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Updated: Jul 12, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Time/frequency-domain characterization of a mid-IR DFG frequency comb via two-photon and heterodyne detection
Abstract:
Mid-infrared frequency combs are nowadays well-appreciated sources for spectroscopy and frequency metrology. Here, a comprehensive approach for characterizing a difference-frequency-generated mid-infrared frequency comb (DFG-comb) both in the time and in the frequency domain is presented. An autocorrelation scheme exploiting mid-infrared two-photon detection is used for characterizing the pulse width and to verify the optimal compression of the generated pulses reaching a pulse duration (FWHM) as low as 196 fs. A second scheme based on mid-infrared heterodyne detection employing two independent narrow-linewidth quantum cascade lasers (QCLs) is used for frequency-narrowing the modes of the DFG-comb down to 9.4 kHz on a 5-ms timescale.
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