Paper 14145-193
Paper 14145-193
Optical testbed and performance evaluation of large liquid-crystal diffractive optics
7 July 2026 • 17:30 - 19:00 CEST | Room B4-M3
Abstract
The TOLIMAN space telescope mission targets revolutionary performance in precision astrometric monitoring of binary stars to detect orbiting companions at micro-arcsecond levels of precision. A key enabling technology is a 125mm diameter patterned diffractive transmission plate with precisely aligned liquid crystal (LC) axes. Assembly of the flight-ready LC TOLIMAN poses immediate challenges to maintain optical transmitted wavefront quality. Along with this, LC polarisation degradation due to temperature and UV exposure is not well understood in an Earth orbit context. Using an optical testbed at the University of Sydney, this paper presents methodologies and outcomes in the pathway to furnish a flight-qualified LC diffractive pupil.
Presenter
Grace Piroscia
The Univ. of Sydney (Australia)
Grace Piroscia is a second-year PhD student at the University of Sydney, affiliated with the Sydney Institute for Astronomy. She graduated from the University of Sydney in 2023 with a Bachelor of Engineering Honours (Mechatronics) and a Bachelor of Science (Physics).
Grace is currently involved in the TOLIMAN space mission, developing the optical testbed and phase retrieval methodology used to measure the optical performance of the TOLIMAN liquid crystal diffractive pupil. Along with this, Grace has been involved in the design and manufacturing of a novel optic developed at the University of Sydney, known as a "Jewel” mask. Jewel Masks facilitate full-pupil non-redundant aperture masking, and Grace is currently developing a wavefront sensing algorithm to facilitate a multi-sensor AO system on SCExAO at the Subaru Telescope using Jewel.
Her research areas of expertise include differentiable modelling, high-resolution imaging and optical instrumentation and manufacturing methods.