Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sum frequency generation from touching wires: A transformation optics
  approach   We employ transformation optics to study analytically nonlinear wave mixing
from a singular geometry of touching plasmonic wires. We obtain the analytic
solution of the near-field and complement it with a solution of the far-field
properties. We find, somewhat surprisingly, that optimal efficiency (in both
regimes) is obtained for the degenerate case of the Second-harmonic generation.
We exploit the analytic solution obtained to trace this behaviour to the
spatial overlap of the input fields near the geometric singularity.

9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an