Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong Optical Confinement between Non-periodic Flat Dielectric Gratings   We present a novel design of optical micro-cavity where the optical energy
resides primarily in free space, therefore is readily accessible to foreign
objects such as atoms, molecules, mechanical resonators, etc. We describe the
physics of these resonators, and propose a design method based on stochastic
optimization. Cavity designs with diffraction-limited mode volumes and quality
factors in the range of $10^4$--$10^6$ are presented. With a purely planar
geometry, the cavity can be easily integrated on-chip using conventional micro-
and nano- fabrication processes.

16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg