Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theory of groove-envelope phase effects in self-diffraction   If two laser beams cross in a medium under shallow angle, the laser-induced
grating consists of only a few grooves. In this situation, the phase between
the grooves of the grating and its envelope is a decisive parameter for
nonlinear effects. Here, models are established for reproducing the
groove-envelope phase effects that have been observed in the interference
pattern of self-diffraction. Four-wave mixing leads to interferences that are
dominant in the spatial region between the orders of diffraction and with
tilted interference fringes in the diagram of transverse coordinate vs. pulse
delay. The vertical interference fringes that are dominant directly on the
diffraction orders, experimentally observed at high intensity close to the
damage threshold, require a model beyond four-wave mixing. A model is suggested
that is based on optical transmission changes with confinement to regions in
the medium that are smaller than the groove spacing.

27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int