Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong electromagnetically induced transparency in atomic media with
  large residual Doppler broadening   Electromagnetically induced transparency and coherent population trapping
were observed in a hot (1000 K) calcium vapor embedded into an electrical gas
discharge. Unexpectedly large transparencies (of up to 70%) were observed under
very unfavorable conditions: probe wavelength shorter than the coupling
wavelength, and coupling Rabi frequency significantly smaller than the residual
Doppler linewidth of the two photon transition. We developed a theoretical
model that shows that the observed results are due to the combined effects of a
strong probe beam and a small open character of the atomic system. Coherent
population trapping also manifests itself as a change in the impedance of the
gas discharge, and the phenomenon can be probed with high sensitivity via the
optogalvanic effect.

28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
1
The categories of this paper are: cs
2
The categories of this paper are: math