Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Polarization entangled photon-pair source based on a type-II PPLN
  waveguide emitting at a telecom wavelength
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph