Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Selected properties of optical spatial solitons in photorefractive media
  and their important applications   Some selected important properties of photorefractive spatial solitons and
their applications have been reviewed in the present paper. Using band
transport model, the governing principle of photorefractive nonlinearity has
been addressed and nonlinear dynamical equations of spatial solitons owing to
this nonlinearity have been discussed. Mechanisms of formation of screening and
photovoltaic solitons of three different configurations i.e., bright, dark and
grey varieties have been examined. Incoherently coupled vector solitons due to
single and two-photon photorefractive phenomena have been highlighted.
Modulation instability, which is precursor to soliton formation has been also
discused briefly. Finally possible applications of photorefractive spatial
solitons have been highlighted.

18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn