Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: All-fiber photonic lantern multimode optical receiver with coherent
  adaptive optics beam combining   A multimode optical receiver for free space optical communications (FSOC)
based on a photonic lantern and adaptive optics coherent beam combining (CBC)
of the lantern's single-mode outputs is proposed and demonstrated for the first
time. The use of optical coherent combining in fiber serves to increase the
signal to noise ratio compared to similar receivers based on electrically
combined signals, and represents an all-fiber approach to low-order adaptive
optics. This optical receiver is demonstrated using a photonic lantern with
three outputs, fibre couplers and active phase locking, and further
investigated under atmospheric conditions with and without turbulence.

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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: nlin
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
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The categories of this paper are: stat