Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Controlling light propagation: a brief review   Recent results by Hoffman et al. showed that it is possible to build a
Negative Refractive Material (NIM) by interleaving InGaAs/AlInAs using current
nanofabrication technologies. Their findings provide the first experimental
proof of a negative refractive semiconductor long posited by transformation
optics. In this paper an overview on semiconductor refractive index theory and
negative refraction is presented, focusing on the results of Hoffman et al. and
the future of the subject based on the theory of Transformation Optics and its
importance to tailor materials electrodynamics properties.

5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph