Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Minimizing the polarization leakage of geometric-phase coronagraphs with
  multiple grating pattern combinations   The design of liquid-crystal diffractive phase plate coronagraphs for
ground-based and space-based high-contrast imaging systems is limited by the
trade-off between spectral bandwidth and polarization leakage. We demonstrate
that by combining phase patterns with a polarization grating (PG) pattern
directly followed by one or several separate PGs, we can suppress the
polarization leakage terms by additional orders of magnitude by diffracting
them out of the beam. \textcolor{black}{Using two PGs composed of a
single-layer liquid crystal structure in the lab, we demonstrate a leakage
suppression of more than an order of magnitude over a bandwidth of 133 nm
centered around 532 nm. At this center wavelength we measure a leakage
suppression of three orders of magnitude.} Furthermore, simulations indicate
that a combination of two multi-layered liquid-crystal PGs can suppress leakage
to $<10^{-5}$ for 1-2.5 $\mu$m and $<10^{-10}$ for 650-800 nm. We introduce
multi-grating solutions with three or more gratings that can be designed to
have no separation of the two circular polarization states, and offer even
deeper suppression of polarization leakage. We present simulations of a
triple-grating solution that has $<10^{-10}$ leakage on the first Airy ring
from 450 nm to 800 nm. We apply the double-grating concept to the Vector-Vortex
coronagraph of charge 4, and demonstrate in the lab that polarization leakage
no longer limits the on-axis suppression for ground-based contrast levels.
Lastly, we report on the successful installation and first-light results of a
double-grating vector Apodizing Phase Plate pupil-plane coronagraph installed
at the Large Binocular Telescope. We discuss the implications of these new
coronagraph architectures for high-contrast imaging systems on the ground and
in space.

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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: quant-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg