Polarization aberration modeling of internal occulters for coronagraphs

Fuente: arXiv
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Main Authors: Jenkins, Emory L., Riggs, A J Eldorado, Douglas, Ewan S., Anche, Ramya M., McKeithen, Dylan M., Shaklan, Stuart B.
Format: Preprint
Published: 2025
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_version_ 1866909754870202368
author Jenkins, Emory L.
Riggs, A J Eldorado
Douglas, Ewan S.
Anche, Ramya M.
McKeithen, Dylan M.
Shaklan, Stuart B.
author_facet Jenkins, Emory L.
Riggs, A J Eldorado
Douglas, Ewan S.
Anche, Ramya M.
McKeithen, Dylan M.
Shaklan, Stuart B.
contents The Habitable Worlds Observatory (HWO) is a flagship mission concept proposing to characterize earth-like exoplanets at high contrast with a coronagraph instrument. The most in-depth, validated contrast error budgets made to date have been at the $10^{-9}$ planet-to-star contrast levels for the Roman Space Telescope. To obtain the raw contrast levels of $\leq 10^{-10}$ contrast needed for HWO, more modeling is needed of the vector diffraction effects within a coronagraph instrument. Several coronagraph architectures are based on the Lyot coronagraph, which utilizes a small occulting spot to block most of the on-axis starlight at a focal plane. In this paper, we present a study of the polarization aberrations generated by internal occulting spots. First, we use finite-difference time-domain (FDTD) modeling to produce the complex transmission of the occulter in each polarization state, and then we separately run those through a closed-loop wavefront control model in FALCO\cite{rigss2018falco} to determine the degradation in achievable contrast. We perform sweeps of such parameters as spot diameter, spot thickness, and angle of incidence to inform the HWO instrument design.
format Preprint
id arxiv_https___arxiv_org_abs_2508_19397
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Polarization aberration modeling of internal occulters for coronagraphs
Jenkins, Emory L.
Riggs, A J Eldorado
Douglas, Ewan S.
Anche, Ramya M.
McKeithen, Dylan M.
Shaklan, Stuart B.
Instrumentation and Methods for Astrophysics
The Habitable Worlds Observatory (HWO) is a flagship mission concept proposing to characterize earth-like exoplanets at high contrast with a coronagraph instrument. The most in-depth, validated contrast error budgets made to date have been at the $10^{-9}$ planet-to-star contrast levels for the Roman Space Telescope. To obtain the raw contrast levels of $\leq 10^{-10}$ contrast needed for HWO, more modeling is needed of the vector diffraction effects within a coronagraph instrument. Several coronagraph architectures are based on the Lyot coronagraph, which utilizes a small occulting spot to block most of the on-axis starlight at a focal plane. In this paper, we present a study of the polarization aberrations generated by internal occulting spots. First, we use finite-difference time-domain (FDTD) modeling to produce the complex transmission of the occulter in each polarization state, and then we separately run those through a closed-loop wavefront control model in FALCO\cite{rigss2018falco} to determine the degradation in achievable contrast. We perform sweeps of such parameters as spot diameter, spot thickness, and angle of incidence to inform the HWO instrument design.
title Polarization aberration modeling of internal occulters for coronagraphs
topic Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2508.19397