Cosmic Evolution through UV Surveys (CETUS): Point spread function analysis of three mirror anastigmat telescope

Abstract

Cosmic Evolution through UV Surveys (CETUS) is a concept for a UV space telescope that was studied with funding from NASA. The CETUS Final Report is posted at arXiv: 1909.10437, but post-report studies are continuing. Here, we describe telescope design options for CETUS including a trade study between a traditional on-axis three-mirror anastigmat (TMA) and freeform off-axis TMA solution considering their alignment sensitivity and tolerances. Different secondary support structures are explored for the on-axis design to analyze the irradiance distribution of the point-spread function (PSF) due to the pupil obscuration and how it influences the simulated starfield at the telescope focal planes. With rigorous and judicious analysis in geometrical optical design and physical wave propagation modeling, we aim to enable the next generation of spaceborne optical observatory for UV astronomy. © 2021 SPIE.