Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Near-field spectroscopy of silicon dioxide thin films   We analyze the results of scanning near-field infrared spectroscopy performed
on thin films of a-SiO2 on Si substrate. The measured near-field signal
exhibits surface-phonon resonances whose strength has a strong thickness
dependence in the range from 2 to 300 {nm}. These observations are compared
with calculations in which the tip of the near-field infrared spectrometer is
modeled either as a point dipole or an elongated spheroid. The latter model
accounts for the antenna effect of the tip and gives a better agreement with
the experiment. Possible applications of the near-field technique for depth
profiling of layered nanostructures are discussed.

22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph