68 research outputs found
Manufacturing of four-quadrant phase mask for nulling interferometry in the thermal infrared
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
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
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
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