Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Super-resolution and non-diffraction longitudinal polarized beam   A method is presented for generation of a subwavelength (0.43 lambda)
longitudinally polarized beam, which propagates without divergence over lengths
of about 4 lambda in free space. This is achieved by controlling the amplitude,
phase and polarization property of the Bessel-Gaussian field on the aperture of
a high numerical aperture focusing lens.

31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph