Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exploiting the optical quadratic nonlinearity of zincblende
  semiconductors for guided-wave terahertz generation: a material comparison   We present a detailed analysis and comparison of dielectric waveguides made
of CdTe, GaP, GaAs and InP for modal phase matched optical difference frequency
generation (DFG) in the terahertz domain. From the form of the DFG equations,
we derived the definition of a very general figure of merit (FOM). In turn,
this FOM enabled us to compare different configurations, by taking into account
linear and nonlinear susceptibility dispersion, terahertz absorption, and a
rigorous evaluation of the waveguide modes properties. The most efficient
waveguides found with this procedure are predicted to approach the quantum
efficiency limit with input optical power in the order of kWs.

20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat