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arXiv · 1604.08334

The VORTEX coronagraphic test bench

Aissa Jolivet·Pierre Piron·Elsa Huby·Olivier Absil·Christian Delacroix·Dimitri Mawet·Jean Surdej·Serge Habraken
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Abstract

In this paper, we present the infrared coronagraphic test bench of the University of Li\`ege named VODCA (Vortex Optical Demonstrator for Coronagraphic Applications). The goal of the bench is to assess the performances of the Annular Groove Phase Masks (AGPMs) at near- to mid-infrared wavelengths. The AGPM is a subwavelength grating vortex coronagraph of charge two (SGVC2) made out of diamond. The bench is designed to be completely achromatic and will be composed of a super continuum laser source emitting in the near to mid-infrared, several parabolas, diaphragms and an infrared camera. This way, we will be able to test the different AGPMs in the M, L, K and H bands. Eventually, the bench will also allow the computation of the incident wavefront aberrations on the coronagraph. A reflective Lyot stop will send most of the stellar light to a second camera to perform low-order wavefront sensing. This second system coupled with a deformable mirror will allow the correction of the wavefront aberrations. We also aim to test other pre- and/or post-coronagraphic concepts such as optimal apodization.

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Aissa Jolivet, Pierre Piron, Elsa Huby, Olivier Absil, Christian Delacroix, Dimitri Mawet, Jean Surdej, Serge Habraken. 2016-04-28. The VORTEX coronagraphic test bench. https://doi.org/10.1117/12.2055791

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