Manufacturing a novel diffractive pupil for the astrometric detection of exoplanets

The TOLIMAN space mission confronts the challenge of detecting Earth analogues in the immediate solar neighbourhood by using novel astrometric techniques. This bespoke, low-cost mission will employ a novel optical and signal encoding system, enabling high-precision measurements that typically require larger instruments. Targeting the Alpha Centauri system, TOLIMAN will utilise an innovative diffractive pupil to mitigate the limitations of a relatively modest satellite and payload infrastructure to make measurements at the extreme precisions required. In this work, we describe the design and manufacturing of the pupil, which employs liquid crystal technologies and substrates with low coefficients of thermal expansion, with the goal of making measurements resistant to inevitable optical distortions and aberrations.