Ronald Roelfsema

Netherlands Institute for Radio Astronomy

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A. Boccaletti

Université Paris Cité

David Mouillet

Université Grenoble Alpes

Rens Waters

SRON Netherlands Institute for Space Research

Jean-Luc Beuzit

Institut de Planétologie et d'Astrophysique de Grenoble

F. Rigal

Université Grenoble Alpes

Julien Charton

ProbaYes (France)

Christoph U. Keller

Leiden Observatory

R. Gratton

Osservatorio Astronomico di Padova

Kjetil Dohlen

Aix-Marseille Université

M. Kasper

Max Planck Institute for Astronomy

Cooperative Institutions

Centre National de la Recherche Scientifique

Institut de Planétologie et d'Astrophysique de Grenoble

Max Planck Institute for Astronomy

Université Grenoble Alpes

Netherlands Institute for Radio Astronomy

Université Joseph Fourier

Laboratoire d’Astrophysique de Marseille

Osservatorio Astronomico di Padova

Office National d'Études et de Recherches Aérospatiales

Observatoire de Paris

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The ZIMPOL high-contrast imaging polarimeter for SPHERE: design, manufacturing, and testing

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2010)

Ronald Roelfsema Hans Martin Schmid Johannes Pragt D. Gisler Rens Waters

ZIMPOL is the high contrast imaging polarimeter subsystem of the ESO SPHERE instrument. ZIMPOL is dedicated to detect the very faint reflected and hence polarized visible light from extrasolar planets. ZIMPOL is located behind an extreme AO system (SAXO) and a stellar coronagraph. SPHERE is foreseen to have first light at the VLT at the end of 2011. ZIMPOL is currently in the manufacturing, integration and testing phase. We describe the optical, polarimetric, mechanical, thermal and electronic design as well as the design trade offs. Specifically emphasized is the optical quality of the key performance component: the Ferro-electric Liquid Crystal polarization modulator (FLC). Furthermore, we describe the ZIMPOL test setup and the first test results on the achieved polarimetric sensitivity and accuracy. These results will give first indications for the expected overall high contrast system performance. SPHERE is an instrument designed and built by a consortium consisting of LAOG, MPIA, LAM, LESIA, Fizeau, INAF, Observatoire de Genève, ETH, NOVA, ONERA and ASTRON in collaboration with ESO.

Coronagraph

Polarimeter

First light

10.1117/12.857045

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SPHERE ZIMPOL: overview and performance simulation

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2008)

C. Thalmann H. M. Schmid A. Boccaletti David Mouillet Kjetil Dohlen

The ESO planet finder instrument SPHERE will search for the polarimetric signature of the reflected light from extrasolar planets, using a VLT telescope, an extreme AO system (SAXO), a stellar coronagraph, and an imaging polarimeter (ZIMPOL). We present the design concept of the ZIMPOL instrument, a single-beam polarimeter that achieves very high polarimetric accuracy using fast polarization modulation and demodulating CCD detectors. Furthermore, we describe comprehensive performance simulations made with the CAOS problem-solving environment. We conclude that direct detection of Jupiter-sized planets in close orbit around the brightest nearby stars is achievable with imaging polarimetry, signal-switching calibration, and angular differential imaging.

Polarimeter

Coronagraph

Orbital mechanics

10.1117/12.789158

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The SPHERE exoplanet imager: status report at PDR

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2007)

Francois Wildi Jean-Luc Beuzit Markus Feldt David Mouillet Kjetil Dohlen

The SPHERE is an exo-solar planet imager, which goal is to detect giant exo-solar planets in the vicinity of bright stars and to characterize them through spectroscopic and polarimetric observations. It is a complete system with a core made of an extreme-Adaptive Optics (AO) turbulence correction, pupil tracker and interferential coronagraphs. At its back end, an Infra-Red Dual-beam Imaging and Spectroscopy science module and an integral field spectrograph work in the Near Infrared (NIR) Y, J, H and Ks bands (0.95 - 2.32μm) and a high resolution polarization camera covers the visible (0.6 - 0.9 μm) region. We describe briefly the science goals of the instrument and deduce the top-level requirements. This paper presents the system architecture, and reviews each of the main sub-systems. The results of the latest end-to-end simulations are shown and an update of the expected performance is given. The project has been officially kicked-off in March 2006, it is presently undergoing Preliminary Design Review and is scheduled for 1st light in early 2011. This paper reviews the present design of SPHERE but focuses on the changes implemented since this project was presented the last time to this audience.

Integral field spectrograph

First light

10.1117/12.734785

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Citations (4)