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SAXO: the extreme adaptive optics system of SPHERE (I) system overview and global laboratory performance

Sauvage, Jean Francois and Mawet, Dimitri (2016) SAXO: the extreme adaptive optics system of SPHERE (I) system overview and global laboratory performance. Journal of Astronomical Telescopes, Instruments, and Systems, 2 (2). Art. No. 025003. ISSN 2329-4124. doi:10.1117/1.JATIS.2.2.025003.

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The direct imaging of exoplanet is a leading field of today’s astronomy. The photons coming from the planet carry precious information on the chemical composition of its atmosphere. The second-generation instrument, Spectro-Polarimetric High contrast Exoplanet Research (SPHERE), dedicated to detection, photometry and spectral characterization of Jovian-like planets, is now in operation on the European very large telescope. This instrument relies on an extreme adaptive optics (XAO) system to compensate for atmospheric turbulence as well as for internal errors with an unprecedented accuracy. We demonstrate the high level of performance reached by the SPHERE XAO system (SAXO) during the assembly integration and test (AIT) period. In order to fully characterize the instrument quality, two AIT periods have been mandatory. In the first phase at Observatoire de Paris, the performance of SAXO itself was assessed. In the second phase at IPAG Grenoble Observatory, the operation of SAXO in interaction with the overall instrument has been optimized. In addition to the first two phases, a final check has been performed after the reintegration of the instrument at Paranal Observatory, in the New Integration Hall before integration at the telescope focus. The final performance aimed by the SPHERE instrument with the help of SAXO is among the highest Strehl ratio pretended for an operational instrument (90% in H band, 43% in V band in a realistic turbulence r0, and wind speed condition), a limit R magnitude for loop closure at 15, and a robustness to high wind speeds. The full-width at half-maximum reached by the instrument is 40 mas for infrared in H band and unprecedented 18.5 mas in V band.

Item Type:Article
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Mawet, Dimitri0000-0002-8895-4735
Additional Information:© 2016 Society of Photo-Optical Instrumentation Engineers (SPIE). Paper 15058 received Jul. 23, 2015; accepted for publication Mar. 31, 2016; published online May 24, 2016. This work was partly funded by the European Commission under FP7 Grant Agreement No. 312430 Optical Infrared Coordination Network for Astronomy, and by the Office National d’Etudes et de Recherches Aerospatiales (ONERA) in the frame of the NAIADE Research Project. SPHERE is an instrument designed and built by a consortium consisting of IPAG, MPIA, LAM, LESIA, Laboratoire Fizeau, INAF, Observatoire de Geneve, ETH, NOVA, ONERA and ASTRON in collaboration with ESO. The authors want to thank ESO and SPHERE consortium for implication and participation to AIT of SAXO instrument. The HODM has been provided by the CILAS company through a joint research and development effort under funding from the European Commission Sixth Framework Programme as part of the Optical Infrared Coordination Network for Astronomy (OPTICON) under Grant No. RII3-Ct-2004-001566 (2004-2008).
Funding AgencyGrant Number
European Research Council (ERC)312430
Office National d’Etudes et de Recherches Aerospatiales (ONERA)UNSPECIFIED
European CommissionRII3-Ct-2004-001566
Subject Keywords:adaptive optics; coronagraph; high contrast imaging; wavefront sensing; control; phase diversity; Shack–Hartmann
Issue or Number:2
Record Number:CaltechAUTHORS:20180615-155611063
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Official Citation:Jean-Francois Sauvage, Thierry Fusco, Anne Costille, David Mouillet, Jean-Luc Beuzit, Kjetil Dohlen, Markus E. Kasper, Marcos Suárez Valles, Christian Soenke, Andrea Baruffolo, Bernardo Salasnich, Sylvain Rochat, Enrico Fedrigo, Pierre Baudoz, Emmanuel Hugot, Arnaud Sevin, Denis Perret, François Wildi, Mark Downing, Philippe Feautrier, Pascal Puget, Arthur Vigan, Jared O’Neal, Julien H. V. Girard, Dimitri Mawet, Hans Martin Schmid, Ronald Roelfsema, "SAXO: the extreme adaptive optics system of SPHERE (I) system overview and global laboratory performance," Journal of Astronomical Telescopes, Instruments, and Systems 2(2), 025003 (24 May 2016).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:87171
Deposited By: George Porter
Deposited On:18 Jun 2018 14:59
Last Modified:15 Nov 2021 20:45

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