Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Properties of entangled photon pairs generated by a CW laser with small
  coherence time: theory and experiment
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga