Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Function Photonic Crystals   In the paper, we present a new kind of function photonic crystals, which
refractive index is a function of space position. Unlike conventional PCs,
which structure grow from two materials, A and B, with different dielectric
constants $\epsilon_{A}$ and $\epsilon_{B}$. By Fermat principle, we give the
motion equations of light in one-dimensional, two-dimensional and
three-dimensional function photonic crystals. For one-dimensional function
photonic crystals, we study the dispersion relation, band gap structure and
transmissivity, and compare them with conventional photonic crystals. By
choosing various refractive index distribution function $n(z)$, we can obtain
more width or more narrow band gap structure than conventional photonic
crystals.

13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph