Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Few-cycle, Broadband, Mid-infrared Optical Parametric Oscillator Pumped
  by a 20-fs Ti:sapphire Laser   We report a few-cycle, broadband, singly-resonant optical parametric
oscillator (OPO) for the mid-infrared based on MgO-doped periodically-poled
LiNbO3 (MgO:PPLN), synchronously pumped by a 20-fs Ti:sapphire laser. By using
crystal interaction lengths as short as 250 um, and careful dispersion
management of input pump pulses and the OPO resonator, near-transform-limited,
few-cycle idler pulses tunable across the mid-infrared have been generated,
with as few as 3.7 optical cycles at 2682 nm. The OPO can be continuously tuned
over 2179-3732 nm by cavity delay tuning, providing up to 33 mW of output power
at 3723 nm. The idler spectra exhibit stable broadband profiles with bandwidths
spaning over 422 nm (FWHM) recorded at 3732 nm. We investigate the effect of
crystal length on spectral bandwidth and pulse duration at a fixed wavelength,
confirming near-transform-limited idler pulses for all grating interaction
lengths. By locking the repetition frequency of the pump laser to a
radio-frequency reference, and without active stabilization of the OPO cavity
length, an idler power stability better than 1.6% rms over >2.75 hours is
obtained when operating at maximum output power, in excellent spatial beam
quality with TEM00 mode profile.

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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex