Design of Vector-Vortex Coronagraphs for Exoplanet Science using a Six Meter Space Telescope

In this paper, we present a concept for an active, 6-meter space telescope (6MST) for space-based general astrophysics and consider its potential for coronagraphy. The telescope operates in spectral regions from ∼100 nm up to 2 µm, thus having the range comparable to LUVOIR and HabEx in the longer wavelength end but extending the range up to the shorter wavelength end of Spitzer. It utilizes a vector-vortex coronagraph for exoplanet work. We evaluate the impact of Primary Mirror (PM) segment gaps on the 20% broadband contrast floor when a charge 4 or charge 6 vortex mask and two 64x64 actuators sequential Deformable Mirrors (DM’s) are used in the coronagraph, and compare the performance of a Lyot-mask and a pupil apodization mask relative to one another.