Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Acoustooptic Bragg Diffraction in 2-Dimensional Photonic Crystals   The paper shows that silicon-based 2D photonic crystal can be a promising
material for acoustooptical devices. Isotropic and anisotropic Bragg
diffraction of light in photonic crystal is considered. The computational
method for calculation of frequency dependences of Bragg angle is developed. A
simple method of optimization of photonic crystal parameters to obtain Bragg
diffraction at necessary light and sound frequency is suggested.

34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs