68 research outputs found

    Manufacturing of four-quadrant phase mask for nulling interferometry in the thermal infrared

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    The Four Quadrant Phase Mask is a key component for the design of advanced coronagraphs that may be used to search exo-planets. The validity of this concept has been demonstrated in the visible and need now to be demonstrated in the mid infrared. For this purpose, two components are manufactured for wavelengths 4.75 and 16.25 μm. This manufacturing requires the deposition of ZnSe layers using Ion Assisted Deposition, followed by a lift off process

    Prototyping coronagraphs for exoplanet characterization with SPHERE

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    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 coronagraphy. This paper briefly introduces the concepts of 2 coronagraphs, the Half-Wave Plate Four Quadrant Phase Masks and the Apodized Pupil Lyot Coronagraph, prototyped within the SPHERE consortium by LESIA (Observatory of Paris) and FIZEAU (University of Nice) respectively. Then, we present the measurements of contrast and sensitivity analysis. The comparison with technical specifications allows to validate the technology for manufacturing these coronagraphs.Comment: 10 pages, will be published in the proceeding of the SPIE conference Volume 7015 "Adaptive Optics", held in Marseille from 23 to 28 june 200

    Manufacturing of four-quadrant phase mask for nulling interferometry in the thermal infrared

    Get PDF
    The Four Quadrant Phase Mask is a key component for the design of advanced coronagraphs that may be used to search exo-planets. The validity of this concept has been demonstrated in the visible and need now to be demonstrated in the mid infrared. For this purpose, two components are manufactured for wavelengths 4.75 and 16.25 μm. This manufacturing requires the deposition of ZnSe layers using Ion Assisted Deposition, followed by a lift off process

    Four Quadrant Phase Mask Coronography on large telescopes

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    International audienc

    Four Quadrant Phase Mask Coronography on large telescopes

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    International audienc

    Imaging Exoplanets with NGST/MIRI

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    A ground-based study for the 4Q coronagraph

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    The Four-Quadrant Phase Mask Coronagraph. III. Laboratory Performance

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    International audienc
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