Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On-chip coherent frequency-domain THz spectroscopy for electrical
  transport   We developed a coherent frequency-domain THz spectroscopic technique on a
coplanar waveguide in the ultrabroad frequency range from 200 MHz to 1.6 THz
based on continuous wave (CW) laser spectroscopy. Optical beating created by
mixing two frequency-tunable CW lasers is focused on photoconductive switches
to generate and detect high-frequency current in a THz circuit. In contrast to
time-domain spectroscopy, our frequency-domain spectroscopy enables
unprecedented frequency resolution of 10 MHz without using complex building
blocks of femtosecond laser optics. Furthermore, due to the coherent nature of
the photomixing technique, we are able to identify the origin of multiple
reflections in the time domain using the Hilbert analysis and inverse Fourier
transform. These results demonstrate that the advantages of on-chip coherent
frequency-domain spectroscopy, such as its broadband, frequency resolution,
usability, and time-domain accessibility, provide a unique capability for
measuring ultrafast electron transport in integrated THz circuits.

18
The categories of this paper are: econ
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin