Imaging & Spectroscopy

Prototyping Liquid-crystal Coronagraphs For Exo-Earth Imaging

By Keith Cowing

Status Report

astro-ph.IM

July 25, 2024

Filed under astro-ph.IM, coronagraph, Earthlike planet, ESA, exoplanet, imaging, SUPPPPRESS, vector vortex coronagraph

Prototyping Liquid-crystal Coronagraphs For Exo-Earth Imaging — Left: First prototype of the tgVVC as manufactured by ImagineOptix. The pattern inaccuracies, retardance errors, and alignment errors result in a non-vortex pattern between crossed polarizers. Adapted from Doelman et al. (2023).14 Right: One of the first liquid-crystal mgVVC patterns manufactured by Colorlink Japan. — astro-ph.IM

This paper presents initial results from the ESA-funded “SUPPPPRESS” project, which aims to develop high-performance liquid-crystal coronagraphs for direct imaging of Earth-like exoplanets in reflected light.

The project focuses on addressing the significant challenge of polarization leakage in vector vortex coronagraphs (VVCs). We utilize newly manufactured multi-grating, liquid-crystal VVCs, consisting of a two- or three-element stack of vortex and grating patterns, to reduce this leakage to the 10−10 contrast level.

We detail the experimental setups, including calibration techniques with polarization microscopes and Mueller matrix ellipsometers to enhance the direct-write accuracy of the liquid-crystal patterns. The performance testing of these coronagraph masks will be conducted on the THD2 high-contrast imaging testbed in Paris.

Iva Laginja, David Doelman, Frans Snik, Pierre Baudoz, Felix Bettonvil, Jeroen H. Rietjens, Chris N. van Dijk, Kristien Peeters, Alexander Eigenraam, Erin Pougheon, Tom van der Wielen, Marco Esposito, Thomas Wijnen, Mariya Krasteva, Matteo Taccola

Comments: 14 pages, 10 figures
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2407.14723 [astro-ph.IM] (or arXiv:2407.14723v1 [astro-ph.IM] for this version)
Journal reference: Proc. SPIE 13092, Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 1309280
Submission history
From: Iva Laginja
[v1] Sat, 20 Jul 2024 02:12:01 UTC (6,638 KB)
https://arxiv.org/abs/2407.14723
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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