Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generation, reflection and transmission of nonlinear harmonic waves by
  direct superposition of anharmonic dipoles   In this paper we describe how to derive the expressions for the higher
nonlinear generation of waves, their transmission and reflection for the case
of a normal incidence plane wave by direct superposition of nonlinear dipoles.
We describe explicitly that the transmitted and reflected nonlinear harmonic
wave can only propagate inside the material if the phase matching condition is
fulfilled and show for the case of second-harmonic-generation that our
calculation yields similar results with coupled-mode-theory (CMT).

36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc