Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhancement of graphene visibility on transparent substrates by
  refractive index optimization   Optical reflection microscopy is one of the main imaging tools to visualize
graphene microstructures. Here is reported a novel method that employs
refractive index optimization in an optical reflection microscope, which
greatly improves the visibility of graphene flakes. To this end, an immersion
liquid with a refractive index that is close to that of the glass support is
used in-between the microscope lens and the support improving the contrast and
resolution of the sample image. Results show that the contrast of single and
few layer graphene crystals and structures can be enhanced by a factor of 4
compared to values commonly achieved with transparent substrates using optical
reflection microscopy lacking refractive index optimization.

10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys