stellar Astrophysics, business, Adaptive optics, Beam (structure)
Abstract

We describe a new concept for future interferometric observations. Our laboratory experiment simulates an interferometer with two telescopes observing through different volumes of atmospheric turbulence. We simulate both vertical and horizontal propagation through the atmosphere; the latter mimics free-space beam propagation without the need for vacuum pipes or fiber optics. Practically, we simulate the effects of atmospheric turbulence using numerically calculated Kolmogorov phase screens injected onto a spatial light modulator. We correct this distorted wavefront using an adaptive optics system to determine the range of turbulence conditions over which we can detect fringes from the two telescopes. Our experiment lays the groundwork for investigating the potential of having movable telescopes in which light propagates from the telescopes to the beam combiner through free space.

Published
2020
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2. CHARA array adaptive optics: complex operational software and performance

Author

T. ten Brummelaar, Douglas R. Gies, Laszlo Sturmann, Denis Mourard, Matthew D. Anderson, Philippe Berio, Cyril Petit, John Monnier, Stefan Kraus, C. B. Lim, Michel Tallon, Michael J. Ireland, Norm Vargas, Judit Sturmann, Chris Farrington, Stephen T. Ridgway, Narsireddy Anugu, Jean Baptiste Le Bouquin, Olli Majoinen, Gail H. Schaefer, Nils H. Turner, Steward Observatory, University of Arizona, Georgia State University, University System of Georgia (USG), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Australian National University (ANU), University of Michigan [Ann Arbor], University of Michigan System, Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), School of Physics and Astronomy [Exeter], University of Exeter, DOTA, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), DOTA, ONERA, Université Paris Saclay [Châtillon], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)

Subjects
Physics - Instrumentation and Detectors, CHARA, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Active galactic nucleus, Computer science, Young stellar object, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, EMCCD, 01 natural sciences, CHARA array, law.invention, 010309 optics, Telescope, [SPI]Engineering Sciences [physics], Software, Optics, Wavefront sensor, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Sensitivity (control systems), Adaptive optics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Throughput (business), ComputingMilieux_MISCELLANEOUS, Astrophysics::Galaxy Astrophysics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Instrumentation and Detectors (physics.ins-det), [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Shack-Hartmann, Long baseline interferometry, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, business
Abstract

The CHARA Array is the longest baseline optical interferometer in the world. Operated with natural seeing, it has delivered landmark sub-milliarcsecond results in the areas of stellar imaging, binaries, and stellar diameters. However, to achieve ambitious observations of faint targets such as young stellar objects and active galactic nuclei, higher sensitivity is required. For that purpose, adaptive optics are developed to correct atmospheric turbulence and non-common path aberrations between each telescope and the beam combiner lab. This paper describes the AO software and its integration into the CHARA system. We also report initial on-sky tests that demonstrate an increase of scientific throughput by sensitivity gain and by extending useful observing time in worse seeing conditions. Our 6 telescopes and 12 AO systems with tens of critical alignments and control loops pose challenges in operation. We describe our methods enabling a single scientist to operate the entire system., Comment: SPIE, Optical and Infrared Interferometry and Imaging VII, Proceedings Volume 11446, 1144622, Dec 14, 2020 "See, https://doi.org/10.1117/12.2561560"

Published
2020
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3. Recent highlights from The CHARA Array

Author

T. ten Brummelaar, Craig Woods, Gail Schaefer, Matthew D. Anderson, Larry Webster, Olli Majoinen, Robert Klement, Judit Sturmann, Steve Golden, Jeremy Jones, Chris Farrington, Nils H. Turner, Laszlo Sturmann, Stephen T. Ridgway, Douglas R. Gies, and Norm Vargas

Subjects
Chara, Interferometry, biology, Computer science, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astronomy, Ranging, Astrophysics::Earth and Planetary Astrophysics, Adaptive optics, biology.organism_classification, Astrophysics::Galaxy Astrophysics, CHARA array
Abstract

The CHARA Array is an optical/infrared interferometer that combines the light from six 1-meter telescopes. With baselines ranging from 34 to 331 meters, CHARA provides sub-milliarcsecond resolution to measure stellar diameters, image stellar surfaces, resolve close binary companions, and study circumstellar environments. In this paper, we present recent highlights from the CHARA Array, focusing on the implementation of adaptive optics, the ongoing development of next generation beam combiners, an update on the community access program, and a discussion about future developments.

Published
2020
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4. MIRC-X polarinterferometry at CHARA

Author

Narsireddy Anugu, Benjamin R. Setterholm, Keith J. C. Johnson, T. ten Brummelaar, Jacob Ennis, Jean-Baptiste Le Bouquin, Aaron Labdon, John D. Monnier, and Stefan Kraus

Subjects
Chara, Physics, biology, Be star, Astrophysics::Instrumentation and Methods for Astrophysics, Polarimetry, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, biology.organism_classification, Polarization (waves), law.invention, Stars, Interferometry, Achromatic lens, law, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Beam splitter
Abstract

We present a new polarimetric mode for the MIRC-X 6-telescope beam combiner at CHARA. Utilizing the extensive u − v coverage afforded by CHARA this mode will be able to resolve and constrain scattered light in environs at milliarcsecond separations of target stars, a largely unexplored parameter space to-date in astronomy. Notably, this upgrade will allow for the investigation of the scattering properties of the inner dust wall at the sublimation radius of Herbig Ae/Be star disks, dust shells surrounding evolved stars, and gas-rich disks around Be stars. Our design adds a series of rotating half-wave plates, achromatic across J- and H-bands, and a polarizing beamsplitter into the MIRC-X beam path. In this work, we also preview on-sky observations, discussing ongoing work calibrating instrumental polarization effects in the CHARA beam path as well as upgrades to the MIRC-X data reduction pipeline.

Published
2020
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5. A new frontier for J-band interferometry: dual-band NIR interferometry with MIRC-X

Author

Narsireddy Anugu, Stefan Kraus, Laszlo Sturmann, John D. Monnier, Jean-Baptiste Le Bouquin, Judit Sturmann, Benjamin R. Setterholm, Tyler Gardner, Gail Schaefer, Cyprien Lanthermann, Claire L. Davies, Aaron Labdon, T. ten Brummelaar, and Jacob Ennis

Subjects
Physics, Interferometry, Optics, Birefringence, business.industry, Infrared, Dispersion (optics), Multi-band device, business, J band, CHARA array
Abstract

In this contribution we report on our work to increase the spectral range of the Michigan Infrared Combiner- eXeter (MIRC-X) instrument at the CHARA array to allow for dual H and J band interferometric observations. We comment on the key science drivers behind this project and the methods of characterisation and correction of instrumental birefringence and dispersion. In addition, we report on the first results from on-sky commissioning in November 2019.

Published
2020
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6. K-band integrated optics beam combiners for CHARA fabricated by ultrafast laser inscription

Author

Ettore Pedretti, T. ten Brummelaar, David Guillaume MacLachlan, Robert R. Thomson, Vincent Coudé du Foresto, Kalaga Madhav, Martin Roth, Aurélien Benoit, Tarun Kumar Sharma, Lucas Labadie, Aline N. Dinkelaker, Fraser A. Pike, Abani Shankar Nayak, and Nicholas Scott

Subjects
Materials science, business.industry, Laser, law.invention, Interferometry, Optics, law, Achromatic lens, K band, Femtosecond, Power dividers and directional couplers, business, Ultrashort pulse, Waveguide
Abstract

We report the ultrafast laser inscription (ULI) and characterization of 3 dB directional achromatic couplers for K-band between 2 and 2.4 μm. The couplers were fabricated in commercial Infrasil glass using 1030 nm femtosecond laser pulses. Straight waveguides inscribed using optimal fabrication parameters exhibit an average propagation loss of ∼1.21 dB over full range of K-band with a single-mode behavior for a length of 17 mm. Directional couplers with different interaction lengths and waveguide widths were fabricated and characterized. We demonstrate that 3 dB achromatic directional couplers for K-band can be fabricated using ULI. These results show that ULI can fabricate highquality couplers for future applications in astronomical interferometry. Our eventual aim is to develop a two-telescope K-band integrated optical beam combiner to replace JouFLU at CHARA.

Published
2020
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7. Progress of the CHARA/SPICA project

Author

Stephane Lagarde, J. Dejonghe, C. Pannetier, Denis Mourard, Karine Perraut, Laszlo Sturmann, C. Bailet, T. ten Brummelaar, Fabien Patru, John Monnier, Sylvestre Lacour, Laurent Jocou, Ph. Berio, Stefan Kraus, D. Lecron, Narsireddy Anugu, Judit Sturmann, Romain Petrov, D. R. Gies, S. Rousseau, Ph. Stee, J.-B. Le Bouquin, Frédéric Cassaing, Nicolas Nardetto, F. Allouche, Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Steward Observatory, University of Arizona, University of Michigan [Ann Arbor], University of Michigan System, University of Exeter, The CHARA Array, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Observatoire de Paris, and Université Paris sciences et lettres (PSL)

Subjects
FOS: Physical sciences, Spica, 01 natural sciences, 7. Clean energy, CHARA array, 010309 optics, [SPI]Engineering Sciences [physics], Optics, 0103 physical sciences, Dispersion (optics), Atmospheric refraction, Astrophysics::Solar and Stellar Astrophysics, Spectral resolution, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, Physics, Chara, [PHYS]Physics [physics], biology, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, biology.organism_classification, Interferometry, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Focus (optics), business
Abstract

International audience; CHARA/SPICA (Stellar Parameters and Images with a Cophased Array) is currently being developed at Observatoire de la Cote d’Azur. It will be installed at the visible focus of the CHARA Array by the end of 2021. It has been designed to perform a large survey of fundamental stellar parameters with, in the possible cases, a detailed imaging of the surface or environment of stars. To reach the required precision and sensitivity, CHARA/SPICA combines a low spectral resolution mode R = 140 in the visible and single-mode fibers fed by the AO stages of CHARA. This setup generates additional needs before the interferometric combination: the compensation of atmospheric refraction and longitudinal dispersion, and the fringe stabilization. In this paper, we present the main features of the 6-telescopes fibered visible beam combiner (SPICA-VIS) together with the first laboratory and on-sky results of the fringe tracker (SPICA-FT). We describe also the new fringe-tracker simulator developed in parallel to SPICA-FT.

Published
2020
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