Liquid-crystal vector vortex coronagraphs for exoplanet imaging: progress from the SUPPPPRESS project

We report on the 1.5 years of progress of the ESA-funded “SUPPPPRESS” project, which aims to develop high-performance liquid-crystal coronagraphs for the direct detection and spectral characterization of Earth-like planets in the habitable zone. The project focuses on improving the contrast performance and increasing the operational spectral bandwidth of the Vector Vortex Coronagraph (VVC). We manufacture multi-grating VVCs, consisting of a two- or three-element stack of vortex and grating patterns, to significantly reduce the impact of polarization leakage and enabling us to fully exploit its achromatic and scale-invariant properties. In this paper, we discuss the improved liquid-crystal mask manufacturing, the multi-grating VVC assembly, and high-contrast imaging testing at the THD2 testbed in Paris.