Black Silicon BRDF and Polarization for Coronagraphic Pupil Masks

Fuente: arXiv
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Autori principali: Jenkins, Emory L., Anche, Ramya M., Van Gorkom, Kyle J., Riggs, A. J. Eldorado, Douglas, Ewan S.
Natura: Preprint
Pubblicazione: 2024
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author Jenkins, Emory L.
Anche, Ramya M.
Van Gorkom, Kyle J.
Riggs, A. J. Eldorado
Douglas, Ewan S.
author_facet Jenkins, Emory L.
Anche, Ramya M.
Van Gorkom, Kyle J.
Riggs, A. J. Eldorado
Douglas, Ewan S.
contents Future space observatories will likely have segmented primaries, causing diffraction effects that reduce coronagraph performance. Reflective binary pupil apodizer masks can mitigate these, with the metamaterial black silicon (BSi) showing promise as a strong absorber. To bring contrast ratios to the $10^-{10}$ level as needed to observe Earth-like exoplanets, feature sizes on these BSi masks will need to be less than $5$ microns when paired with MEMS (micro-electromechanical systems) deformable mirrors. As scalar diffraction cannot reliably model this feature size, we developed a Finite-Difference Time-Domain (FDTD) model of BSi masks using Meep software. We characterize the FDTD-derived polarization-dependent bidirectional reflectance distribution function of BSi and discuss the model's shortcomings.
format Preprint
id arxiv_https___arxiv_org_abs_2406_19028
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Black Silicon BRDF and Polarization for Coronagraphic Pupil Masks
Jenkins, Emory L.
Anche, Ramya M.
Van Gorkom, Kyle J.
Riggs, A. J. Eldorado
Douglas, Ewan S.
Instrumentation and Methods for Astrophysics
Future space observatories will likely have segmented primaries, causing diffraction effects that reduce coronagraph performance. Reflective binary pupil apodizer masks can mitigate these, with the metamaterial black silicon (BSi) showing promise as a strong absorber. To bring contrast ratios to the $10^-{10}$ level as needed to observe Earth-like exoplanets, feature sizes on these BSi masks will need to be less than $5$ microns when paired with MEMS (micro-electromechanical systems) deformable mirrors. As scalar diffraction cannot reliably model this feature size, we developed a Finite-Difference Time-Domain (FDTD) model of BSi masks using Meep software. We characterize the FDTD-derived polarization-dependent bidirectional reflectance distribution function of BSi and discuss the model's shortcomings.
title Black Silicon BRDF and Polarization for Coronagraphic Pupil Masks
topic Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2406.19028