Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Calibration of the instrumental polarization effects of SCExAO-CHARIS'
  spectropolarimetric mode   SCExAO at the Subaru telescope is a visible and near-infrared high-contrast
imaging instrument employing extreme adaptive optics and coronagraphy. The
instrument feeds the near-infrared light (JHK) to the integral field
spectrograph CHARIS. Recently, a Wollaston prism was added to CHARIS' optical
path, giving CHARIS a spectropolarimetric capability that is unique among
high-contrast imaging instruments. We present a detailed Mueller matrix model
describing the instrumental polarization effects of the complete optical path,
thus the telescope and instrument. The 22 wavelength bins of CHARIS provide a
unique opportunity to investigate in detail the wavelength dependence of the
instrumental polarization effects. From measurements with the internal light
source, we find that the image derotator (K-mirror) produces strong
wavelength-dependent crosstalk, in the worst case converting ~95% of the
incident linear polarization to circularly polarized light that cannot be
measured. Theoretical calculations show that the magnitude of the instrumental
polarization of the telescope varies with wavelength between approximately 0.5%
and 0.7%, and that its angle is exactly equal to the altitude angle of the
telescope. We plan to more accurately determine the instrumental polarization
of the telescope with observations of a polarization standard star, and fit
more comprehensive physical models to all experimental data. In addition, we
plan to integrate the complete Mueller matrix model into the existing CHARIS
post-processing pipeline, with the aim to achieve a polarimetric accuracy of
<0.1% in the degree of linear polarization. Our calibrations of CHARIS'
spectropolarimetric mode will enable unique quantitative polarimetric studies
of circumstellar disks and planetary and brown dwarf companions.

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The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
2
The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
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The categories of this paper are: funct-an
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The categories of this paper are: ao-sci
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio