Enhanced wavefront sensing for the Roman Coronagraph Instrument: Gaussian probes and compact model validation
arXiv:2607.12805
The paper evaluates the use of Gaussian probe patterns for focal‑plane wavefront sensing in the Roman Space Telescope's Coronagraph Instrument, showing via simulations that they can improve signal‑to‑noise, reduce exposure time, and enable operation on fainter stars.
Abstract
The Coronagraph Instrument on the Roman Space Telescope will be the first space-based system to demonstrate closed-loop focal-plane wavefront sensing and control, a key step towards the Habitable Worlds Observatory. Beyond the baseline Hybrid Lyot Coronagraph, "enhanced modes" are being developed to improve efficiency and science yield. One such mode uses Gaussian probes for electric field estimation, extending the linear regime and allowing higher probe amplitudes. This may increase signal-to-noise, reduce exposure time, accelerate dark hole convergence, and extend operation to stars as faint as . For those reasons, it was selected by the Coronagraph Community Participation Program's Hardware Working Group as the first technology demonstration carried out on Roman in early 2027. We present numerical simulations using a noise-free compact software model, which demonstrate the benefits of replacing the nominal probes with Gaussian probes.
13 pages, 5 figures. Accepted for publication in the proceedings of the 2026 SPIE Astronomical Telescopes + Instrumentation conference (14145-181)