Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Propagation of videopulse through a thin layer of two-level atoms
  possessing permanent dipole moments   The excitation of a thin layer of two-level permanent dipole moment atoms by
ultimately short (less than field oscillation period) electromagnetic pulses
(videopulse) is observed. The numerical analysis of matter equations free of
rotating wave approximation and relaxation reveals a strong affect of local
field and Stark effect on temporal behavior of transmitted field. Specifically
it is demonstrated that a dense film irradiated by videopulse emits a short
response with a delay much longer even than the characteristic cooperative time
of atom ensemble. It is supposed that the local field in the thin layer of
permanent dipole atoms is able to re-pump the atomic subsystem. The close
analogy to nonlinear pendulum motion is discuused.

19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics