Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Demonstration of an electric field conjugation algorithm for improved
  starlight rejection through a single mode optical fiber   Linking a coronagraph instrument to a spectrograph via a single mode optical
fiber is a pathway towards detailed characterization of exoplanet atmospheres
with current and future ground- and space-based telescopes. However, given the
extreme brightness ratio and small angular separation between planets and their
host stars, the planet signal-to-noise ratio will likely be limited by the
unwanted coupling of starlight into the fiber. To address this issue, we
utilize a wavefront control loop and a deformable mirror to systematically
reject starlight from the fiber by measuring what is transmitted through the
fiber. The wavefront control algorithm is based on the formalism of electric
field conjugation (EFC), which in our case accounts for the spatial mode
selectivity of the fiber. This is achieved by using a control output that is
the overlap integral of the electric field with the fundamental mode of a
single mode fiber. This quantity can be estimated by pair-wise image plane
probes injected using a deformable mirror. We present simulation and laboratory
results that demonstrate our approach offers a significant improvement in
starlight suppression through the fiber relative to a conventional EFC
controller. With our experimental setup, which provides an initial normalized
intensity of $3\times10^{-4}$ in the fiber at an angular separation of
$4\lambda/D$, we obtain a final normalized intensity of $3\times 10^{-6}$ in
monochromatic light at $\lambda=635$~nm through the fiber (100x suppression
factor) and $2\times 10^{-5}$ in $\Delta\lambda/\lambda=8\%$ broadband light
about $\lambda=625$~nm (10x suppression factor). The fiber-based approach
improves the sensitivity of spectral measurements at high contrast and may
serve as an integral part of future space-based exoplanet imaging missions as
well as ground-based instruments.

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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
2
The categories of this paper are: math
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
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The categories of this paper are: stat
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
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The categories of this paper are: ao-sci