Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Polarization-independent single-photon switch based on a fiber-optical
  Sagnac interferometer for quantum communication networks
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph