Coronagraphs

Halftoning for High-contrast Imaging : Developments for the SPHERE and EPICS Instruments

Controlling the amplitude of light is crucial for many scientific applications, such as in imaging systems, astronomical instruments or laser physics. We provide a brief overview of recent R&D activities at ESO using halftoning, the process of presenting a continuous image through use of dots. Customised filters with spatially varying transmission are produced using a binary array of (...)

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The High Order Test Bench : Evaluating High Contrast Imaging Concepts for SPHERE and EPICS

The High Order Test bench (HOT) is an adaptive optics facility developed at ESO to test high contrast imaging instrument technologies and concepts. HOT reproduces realistically in the laboratory the conditions encountered at a telescope, including turbulence, high order adaptive optics correction and coronagraphy. Experiments carried out with HOT will be discussed mainly in the context of the (...)

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Laboratory Demonstration of Efficient XAO Coronagraphy in the Context of SPHERE

Extreme adaptive optics systems (XAO) dedicated to the search for extrasolar planets are currently being developed for 8-10 m telescopes. The high-order test bench (HOT) is a high-contrast imaging adaptive optics bench developed at the European Southern Observatory to test and optimize different techniques and technologies (e.g., wavefront sensors, coronagraphs, speckle calibration methods, (...)

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Apodized Lyot coronagraph for SPHERE/VLT. I. Detailed numerical study

SPHERE (which stands for Spectro-Polarimetric High-contrast Exoplanet REsearch) is a second-generation Very Large Telescope (VLT) instrument dedicated to high-contrast direct imaging of exoplanets whose first-light is scheduled for 2011. Within this complex instrument one of the central components is the apodized Lyot coronagraph (ALC). The principal aim of this paper is to report the first (...)

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Apodized Lyot coronagraph for SPHERE/VLT : II. Laboratory tests and performance

SPHERE (which stands for Spectro-Polarimetric High-contrast Exoplanet REsearch) is a second-generation Very Large Telescope (VLT) instrument dedicated to high-contrast direct imaging of exoplanets whose first-light is scheduled for 2011. Within this complex instrument one of the central components is the apodized Lyot coronagraph (ALC). The principal aim of this paper is to report the first (...)

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Prototyping coronagraphs for exoplanet characterization with SPHERE

The detection and characterization of extrasolar planets with SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch) is challenging and in particular relies on the ability of a coronagraph to attenuate the diffracted starlight. SPHERE includes 3 instruments, 2 of which can be operated simultaneously in the near IR from 0.95 to 1.8 microns. This requirements is extremely critical for (...)

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