Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three-Dimensional Wave Behaviour of Light   We describe a simple experimental apparatus which allows one to observe the
wave properties of light in a new way. This apparatus also makes possible to
introduce and illustrate, in a very suggestive way, some fundamental principles
of quantum theory.

17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex