Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Orbital angular momentum beam instabilities in engineered nonlinear
  colloidal media   In this letter, we experimentally demonstrate the evolution of the optical
vortex beams of different topological charges propagating in engineered
nano-colloidal suspension of negative polarizability with saturable
nonlinearities. Due to the high power of the incident beam, the modulation
instability leads to an exponential growth of weak perturbations and thus
splits the original vortex beam into a necklace beam consisting of several
bright spots. The number of observed bright spots is intrinsically determined
by the topological charge of the incident beam and agrees well with the
predictions of our linear stability analysis and numerical simulations. Besides
contributing to the fundamental science of light-matter interactions in
engineered soft-matter media, this work opens new opportunities for dynamic
optical manipulation and transmission of light through scattering media as well
as formation of complex optical patterns and light filamentation in naturally
existing colloids such as fog and clouds.

1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat