Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Generation of Topological Vector Solitons from Bessel-Like Beams   Coupled solitary waves in optics literature, are coined vector solitons to
reflect their particle-like nature that remains intact even after mutual
collisions. They are born from a nonlinear change in the refractive index of an
optical material induced by the light intensity. We've discovered that the
second harmonic intensity profile generated by Bessel-like beams, is composed
of solitons of various geometries surrounded by concentric rings; one of which
is two central solitons of similar radius knotted by ellipsoidal concentric
rings. We observe that their geometry and intensity distribution is dependent
on the topological charge of the fundamental Bessel beams incident on the
nonlinear medium. We show that their spatial profile is invariant against
propagation. We observe that their behavior is similar to that of screw
dislocations in wave trains: they collide and rebound at a 90$^\circ$ angle
from the beam propagation direction. In this way, we have generated linked
frequency doubled Bessel-type vector solitons with different topologies, that
are knotted as they oscillate along the optical axis, when propagating in the
laboratory environment.

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The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
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The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: q-fin
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The categories of this paper are: plasm-ph