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.
@article{arxiv.2407.14723,
title = {Prototyping liquid-crystal coronagraphs for exo-Earth imaging},
author = {Iva Laginja and David Doelman and Frans Snik and Pierre Baudoz and Felix Bettonvil and Jeroen H. Rietjens and Chris N. van Dijk and Kristien Peeters and Alexander Eigenraam and Erin Pougheon and Tom van der Wielen and Marco Esposito and Thomas Wijnen and Mariya Krasteva and Matteo Taccola},
journal= {arXiv preprint arXiv:2407.14723},
year = {2024}
}