Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-Photon Dual-Comb LiDAR   The interferometric signals produced in conventional dual-comb laser ranging
require femtosecond lasers with long-term f_CEO stability, and are limited to
an upper sampling rate by radio-frequency aliasing considerations. By using
cross-polarized dual combs and two-photon detection we demonstrate
carrier-phase-insensitive cross-correlations at sampling rates of up to 12x the
conventional dual-comb aliasing limit, recording these in a digitizer-based
acquisition system to implement ranging with sub-100-nm precision. We then
extend this concept to show how the high data burden of conventional dual-comb
acquisition can be eliminated by using a simple microcontroller as a
ns-precision stopwatch to record the time intervals separating the two-photon
cross-correlation pulses, providing real-time and continuous LiDAR-like
distance metrology capable of sub-100 nm precision and dynamic acquisition for
unlimited periods.

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The categories of this paper are: math
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The categories of this paper are: stat
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio