Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An Eight-Octant Phase-Mask Coronagraph   We present numerical simulations and laboratory experiments on an
eight-octant phase-mask (EOPM) coronagraph. The numerical simulations suggest
that an achievable contrast for the EOPM coronagraph can be greatly improved as
compared to that of a four-quadrant phase-mask (FQPM) coronagraph for a
partially resolved star. On-sky transmission maps reveal that the EOPM
coronagraph has relatively high optical throughput, a small inner working angle
and large discovery space. We have manufactured an eight-segment phase mask
utilizing a nematic liquid-crystal device, which can be easily switched between
the FQPM and the EOPM modes. The laboratory experiments demonstrate that the
EOPM coronagraph has a better tolerance of the tip-tilt error than the FQPM
one. We also discuss feasibility of a fully achromatic and high-throughput EOPM
coronagraph utilizing a polarization interferometric technique.

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The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org