Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Preamplified photodetectors for high-fidelity postselecting optical
  devices   The fidelity of postselecting devices based on direct photon number detection
can be significantly improved by insertion of a phase-insensitive optical
amplifier in front of the detector. The scheme is simple, and the cost to the
probability of obtaining the appropriate detector outcome is low.

5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an