Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three-dimensional dielectric photonic crystal structures for
  laser-driven acceleration   We present the design and simulation of a three-dimensional photonic crystal
waveguide for linear laser-driven acceleration in vacuum. The structure
confines a synchronous speed-of-light accelerating mode in both transverse
dimensions. We report the properties of this mode, including sustainable
gradient and optical-to-beam efficiency. We present a novel method for
confining a particle beam using optical fields as focusing elements. This
technique, combined with careful structure design, is shown to have a large
dynamic aperture and minimal emittance growth, even over millions of optical
wavelengths.

16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
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
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga