Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-resolution and gapless dual comb spectroscopy with current-tuned
  quantum cascade lasers   We present gapless, high-resolution absorption and dispersion spectra
obtained with quantum cascade laser frequency combs covering 55 cm$^{-1}$.
Using phase-sensitive dual comb design, the comb lines are gradually swept over
10 GHz, corresponding to the free spectral range of the laser devices, by
applying a current modulation. We show that with interleaving the spectral
point spacing is reduced by more than four orders of magnitude over the full
spectral span of the frequency comb. The potential of this technique for
high-precision gas sensing is illustrated by measuring the low pressure (107
hPa) absorption and dispersion spectra of methane spanning the range of 1170
cm$^{-1}$ - 1225 cm$^{-1}$ with a resolution of 0.001 cm$^{-1}$.

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The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs