Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Narrowband spectroscopy by all-optical correlation of broadband pulses   High peak power ultrafast lasers are widely used in nonlinear spectroscopy
but often limit its spectral resolution because of the broad frequency
bandwidth of ultrashort laser pulses. Improving the resolution by achieving
spectrally narrow excitation of, or emission from, the resonant medium by means
of multi-photon interferences has been the focus of many recent developments in
ultrafast spectroscopy. We demonstrate an alternative approach, in which high
resolution is exercised by detecting narrow spectral correlations between
broadband excitation and emission optical fields. All-optical correlation
analysis, easily incorporated into the traditional spectroscopic setup, enables
direct, robust and simultaneous detection of multiple narrow resonances with a
single femtosecond pulse.

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The categories of this paper are: nlin
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: econ
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The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
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The categories of this paper are: quant-ph
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The categories of this paper are: adap-org
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The categories of this paper are: gr-qc
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The categories of this paper are: cs