Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-photocurrent devices   Heterodyne, eight-port homodyne and six-port homodyne detectors belong to the
class of two-photocurrent devices. Their full equivalence in probing radiation
field has been proved both for ideal and not fully efficient photodetectors.
The output probability distribution has been also evaluated for a generic probe
mode.

18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex