Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Subnanosecond Ellipticity Detector for Laser Radiation (second version,
  extended)   Two types of room temperature detectors of terahertz laser radiation have
been developed which allow in an all-electric manner to determine the plane of
polarization of linearly polarized radiation and the Stokes parameters of
elliptically polarized radiation, respectively. The operation of the detectors
is based on photogalvanic effects in semiconductor quantum well structures of
low symmetry. The photogalvanic effects have nanoseconds time constants at room
temperature making a high time resolution of the polarization detectors
possible.

28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex