Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Alignment-to-orientation conversion in a magnetic field at nonlinear
  excitation of the $D_2$ line of rubidium: experiment and theory   We studied alignment-to-orientation conversion caused by excited-state level
crossings in a nonzero magnetic field of both atomic rubidium isotopes.
Experimental measurements were performed on the transitions of the $D_2$ line
of rubidium. These measured signals were described by a theoretical model that
takes into account all neighboring hyperfine transitions, the mixing of
magnetic sublevels in an external magnetic field, the coherence properties of
the exciting laser radiation, and the Doppler effect. In the experiments laser
induced fluorescence (LIF) components were observed at linearly polarized
excitation and their difference was taken afterwards. By observing the two
oppositely circularly polarized components we were able to see structures not
visible in the difference graphs, which yields deeper insight into the
processes responsible for these signals. We studied how these signals are
dependent on laser power density and how they are affected when the exciting
laser is tuned to different hyperfine transitions. The comparison between
experiment and theory was carried out fulfilling the nonlinear absorption
conditions.

5
The categories of this paper are: gr-qc
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The categories of this paper are: econ
8
The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th