Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Orbital angular momentum light frequency conversion and interference
  with quasi-phase matching crystals
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an