Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conversion of out-of-phase to in-phase order in coupled laser arrays
  with second harmonics   A novel method for converting an array of out-of-phase lasers into one of
in-phase lasers that can be tightly focused is presented. The method exploits
second harmonic generation and can be adapted for different laser arrays
geometries. Experimental and calculated results, presented for negatively
coupled lasers formed in a square, honeycomb, and triangular geometries are in
good agreement.

29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
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The categories of this paper are: q-alg
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph